solana_runtime/

bank.rs

//! The `bank` module tracks client accounts and the progress of on-chain
//! programs.
//!
//! A single bank relates to a block produced by a single leader and each bank
//! except for the genesis bank points back to a parent bank.
//!
//! The bank is the main entrypoint for processing verified transactions with the function
//! `Bank::process_transactions`
//!
//! It does this by loading the accounts using the reference it holds on the account store,
//! and then passing those to an InvokeContext which handles loading the programs specified
//! by the Transaction and executing it.
//!
//! The bank then stores the results to the accounts store.
//!
//! It then has APIs for retrieving if a transaction has been processed and it's status.
//! See `get_signature_status` et al.
//!
//! Bank lifecycle:
//!
//! A bank is newly created and open to transactions. Transactions are applied
//! until either the bank reached the tick count when the node is the leader for that slot, or the
//! node has applied all transactions present in all `Entry`s in the slot.
//!
//! Once it is complete, the bank can then be frozen. After frozen, no more transactions can
//! be applied or state changes made. At the frozen step, rent will be applied and various
//! sysvar special accounts update to the new state of the system.
//!
//! After frozen, and the bank has had the appropriate number of votes on it, then it can become
//! rooted. At this point, it will not be able to be removed from the chain and the
//! state is finalized.
//!
//! It offers a high-level API that signs transactions
//! on behalf of the caller, and a low-level API for when they have
//! already been signed and verified.
pub use {
    crate::slot_params::DEFAULT_MAX_ENTRY_BYTES_PER_SLOT,
    partitioned_epoch_rewards::KeyedRewardsAndNumPartitions, solana_leader_schedule::SlotLeader,
    solana_reward_info::RewardType,
};
use {
    crate::{
        account_saver::collect_accounts_to_store,
        alpenglow_epoch_type::AlpenglowEpochType,
        bank::{
            entry_bytes_budget::EntryBytesBudget,
            metrics::*,
            partitioned_epoch_rewards::{CachedVoteAccounts, EpochRewardStatus},
        },
        bank_forks::BankForks,
        block_component_processor::{
            BlockComponentProcessor,
            vote_reward::epoch_inflation_account_state::EpochInflationAccountState,
        },
        epoch_stakes::{
            BLSPubkeyToRankMap, DeserializableVersionedEpochStakes, NodeVoteAccounts,
            VersionedEpochStakes,
        },
        inflation_rewards::points::InflationPointCalculationEvent,
        installed_scheduler_pool::{BankWithScheduler, InstalledSchedulerRwLock},
        leader_schedule_utils::leader_schedule_from_vote_accounts,
        rent_collector::RentCollector,
        reward_info::RewardInfo,
        runtime_config::RuntimeConfig,
        slot_params::{SlotParams, SlotParamsArchive},
        stake_account::StakeAccount,
        stake_history::StakeHistory as CowStakeHistory,
        stake_weighted_timestamp::{
            MAX_ALLOWABLE_DRIFT_PERCENTAGE_FAST, MAX_ALLOWABLE_DRIFT_PERCENTAGE_SLOW_V2,
            MaxAllowableDrift, calculate_stake_weighted_timestamp,
        },
        stakes::{
            DelegatedStakes, DeserializableDelegationStakes, SerdeStakesToStakeFormat, Stakes,
            StakesCache,
        },
        status_cache::{SlotDelta, StatusCache},
        sysvar_account::{create_account, create_account_with_bincode, from_account},
        transaction_batch::{OwnedOrBorrowed, TransactionBatch},
    },
    accounts_lt_hash::AccountsLtHashAsyncProgress,
    agave_bls_cert_verify::cert_verify::{self, Error as CertVerifyError},
    agave_feature_set::{self as feature_set, FeatureSet},
    agave_precompiles::{get_precompile, get_precompiles, is_precompile},
    agave_reserved_account_keys::ReservedAccountKeys,
    agave_snapshots::snapshot_hash::SnapshotHash,
    agave_transaction_view::{
        resolved_transaction_view::ResolvedTransactionView,
        transaction_data::TransactionData,
        transaction_version::TransactionVersion,
        transaction_view::{SanitizedTransactionView, UnsanitizedTransactionView},
    },
    agave_votor_messages::{
        certificate::{CertSignature, Certificate, GenesisCert},
        migration::GENESIS_CERTIFICATE_ACCOUNT,
        unverified_vote_message::UnverifiedCertificate,
        wire::{WireBlockCertMessage, WireCertSignature},
    },
    ahash::AHashSet,
    crossbeam_utils::CachePadded,
    log::*,
    partitioned_epoch_rewards::PartitionedRewardsCalculation,
    rayon::ThreadPool,
    serde::{Deserialize, Serialize},
    solana_account::{
        Account, AccountSharedData, InheritableAccountFields, ReadableAccount, WritableAccount,
    },
    solana_accounts_db::{
        account_locks::validate_account_locks,
        account_storage_entry::AccountStorageEntry,
        accounts::{AccountAddressFilter, Accounts},
        accounts_db::{AccountsDb, AccountsDbConfig},
        accounts_hash::AccountsLtHash,
        accounts_index::IndexKey,
        accounts_scan::ScanResult,
        accounts_update_notifier_interface::AccountsUpdateNotifier,
        ancestors::Ancestors,
        blockhash_queue::BlockhashQueue,
        storable_accounts::StorableAccounts,
        utils::create_account_shared_data,
    },
    solana_builtins::{BUILTINS, STATELESS_BUILTINS},
    solana_clock::{
        BankId, Epoch, INITIAL_RENT_EPOCH, MAX_PROCESSING_AGE, MAX_TRANSACTION_FORWARDING_DELAY,
        Slot, SlotIndex, UnixTimestamp,
    },
    solana_cluster_type::ClusterType,
    solana_compute_budget::compute_budget::ComputeBudget,
    solana_cost_model::cost_tracker::CostTracker,
    solana_epoch_info::EpochInfo,
    solana_epoch_schedule::EpochSchedule,
    solana_feature_gate_interface as feature,
    solana_fee::FeeFeatures,
    solana_fee_calculator::FeeRateGovernor,
    solana_fee_structure::{FeeDetails, FeeStructure},
    solana_genesis_config::GenesisConfig,
    solana_hard_forks::HardForks,
    solana_hash::Hash,
    solana_inflation::Inflation,
    solana_keypair::Keypair,
    solana_lattice_hash::lt_hash::LtHash,
    solana_measure::{measure::Measure, measure_time, measure_us},
    solana_message::{
        AccountKeys, SanitizedMessage, inner_instruction::InnerInstructions, v0::LoadedAddresses,
    },
    solana_nonce_account::verify_nonce_account,
    solana_packet::PACKET_DATA_SIZE,
    solana_precompile_error::PrecompileError,
    solana_program_runtime::{
        invoke_context::BuiltinFunctionRegisterer,
        loaded_programs::{ProgramRuntimeEnvironment, ProgramRuntimeEnvironments},
        program_cache_entry::ProgramCacheEntry,
    },
    solana_pubkey::Pubkey,
    solana_rent::Rent,
    solana_runtime_transaction::{
        runtime_transaction::RuntimeTransaction, transaction_meta::TransactionConfiguration,
        transaction_with_meta::TransactionWithMeta,
    },
    solana_sdk_ids::{bpf_loader_upgradeable, incinerator, native_loader, system_program},
    solana_sha256_hasher::hashv,
    solana_signature::Signature,
    solana_slot_hashes::SlotHashes,
    solana_slot_history::{Check, SlotHistory},
    solana_stake_history::{StakeHistory, sysvar as stake_history},
    solana_stake_interface::state::Delegation,
    solana_svm::{
        account_loader::LoadedTransaction,
        account_overrides::AccountOverrides,
        transaction_balances::{BalanceCollector, SvmTokenInfo},
        transaction_commit_result::{CommittedTransaction, TransactionCommitResult},
        transaction_error_metrics::TransactionErrorMetrics,
        transaction_execution_result::{
            TransactionExecutionDetails, TransactionLoadedAccountsStats,
        },
        transaction_processing_result::{
            ProcessedTransaction, TransactionProcessingResult,
            TransactionProcessingResultExtensions,
        },
        transaction_processor::{
            ExecutionRecordingConfig, TransactionBatchProcessor, TransactionLogMessages,
            TransactionProcessingConfig, TransactionProcessingEnvironment,
        },
    },
    solana_svm_callback::{AccountState, InvokeContextCallback, TransactionProcessingCallback},
    solana_svm_timings::{ExecuteTimingType, ExecuteTimings},
    solana_svm_transaction::svm_message::SVMMessage,
    solana_syscalls::create_program_runtime_environment,
    solana_system_transaction as system_transaction,
    solana_sysvar::{self as sysvar, last_restart_slot::LastRestartSlot},
    solana_sysvar_id::SysvarId,
    solana_transaction::{
        Transaction, TransactionVerificationMode,
        sanitized::{MAX_TX_ACCOUNT_LOCKS, MessageHash, SanitizedTransaction},
        versioned::VersionedTransaction,
    },
    solana_transaction_context::{
        transaction::TransactionReturnData, transaction_accounts::KeyedAccountSharedData,
    },
    solana_transaction_error::{AddressLoaderError, TransactionError, TransactionResult as Result},
    solana_vote::{
        vote_account::{VoteAccount, VoteAccounts, VoteAccountsHashMap},
        vote_parser,
    },
    solana_vote_interface::state::VoteStateV4,
    std::{
        collections::{HashMap, HashSet},
        fmt,
        ops::AddAssign,
        path::PathBuf,
        slice,
        sync::{
            Arc, LazyLock, LockResult, Mutex, OnceLock, RwLock, RwLockReadGuard, RwLockWriteGuard,
            Weak,
            atomic::{
                AtomicBool, AtomicI64, AtomicU64,
                Ordering::{AcqRel, Acquire, Relaxed, Release},
            },
        },
        time::{Duration, Instant},
    },
    thiserror::Error,
    wincode::{SchemaRead, SchemaWrite},
};
#[cfg(feature = "dev-context-only-utils")]
use {
    dashmap::DashSet,
    qualifier_attr::{field_qualifiers, qualifiers},
    rayon::iter::{IntoParallelRefIterator, ParallelIterator},
    solana_accounts_db::accounts_db::{
        ACCOUNTS_DB_CONFIG_FOR_BENCHMARKS, ACCOUNTS_DB_CONFIG_FOR_TESTING,
    },
    solana_nonce as nonce,
    solana_nonce_account::{SystemAccountKind, get_system_account_kind},
    solana_program_runtime::sysvar_cache::SysvarCache,
    solana_svm::program_loader::load_program_with_pubkey,
};

mod accounts_lt_hash;
mod address_lookup_table;
pub mod bank_hash_details;
pub mod builtins;
mod check_transactions;
pub mod entry_bytes_budget;
mod fee_distribution;
mod metrics;
pub(crate) mod partitioned_epoch_rewards;
mod recent_blockhashes_account;
mod serde_snapshot;
mod sysvar_cache;
pub(crate) mod tests;

pub const SECONDS_PER_YEAR: f64 = 365.25 * 24.0 * 60.0 * 60.0;

pub const MAX_LEADER_SCHEDULE_STAKES: Epoch = 5;

/// This will be guaranteed through the VAT rules,
/// only the top 2000 validators by stake will be present in vote account structures.
// This const is mirrored in agave-votor-transport crate, so if it is ever changed here
// it must also be changed there as well.
pub const MAX_ALPENGLOW_VOTE_ACCOUNTS: usize = 2000;

/// Default 400ms-slot Validator Admission Ticket burn amount.
///
/// Use this for conservative genesis/test funding defaults. Runtime VAT
/// filtering and burns must use the bank's effective slot params instead.
pub const DEFAULT_VAT_TO_BURN_PER_EPOCH: u64 =
    crate::slot_params::LEGACY_SLOT_PARAMS.vat_to_burn_per_epoch();

/// The off-curve account where we store the Alpenglow clock. The clock sysvar has seconds
/// resolution while the Alpenglow clock has nanosecond resolution.
static NANOSECOND_CLOCK_ACCOUNT: LazyLock<Pubkey> = LazyLock::new(|| {
    let (pubkey, _) =
        Pubkey::find_program_address(&[b"alpenclock"], &agave_feature_set::alpenglow::id());
    pubkey
});

pub type BankStatusCache = StatusCache<Result<()>>;
#[cfg_attr(
    feature = "frozen-abi",
    frozen_abi(digest = "2RGYA9GpP1epajQ4CxQpCHMJPnLLBoseMbAyLJhTjsGS")
)]
pub type BankSlotDelta = SlotDelta<Result<()>>;

#[derive(Default, Copy, Clone, Debug, PartialEq, Eq)]
pub struct SquashTiming {
    pub squash_accounts_ms: u64,
    pub squash_accounts_cache_ms: u64,
    pub squash_cache_ms: u64,
}

impl AddAssign for SquashTiming {
    fn add_assign(&mut self, rhs: Self) {
        self.squash_accounts_ms += rhs.squash_accounts_ms;
        self.squash_accounts_cache_ms += rhs.squash_accounts_cache_ms;
        self.squash_cache_ms += rhs.squash_cache_ms;
    }
}

#[derive(Clone, Debug, Default, PartialEq)]
pub struct CollectorFeeDetails {
    transaction_fee: u64,
    priority_fee: u64,
}

impl CollectorFeeDetails {
    pub(crate) fn accumulate(&mut self, fee_details: &FeeDetails) {
        self.transaction_fee = self
            .transaction_fee
            .saturating_add(fee_details.transaction_fee());
        self.priority_fee = self
            .priority_fee
            .saturating_add(fee_details.prioritization_fee());
    }

    pub fn total_transaction_fee(&self) -> u64 {
        self.transaction_fee.saturating_add(self.priority_fee)
    }

    pub fn total_priority_fee(&self) -> u64 {
        self.priority_fee
    }
}

impl From<FeeDetails> for CollectorFeeDetails {
    fn from(fee_details: FeeDetails) -> Self {
        CollectorFeeDetails {
            transaction_fee: fee_details.transaction_fee(),
            priority_fee: fee_details.prioritization_fee(),
        }
    }
}

#[derive(Debug)]
pub struct BankRc {
    /// where all the Accounts are stored
    pub accounts: Arc<Accounts>,

    /// Previous checkpoint of this bank
    pub(crate) parent: RwLock<Option<Arc<Bank>>>,

    pub(crate) bank_id_generator: Arc<AtomicU64>,
}

impl BankRc {
    #[cfg_attr(feature = "dev-context-only-utils", qualifiers(pub))]
    pub(crate) fn new(accounts: Accounts) -> Self {
        Self {
            accounts: Arc::new(accounts),
            parent: RwLock::new(None),
            bank_id_generator: Arc::new(AtomicU64::new(0)),
        }
    }
}

pub struct LoadAndExecuteTransactionsOutput {
    // Vector of results indicating whether a transaction was processed or could not
    // be processed. Note processed transactions can still have failed!
    pub processing_results: Vec<TransactionProcessingResult>,
    // Processed transaction counts used to update bank transaction counts and
    // for metrics reporting.
    pub processed_counts: ProcessedTransactionCounts,
    // Balances accumulated for TransactionStatusSender when transaction
    // balance recording is enabled.
    pub balance_collector: Option<BalanceCollector>,
}

#[derive(Debug, PartialEq)]
pub struct TransactionSimulationResult {
    pub result: Result<()>,
    pub logs: TransactionLogMessages,
    pub post_simulation_accounts: Vec<KeyedAccountSharedData>,
    pub units_consumed: u64,
    pub loaded_accounts_data_size: u32,
    pub return_data: Option<TransactionReturnData>,
    pub inner_instructions: Option<Vec<InnerInstructions>>,
    pub fee: Option<u64>,
    pub pre_balances: Option<Vec<u64>>,
    pub post_balances: Option<Vec<u64>>,
    pub pre_token_balances: Option<Vec<SvmTokenInfo>>,
    pub post_token_balances: Option<Vec<SvmTokenInfo>>,
}

impl TransactionSimulationResult {
    pub fn new_error(err: TransactionError) -> Self {
        Self {
            fee: None,
            inner_instructions: None,
            loaded_accounts_data_size: 0,
            logs: vec![],
            post_balances: None,
            post_simulation_accounts: vec![],
            post_token_balances: None,
            pre_balances: None,
            pre_token_balances: None,
            result: Err(err),
            return_data: None,
            units_consumed: 0,
        }
    }
}

#[derive(Clone, Debug)]
pub struct TransactionBalancesSet {
    pub pre_balances: TransactionBalances,
    pub post_balances: TransactionBalances,
}

impl TransactionBalancesSet {
    pub fn new(pre_balances: TransactionBalances, post_balances: TransactionBalances) -> Self {
        assert_eq!(pre_balances.len(), post_balances.len());
        Self {
            pre_balances,
            post_balances,
        }
    }
}
pub type TransactionBalances = Vec<Vec<u64>>;

pub type PreCommitResult<'a> = Result<Option<RwLockReadGuard<'a, Hash>>>;

#[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Default)]
pub enum TransactionLogCollectorFilter {
    All,
    AllWithVotes,
    #[default]
    None,
    OnlyMentionedAddresses,
}

#[derive(Debug, Default)]
pub struct TransactionLogCollectorConfig {
    pub mentioned_addresses: HashSet<Pubkey>,
    pub filter: TransactionLogCollectorFilter,
}

#[derive(Clone, Debug, PartialEq, Eq)]
pub struct TransactionLogInfo {
    pub signature: Signature,
    pub result: Result<()>,
    pub is_vote: bool,
    pub log_messages: TransactionLogMessages,
}

#[derive(Default, Debug)]
pub struct TransactionLogCollector {
    // All the logs collected for from this Bank.  Exact contents depend on the
    // active `TransactionLogCollectorFilter`
    pub logs: Vec<TransactionLogInfo>,

    // For each `mentioned_addresses`, maintain a list of indices into `logs` to easily
    // locate the logs from transactions that included the mentioned addresses.
    pub mentioned_address_map: HashMap<Pubkey, Vec<usize>>,
}

impl TransactionLogCollector {
    pub fn get_logs_for_address(
        &self,
        address: Option<&Pubkey>,
    ) -> Option<Vec<TransactionLogInfo>> {
        match address {
            None => Some(self.logs.clone()),
            Some(address) => self.mentioned_address_map.get(address).map(|log_indices| {
                log_indices
                    .iter()
                    .filter_map(|i| self.logs.get(*i).cloned())
                    .collect()
            }),
        }
    }
}

#[derive(Error, Debug, Serialize, Deserialize)]
pub enum VATHealthError {
    #[error("vote account not found")]
    VoteAccountNotFound,
    #[error("missing BLS pubkey")]
    NoBLSPubkey,
    #[error("insufficient lamports in vote account: {0} < {1}")]
    InsufficientFundsInVoteAccount(u64, u64),
}

/// Bank's common fields shared by all supported snapshot versions for deserialization.
/// Sync fields with BankFieldsToSerialize! This is paired with it.
/// All members are made public to remain Bank's members private and to make versioned deserializer workable on this
/// Note that some fields are missing from the serializer struct. This is because of fields added later.
/// Since it is difficult to insert fields to serialize/deserialize against existing code already deployed,
/// new fields can be optionally serialized and optionally deserialized. At some point, the serialization and
/// deserialization will use a new mechanism or otherwise be in sync more clearly.
#[derive(Clone, Debug)]
#[cfg_attr(
    feature = "dev-context-only-utils",
    field_qualifiers(
        blockhash_queue(pub),
        hash(pub),
        parent_hash(pub),
        parent_slot(pub),
        hard_forks(pub),
        transaction_count(pub),
        tick_height(pub),
        signature_count(pub),
        capitalization(pub),
        max_tick_height(pub),
        hashes_per_tick(pub),
        ticks_per_slot(pub),
        ns_per_slot(pub),
        genesis_creation_time(pub),
        slots_per_year(pub),
        slot(pub),
        block_height(pub),
        leader_id(pub),
        fee_rate_governor(pub),
        epoch_schedule(pub),
        inflation(pub),
        stakes(pub),
        is_delta(pub),
        accounts_data_len(pub),
        versioned_epoch_stakes(pub),
        accounts_lt_hash(pub),
        bank_hash_stats(pub),
        block_id(pub),
    )
)]
pub struct BankFieldsToDeserialize {
    pub(crate) blockhash_queue: BlockhashQueue,
    pub(crate) hash: Hash,
    pub(crate) parent_hash: Hash,
    pub(crate) parent_slot: Slot,
    pub(crate) hard_forks: HardForks,
    pub(crate) transaction_count: u64,
    pub(crate) tick_height: u64,
    pub(crate) signature_count: u64,
    pub(crate) capitalization: u64,
    pub(crate) max_tick_height: u64,
    pub(crate) hashes_per_tick: Option<u64>,
    pub(crate) ticks_per_slot: u64,
    pub(crate) ns_per_slot: u128,
    pub(crate) genesis_creation_time: UnixTimestamp,
    pub(crate) slots_per_year: f64,
    pub(crate) slot: Slot,
    pub(crate) block_height: u64,
    pub(crate) leader_id: Pubkey,
    pub(crate) fee_rate_governor: FeeRateGovernor,
    pub(crate) epoch_schedule: EpochSchedule,
    pub(crate) inflation: Inflation,
    pub(crate) stakes: DeserializableDelegationStakes,
    /// Transformed into `HashMap<Epoch, VersionedEpochStakes>` in `serde_snapshot` and passed to
    /// `Bank::new_from_snapshot` as separate parameter for performance (conversion is time consuming)
    pub(crate) versioned_epoch_stakes: Vec<(Epoch, DeserializableVersionedEpochStakes)>,
    pub(crate) is_delta: bool,
    pub(crate) accounts_data_len: u64,
    pub(crate) accounts_lt_hash: AccountsLtHash,
    pub(crate) bank_hash_stats: BankHashStats,
    pub(crate) block_id: Option<Hash>, // Option wrapper can be removed in version after v4.1
}

#[cfg(feature = "dev-context-only-utils")]
impl Default for BankFieldsToDeserialize {
    fn default() -> Self {
        Self {
            blockhash_queue: BlockhashQueue::default(),
            hash: Hash::default(),
            parent_hash: Hash::default(),
            parent_slot: Slot::default(),
            hard_forks: HardForks::default(),
            transaction_count: u64::default(),
            tick_height: u64::default(),
            signature_count: u64::default(),
            capitalization: u64::default(),
            max_tick_height: u64::default(),
            hashes_per_tick: Option::<u64>::default(),
            ticks_per_slot: u64::default(),
            ns_per_slot: u128::default(),
            genesis_creation_time: UnixTimestamp::default(),
            slots_per_year: f64::default(),
            slot: Slot::default(),
            block_height: u64::default(),
            leader_id: Pubkey::default(),
            fee_rate_governor: FeeRateGovernor::default(),
            epoch_schedule: EpochSchedule::default(),
            inflation: Inflation::default(),
            stakes: DeserializableDelegationStakes {
                vote_accounts: VoteAccounts::default(),
                stake_delegations: Vec::default(),
                unused: u64::default(),
                epoch: Epoch::default(),
                stake_history: CowStakeHistory::default(),
            },
            versioned_epoch_stakes: Vec::default(),
            is_delta: bool::default(),
            accounts_data_len: u64::default(),
            accounts_lt_hash: AccountsLtHash(LtHash::identity()),
            bank_hash_stats: BankHashStats::default(),
            block_id: Option::<Hash>::default(),
        }
    }
}

/// Bank's common fields shared by all supported snapshot versions for serialization.
/// This was separated from BankFieldsToDeserialize to avoid cloning by using refs.
/// So, sync fields with BankFieldsToDeserialize!
/// all members are made public to keep Bank private and to make versioned serializer workable on this.
/// Note that some fields are missing from the serializer struct. This is because of fields added later.
/// Since it is difficult to insert fields to serialize/deserialize against existing code already deployed,
/// new fields can be optionally serialized and optionally deserialized. At some point, the serialization and
/// deserialization will use a new mechanism or otherwise be in sync more clearly.
#[derive(Debug)]
pub struct BankFieldsToSerialize {
    pub blockhash_queue: BlockhashQueue,
    pub hash: Hash,
    pub parent_hash: Hash,
    pub parent_slot: Slot,
    pub hard_forks: HardForks,
    pub transaction_count: u64,
    pub tick_height: u64,
    pub signature_count: u64,
    pub capitalization: u64,
    pub max_tick_height: u64,
    pub hashes_per_tick: Option<u64>,
    pub ticks_per_slot: u64,
    pub ns_per_slot: u128,
    pub genesis_creation_time: UnixTimestamp,
    pub slots_per_year: f64,
    pub slot: Slot,
    pub block_height: u64,
    pub leader_id: Pubkey,
    pub fee_rate_governor: FeeRateGovernor,
    pub epoch_schedule: EpochSchedule,
    pub inflation: Inflation,
    pub stakes: Stakes<StakeAccount<Delegation>>,
    pub is_delta: bool,
    pub accounts_data_len: u64,
    pub versioned_epoch_stakes: HashMap<u64, VersionedEpochStakes>,
    pub accounts_lt_hash: AccountsLtHash,
    pub block_id: Hash,
}

// Can't derive PartialEq because RwLock doesn't implement PartialEq
#[cfg(feature = "dev-context-only-utils")]
impl PartialEq for Bank {
    fn eq(&self, other: &Self) -> bool {
        if std::ptr::eq(self, other) {
            return true;
        }
        // Suppress rustfmt until https://github.com/rust-lang/rustfmt/issues/5920 is fixed ...
        #[rustfmt::skip]
        let Self {
            rc: _,
            status_cache: _,
            store_transaction_signatures_in_status_cache,
            blockhash_queue,
            max_processing_age,
            partitioned_rewards_stake_account_stores_per_block,
            ancestors: _,
            hash,
            parent_hash,
            parent_slot,
            hard_forks,
            transaction_count,
            non_vote_transaction_count_since_restart: _,
            transaction_error_count: _,
            transaction_entries_count: _,
            transactions_per_entry_max: _,
            entry_bytes_consumed: _,
            tick_height,
            signature_count,
            capitalization,
            max_tick_height,
            hashes_per_tick,
            ticks_per_slot,
            ns_per_slot,
            genesis_creation_time,
            slots_per_year,
            slot_params: _,
            slot,
            bank_id: _,
            epoch,
            block_height,
            leader,
            fee_rate_governor,
            rent_collector,
            epoch_schedule,
            inflation,
            stakes_cache,
            epoch_stakes,
            is_delta,
            #[cfg(feature = "dev-context-only-utils")]
            hash_overrides,
            accounts_lt_hash,
            is_alpenglow,
            // TODO: Confirm if all these fields are intentionally ignored!
            rewards: _,
            cluster_type: _,
            transaction_debug_keys: _,
            transaction_log_collector_config: _,
            transaction_log_collector: _,
            feature_set: _,
            reserved_account_keys: _,
            drop_callback: _,
            freeze_started: _,
            vote_only_bank: _,
            should_replay_from_blockstore: _,
            cost_tracker: _,
            accounts_data_size_initial: _,
            accounts_data_size_delta_on_chain: _,
            accounts_data_size_delta_off_chain: _,
            epoch_reward_status: _,
            transaction_processor: _,
            collector_fee_details: _,
            compute_budget: _,
            transaction_account_lock_limit: _,
            fee_structure: _,
            accounts_lt_hash_async_progress: _,
            block_id,
            expected_bank_hash: _,
            bank_hash_stats: _,
            epoch_rewards_calculation_cache: _,
            block_component_processor: _,
            transaction_execution_gate: _,
            // Ignore new fields explicitly if they do not impact PartialEq.
            // Adding ".." will remove compile-time checks that if a new field
            // is added to the struct, this PartialEq is accordingly updated.
        } = self;
        *store_transaction_signatures_in_status_cache
            == other.store_transaction_signatures_in_status_cache
            && *blockhash_queue.read().unwrap() == *other.blockhash_queue.read().unwrap()
            && *max_processing_age == other.max_processing_age
            && *partitioned_rewards_stake_account_stores_per_block
                == other.partitioned_rewards_stake_account_stores_per_block
            && *hash.read().unwrap() == *other.hash.read().unwrap()
            && parent_hash == &other.parent_hash
            && parent_slot == &other.parent_slot
            && *hard_forks.read().unwrap() == *other.hard_forks.read().unwrap()
            && transaction_count.load(Relaxed) == other.transaction_count.load(Relaxed)
            && tick_height.load(Relaxed) == other.tick_height.load(Relaxed)
            && signature_count.load(Relaxed) == other.signature_count.load(Relaxed)
            && capitalization.load(Relaxed) == other.capitalization.load(Relaxed)
            && max_tick_height == &other.max_tick_height
            && *hashes_per_tick.read().unwrap() == *other.hashes_per_tick.read().unwrap()
            && ticks_per_slot == &other.ticks_per_slot
            && ns_per_slot == &other.ns_per_slot
            && genesis_creation_time == &other.genesis_creation_time
            && slots_per_year == &other.slots_per_year
            && slot == &other.slot
            && epoch == &other.epoch
            && block_height == &other.block_height
            && leader == &other.leader
            && fee_rate_governor == &other.fee_rate_governor
            && rent_collector == &other.rent_collector
            && epoch_schedule == &other.epoch_schedule
            && *inflation.read().unwrap() == *other.inflation.read().unwrap()
            && *stakes_cache.stakes() == *other.stakes_cache.stakes()
            && epoch_stakes == &other.epoch_stakes
            && is_delta.load(Relaxed) == other.is_delta.load(Relaxed)
            // No deadlock is possible, when Arc::ptr_eq() returns false, because of being
            // different Mutexes.
            && (Arc::ptr_eq(hash_overrides, &other.hash_overrides) ||
                *hash_overrides.lock().unwrap() == *other.hash_overrides.lock().unwrap())
            && *accounts_lt_hash.lock().unwrap() == *other.accounts_lt_hash.lock().unwrap()
            && *block_id.read().unwrap() == *other.block_id.read().unwrap()
            && is_alpenglow.load(Relaxed) == other.is_alpenglow()
    }
}

#[cfg(feature = "dev-context-only-utils")]
impl BankFieldsToSerialize {
    /// Create a new BankFieldsToSerialize where basically every field is defaulted.
    /// Only use for tests; many of the fields are invalid!
    pub fn default_for_tests() -> Self {
        Self {
            blockhash_queue: BlockhashQueue::default(),
            hash: Hash::default(),
            parent_hash: Hash::default(),
            parent_slot: Slot::default(),
            hard_forks: HardForks::default(),
            transaction_count: u64::default(),
            tick_height: u64::default(),
            signature_count: u64::default(),
            capitalization: u64::default(),
            max_tick_height: u64::default(),
            hashes_per_tick: Option::default(),
            ticks_per_slot: u64::default(),
            ns_per_slot: u128::default(),
            genesis_creation_time: UnixTimestamp::default(),
            slots_per_year: f64::default(),
            slot: Slot::default(),
            block_height: u64::default(),
            leader_id: Pubkey::default(),
            fee_rate_governor: FeeRateGovernor::default(),
            epoch_schedule: EpochSchedule::default(),
            inflation: Inflation::default(),
            stakes: Stakes::<StakeAccount<Delegation>>::default(),
            is_delta: bool::default(),
            accounts_data_len: u64::default(),
            versioned_epoch_stakes: HashMap::default(),
            accounts_lt_hash: AccountsLtHash(LtHash([0x7E57; LtHash::NUM_ELEMENTS])),
            block_id: Hash::default(),
        }
    }
}

#[derive(Debug)]
pub enum RewardCalculationEvent<'a, 'b> {
    Staking(&'a Pubkey, &'b InflationPointCalculationEvent),
}
/// type alias is not supported for trait in rust yet. As a workaround, we define the
/// `RewardCalcTracer` trait explicitly and implement it on any type that implement
/// `Fn(&RewardCalculationEvent) + Send + Sync`.
pub trait RewardCalcTracer: Fn(&RewardCalculationEvent) + Send + Sync {}

impl<T: Fn(&RewardCalculationEvent) + Send + Sync> RewardCalcTracer for T {}

fn null_tracer() -> Option<impl RewardCalcTracer> {
    None::<fn(&RewardCalculationEvent)>
}

pub trait DropCallback: fmt::Debug {
    fn callback(&self, b: &Bank);
    fn clone_box(&self) -> Box<dyn DropCallback + Send + Sync>;
}

#[derive(Debug, Default)]
pub struct OptionalDropCallback(Option<Box<dyn DropCallback + Send + Sync>>);

#[derive(Default, Debug, Clone, PartialEq)]
#[cfg(feature = "dev-context-only-utils")]
pub struct HashOverrides {
    hashes: HashMap<Slot, HashOverride>,
}

#[cfg(feature = "dev-context-only-utils")]
impl HashOverrides {
    fn get_hash_override(&self, slot: Slot) -> Option<&HashOverride> {
        self.hashes.get(&slot)
    }

    fn get_blockhash_override(&self, slot: Slot) -> Option<&Hash> {
        self.get_hash_override(slot)
            .map(|hash_override| &hash_override.blockhash)
    }

    fn get_bank_hash_override(&self, slot: Slot) -> Option<&Hash> {
        self.get_hash_override(slot)
            .map(|hash_override| &hash_override.bank_hash)
    }

    pub fn add_override(&mut self, slot: Slot, blockhash: Hash, bank_hash: Hash) {
        let is_new = self
            .hashes
            .insert(
                slot,
                HashOverride {
                    blockhash,
                    bank_hash,
                },
            )
            .is_none();
        assert!(is_new);
    }
}

#[derive(Debug, Clone, PartialEq)]
#[cfg(feature = "dev-context-only-utils")]
struct HashOverride {
    blockhash: Hash,
    bank_hash: Hash,
}

/// Manager for the state of all accounts and programs after processing its entries.
pub struct Bank {
    /// References to accounts, parent and signature status
    pub rc: BankRc,

    /// A cache of signature statuses
    pub status_cache: Arc<RwLock<BankStatusCache>>,

    /// Derived from RuntimeConfig::skip_transaction_signatures_in_status_cache.
    store_transaction_signatures_in_status_cache: bool,

    /// FIFO queue of `recent_blockhash` items
    blockhash_queue: RwLock<BlockhashQueue>,

    /// Maximum age in slots a blockhash can be for a tx to be processed.
    max_processing_age: usize,

    /// Number of stake accounts to store in each block during partitioned rewards.
    partitioned_rewards_stake_account_stores_per_block: u64,

    /// The set of parents including this bank
    pub ancestors: Ancestors,

    /// Hash of this Bank's state. Only meaningful after freezing.
    hash: RwLock<Hash>,

    /// Hash of this Bank's parent's state
    parent_hash: Hash,

    /// parent's slot
    parent_slot: Slot,

    /// slots to hard fork at
    hard_forks: Arc<RwLock<HardForks>>,

    /// The number of committed transactions since genesis.
    transaction_count: AtomicU64,

    /// The number of non-vote transactions committed since the most
    /// recent boot from snapshot or genesis. This value is only stored in
    /// blockstore for the RPC method "getPerformanceSamples". It is not
    /// retained within snapshots, but is preserved in `Bank::new_from_parent`.
    non_vote_transaction_count_since_restart: AtomicU64,

    /// The number of transaction errors in this slot
    transaction_error_count: AtomicU64,

    /// The number of transaction entries in this slot
    transaction_entries_count: AtomicU64,

    /// The max number of transaction in an entry in this slot
    transactions_per_entry_max: AtomicU64,

    /// The number of entry bytes reserved for recording in this slot.
    entry_bytes_consumed: EntryBytesBudget,

    /// Bank tick height
    tick_height: AtomicU64,

    /// The number of signatures from valid transactions in this slot
    signature_count: AtomicU64,

    /// Total capitalization, used to calculate inflation
    capitalization: AtomicU64,

    // Bank max_tick_height
    max_tick_height: u64,

    /// The number of hashes in each tick. None value means hashing is disabled.
    hashes_per_tick: RwLock<Option<u64>>,

    /// The number of ticks in each slot.
    ticks_per_slot: u64,

    /// length of a slot in ns
    pub ns_per_slot: u128,

    /// genesis time, used for computed clock
    genesis_creation_time: UnixTimestamp,

    /// The number of slots per year, used for inflation
    slots_per_year: f64,

    /// Slot-scoped parameter history used for slot-relative parameter lookups.
    slot_params: SlotParamsArchive,

    /// Bank slot (i.e. block)
    slot: Slot,

    bank_id: BankId,

    /// Bank epoch
    epoch: Epoch,

    /// Bank block_height
    block_height: u64,

    /// The leader who produced this block
    leader: SlotLeader,

    /// Track cluster signature throughput and adjust fee rate
    pub(crate) fee_rate_governor: FeeRateGovernor,

    /// latest rent collector, knows the epoch
    rent_collector: RentCollector,

    /// initialized from genesis
    pub(crate) epoch_schedule: EpochSchedule,

    /// inflation specs
    inflation: Arc<RwLock<Inflation>>,

    /// cache of vote_account and stake_account state for this fork
    stakes_cache: StakesCache,

    /// staked nodes on epoch boundaries, saved off when a bank.slot() is at
    ///   a leader schedule calculation boundary
    epoch_stakes: HashMap<Epoch, VersionedEpochStakes>,

    /// A boolean reflecting whether any entries were recorded into the PoH
    /// stream for the slot == self.slot
    is_delta: AtomicBool,

    /// Protocol-level rewards that were distributed by this bank
    pub rewards: RwLock<Vec<(Pubkey, RewardInfo)>>,

    pub cluster_type: Option<ClusterType>,

    transaction_debug_keys: Option<Arc<HashSet<Pubkey>>>,

    // Global configuration for how transaction logs should be collected across all banks
    pub transaction_log_collector_config: Arc<RwLock<TransactionLogCollectorConfig>>,

    // Logs from transactions that this Bank executed collected according to the criteria in
    // `transaction_log_collector_config`
    pub transaction_log_collector: Arc<RwLock<TransactionLogCollector>>,

    pub feature_set: Arc<FeatureSet>,

    /// Set of reserved account keys that cannot be write locked
    reserved_account_keys: Arc<ReservedAccountKeys>,

    /// callback function only to be called when dropping and should only be called once
    pub drop_callback: RwLock<OptionalDropCallback>,

    pub freeze_started: AtomicBool,

    vote_only_bank: bool,

    /// Whether ReplayStage should execute this bank from blockstore.
    /// This defaults to true. Banks created for local block production opt out because BankingStage
    /// executes them instead.
    should_replay_from_blockstore: bool,

    cost_tracker: RwLock<CostTracker>,

    /// The initial accounts data size at the start of this Bank, before processing any transactions/etc
    accounts_data_size_initial: u64,
    /// The change to accounts data size in this Bank, due on-chain events (i.e. transactions)
    accounts_data_size_delta_on_chain: AtomicI64,
    /// The change to accounts data size in this Bank, due to off-chain events (i.e. rent collection)
    accounts_data_size_delta_off_chain: AtomicI64,

    epoch_reward_status: EpochRewardStatus,

    transaction_processor: TransactionBatchProcessor<BankForks>,

    /// Collected fee details
    collector_fee_details: RwLock<CollectorFeeDetails>,

    /// The compute budget to use for transaction execution.
    compute_budget: Option<ComputeBudget>,

    /// The max number of accounts that a transaction may lock.
    transaction_account_lock_limit: Option<usize>,

    /// Fee structure to use for assessing transaction fees.
    fee_structure: FeeStructure,

    /// blockhash and bank_hash overrides keyed by slot for simulated block production.
    /// This _field_ was needed to be DCOU-ed to avoid 2 locks per bank freezing...
    #[cfg(feature = "dev-context-only-utils")]
    hash_overrides: Arc<Mutex<HashOverrides>>,

    /// The lattice hash of all accounts
    ///
    /// The value is only meaningful after freezing.
    accounts_lt_hash: Mutex<AccountsLtHash>,

    /// Track progress of the asynchronous accounts lt hashing for this Bank.
    accounts_lt_hash_async_progress: Arc<AccountsLtHashAsyncProgress>,

    /// The unique identifier for the corresponding block for this bank.
    /// None for banks that have not yet completed replay or for leader banks as we cannot populate block_id
    /// until bankless leader. Can be computed directly from shreds without needing to execute transactions.
    block_id: RwLock<Option<Hash>>,

    /// Expected bank hash provided by block footer (if any). Set when processing footer; verified
    /// later when the bank is frozen.
    expected_bank_hash: RwLock<Option<Hash>>,

    /// Accounts stats for computing the bank hash
    bank_hash_stats: AtomicBankHashStats,

    /// The cache of epoch rewards calculation results
    /// This is used to avoid recalculating the same epoch rewards at epoch boundary.
    /// The hashmap is keyed by parent_hash.
    epoch_rewards_calculation_cache: Arc<Mutex<HashMap<Hash, Arc<PartitionedRewardsCalculation>>>>,

    /// Block component processor for validating block headers/footers and clock bounds. We
    /// currently write to this during replay, as we process block components one at a time, and
    /// read from this once replay is complete.
    pub block_component_processor: RwLock<BlockComponentProcessor>,

    /// Cached Alpenglow migration state, derived from the genesis certificate account.
    is_alpenglow: AtomicBool,

    /// Coordinates transaction execution with retirement of an unfrozen Bank. Padding keeps the
    /// frequently mutated lock state from sharing a cache line with unrelated Bank fields.
    transaction_execution_gate: CachePadded<TransactionExecutionGate>,
}

#[derive(Default)]
struct TransactionExecutionGate {
    lock: RwLock<()>,
    quiesce_requested: AtomicBool,
}

/// Proof that transaction execution has been admitted for a specific [`Bank`].
///
/// The guard is Bank-bound so guarded operations cannot accidentally use an execution token from
/// a different Bank. Dropping it allows Bank retirement to make progress.
#[must_use = "the transaction execution guard must be held while executing transactions"]
pub struct TxExecutionGuard<'a> {
    bank: &'a Bank,
    _lock_guard: RwLockReadGuard<'a, ()>,
}

impl TxExecutionGuard<'_> {
    /// Loads and executes transactions against the Bank that admitted this guard.
    pub fn load_and_execute_transactions(
        &self,
        batch: &TransactionBatch<impl TransactionWithMeta>,
        max_age: usize,
        timings: &mut ExecuteTimings,
        error_counters: &mut TransactionErrorMetrics,
        processing_config: TransactionProcessingConfig,
    ) -> LoadAndExecuteTransactionsOutput {
        self.bank.do_load_and_execute_transactions(
            batch,
            max_age,
            timings,
            error_counters,
            processing_config,
        )
    }

    fn commit_transactions(
        &self,
        sanitized_txs: &[impl TransactionWithMeta],
        processing_results: Vec<TransactionProcessingResult>,
        processed_counts: &ProcessedTransactionCounts,
        timings: &mut ExecuteTimings,
    ) -> Vec<TransactionCommitResult> {
        self.bank
            .commit_transactions(sanitized_txs, processing_results, processed_counts, timings)
    }
}

#[derive(Debug, Default)]
pub struct NewBankOptions {
    pub vote_only_bank: bool,
}

#[cfg(feature = "dev-context-only-utils")]
#[derive(Debug)]
pub struct BankTestConfig {
    pub accounts_db_config: AccountsDbConfig,
}

#[cfg(feature = "dev-context-only-utils")]
impl Default for BankTestConfig {
    fn default() -> Self {
        Self {
            accounts_db_config: ACCOUNTS_DB_CONFIG_FOR_TESTING,
        }
    }
}

#[derive(Debug, Default, PartialEq)]
pub struct ProcessedTransactionCounts {
    pub processed_transactions_count: u64,
    pub processed_non_vote_transactions_count: u64,
    pub processed_with_successful_result_count: u64,
    pub signature_count: u64,
}

/// Account stats for computing the bank hash
/// This struct is serialized and stored in the snapshot.
#[repr(C)]
#[cfg_attr(feature = "frozen-abi", derive(AbiExample, StableAbi, StableAbiSample))]
#[derive(Clone, Default, Debug, Serialize, Deserialize, PartialEq, Eq, SchemaRead, SchemaWrite)]
pub struct BankHashStats {
    pub num_updated_accounts: u64,
    pub num_removed_accounts: u64,
    pub num_lamports_stored: u64,
    pub total_data_len: u64,
    pub num_executable_accounts: u64,
}

impl BankHashStats {
    pub fn update<T: ReadableAccount>(&mut self, account: &T) {
        if account.lamports() == 0 {
            self.num_removed_accounts += 1;
        } else {
            self.num_updated_accounts += 1;
        }
        self.total_data_len = self
            .total_data_len
            .wrapping_add(account.data().len() as u64);
        if account.executable() {
            self.num_executable_accounts += 1;
        }
        self.num_lamports_stored = self.num_lamports_stored.wrapping_add(account.lamports());
    }
    pub fn accumulate(&mut self, other: &BankHashStats) {
        self.num_updated_accounts += other.num_updated_accounts;
        self.num_removed_accounts += other.num_removed_accounts;
        self.total_data_len = self.total_data_len.wrapping_add(other.total_data_len);
        self.num_lamports_stored = self
            .num_lamports_stored
            .wrapping_add(other.num_lamports_stored);
        self.num_executable_accounts += other.num_executable_accounts;
    }
}

#[derive(Debug, Default)]
pub struct AtomicBankHashStats {
    pub num_updated_accounts: AtomicU64,
    pub num_removed_accounts: AtomicU64,
    pub num_lamports_stored: AtomicU64,
    pub total_data_len: AtomicU64,
    pub num_executable_accounts: AtomicU64,
}

impl AtomicBankHashStats {
    pub fn new(stat: &BankHashStats) -> Self {
        AtomicBankHashStats {
            num_updated_accounts: AtomicU64::new(stat.num_updated_accounts),
            num_removed_accounts: AtomicU64::new(stat.num_removed_accounts),
            num_lamports_stored: AtomicU64::new(stat.num_lamports_stored),
            total_data_len: AtomicU64::new(stat.total_data_len),
            num_executable_accounts: AtomicU64::new(stat.num_executable_accounts),
        }
    }

    pub fn accumulate(&self, other: &BankHashStats) {
        self.num_updated_accounts
            .fetch_add(other.num_updated_accounts, Relaxed);
        self.num_removed_accounts
            .fetch_add(other.num_removed_accounts, Relaxed);
        self.total_data_len.fetch_add(other.total_data_len, Relaxed);
        self.num_lamports_stored
            .fetch_add(other.num_lamports_stored, Relaxed);
        self.num_executable_accounts
            .fetch_add(other.num_executable_accounts, Relaxed);
    }

    pub fn load(&self) -> BankHashStats {
        BankHashStats {
            num_updated_accounts: self.num_updated_accounts.load(Relaxed),
            num_removed_accounts: self.num_removed_accounts.load(Relaxed),
            num_lamports_stored: self.num_lamports_stored.load(Relaxed),
            total_data_len: self.total_data_len.load(Relaxed),
            num_executable_accounts: self.num_executable_accounts.load(Relaxed),
        }
    }
}

struct NewEpochBundle {
    stake_history: CowStakeHistory,
    /// Vote accounts computed from the stakes cache for the current
    /// (distribution) epoch *before* applying any VAT filtering.
    unfiltered_distribution_vote_accounts: VoteAccounts,
    /// Current effective stake delegated to each vote account pubkey.
    delegated_stakes: DelegatedStakes,
    /// Vote accounts computed from the stakes cache for the current
    /// (distribution) epoch *after* applying VAT filtering.
    filtered_distribution_vote_accounts: VoteAccounts,
    rewards_calculation: Arc<PartitionedRewardsCalculation>,
    calculate_activated_stake_time_us: u64,
    update_rewards_with_thread_pool_time_us: u64,
}

impl Bank {
    fn default_with_accounts(accounts: Accounts) -> Self {
        let partitioned_rewards_stake_account_stores_per_block = accounts
            .accounts_db
            .partitioned_epoch_rewards_config
            .stake_account_stores_per_block;
        let mut bank = Self {
            rc: BankRc::new(accounts),
            status_cache: Arc::<RwLock<BankStatusCache>>::default(),
            store_transaction_signatures_in_status_cache: !RuntimeConfig::default()
                .skip_transaction_signatures_in_status_cache,
            blockhash_queue: RwLock::<BlockhashQueue>::default(),
            max_processing_age: MAX_PROCESSING_AGE,
            partitioned_rewards_stake_account_stores_per_block,
            ancestors: Ancestors::default(),
            hash: RwLock::<Hash>::default(),
            parent_hash: Hash::default(),
            parent_slot: Slot::default(),
            hard_forks: Arc::<RwLock<HardForks>>::default(),
            transaction_count: AtomicU64::default(),
            non_vote_transaction_count_since_restart: AtomicU64::default(),
            transaction_error_count: AtomicU64::default(),
            transaction_entries_count: AtomicU64::default(),
            transactions_per_entry_max: AtomicU64::default(),
            entry_bytes_consumed: EntryBytesBudget::new(DEFAULT_MAX_ENTRY_BYTES_PER_SLOT),
            tick_height: AtomicU64::default(),
            signature_count: AtomicU64::default(),
            capitalization: AtomicU64::default(),
            max_tick_height: u64::default(),
            hashes_per_tick: RwLock::default(),
            ticks_per_slot: u64::default(),
            ns_per_slot: u128::default(),
            genesis_creation_time: UnixTimestamp::default(),
            slots_per_year: f64::default(),
            slot_params: SlotParamsArchive::default(),
            slot: Slot::default(),
            bank_id: BankId::default(),
            epoch: Epoch::default(),
            block_height: u64::default(),
            leader: SlotLeader::default(),
            fee_rate_governor: FeeRateGovernor::default(),
            rent_collector: RentCollector::default(),
            epoch_schedule: EpochSchedule::default(),
            inflation: Arc::<RwLock<Inflation>>::default(),
            stakes_cache: StakesCache::default(),
            epoch_stakes: HashMap::<Epoch, VersionedEpochStakes>::default(),
            is_delta: AtomicBool::default(),
            rewards: RwLock::<Vec<(Pubkey, RewardInfo)>>::default(),
            cluster_type: Option::<ClusterType>::default(),
            transaction_debug_keys: Option::<Arc<HashSet<Pubkey>>>::default(),
            transaction_log_collector_config: Arc::<RwLock<TransactionLogCollectorConfig>>::default(
            ),
            transaction_log_collector: Arc::<RwLock<TransactionLogCollector>>::default(),
            feature_set: Arc::<FeatureSet>::default(),
            reserved_account_keys: Arc::<ReservedAccountKeys>::default(),
            drop_callback: RwLock::new(OptionalDropCallback(None)),
            freeze_started: AtomicBool::default(),
            vote_only_bank: false,
            should_replay_from_blockstore: true,
            cost_tracker: RwLock::<CostTracker>::default(),
            accounts_data_size_initial: 0,
            accounts_data_size_delta_on_chain: AtomicI64::new(0),
            accounts_data_size_delta_off_chain: AtomicI64::new(0),
            epoch_reward_status: EpochRewardStatus::default(),
            transaction_processor: TransactionBatchProcessor::default(),
            collector_fee_details: RwLock::new(CollectorFeeDetails::default()),
            compute_budget: None,
            transaction_account_lock_limit: None,
            fee_structure: FeeStructure::default(),
            #[cfg(feature = "dev-context-only-utils")]
            hash_overrides: Arc::new(Mutex::new(HashOverrides::default())),
            accounts_lt_hash: Mutex::new(AccountsLtHash(LtHash::identity())),
            accounts_lt_hash_async_progress: Arc::new(AccountsLtHashAsyncProgress::new()),
            block_id: RwLock::new(None),
            expected_bank_hash: RwLock::new(None),
            bank_hash_stats: AtomicBankHashStats::default(),
            epoch_rewards_calculation_cache: Arc::new(Mutex::new(HashMap::default())),
            block_component_processor: RwLock::new(BlockComponentProcessor::default()),
            is_alpenglow: AtomicBool::new(false),
            transaction_execution_gate: CachePadded::new(TransactionExecutionGate::default()),
        };

        bank.transaction_processor =
            TransactionBatchProcessor::new_uninitialized(bank.slot, bank.epoch);

        bank.accounts_data_size_initial = bank.calculate_accounts_data_size().unwrap();

        bank
    }

    #[expect(clippy::too_many_arguments)]
    pub fn new_from_genesis(
        genesis_config: &GenesisConfig,
        runtime_config: Arc<RuntimeConfig>,
        paths: Vec<PathBuf>,
        debug_keys: Option<Arc<HashSet<Pubkey>>>,
        accounts_db_config: AccountsDbConfig,
        accounts_update_notifier: Option<AccountsUpdateNotifier>,
        #[cfg_attr(not(feature = "dev-context-only-utils"), expect(unused))]
        leader_for_tests: Option<SlotLeader>,
        exit: Arc<AtomicBool>,
        #[cfg_attr(not(feature = "dev-context-only-utils"), expect(unused))] genesis_hash: Option<
            Hash,
        >,
        #[cfg_attr(not(feature = "dev-context-only-utils"), expect(unused))] feature_set: Option<
            FeatureSet,
        >,
    ) -> Self {
        // Initialize the rewards thread pool while creating the first bank so
        // the first epoch boundary crossing does not pay the cost.
        let _rewards_calculation_thread_pool = rewards_calculation_thread_pool();
        let accounts_db =
            AccountsDb::new_with_config(paths, accounts_db_config, accounts_update_notifier, exit);
        let accounts = Accounts::new(Arc::new(accounts_db));
        let mut bank = Self::default_with_accounts(accounts);
        bank.ancestors = Ancestors::from(vec![bank.slot()]);
        bank.compute_budget = runtime_config.compute_budget;
        bank.store_transaction_signatures_in_status_cache =
            !runtime_config.skip_transaction_signatures_in_status_cache;
        if let Some(compute_budget) = &bank.compute_budget {
            bank.transaction_processor
                .set_execution_cost(compute_budget.to_cost());
        }
        bank.transaction_account_lock_limit = runtime_config.transaction_account_lock_limit;
        bank.transaction_debug_keys = debug_keys;
        bank.cluster_type = Some(genesis_config.cluster_type);

        #[cfg(feature = "dev-context-only-utils")]
        {
            bank.feature_set = Arc::new(feature_set.unwrap_or_default());
        }

        #[cfg(not(feature = "dev-context-only-utils"))]
        bank.process_genesis_config(genesis_config);
        #[cfg(feature = "dev-context-only-utils")]
        bank.process_genesis_config(genesis_config, leader_for_tests, genesis_hash);

        bank.compute_and_apply_genesis_features();

        // genesis needs stakes for all epochs up to the epoch implied by
        //  slot = 0 and genesis configuration
        {
            let stakes = bank.get_top_epoch_stakes();
            let stakes = SerdeStakesToStakeFormat::from(stakes);
            for epoch in 0..=bank.get_leader_schedule_epoch(bank.slot) {
                bank.epoch_stakes
                    .insert(epoch, VersionedEpochStakes::new(stakes.clone(), epoch));
            }
            bank.update_stake_history(None);
        }
        bank.update_clock(None);
        bank.update_rent();
        bank.update_epoch_schedule();
        bank.update_recent_blockhashes();
        bank.update_last_restart_slot();
        bank.transaction_processor
            .fill_missing_sysvar_cache_entries(&bank);
        if bank.get_alpenglow_genesis_certificate().is_some() {
            bank.set_is_alpenglow();
        }
        bank
    }

    /// Create a new bank that points to an immutable checkpoint of another bank.
    pub fn new_from_parent(parent: Arc<Bank>, leader: SlotLeader, slot: Slot) -> Self {
        Self::_new_from_parent(
            parent,
            leader,
            slot,
            null_tracer(),
            NewBankOptions::default(),
        )
    }

    pub fn new_from_parent_with_options(
        parent: Arc<Bank>,
        leader: SlotLeader,
        slot: Slot,
        new_bank_options: NewBankOptions,
    ) -> Self {
        Self::_new_from_parent(parent, leader, slot, null_tracer(), new_bank_options)
    }

    pub fn new_from_parent_with_tracer(
        parent: Arc<Bank>,
        leader: SlotLeader,
        slot: Slot,
        reward_calc_tracer: impl RewardCalcTracer,
    ) -> Self {
        Self::_new_from_parent(
            parent,
            leader,
            slot,
            Some(reward_calc_tracer),
            NewBankOptions::default(),
        )
    }

    fn get_rent_collector_from(rent_collector: &RentCollector, epoch: Epoch) -> RentCollector {
        rent_collector.clone_with_epoch(epoch)
    }

    fn _new_from_parent(
        parent: Arc<Bank>,
        leader: SlotLeader,
        slot: Slot,
        reward_calc_tracer: Option<impl RewardCalcTracer>,
        new_bank_options: NewBankOptions,
    ) -> Self {
        let mut time = Measure::start("bank::new_from_parent");
        let NewBankOptions { vote_only_bank } = new_bank_options;

        parent.freeze();
        assert_ne!(slot, parent.slot());

        let epoch_schedule = parent.epoch_schedule().clone();
        let epoch = epoch_schedule.get_epoch(slot);

        let (rc, bank_rc_creation_time_us) = measure_us!({
            let accounts_db = Arc::clone(&parent.rc.accounts.accounts_db);
            BankRc {
                accounts: Arc::new(Accounts::new(accounts_db)),
                parent: RwLock::new(Some(Arc::clone(&parent))),
                bank_id_generator: Arc::clone(&parent.rc.bank_id_generator),
            }
        });

        let (status_cache, status_cache_time_us) = measure_us!(Arc::clone(&parent.status_cache));

        let (fee_rate_governor, fee_components_time_us) = measure_us!(
            FeeRateGovernor::new_derived(&parent.fee_rate_governor, parent.signature_count())
        );

        let bank_id = rc.bank_id_generator.fetch_add(1, Relaxed) + 1;
        let (blockhash_queue, blockhash_queue_time_us) =
            measure_us!(RwLock::new(parent.blockhash_queue.read().unwrap().clone()));

        let (stakes_cache, stakes_cache_time_us) =
            measure_us!(StakesCache::new(parent.stakes_cache.stakes().clone()));

        let (epoch_stakes, epoch_stakes_time_us) = measure_us!(parent.epoch_stakes.clone());

        let (transaction_processor, builtin_program_ids_time_us) = measure_us!(
            TransactionBatchProcessor::new_from(&parent.transaction_processor, slot, epoch)
        );

        let (transaction_debug_keys, transaction_debug_keys_time_us) =
            measure_us!(parent.transaction_debug_keys.clone());

        let (transaction_log_collector_config, transaction_log_collector_config_time_us) =
            measure_us!(parent.transaction_log_collector_config.clone());

        let (feature_set, feature_set_time_us) = measure_us!(parent.feature_set.clone());

        let accounts_data_size_initial = parent.load_accounts_data_size();
        let mut new = Self {
            rc,
            status_cache,
            store_transaction_signatures_in_status_cache: parent
                .store_transaction_signatures_in_status_cache,
            slot,
            bank_id,
            epoch,
            blockhash_queue,
            max_processing_age: parent.max_processing_age,
            partitioned_rewards_stake_account_stores_per_block: parent
                .partitioned_rewards_stake_account_stores_per_block,
            // TODO: clean this up, so much special-case copying...
            hashes_per_tick: RwLock::new(parent.hashes_per_tick()),
            ticks_per_slot: parent.ticks_per_slot,
            ns_per_slot: parent.ns_per_slot,
            genesis_creation_time: parent.genesis_creation_time,
            slots_per_year: parent.slots_per_year,
            slot_params: parent.slot_params.clone(),
            epoch_schedule,
            rent_collector: Self::get_rent_collector_from(&parent.rent_collector, epoch),
            max_tick_height: slot
                .checked_add(1)
                .expect("max tick height addition overflowed")
                .checked_mul(parent.ticks_per_slot)
                .expect("max tick height multiplication overflowed"),
            block_height: parent
                .block_height
                .checked_add(1)
                .expect("block height addition overflowed"),
            fee_rate_governor,
            capitalization: AtomicU64::new(parent.capitalization()),
            vote_only_bank,
            should_replay_from_blockstore: true,
            inflation: parent.inflation.clone(),
            transaction_count: AtomicU64::new(parent.transaction_count()),
            non_vote_transaction_count_since_restart: AtomicU64::new(
                parent.non_vote_transaction_count_since_restart(),
            ),
            transaction_error_count: AtomicU64::new(0),
            transaction_entries_count: AtomicU64::new(0),
            transactions_per_entry_max: AtomicU64::new(0),
            entry_bytes_consumed: EntryBytesBudget::new(parent.entry_bytes_budget().slot_limit()),
            // we will .clone_with_epoch() this soon after stake data update; so just .clone() for now
            stakes_cache,
            epoch_stakes,
            parent_hash: parent.hash(),
            parent_slot: parent.slot(),
            leader,
            ancestors: Ancestors::default(),
            hash: RwLock::new(Hash::default()),
            is_delta: AtomicBool::new(false),
            tick_height: AtomicU64::new(parent.tick_height.load(Relaxed)),
            signature_count: AtomicU64::new(0),
            hard_forks: parent.hard_forks.clone(),
            rewards: RwLock::new(vec![]),
            cluster_type: parent.cluster_type,
            transaction_debug_keys,
            transaction_log_collector_config,
            transaction_log_collector: Arc::new(RwLock::new(TransactionLogCollector::default())),
            feature_set: Arc::clone(&feature_set),
            reserved_account_keys: parent.reserved_account_keys.clone(),
            drop_callback: RwLock::new(OptionalDropCallback(
                parent
                    .drop_callback
                    .read()
                    .unwrap()
                    .0
                    .as_ref()
                    .map(|drop_callback| drop_callback.clone_box()),
            )),
            freeze_started: AtomicBool::new(false),
            cost_tracker: RwLock::new(parent.read_cost_tracker().unwrap().new_from_parent_limits()),
            accounts_data_size_initial,
            accounts_data_size_delta_on_chain: AtomicI64::new(0),
            accounts_data_size_delta_off_chain: AtomicI64::new(0),
            epoch_reward_status: parent.epoch_reward_status.clone(),
            transaction_processor,
            collector_fee_details: RwLock::new(CollectorFeeDetails::default()),
            compute_budget: parent.compute_budget,
            transaction_account_lock_limit: parent.transaction_account_lock_limit,
            fee_structure: parent.fee_structure.clone(),
            #[cfg(feature = "dev-context-only-utils")]
            hash_overrides: parent.hash_overrides.clone(),
            accounts_lt_hash: Mutex::new(parent.accounts_lt_hash.lock().unwrap().clone()),
            accounts_lt_hash_async_progress: Arc::new(AccountsLtHashAsyncProgress::new()),
            block_id: RwLock::new(None),
            expected_bank_hash: RwLock::new(None),
            bank_hash_stats: AtomicBankHashStats::default(),
            epoch_rewards_calculation_cache: parent.epoch_rewards_calculation_cache.clone(),
            block_component_processor: RwLock::new(BlockComponentProcessor::default()),
            is_alpenglow: AtomicBool::new(parent.is_alpenglow()),
            transaction_execution_gate: CachePadded::new(TransactionExecutionGate::default()),
        };

        let (_, ancestors_time_us) = measure_us!({
            let mut ancestors = Vec::with_capacity(parent.ancestors.len() + 1);
            ancestors.push(new.slot());
            ancestors.extend(new.parents_iter().map(|parent| parent.slot()));
            new.ancestors = Ancestors::from(ancestors);
        });

        let prepare_timings = new.prepare_for_block_execution(
            parent.epoch(),
            parent.slot(),
            parent.capitalization(),
            parent.block_height(),
            reward_calc_tracer,
        );

        time.stop();
        report_new_bank_metrics(
            slot,
            parent.slot(),
            new.block_height,
            NewBankTimings {
                bank_rc_creation_time_us,
                total_elapsed_time_us: time.as_us(),
                status_cache_time_us,
                fee_components_time_us,
                blockhash_queue_time_us,
                stakes_cache_time_us,
                epoch_stakes_time_us,
                builtin_program_ids_time_us,
                executor_cache_time_us: 0,
                transaction_debug_keys_time_us,
                transaction_log_collector_config_time_us,
                feature_set_time_us,
                ancestors_time_us,
                update_epoch_time_us: prepare_timings.update_epoch_time_us,
                distribute_rewards_time_us: prepare_timings.distribute_rewards_time_us,
                cache_preparation_time_us: prepare_timings.cache_preparation_time_us,
                update_sysvars_time_us: prepare_timings.update_sysvars_time_us,
                fill_sysvar_cache_time_us: prepare_timings.fill_sysvar_cache_time_us,
            },
        );

        report_loaded_programs_stats(
            &parent
                .transaction_processor
                .global_program_cache
                .read()
                .unwrap(),
            parent.slot(),
        );

        new.transaction_processor
            .global_program_cache
            .write()
            .unwrap()
            .stats
            .reset();

        new
    }

    pub fn set_fork_graph_in_program_cache(&self, fork_graph: Weak<RwLock<BankForks>>) {
        self.transaction_processor
            .global_program_cache
            .write()
            .unwrap()
            .set_fork_graph(fork_graph);
    }

    fn prepare_program_cache_for_upcoming_feature_set(&self) {
        let (_epoch, slot_index) = self.epoch_schedule.get_epoch_and_slot_index(self.slot);
        let slots_in_epoch = self.epoch_schedule.get_slots_in_epoch(self.epoch);
        let (upcoming_feature_set, _newly_activated) = self.compute_active_feature_set(true);

        // Recompile loaded programs one at a time before the next epoch hits
        let slots_in_recompilation_phase =
            (solana_program_runtime::loaded_programs::MAX_LOADED_ENTRY_COUNT as u64)
                .min(slots_in_epoch)
                .checked_div(2)
                .unwrap();

        let mut epoch_boundary_preparation = self
            .transaction_processor
            .epoch_boundary_preparation
            .write()
            .unwrap();

        if let Some(upcoming_environment) = epoch_boundary_preparation.upcoming_environment.as_ref()
        {
            let upcoming_environment = upcoming_environment.clone();
            if let Some((key, program_to_recompile)) =
                epoch_boundary_preparation.programs_to_recompile.pop()
            {
                drop(epoch_boundary_preparation);
                self.transaction_processor
                    .prepare_one_program_for_upcoming_feature_set(
                        self,
                        &upcoming_environment,
                        &key,
                        &program_to_recompile.stats,
                    );
            }
        } else if slot_index.saturating_add(slots_in_recompilation_phase) >= slots_in_epoch {
            // Anticipate the upcoming program runtime environment for the next epoch,
            // so we can try to recompile loaded programs before the feature transition hits.
            let new_environment = self.create_program_runtime_environment(&upcoming_feature_set);
            let mut upcoming_environment = self
                .transaction_processor
                .program_runtime_environment
                .clone();
            // Here we actually want to compare the content of the environments, thus the deref.
            let changed_program_runtime_environment = *upcoming_environment != *new_environment;
            if changed_program_runtime_environment {
                upcoming_environment = new_environment;
                let program_cache_guard = self
                    .transaction_processor
                    .global_program_cache
                    .read()
                    .unwrap();
                epoch_boundary_preparation.programs_to_recompile =
                    program_cache_guard.get_flattened_entries();
                epoch_boundary_preparation
                    .programs_to_recompile
                    .sort_by_cached_key(|(_id, program)| program.retention_score());
            } else {
                epoch_boundary_preparation.programs_to_recompile.clear();
            }
            epoch_boundary_preparation.upcoming_epoch = self.epoch.saturating_add(1);
            epoch_boundary_preparation.upcoming_environment = Some(upcoming_environment);
        }
    }

    pub fn prune_program_cache(&self, bank_forks: &BankForks) {
        let upcoming_environment = self
            .transaction_processor
            .epoch_boundary_preparation
            .write()
            .unwrap()
            .reroot(self.epoch());
        self.transaction_processor
            .global_program_cache
            .write()
            .unwrap()
            .prune(
                self.slot(),
                upcoming_environment.map(|_| {
                    ProgramRuntimeEnvironment::clone(
                        &self.transaction_processor.program_runtime_environment,
                    )
                }),
                bank_forks,
            );
    }

    pub fn prune_program_cache_by_deployment_slot(&self, deployment_slot: Slot) {
        self.transaction_processor
            .global_program_cache
            .write()
            .unwrap()
            .prune_by_deployment_slot(deployment_slot);
    }

    /// Epoch in which the new cooldown warmup rate for stake was activated
    pub fn new_warmup_cooldown_rate_epoch(&self) -> Option<Epoch> {
        self.feature_set
            .new_warmup_cooldown_rate_epoch(&self.epoch_schedule)
    }

    fn use_fixed_point_stake_math(&self) -> bool {
        self.feature_set
            .snapshot()
            .upgrade_bpf_stake_program_to_v5_1
    }

    /// Get cached vote account state from the past few epochs so that some vote
    /// state configuration changes are delayed before being used in reward
    /// calculation.
    fn get_cached_vote_accounts<'a>(
        &'a self,
        rewarded_epoch: Epoch,
        distribution_epoch_vote_accounts: &'a VoteAccounts,
    ) -> CachedVoteAccounts<'a> {
        // Snapshot of vote account state from the beginning of the epoch prior to
        // the rewarded epoch. This snapshot state is saved a full epoch before
        // being used to prevent last minute commission rugs.
        let snapshot_epoch_vote_accounts = self
            .epoch_stakes(rewarded_epoch)
            .map(|epoch_stakes| epoch_stakes.stakes().vote_accounts());

        // Vote account state from the beginning of the rewarded epoch.
        let rewarded_epoch_vote_accounts = self
            .epoch_stakes(self.epoch())
            .map(|epoch_stakes| epoch_stakes.stakes().vote_accounts());

        CachedVoteAccounts {
            snapshot_epoch_vote_accounts,
            rewarded_epoch_vote_accounts,
            distribution_epoch_vote_accounts,
        }
    }

    /// Returns updated stake history and vote accounts that includes new
    /// activated stake from the last epoch.
    fn compute_new_epoch_caches_and_rewards(
        &self,
        thread_pool: &ThreadPool,
        rewarded_epoch: Epoch,
        reward_calc_tracer: Option<impl RewardCalcTracer>,
        rewards_metrics: &mut RewardsMetrics,
    ) -> NewEpochBundle {
        // Add new entry to stakes.stake_history, set appropriate epoch and
        // update vote accounts with warmed up stakes before saving a
        // snapshot of stakes in epoch stakes
        let stakes = self.stakes_cache.stakes();
        let stake_delegations = stakes.stake_delegations_vec();
        let (
            (
                stake_history,
                unfiltered_distribution_vote_accounts,
                delegated_stakes,
                reward_epoch_delegated_stakes,
            ),
            calculate_activated_stake_time_us,
        ) = measure_us!(stakes.calculate_activated_stake(
            self.epoch(),
            thread_pool,
            self.new_warmup_cooldown_rate_epoch(),
            &stake_delegations,
            self.use_fixed_point_stake_math(),
        ));
        debug_assert_eq!(reward_epoch_delegated_stakes.epoch, rewarded_epoch);

        // Apply stake rewards and commission using the VAT-filtered distribution
        // vote-account snapshot.
        let filtered_distribution_vote_accounts = unfiltered_distribution_vote_accounts
            .clone_and_filter_for_vat(
                MAX_ALPENGLOW_VOTE_ACCOUNTS,
                self.minimum_vote_account_balance_for_vat(),
            );
        if AlpenglowEpochType::is_alpenglow_or_migration_epoch(self, rewarded_epoch) {
            reward_epoch_delegated_stakes.set(self, &filtered_distribution_vote_accounts);
        }
        let cached_vote_accounts =
            self.get_cached_vote_accounts(rewarded_epoch, &filtered_distribution_vote_accounts);
        let (rewards_calculation, update_rewards_with_thread_pool_time_us) =
            measure_us!(self.calculate_rewards(
                &stake_history,
                stake_delegations,
                cached_vote_accounts,
                rewarded_epoch,
                reward_epoch_delegated_stakes,
                reward_calc_tracer,
                thread_pool,
                rewards_metrics,
            ));
        NewEpochBundle {
            stake_history,
            unfiltered_distribution_vote_accounts,
            delegated_stakes,
            filtered_distribution_vote_accounts,
            rewards_calculation,
            calculate_activated_stake_time_us,
            update_rewards_with_thread_pool_time_us,
        }
    }

    /// process for the start of a new epoch
    fn process_new_epoch(
        &mut self,
        parent_epoch: Epoch,
        parent_slot: Slot,
        parent_capitalization: u64,
        parent_height: u64,
        reward_calc_tracer: Option<impl RewardCalcTracer>,
    ) {
        let epoch = self.epoch();
        let slot = self.slot();
        let thread_pool = rewards_calculation_thread_pool();

        let (_, apply_feature_activations_time_us) = measure_us!(
            thread_pool.install(|| { self.compute_and_apply_new_feature_activations() })
        );

        let mut rewards_metrics = RewardsMetrics::default();
        let NewEpochBundle {
            stake_history,
            unfiltered_distribution_vote_accounts,
            delegated_stakes,
            filtered_distribution_vote_accounts,
            rewards_calculation,
            calculate_activated_stake_time_us,
            update_rewards_with_thread_pool_time_us,
        } = self.compute_new_epoch_caches_and_rewards(
            thread_pool,
            parent_epoch,
            reward_calc_tracer,
            &mut rewards_metrics,
        );

        self.stakes_cache.activate_epoch(
            epoch,
            stake_history,
            unfiltered_distribution_vote_accounts,
            delegated_stakes,
        );

        // Save a snapshot of stakes for use in consensus and stake weighted networking
        let leader_schedule_epoch = self.epoch_schedule.get_leader_schedule_epoch(slot);
        let (_, update_epoch_stakes_time_us) = measure_us!(self.update_epoch_stakes(
            leader_schedule_epoch,
            Some(filtered_distribution_vote_accounts),
        ));

        // Distribute rewards commission to vote accounts and cache stake rewards
        // for partitioned distribution in the upcoming slots.
        let (epoch_rewards, begin_partitioned_rewards_time_us) =
            measure_us!(self.begin_partitioned_rewards(
                parent_epoch,
                parent_slot,
                parent_height,
                &rewards_calculation,
                &mut rewards_metrics,
                thread_pool,
            ));

        // the vote reward account state should be created at the epoch boundary in which we
        // activate alpenglow as it will need info from the previous epoch.
        if self.feature_set.snapshot().alpenglow {
            let epoch_start_capitalization = parent_capitalization;
            EpochInflationAccountState::new_epoch_update_account(
                self,
                epoch_start_capitalization,
                epoch_rewards,
            );
        }

        report_new_epoch_metrics(
            epoch,
            slot,
            parent_slot,
            NewEpochTimings {
                apply_feature_activations_time_us,
                calculate_activated_stake_time_us,
                update_epoch_stakes_time_us,
                update_rewards_with_thread_pool_time_us,
                begin_partitioned_rewards_time_us,
            },
            rewards_metrics,
        );

        let program_runtime_environment =
            self.create_program_runtime_environment(&self.feature_set);
        self.transaction_processor
            .set_program_runtime_environment(program_runtime_environment);
    }

    pub fn proper_ancestors_set(&self) -> HashSet<Slot> {
        HashSet::from_iter(self.proper_ancestors())
    }

    /// Returns all ancestors excluding self.slot.
    pub(crate) fn proper_ancestors(&self) -> impl Iterator<Item = Slot> + '_ {
        self.ancestors
            .keys()
            .into_iter()
            .filter(move |slot| *slot != self.slot)
    }

    pub fn set_callback(&self, callback: Option<Box<dyn DropCallback + Send + Sync>>) {
        *self.drop_callback.write().unwrap() = OptionalDropCallback(callback);
    }

    pub fn vote_only_bank(&self) -> bool {
        self.vote_only_bank
    }

    pub fn should_replay_from_blockstore(&self) -> bool {
        self.should_replay_from_blockstore
    }

    // Indicate that this bank is a live leader bank
    pub fn mark_leader_bank(mut self) -> Self {
        self.should_replay_from_blockstore = false;
        self
    }

    /// Like `new_from_parent` but additionally:
    /// * Doesn't assume that the parent is anywhere near `slot`, parent could be millions of slots
    ///   in the past
    /// * Adjusts the new bank's tick height to avoid having to run PoH for millions of slots
    /// * Freezes the new bank, assuming that the user will `Bank::new_from_parent` from this bank
    pub fn warp_from_parent(parent: Arc<Bank>, leader: SlotLeader, slot: Slot) -> Self {
        parent.freeze();
        let parent_timestamp = parent.clock().unix_timestamp;
        let mut new = Bank::new_from_parent(parent, leader, slot);
        new.update_epoch_stakes(new.epoch_schedule().get_epoch(slot), None);
        new.tick_height.store(new.max_tick_height(), Relaxed);

        let mut clock = new.clock();
        clock.epoch_start_timestamp = parent_timestamp;
        clock.unix_timestamp = parent_timestamp;
        new.update_sysvar_account(&sysvar::clock::id(), |account| {
            create_account(
                &clock,
                new.inherit_specially_retained_account_fields(account),
            )
        });
        new.transaction_processor
            .fill_missing_sysvar_cache_entries(&new);
        new.freeze();
        new
    }

    fn load_rent_from_account_for_snapshot_load(
        accounts: &Accounts,
        ancestors: &Ancestors,
    ) -> Rent {
        // The serialized rent collector is deprecated. Instead, reconstruct from fields plus
        // the rent sysvar account state.
        let rent_sysvar = accounts
            .load_with_fixed_root_do_not_populate_read_cache(ancestors, &sysvar::rent::id())
            .expect("snapshot must contain rent sysvar account")
            .0;
        from_account::<sysvar::rent::Rent>(&rent_sysvar)
            .expect("snapshot must contain well-formed rent sysvar account")
    }

    /// Complete bank initialization for block execution. Performs epoch
    /// processing, sysvar updates, program cache preparation, and LT hash
    /// cache population -- the post-construction sequence shared by
    /// `_new_from_parent` and the block-test path.
    fn prepare_for_block_execution(
        &mut self,
        parent_epoch: Epoch,
        parent_slot: Slot,
        parent_capitalization: u64,
        parent_block_height: u64,
        reward_calc_tracer: Option<impl RewardCalcTracer>,
    ) -> PrepareBlockExecutionStats {
        let slot = self.slot;

        // Following code may touch AccountsDb, requiring proper ancestors
        let (_, update_epoch_time_us) = measure_us!({
            if parent_epoch < self.epoch() {
                self.process_new_epoch(
                    parent_epoch,
                    parent_slot,
                    parent_capitalization,
                    parent_block_height,
                    reward_calc_tracer,
                );
            } else {
                // Save a snapshot of stakes for use in consensus and stake weighted networking
                let leader_schedule_epoch = self.epoch_schedule().get_leader_schedule_epoch(slot);
                self.update_epoch_stakes(leader_schedule_epoch, None);
            }
        });

        let (_, distribute_rewards_time_us) =
            measure_us!(self.distribute_partitioned_epoch_rewards());

        let (_, cache_preparation_time_us) =
            measure_us!(self.prepare_program_cache_for_upcoming_feature_set());

        // Update sysvars before processing transactions
        let (_, update_sysvars_time_us) = measure_us!({
            self.update_slot_hashes();
            self.update_stake_history(Some(parent_epoch));

            if self.is_alpenglow() {
                // Alpenglow banks have the timestamp populated via the footer
                // We only populate the slot here
                self.update_clock_slot_for_alpenglow();
            } else {
                // PoH banks have the timestamp and slot populated at the beginning
                // Note: The first alpenglow bank will have the timestamp populated
                // here at the beginning as well as at the end via the footer - this is intentional.
                self.update_clock(Some(parent_epoch));
            }
            self.update_last_restart_slot()
        });

        let (_, fill_sysvar_cache_time_us) = measure_us!(
            self.transaction_processor
                .fill_missing_sysvar_cache_entries(self)
        );

        PrepareBlockExecutionStats {
            update_epoch_time_us,
            distribute_rewards_time_us,
            cache_preparation_time_us,
            update_sysvars_time_us,
            fill_sysvar_cache_time_us,
        }
    }

    /// Create a bank from explicit arguments and deserialized fields from snapshot
    pub(crate) fn new_from_snapshot(
        bank_rc: BankRc,
        genesis_config: &GenesisConfig,
        runtime_config: Arc<RuntimeConfig>,
        fields: BankFieldsToDeserialize,
        leader_for_tests: Option<SlotLeader>,
        debug_keys: Option<Arc<HashSet<Pubkey>>>,
        accounts_data_size_initial: u64,
        epoch_stakes: HashMap<Epoch, VersionedEpochStakes>,
    ) -> Self {
        let now = Instant::now();
        let slot = fields.slot;
        let epoch = fields.epoch_schedule.get_epoch(slot);
        let ancestors = Ancestors::from(vec![slot]);
        // Initialize the rewards thread pool while creating the first bank so
        // the first epoch boundary crossing does not pay the cost.
        let rewards_calculation_thread_pool = rewards_calculation_thread_pool();
        // For backward compatibility, we can only serialize and deserialize
        // Stakes<Delegation> in BankFieldsTo{Serialize,Deserialize}. But Bank
        // caches Stakes<StakeAccount>. Below Stakes<StakeAccount> is obtained
        // from Stakes<Delegation> by reading the full account state from
        // accounts-db. Note that it is crucial that these accounts are loaded
        // at the right slot and match precisely with serialized Delegations.
        //
        // Note that we are disabling the read cache while we populate the stakes cache.
        // The stakes accounts will not be expected to be loaded again.
        // If we populate the read cache with these loads, then we'll just soon have to evict these.
        let (stakes, stakes_time) = measure_time!(
            Stakes::load_from_deserialized_delegations(fields.stakes, |pubkey| {
                let (account, _slot) = bank_rc
                    .accounts
                    .load_with_fixed_root_do_not_populate_read_cache(&ancestors, pubkey)?;
                Some(account)
            })
            .expect(
                "Stakes cache is inconsistent with accounts-db. This can indicate a corrupted \
                 snapshot or bugs in cached accounts or accounts-db.",
            )
        );
        info!("Loading Stakes took: {stakes_time}");
        assert!(
            fields.versioned_epoch_stakes.is_empty(),
            "should be already converted and passed in epoch_stakes parameter"
        );
        assert!(
            !epoch_stakes.is_empty(),
            "should be populated (from fields.versioned_epoch_stakes)"
        );

        // Compute and validate the slot leader from epoch stakes.
        let compute_leader = || {
            if slot == 0 {
                // Genesis snapshot has no leader for the genesis block.
                // Instead the leader is set to the maximum delegated vote account.
                stakes
                    .highest_staked_node()
                    .expect("genesis snapshot should contain at least one staked vote account")
            } else {
                Self::slot_leader_from_epoch_stakes(
                    fields.slot,
                    &fields.epoch_schedule,
                    &epoch_stakes,
                )
            }
        };
        #[cfg(not(feature = "dev-context-only-utils"))]
        let leader = {
            _ = leader_for_tests;
            compute_leader()
        };
        #[cfg(feature = "dev-context-only-utils")]
        let leader = leader_for_tests.unwrap_or_else(compute_leader);
        assert_eq!(
            fields.leader_id, leader.id,
            "snapshot leader_id does not match computed slot leader"
        );

        let stakes_accounts_load_duration = now.elapsed();
        let rent = Self::load_rent_from_account_for_snapshot_load(&bank_rc.accounts, &ancestors);
        let partitioned_rewards_stake_account_stores_per_block = bank_rc
            .accounts
            .accounts_db
            .partitioned_epoch_rewards_config
            .stake_account_stores_per_block;
        let mut bank = Self {
            rc: bank_rc,
            status_cache: Arc::<RwLock<BankStatusCache>>::default(),
            store_transaction_signatures_in_status_cache: !runtime_config
                .skip_transaction_signatures_in_status_cache,
            blockhash_queue: RwLock::new(fields.blockhash_queue),
            max_processing_age: MAX_PROCESSING_AGE,
            partitioned_rewards_stake_account_stores_per_block,
            ancestors,
            hash: RwLock::new(fields.hash),
            parent_hash: fields.parent_hash,
            parent_slot: fields.parent_slot,
            hard_forks: Arc::new(RwLock::new(fields.hard_forks)),
            transaction_count: AtomicU64::new(fields.transaction_count),
            non_vote_transaction_count_since_restart: AtomicU64::default(),
            transaction_error_count: AtomicU64::default(),
            transaction_entries_count: AtomicU64::default(),
            transactions_per_entry_max: AtomicU64::default(),
            entry_bytes_consumed: EntryBytesBudget::new(DEFAULT_MAX_ENTRY_BYTES_PER_SLOT),
            tick_height: AtomicU64::new(fields.tick_height),
            signature_count: AtomicU64::new(fields.signature_count),
            capitalization: AtomicU64::new(fields.capitalization),
            max_tick_height: fields.max_tick_height,
            hashes_per_tick: RwLock::new(fields.hashes_per_tick),
            ticks_per_slot: fields.ticks_per_slot,
            ns_per_slot: fields.ns_per_slot,
            genesis_creation_time: fields.genesis_creation_time,
            slots_per_year: fields.slots_per_year,
            slot_params: SlotParamsArchive::default(),
            slot,
            bank_id: 0,
            epoch,
            block_height: fields.block_height,
            leader,
            fee_rate_governor: fields.fee_rate_governor,
            rent_collector: RentCollector::new(
                epoch,
                fields.epoch_schedule.clone(),
                fields.slots_per_year,
                rent,
            ),
            epoch_schedule: fields.epoch_schedule,
            inflation: Arc::new(RwLock::new(fields.inflation)),
            stakes_cache: StakesCache::new(stakes),
            epoch_stakes,
            is_delta: AtomicBool::new(fields.is_delta),
            rewards: RwLock::new(vec![]),
            cluster_type: Some(genesis_config.cluster_type),
            transaction_debug_keys: debug_keys,
            transaction_log_collector_config: Arc::<RwLock<TransactionLogCollectorConfig>>::default(
            ),
            transaction_log_collector: Arc::<RwLock<TransactionLogCollector>>::default(),
            feature_set: Arc::<FeatureSet>::default(),
            reserved_account_keys: Arc::<ReservedAccountKeys>::default(),
            drop_callback: RwLock::new(OptionalDropCallback(None)),
            freeze_started: AtomicBool::new(fields.hash != Hash::default()),
            vote_only_bank: false,
            should_replay_from_blockstore: true,
            cost_tracker: RwLock::new(CostTracker::default()),
            accounts_data_size_initial,
            accounts_data_size_delta_on_chain: AtomicI64::new(0),
            accounts_data_size_delta_off_chain: AtomicI64::new(0),
            epoch_reward_status: EpochRewardStatus::default(),
            transaction_processor: TransactionBatchProcessor::default(),
            // collector_fee_details is not serialized to snapshot
            collector_fee_details: RwLock::new(CollectorFeeDetails::default()),
            compute_budget: runtime_config.compute_budget,
            transaction_account_lock_limit: runtime_config.transaction_account_lock_limit,
            fee_structure: FeeStructure::default(),
            #[cfg(feature = "dev-context-only-utils")]
            hash_overrides: Arc::new(Mutex::new(HashOverrides::default())),
            accounts_lt_hash: Mutex::new(fields.accounts_lt_hash),
            accounts_lt_hash_async_progress: Arc::new(AccountsLtHashAsyncProgress::new()),
            block_id: RwLock::new(fields.block_id),
            bank_hash_stats: AtomicBankHashStats::new(&fields.bank_hash_stats),
            epoch_rewards_calculation_cache: Arc::new(Mutex::new(HashMap::default())),
            expected_bank_hash: RwLock::new(None),
            block_component_processor: RwLock::new(BlockComponentProcessor::default()),
            is_alpenglow: AtomicBool::new(false),
            transaction_execution_gate: CachePadded::new(TransactionExecutionGate::default()),
        };

        if bank.get_alpenglow_genesis_certificate().is_some() {
            bank.set_is_alpenglow();
        }

        // Sanity assertions between bank snapshot and genesis config
        // Consider removing from serializable bank state
        // (BankFieldsToSerialize/BankFieldsToDeserialize) and initializing
        // from the passed in genesis_config instead (as new()/new_from_genesis() already do)
        assert_eq!(
            bank.genesis_creation_time, genesis_config.creation_time,
            "Bank snapshot genesis creation time does not match genesis.bin creation time. The \
             snapshot and genesis.bin might pertain to different clusters"
        );
        assert_eq!(bank.ticks_per_slot, genesis_config.ticks_per_slot);
        assert_eq!(bank.max_tick_height, (bank.slot + 1) * bank.ticks_per_slot);
        assert_eq!(bank.epoch_schedule, genesis_config.epoch_schedule);

        bank.refresh_slot_params_from_snapshot(genesis_config);
        bank.initialize_after_snapshot_restore(|| rewards_calculation_thread_pool);

        datapoint_info!(
            "bank-new-from-fields",
            (
                "accounts_data_len-from-snapshot",
                fields.accounts_data_len as i64,
                i64
            ),
            (
                "accounts_data_len-from-generate_index",
                accounts_data_size_initial as i64,
                i64
            ),
            (
                "stakes_accounts_load_duration_us",
                stakes_accounts_load_duration.as_micros(),
                i64
            ),
        );
        bank
    }

    /// Compute the slot leader from epoch stakes during snapshot restoration.
    fn slot_leader_from_epoch_stakes(
        slot: Slot,
        epoch_schedule: &EpochSchedule,
        epoch_stakes: &HashMap<Epoch, VersionedEpochStakes>,
    ) -> SlotLeader {
        let (epoch, slot_index) = epoch_schedule.get_epoch_and_slot_index(slot);
        let epoch_vote_accounts = epoch_stakes
            .get(&epoch)
            .expect("epoch stakes should contain current epoch")
            .stakes()
            .vote_accounts();
        let leader_schedule =
            leader_schedule_from_vote_accounts(epoch, epoch_schedule, epoch_vote_accounts.as_ref())
                .expect("leader schedule should be computable from epoch stakes");
        leader_schedule.get_slot_leader_at_index(slot_index as usize)
    }

    /// Return subset of bank fields representing serializable state
    pub(crate) fn get_fields_to_serialize(&self) -> BankFieldsToSerialize {
        BankFieldsToSerialize {
            blockhash_queue: self.blockhash_queue.read().unwrap().clone(),
            hash: *self.hash.read().unwrap(),
            parent_hash: self.parent_hash,
            parent_slot: self.parent_slot,
            hard_forks: self.hard_forks.read().unwrap().clone(),
            transaction_count: self.transaction_count.load(Relaxed),
            tick_height: self.tick_height.load(Relaxed),
            signature_count: self.signature_count.load(Relaxed),
            capitalization: self.capitalization.load(Relaxed),
            max_tick_height: self.max_tick_height,
            hashes_per_tick: *self.hashes_per_tick.read().unwrap(),
            ticks_per_slot: self.ticks_per_slot,
            ns_per_slot: self.ns_per_slot,
            genesis_creation_time: self.genesis_creation_time,
            slots_per_year: self.slots_per_year,
            slot: self.slot,
            block_height: self.block_height,
            leader_id: self.leader.id,
            fee_rate_governor: self.fee_rate_governor.clone(),
            epoch_schedule: self.epoch_schedule.clone(),
            inflation: *self.inflation.read().unwrap(),
            stakes: self.stakes_cache.stakes().clone(),
            is_delta: self.is_delta.load(Relaxed),
            accounts_data_len: self.load_accounts_data_size(),
            versioned_epoch_stakes: self.epoch_stakes.clone(),
            accounts_lt_hash: self.accounts_lt_hash.lock().unwrap().clone(),
            block_id: self.block_id().expect("block id must be set"),
        }
    }

    pub fn leader(&self) -> &SlotLeader {
        &self.leader
    }

    pub fn leader_id(&self) -> &Pubkey {
        &self.leader.id
    }

    pub fn genesis_creation_time(&self) -> UnixTimestamp {
        self.genesis_creation_time
    }

    pub fn slot(&self) -> Slot {
        self.slot
    }

    pub fn bank_id(&self) -> BankId {
        self.bank_id
    }

    pub fn epoch(&self) -> Epoch {
        self.epoch
    }

    pub fn first_normal_epoch(&self) -> Epoch {
        self.epoch_schedule().first_normal_epoch
    }

    pub fn freeze_lock(&self) -> RwLockReadGuard<'_, Hash> {
        self.hash.read().unwrap()
    }

    /// Acquires permission to execute transactions unless this Bank is being quiesced.
    pub fn try_enter_transaction_execution(&self) -> Option<TxExecutionGuard<'_>> {
        // If quiesce has been requested, don't allow new transaction execution to start.
        // We do this before grabbing the lock to prevent some starvation scenario where
        // bank can't be retired because scheduler keeps scheduling and we hold the read
        // lock forever.
        if self
            .transaction_execution_gate
            .quiesce_requested
            .load(Acquire)
        {
            return None;
        }
        let lock_guard = self.transaction_execution_gate.lock.read().unwrap();

        // We check the quiesce requested flag again after acquiring the lock to ensure
        // that we don't allow new transaction execution to start if quiesce was requested
        // while we were waiting for the lock.
        if self
            .transaction_execution_gate
            .quiesce_requested
            .load(Acquire)
        {
            None
        } else {
            Some(TxExecutionGuard {
                bank: self,
                _lock_guard: lock_guard,
            })
        }
    }

    /// Waits for in-flight BankingStage commits to finish without freezing the bank.
    ///
    /// BankingStage holds the read side of this lock from before a successful PoH record until
    /// after the matching account commit.
    pub fn wait_for_inflight_commits(&self) {
        drop(self.hash.write().unwrap());
    }

    /// Rejects new transaction execution and waits for admitted execution and commits to finish.
    pub fn quiesce_transaction_execution(&self) {
        // Signal no new work should be started
        self.transaction_execution_gate
            .quiesce_requested
            .store(true, Release);
        // Quiesce execute and load
        drop(self.transaction_execution_gate.lock.write().unwrap());
        // Quiesce record and commit
        self.wait_for_inflight_commits();
    }

    pub fn hash(&self) -> Hash {
        *self.hash.read().unwrap()
    }

    pub fn is_frozen(&self) -> bool {
        *self.hash.read().unwrap() != Hash::default()
    }

    pub fn freeze_started(&self) -> bool {
        self.freeze_started.load(Relaxed)
    }

    pub fn status_cache_ancestors(&self) -> Vec<u64> {
        let (min, mut ancestors) = {
            let status_cache = self.status_cache.read().unwrap();
            let roots = status_cache.roots();
            let mut ancestors = Vec::with_capacity(roots.len() + self.ancestors.len());
            let mut min = Slot::MAX;
            for root in roots {
                ancestors.push(*root);
                min = min.min(*root);
            }
            (if roots.is_empty() { 0 } else { min }, ancestors)
        };

        ancestors.extend(self.ancestors.iter().filter(|ancestor| *ancestor >= min));
        ancestors.sort_unstable();
        ancestors.dedup();
        ancestors
    }

    /// computed unix_timestamp at this slot height
    pub fn unix_timestamp_from_genesis(&self) -> i64 {
        self.genesis_creation_time.saturating_add(
            (self.slot as u128)
                .saturating_mul(self.ns_per_slot)
                .saturating_div(1_000_000_000) as i64,
        )
    }

    /// Returns a reference to the [`VersionedEpochStakes`] corresponding to the given [`Slot`].
    pub fn epoch_stakes_from_slot(&self, slot: Slot) -> Option<&VersionedEpochStakes> {
        let epoch = self.epoch_schedule().get_epoch(slot);
        self.epoch_stakes(epoch)
    }

    /// Returns a reference to [`BLSPubkeyToRankMap`] for the given `slot`.
    pub fn get_rank_map(&self, slot: Slot) -> Option<&Arc<BLSPubkeyToRankMap>> {
        self.epoch_stakes_from_slot(slot)
            .map(|stake| stake.bls_pubkey_to_rank_map())
    }

    fn update_sysvar_account<F>(&self, pubkey: &Pubkey, updater: F)
    where
        F: Fn(&Option<AccountSharedData>) -> AccountSharedData,
    {
        let old_account = self.get_account_with_fixed_root(pubkey);
        let mut new_account = updater(&old_account);

        // When new sysvar comes into existence (with RENT_UNADJUSTED_INITIAL_BALANCE lamports),
        // this code ensures that the sysvar's balance is adjusted to be rent-exempt.
        //
        // More generally, this code always re-calculates for possible sysvar data size change,
        // although there is no such sysvars currently.
        self.adjust_sysvar_balance_for_rent(&mut new_account);
        self.store_account_and_update_capitalization(pubkey, &new_account);
    }

    fn inherit_specially_retained_account_fields(
        &self,
        old_account: &Option<AccountSharedData>,
    ) -> InheritableAccountFields {
        const RENT_UNADJUSTED_INITIAL_BALANCE: u64 = 1;

        (
            old_account
                .as_ref()
                .map(|a| a.lamports())
                .unwrap_or(RENT_UNADJUSTED_INITIAL_BALANCE),
            old_account
                .as_ref()
                .map(|a| a.rent_epoch())
                .unwrap_or(INITIAL_RENT_EPOCH),
        )
    }

    pub fn clock(&self) -> sysvar::clock::Clock {
        from_account(&self.get_account(&sysvar::clock::id()).unwrap_or_default())
            .unwrap_or_default()
    }

    fn update_clock(&self, parent_epoch: Option<Epoch>) {
        let mut unix_timestamp = self.clock().unix_timestamp;
        // set epoch_start_timestamp to None to warp timestamp
        let epoch_start_timestamp = {
            let epoch = if let Some(epoch) = parent_epoch {
                epoch
            } else {
                self.epoch()
            };
            let first_slot_in_epoch = self.epoch_schedule().get_first_slot_in_epoch(epoch);
            Some((first_slot_in_epoch, self.clock().epoch_start_timestamp))
        };
        let max_allowable_drift = MaxAllowableDrift {
            fast: MAX_ALLOWABLE_DRIFT_PERCENTAGE_FAST,
            slow: MAX_ALLOWABLE_DRIFT_PERCENTAGE_SLOW_V2,
        };

        let ancestor_timestamp = self.clock().unix_timestamp;
        if let Some(timestamp_estimate) =
            self.get_timestamp_estimate(max_allowable_drift, epoch_start_timestamp)
        {
            unix_timestamp = timestamp_estimate;
            if timestamp_estimate < ancestor_timestamp {
                unix_timestamp = ancestor_timestamp;
            }
        }
        datapoint_info!(
            "bank-timestamp-correction",
            ("slot", self.slot(), i64),
            ("from_genesis", self.unix_timestamp_from_genesis(), i64),
            ("corrected", unix_timestamp, i64),
            ("ancestor_timestamp", ancestor_timestamp, i64),
        );
        let mut epoch_start_timestamp =
            // On epoch boundaries, update epoch_start_timestamp
            if parent_epoch.is_some() && parent_epoch.unwrap() != self.epoch() {
                unix_timestamp
            } else {
                self.clock().epoch_start_timestamp
            };
        if self.slot == 0 {
            unix_timestamp = self.unix_timestamp_from_genesis();
            epoch_start_timestamp = self.unix_timestamp_from_genesis();
        }
        let clock = sysvar::clock::Clock {
            slot: self.slot,
            epoch_start_timestamp,
            epoch: self.epoch_schedule().get_epoch(self.slot),
            leader_schedule_epoch: self.epoch_schedule().get_leader_schedule_epoch(self.slot),
            unix_timestamp,
        };
        self.update_sysvar_account(&sysvar::clock::id(), |account| {
            create_account(
                &clock,
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    /// In Alpenglow the clock sysvar's timestamp is populated from the block footer.
    /// The timestamp value on the block footer is used as an estimate for when the block *ended*.
    /// This is applied at the end of execution on the bank for use in the child.
    ///
    /// However we still need to update the slot and epoch fields for the clock sysvar at the *start*
    /// of the bank, as transactions executing in this bank need to be able to read these values.
    /// This function updates the slot and epoch fields while preserving the timestamp fields from the parent
    /// bank's footer.
    fn update_clock_slot_for_alpenglow(&self) {
        let clock = self.clock();
        let epoch_start_timestamp = match (self.slot, self.parent()) {
            (0, _) => self.unix_timestamp_from_genesis(),
            (_, Some(parent)) if parent.epoch() != self.epoch() => clock.unix_timestamp,
            _ => clock.epoch_start_timestamp,
        };
        let clock = sysvar::clock::Clock {
            slot: self.slot,
            epoch: self.epoch_schedule().get_epoch(self.slot),
            leader_schedule_epoch: self.epoch_schedule().get_leader_schedule_epoch(self.slot),
            epoch_start_timestamp,
            unix_timestamp: clock.unix_timestamp,
        };
        self.update_sysvar_account(&sysvar::clock::id(), |account| {
            create_account(
                &clock,
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    pub fn update_last_restart_slot(&self) {
        // First, see what the currently stored last restart slot is.
        let current_last_restart_slot = self
            .get_account(&sysvar::last_restart_slot::id())
            .and_then(|account| {
                let lrs: Option<LastRestartSlot> = from_account(&account);
                lrs
            })
            .map(|account| account.last_restart_slot);

        let last_restart_slot = {
            let slot = self.slot;
            let hard_forks_r = self.hard_forks.read().unwrap();

            // Only consider hard forks <= this bank's slot to avoid prematurely applying
            // a hard fork that is set to occur in the future.
            hard_forks_r
                .iter()
                .rev()
                .find(|(hard_fork, _)| *hard_fork <= slot)
                .map(|(slot, _)| *slot)
                .unwrap_or(0)
        };

        // Only need to write if the last restart has changed
        if current_last_restart_slot != Some(last_restart_slot) {
            self.update_sysvar_account(&sysvar::last_restart_slot::id(), |account| {
                create_account(
                    &LastRestartSlot { last_restart_slot },
                    self.inherit_specially_retained_account_fields(account),
                )
            });
        }
    }

    pub fn set_sysvar_for_tests<T>(&self, sysvar: &T)
    where
        T: Serialize + SysvarId,
    {
        self.update_sysvar_account(&T::id(), |account| {
            create_account_with_bincode(
                sysvar,
                self.inherit_specially_retained_account_fields(account),
            )
        });
        // Simply force fill sysvar cache rather than checking which sysvar was
        // actually updated since tests don't need to be optimized for performance.
        self.transaction_processor
            .reset_and_fill_sysvar_cache_entries(self);
    }

    fn update_slot_history(&self) {
        self.update_sysvar_account(&sysvar::slot_history::id(), |account| {
            let mut slot_history = account
                .as_ref()
                .map(|account| wincode::deserialize::<SlotHistory>(account.data()).unwrap())
                .unwrap_or_default();
            slot_history.add(self.slot());
            create_account(
                &slot_history,
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    fn update_slot_hashes(&self) {
        self.update_sysvar_account(&sysvar::slot_hashes::id(), |account| {
            let mut slot_hashes = account
                .as_ref()
                .map(|account| wincode::deserialize::<SlotHashes>(account.data()).unwrap())
                .unwrap_or_default();
            slot_hashes.add(self.parent_slot, self.parent_hash);
            create_account(
                &slot_hashes,
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    pub fn get_slot_history(&self) -> Option<SlotHistory> {
        wincode::deserialize::<SlotHistory>(self.get_account(&sysvar::slot_history::id())?.data())
            .ok()
    }

    fn update_epoch_stakes(
        &mut self,
        leader_schedule_epoch: Epoch,
        prefiltered_distribution_vote_accounts: Option<VoteAccounts>,
    ) {
        // update epoch_stakes cache
        //  if my parent didn't populate for this staker's epoch, we've
        //  crossed a boundary
        if !self.epoch_stakes.contains_key(&leader_schedule_epoch) {
            self.epoch_stakes.retain(|&epoch, _| {
                // Note the greater-than-or-equal (and the `- 1`) is needed here
                // to ensure we retain the oldest epoch, if that epoch is 0.
                epoch >= leader_schedule_epoch.saturating_sub(MAX_LEADER_SCHEDULE_STAKES - 1)
            });
            // At the epoch boundary, `compute_new_epoch_caches_and_rewards`
            // has already produced the VAT-filtered vote-account snapshot;
            // reuse it here instead of re-cloning and re-filtering the
            // `stakes_cache`. Other callers (same-epoch refresh, warps)
            // fall back to `get_top_epoch_stakes`.
            let stakes = match prefiltered_distribution_vote_accounts {
                Some(prefiltered) => Stakes::new(prefiltered, self.epoch()),
                None => self.get_top_epoch_stakes(),
            };
            let stakes = SerdeStakesToStakeFormat::from(stakes);
            let new_epoch_stakes = VersionedEpochStakes::new(stakes, leader_schedule_epoch);
            info!(
                "new epoch stakes, epoch: {}, total_stake: {}",
                leader_schedule_epoch,
                new_epoch_stakes.total_stake(),
            );

            self.maybe_burn_vat_from_staked_accounts(&new_epoch_stakes);

            // It is expensive to log the details of epoch stakes. Only log them at "trace"
            // level for debugging purpose.
            if log::log_enabled!(log::Level::Trace) {
                let vote_stakes: HashMap<_, _> = self
                    .stakes_cache
                    .stakes()
                    .vote_accounts()
                    .delegated_stakes()
                    .map(|(pubkey, stake)| (*pubkey, stake))
                    .collect();
                trace!("new epoch stakes, stakes: {vote_stakes:#?}");
            }
            self.epoch_stakes
                .insert(leader_schedule_epoch, new_epoch_stakes);
        }
    }

    /// Burn the Validator Admission ticket from each vote account if Alpenglow is enabled
    ///
    /// Note: This must ONLY be called after the vote accounts have been filtered (`clone_and_filter_for_vat`)
    /// to the top `MAX_ALPENGLOW_VOTE_ACCOUNTS` that contain enough balance for admission.
    fn maybe_burn_vat_from_staked_accounts(&mut self, epoch_stakes: &VersionedEpochStakes) {
        let feature_snapshot = self.feature_set.snapshot();
        if !feature_snapshot.alpenglow {
            return;
        }

        let vat_to_burn_per_epoch = self.vat_to_burn_per_epoch();
        let vote_accounts = epoch_stakes.stakes().vote_accounts();
        debug_assert!(vote_accounts.len() <= 2000);
        // +1 for the incinerator account
        let mut accounts_to_store: Vec<(Pubkey, AccountSharedData)> =
            Vec::with_capacity(vote_accounts.len() + 1);
        let mut total_vat = 0u64;

        // Vote accounts have already been filtered by clone_and_filter_for_vat to only include
        // accounts with non-zero stake and sufficient balance.
        for (vote_pubkey, _stake) in vote_accounts.delegated_stakes() {
            let mut account = self.get_account(vote_pubkey).unwrap();
            total_vat += vat_to_burn_per_epoch;
            account.set_lamports(
                account
                    .lamports()
                    .checked_sub(vat_to_burn_per_epoch)
                    .expect(
                        "Vote accounts should have already been filtered to contain enough \
                         balance for the VAT",
                    ),
            );
            accounts_to_store.push((*vote_pubkey, account));
        }

        // Per SIMD-0357, transfer collected VAT to the incinerator account.
        let mut incinerator_account = self.get_account(&incinerator::id()).unwrap_or_default();
        incinerator_account.set_lamports(
            incinerator_account
                .lamports()
                .checked_add(total_vat)
                .unwrap(),
        );
        accounts_to_store.push((incinerator::id(), incinerator_account));

        self.store_accounts((self.slot, accounts_to_store.as_slice()), None);
        info!(
            "Transferred total VAT of {total_vat} lamports to incinerator from staked vote \
             accounts"
        );
    }

    #[cfg(feature = "dev-context-only-utils")]
    pub fn set_epoch_stakes_for_test(&mut self, epoch: Epoch, stakes: VersionedEpochStakes) {
        self.epoch_stakes.insert(epoch, stakes);
    }

    fn update_rent(&self) {
        self.update_sysvar_account(&sysvar::rent::id(), |account| {
            create_account(
                &self.rent_collector.rent,
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    fn update_epoch_schedule(&self) {
        self.update_sysvar_account(&sysvar::epoch_schedule::id(), |account| {
            create_account(
                self.epoch_schedule(),
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    fn update_stake_history(&self, epoch: Option<Epoch>) {
        if epoch == Some(self.epoch()) {
            return;
        }
        // if I'm the first Bank in an epoch, ensure stake_history is updated
        self.update_sysvar_account(&stake_history::id(), |account| {
            create_account::<StakeHistory>(
                self.stakes_cache.stakes().history(),
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    /// Rebuilds slot-param state from the current feature set.
    fn refresh_slot_params(&mut self) {
        self.refresh_slot_params_with_baseline(self.slot_params.baseline_params());
    }

    fn refresh_slot_params_from_snapshot(&mut self, genesis_config: &GenesisConfig) {
        let (feature_set, _) = self.compute_active_feature_set(false);
        self.refresh_slot_params_with_baseline(
            self.snapshot_restore_slot_params_baseline(genesis_config, &feature_set),
        );
    }

    /// Rebuilds cached slot params while preserving the supplied slot-0 baseline.
    ///
    /// The cache is not serialized into snapshots; it is reconstructed from
    /// existing Bank fields during genesis and snapshot restore.
    fn refresh_slot_params_with_baseline(&mut self, baseline_params: SlotParams) {
        self.slot_params =
            SlotParamsArchive::new(&self.feature_set, &self.epoch_schedule, baseline_params);
    }

    /// Builds slot-0 params from the genesis config.
    fn genesis_config_slot_params(
        genesis_config: &GenesisConfig,
        partitioned_rewards_stake_account_stores_per_block: u64,
    ) -> SlotParams {
        SlotParams::genesis_baseline(
            genesis_config.ns_per_slot(),
            genesis_config.slots_per_year(),
            genesis_config.hashes_per_tick(),
            partitioned_rewards_stake_account_stores_per_block,
        )
    }

    /// Builds the slot-param baseline from the restored bank fields.
    ///
    /// Snapshot fields represent the cluster's current reality. This can
    /// differ from genesis for values, such as `hashes_per_tick`, that were
    /// changed by older feature gates before slot-time reductions existed.
    fn restored_bank_slot_params(&self) -> SlotParams {
        SlotParams::genesis_baseline(
            self.ns_per_slot,
            self.slots_per_year,
            self.hashes_per_tick(),
            self.partitioned_rewards_stake_account_stores_per_block,
        )
    }

    /// Returns true if any slot-time reduction has taken effect by this bank.
    ///
    /// Feature activation happens in one epoch, but slot params become effective
    /// at the start of the following epoch.
    fn any_slot_time_reduction_effective(
        &self,
        feature_set: &FeatureSet,
        ns_per_slot: u128,
    ) -> bool {
        SlotParamsArchive::any_slot_time_reduction_effective(
            &self.epoch_schedule,
            self.slot,
            feature_set,
            ns_per_slot,
        )
    }

    /// Selects the slot-param baseline to use when reconstructing from snapshot.
    ///
    /// Before any slot-time reduction is effective, the baseline should match
    /// restored bank fields because historical non-slot-time feature gates may
    /// have already changed some values away from genesis. Once a slot-time
    /// reduction is effective, keep the genesis baseline so historical lookups
    /// for pre-reduction slots remain correct.
    fn snapshot_restore_slot_params_baseline(
        &self,
        genesis_config: &GenesisConfig,
        feature_set: &FeatureSet,
    ) -> SlotParams {
        if self.any_slot_time_reduction_effective(feature_set, genesis_config.ns_per_slot()) {
            Self::genesis_config_slot_params(
                genesis_config,
                self.partitioned_rewards_stake_account_stores_per_block,
            )
        } else {
            // Default to whatever is in the bank if we've never enabled any
            // slot time reductions. This prevents resetting any slot params
            // that may have been changed previously back to genesis.
            self.restored_bank_slot_params()
        }
    }

    /// Returns the slot params effective at `slot`.
    fn slot_params_at_slot(&self, slot: Slot) -> SlotParams {
        self.slot_params.params_at_slot(slot)
    }

    /// Returns the slot params that should be effective for this bank's slot.
    fn current_slot_params(&self) -> SlotParams {
        self.slot_params_at_slot(self.slot)
    }

    /// Returns the Validator Admission Ticket burn for this bank's slot params.
    pub(crate) fn vat_to_burn_per_epoch(&self) -> u64 {
        self.current_slot_params().vat_to_burn_per_epoch()
    }

    pub fn get_vat_health_for_next_epoch(
        &self,
        vote_account_pubkey: &Pubkey,
    ) -> std::result::Result<(), VATHealthError> {
        let vote_accounts = self.vote_accounts();

        let Some((_, vote_account)) = vote_accounts.get(vote_account_pubkey) else {
            return Err(VATHealthError::VoteAccountNotFound);
        };

        if vote_account
            .vote_state_view()
            .bls_pubkey_compressed()
            .is_none()
        {
            return Err(VATHealthError::NoBLSPubkey);
        }

        let my_balance = vote_account.lamports();
        let minimum_required_balance = self
            .minimum_vote_account_balance_for_vat()
            .saturating_add(vote_account.vote_state_view().pending_delegator_rewards());
        if vote_account.lamports() < minimum_required_balance {
            return Err(VATHealthError::InsufficientFundsInVoteAccount(
                my_balance,
                minimum_required_balance,
            ));
        }

        Ok(())
    }

    /// Returns the effective slot duration for `slot`.
    pub fn ns_per_slot_at_slot(&self, slot: Slot) -> u128 {
        self.slot_params_at_slot(slot).ns_per_slot()
    }

    /// Returns slots/year for the slot params active at `epoch` start.
    fn slots_per_year_for_epoch(&self, epoch: Epoch) -> f64 {
        let first_slot = self.epoch_schedule().get_first_slot_in_epoch(epoch);
        self.slot_params_at_slot(first_slot).slots_per_year()
    }

    /// Returns the wall-clock duration in years for `[start_slot, end_slot)`.
    fn slot_range_duration_in_years(&self, start_slot: Slot, end_slot: Slot) -> f64 {
        if start_slot >= end_slot {
            return 0.0;
        }

        let mut cursor = start_slot;
        let mut params = self.slot_params.baseline_params();
        let mut duration = 0.0;

        for (effective_slot, effective_params) in self.slot_params.param_transitions() {
            if effective_slot <= start_slot {
                params = effective_params;
                continue;
            }
            if effective_slot >= end_slot {
                break;
            }

            duration += (effective_slot - cursor) as f64 / params.slots_per_year();
            cursor = effective_slot;
            params = effective_params;
        }

        duration + (end_slot - cursor) as f64 / params.slots_per_year()
    }

    /// Returns the exact wall-clock duration in nanoseconds for `start_slot..=end_slot`.
    pub fn slot_range_duration_nanos(&self, start_slot: Slot, end_slot: Slot) -> u128 {
        self.slot_params
            .slot_range_duration_nanos(start_slot, end_slot)
    }

    pub fn epoch_duration_in_years(&self, epoch: Epoch) -> f64 {
        // period: time that has passed as a fraction of a year, basically the length of
        //  an epoch as a fraction of a year
        //  calculated as: slots_elapsed / (slots / year)
        self.epoch_schedule().get_slots_in_epoch(epoch) as f64
            / self.slots_per_year_for_epoch(epoch)
    }

    pub fn max_processing_age(&self) -> usize {
        self.max_processing_age
    }

    // Calculates the starting-slot for inflation from the activation slot.
    // This method assumes that `pico_inflation` will be enabled before `full_inflation`, giving
    // precedence to the latter. However, since `pico_inflation` is fixed-rate Inflation, should
    // `pico_inflation` be enabled 2nd, the incorrect start slot provided here should have no
    // effect on the inflation calculation.
    fn get_inflation_start_slot(&self) -> Slot {
        let mut slots = self
            .feature_set
            .full_inflation_features_enabled()
            .iter()
            .filter_map(|id| self.feature_set.activated_slot(id))
            .collect::<Vec<_>>();
        slots.sort_unstable();
        slots.first().cloned().unwrap_or_else(|| {
            self.feature_set
                .activated_slot(&feature_set::pico_inflation::id())
                .unwrap_or(0)
        })
    }

    /// Returns slots since inflation started, aligned to the first slot used for rewards accrual.
    fn get_inflation_num_slots(&self) -> u64 {
        let inflation_start_slot = self.inflation_start_slot_aligned_to_rewards();
        self.epoch_schedule().get_first_slot_in_epoch(self.epoch()) - inflation_start_slot
    }

    /// Returns the inflation rewards start slot aligned to an epoch boundary.
    fn inflation_start_slot_aligned_to_rewards(&self) -> Slot {
        let inflation_activation_slot = self.get_inflation_start_slot();
        self.epoch_schedule().get_first_slot_in_epoch(
            self.epoch_schedule()
                .get_epoch(inflation_activation_slot)
                .saturating_sub(1),
        )
    }

    /// Returns elapsed inflation time in years for slots since inflation started.
    pub fn slot_in_year_for_inflation(&self) -> f64 {
        let num_slots = self.get_inflation_num_slots();
        let inflation_start_slot = self.inflation_start_slot_aligned_to_rewards();
        self.slot_range_duration_in_years(inflation_start_slot, inflation_start_slot + num_slots)
    }

    /// For a given `capitalization` (total_supply in lamports) and `epoch`, returns the
    /// `epoch inflation rewards` in lamports.
    pub(crate) fn calculate_epoch_inflation_rewards(
        &self,
        capitalization: u64,
        epoch: Epoch,
    ) -> u64 {
        let slot_in_year = self.slot_in_year_for_inflation();
        let validator_rate = self.inflation.read().unwrap().validator(slot_in_year);
        let epoch_duration_in_years = self.epoch_duration_in_years(epoch);
        (validator_rate * capitalization as f64 * epoch_duration_in_years) as u64
    }

    fn update_recent_blockhashes_locked(&self, locked_blockhash_queue: &BlockhashQueue) {
        #[expect(deprecated)]
        self.update_sysvar_account(&sysvar::recent_blockhashes::id(), |account| {
            let recent_blockhash_iter = locked_blockhash_queue.get_recent_blockhashes();
            recent_blockhashes_account::create_account_with_data_and_fields(
                recent_blockhash_iter,
                self.inherit_specially_retained_account_fields(account),
            )
        });
    }

    pub fn update_recent_blockhashes(&self) {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        self.update_recent_blockhashes_locked(&blockhash_queue);
    }

    fn get_timestamp_estimate(
        &self,
        max_allowable_drift: MaxAllowableDrift,
        epoch_start_timestamp: Option<(Slot, UnixTimestamp)>,
    ) -> Option<UnixTimestamp> {
        let mut get_timestamp_estimate_time = Measure::start("get_timestamp_estimate");
        let slots_per_epoch = self.epoch_schedule().slots_per_epoch;
        let vote_accounts = self.vote_accounts();
        let recent_timestamps = vote_accounts.iter().filter_map(|(pubkey, (_, account))| {
            let vote_state = account.vote_state_view();
            let last_timestamp = vote_state.last_timestamp();
            let slot_delta = self.slot().checked_sub(last_timestamp.slot)?;
            (slot_delta <= slots_per_epoch)
                .then_some((*pubkey, (last_timestamp.slot, last_timestamp.timestamp)))
        });
        let elapsed_slot_duration = |from_slot: Slot, to_slot: Slot| {
            if from_slot >= to_slot {
                Duration::ZERO
            } else {
                Duration::from_nanos_u128(
                    self.slot_range_duration_nanos(from_slot.saturating_add(1), to_slot),
                )
            }
        };
        let epoch = self.epoch_schedule().get_epoch(self.slot());
        let stakes = self.epoch_vote_accounts(epoch)?;
        let stake_weighted_timestamp = calculate_stake_weighted_timestamp(
            recent_timestamps,
            stakes,
            self.slot(),
            elapsed_slot_duration,
            epoch_start_timestamp,
            max_allowable_drift,
        );
        get_timestamp_estimate_time.stop();
        datapoint_info!(
            "bank-timestamp",
            (
                "get_timestamp_estimate_us",
                get_timestamp_estimate_time.as_us(),
                i64
            ),
        );
        stake_weighted_timestamp
    }

    /// Recalculates the bank hash
    ///
    /// This is used by ledger-tool when creating a snapshot, which
    /// recalculates the bank hash.
    ///
    /// Note that the account state is *not* allowed to change by rehashing.
    /// If modifying accounts in ledger-tool is needed, create a new bank.
    pub fn rehash(&self) {
        let mut hash = self.hash.write().unwrap();
        let new = self.hash_internal_state();
        if new != *hash {
            warn!("Updating bank hash to {new}");
            *hash = new;
        }
    }

    pub fn freeze(&self) {
        // This lock prevents any new commits from BankingStage
        // `Consumer::execute_and_commit_transactions_locked()` from
        // coming in after the last tick is observed. This is because in
        // BankingStage, any transaction successfully recorded in
        // `record_transactions()` is recorded after this `hash` lock
        // is grabbed. At the time of the successful record,
        // this means the PoH has not yet reached the last tick,
        // so this means freeze() hasn't been called yet. And because
        // BankingStage doesn't release this hash lock until both
        // record and commit are finished, those transactions will be
        // committed before this write lock can be obtained here.
        let mut hash = self.hash.write().unwrap();
        if *hash == Hash::default() {
            // finish up any deferred changes to account state
            self.distribute_transaction_fee_details();
            self.update_slot_history();
            self.run_incinerator();

            // freeze is a one-way trip, idempotent
            self.freeze_started.store(true, Relaxed);
            // updating the accounts lt hash must happen *outside* of hash_internal_state() so
            // that rehash() can be called and *not* modify self.accounts_lt_hash.
            self.finish_accounts_lt_hash_updates();
            *hash = self.hash_internal_state();
            self.rc.accounts.accounts_db.mark_slot_frozen(self.slot());
        }
    }

    /// Freeze the bank and verify its computed bank hash against the expected bank hash,
    /// If hashes do not match, return Err with (expected_hash, computed_hash)
    pub fn freeze_and_verify_bank_hash(&self) -> std::result::Result<(), (Hash, Hash)> {
        self.freeze();
        let computed_hash = self.hash();

        if let Some(expected_hash) = self.expected_bank_hash()
            && expected_hash != computed_hash
        {
            return Err((expected_hash, computed_hash));
        }
        Ok(())
    }

    /// Set the expected bank hash (from an external footer).  This is stored for later verification
    /// when the bank is frozen.
    pub fn set_expected_bank_hash(&self, hash: Hash) {
        *self.expected_bank_hash.write().unwrap() = Some(hash);
    }

    /// Returns the expected bank hash if any.
    pub fn expected_bank_hash(&self) -> Option<Hash> {
        *self.expected_bank_hash.read().unwrap()
    }

    // dangerous; don't use this; this is only needed for ledger-tool's special command
    #[cfg(feature = "dev-context-only-utils")]
    pub fn unfreeze_for_ledger_tool(&self) {
        self.freeze_started.store(false, Relaxed);
    }

    pub fn epoch_schedule(&self) -> &EpochSchedule {
        &self.epoch_schedule
    }

    /// squash the parent's state up into this Bank,
    ///   this Bank becomes a root
    /// Note that this function is not thread-safe. If it is called concurrently on the same bank
    /// by multiple threads, the end result could be inconsistent.
    /// Calling code does not currently call this concurrently.
    pub fn squash(&self) -> SquashTiming {
        self.freeze();

        //this bank and all its parents are now on the rooted path
        let mut roots = Vec::with_capacity(self.ancestors.len());
        roots.push(self.slot());
        roots.extend(self.parents_iter().map(|parent| parent.slot()));

        let mut total_cache_us = 0;

        let mut squash_accounts_time = Measure::start("squash_accounts_time");
        for slot in roots.iter().rev() {
            // root forks cannot be purged
            let add_root_timing = self.rc.accounts.add_root(*slot);
            total_cache_us += add_root_timing.cache_us;
        }
        squash_accounts_time.stop();

        *self.rc.parent.write().unwrap() = None;

        let mut squash_cache_time = Measure::start("squash_cache_time");
        self.status_cache
            .write()
            .unwrap()
            .add_roots(roots.iter().copied());
        squash_cache_time.stop();

        SquashTiming {
            squash_accounts_ms: squash_accounts_time.as_ms(),
            squash_accounts_cache_ms: total_cache_us / 1000,
            squash_cache_ms: squash_cache_time.as_ms(),
        }
    }

    /// Return the more recent checkpoint of this bank instance.
    pub fn parent(&self) -> Option<Arc<Bank>> {
        self.rc.parent.read().unwrap().clone()
    }

    pub fn parent_slot(&self) -> Slot {
        self.parent_slot
    }

    pub fn parent_hash(&self) -> Hash {
        self.parent_hash
    }

    fn process_genesis_config(
        &mut self,
        genesis_config: &GenesisConfig,
        #[cfg(feature = "dev-context-only-utils")] leader_for_tests: Option<SlotLeader>,
        #[cfg(feature = "dev-context-only-utils")] genesis_hash: Option<Hash>,
    ) {
        // Bootstrap validator collects fees until `new_from_parent` is called.
        self.fee_rate_governor = genesis_config.fee_rate_governor.clone();

        for (pubkey, account) in genesis_config.accounts.iter() {
            assert!(
                self.get_account(pubkey).is_none(),
                "{pubkey} repeated in genesis config"
            );
            let account_shared_data = create_account_shared_data(account);
            self.store_account_without_stakes_cache(pubkey, &account_shared_data);
            self.capitalization.fetch_add(account.lamports(), Relaxed);
            self.accounts_data_size_initial += account.data().len() as u64;
        }

        for (pubkey, account) in genesis_config.rewards_pools.iter() {
            assert!(
                self.get_account(pubkey).is_none(),
                "{pubkey} repeated in genesis config"
            );
            let account_shared_data = create_account_shared_data(account);
            self.store_account_without_stakes_cache(pubkey, &account_shared_data);
            self.accounts_data_size_initial += account.data().len() as u64;
        }

        self.stakes_cache = StakesCache::new(Stakes::new_from_accounts_for_genesis(
            self.new_warmup_cooldown_rate_epoch(),
            genesis_config.accounts.iter(),
            self.use_fixed_point_stake_math(),
        ));

        // After storing genesis accounts, the bank stakes cache will be warmed
        // up and can be used to set the leader id to the highest staked
        // node.
        let leader = self.stakes_cache.stakes().highest_staked_node();
        // If a leader is specified for test purposes, use that and if no leader found, use a random one.
        #[cfg(feature = "dev-context-only-utils")]
        let leader = leader_for_tests
            .or(leader)
            .or(Some(SlotLeader::new_unique()));
        self.leader = leader.expect("genesis processing failed because no staked nodes exist");

        #[cfg(not(feature = "dev-context-only-utils"))]
        let genesis_hash = genesis_config.hash();
        #[cfg(feature = "dev-context-only-utils")]
        let genesis_hash = genesis_hash.unwrap_or(genesis_config.hash());

        self.blockhash_queue.write().unwrap().genesis_hash(
            &genesis_hash,
            genesis_config.fee_rate_governor.lamports_per_signature,
        );

        self.hashes_per_tick = RwLock::new(genesis_config.hashes_per_tick());
        self.ticks_per_slot = genesis_config.ticks_per_slot();
        self.ns_per_slot = genesis_config.ns_per_slot();
        self.genesis_creation_time = genesis_config.creation_time;
        self.max_tick_height = (self.slot + 1) * self.ticks_per_slot;
        self.slots_per_year = genesis_config.slots_per_year();

        self.epoch_schedule = genesis_config.epoch_schedule.clone();
        self.refresh_slot_params_with_baseline(Self::genesis_config_slot_params(
            genesis_config,
            self.partitioned_rewards_stake_account_stores_per_block,
        ));

        self.inflation = Arc::new(RwLock::new(genesis_config.inflation));

        self.rent_collector = RentCollector::new(
            self.epoch,
            self.epoch_schedule().clone(),
            self.slots_per_year,
            genesis_config.rent.clone(),
        );
    }

    fn burn_and_purge_account(&self, program_id: &Pubkey, mut account: AccountSharedData) {
        let old_data_size = account.data().len();
        self.capitalization.fetch_sub(account.lamports(), Relaxed);
        // Both resetting account balance to 0 and zeroing the account data
        // is needed to really purge from AccountsDb and flush the Stakes cache
        account.set_lamports(0);
        account.data_as_mut_slice().fill(0);
        self.store_account(program_id, &account);
        self.calculate_and_update_accounts_data_size_delta_off_chain(old_data_size, 0);
    }

    /// Add a precompiled program account
    pub fn add_precompiled_account(&self, program_id: &Pubkey) {
        self.add_precompiled_account_with_owner(program_id, native_loader::id())
    }

    // Used by tests to simulate clusters with precompiles that aren't owned by the native loader
    fn add_precompiled_account_with_owner(&self, program_id: &Pubkey, owner: Pubkey) {
        if let Some(account) = self.get_account_with_fixed_root(program_id) {
            if account.executable() {
                return;
            } else {
                // malicious account is pre-occupying at program_id
                self.burn_and_purge_account(program_id, account);
            }
        };

        assert!(
            !self.freeze_started(),
            "Can't change frozen bank by adding not-existing new precompiled program \
             ({program_id}). Maybe, inconsistent program activation is detected on snapshot \
             restore?"
        );

        // Add a bogus executable account, which will be loaded and ignored.
        let (lamports, rent_epoch) = self.inherit_specially_retained_account_fields(&None);

        let account = AccountSharedData::from(Account {
            lamports,
            owner,
            data: vec![],
            executable: true,
            rent_epoch,
        });
        self.store_account_and_update_capitalization(program_id, &account);
    }

    #[allow(deprecated)]
    pub fn set_rent_burn_percentage(&mut self, burn_percent: u8) {
        self.rent_collector.rent.burn_percent = burn_percent;
    }

    pub fn set_hashes_per_tick(&self, hashes_per_tick: Option<u64>) {
        *self.hashes_per_tick.write().unwrap() = hashes_per_tick;
    }

    /// Return the last block hash registered.
    pub fn last_blockhash(&self) -> Hash {
        self.blockhash_queue.read().unwrap().last_hash()
    }

    pub fn last_blockhash_and_lamports_per_signature(&self) -> (Hash, u64) {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        let last_hash = blockhash_queue.last_hash();
        let last_lamports_per_signature = blockhash_queue
            .get_lamports_per_signature(&last_hash)
            .unwrap(); // safe so long as the BlockhashQueue is consistent
        (last_hash, last_lamports_per_signature)
    }

    pub fn is_blockhash_valid(&self, hash: &Hash) -> bool {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        blockhash_queue.is_hash_valid_for_age(hash, self.max_processing_age())
    }

    pub fn get_minimum_balance_for_rent_exemption(&self, data_len: usize) -> u64 {
        self.rent_collector.rent.minimum_balance(data_len).max(1)
    }

    pub fn get_lamports_per_signature(&self) -> u64 {
        self.fee_rate_governor.lamports_per_signature
    }

    /// Convert Agave's active feature set into the fee crate's narrowed feature view.
    pub fn fee_features(&self) -> FeeFeatures {
        FeeFeatures {}
    }

    pub fn get_lamports_per_signature_for_blockhash(&self, hash: &Hash) -> Option<u64> {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        blockhash_queue.get_lamports_per_signature(hash)
    }

    pub fn get_fee_for_message(&self, message: &SanitizedMessage) -> Option<u64> {
        {
            let blockhash_queue = self.blockhash_queue.read().unwrap();
            blockhash_queue.get_lamports_per_signature(message.recent_blockhash())
        }
        .or_else(|| {
            let nonce_address = message.get_durable_nonce()?;
            let nonce_account = self.get_account_with_fixed_root(nonce_address)?;
            verify_nonce_account(&nonce_account, message.recent_blockhash())
                .map(|nonce_data| nonce_data.get_lamports_per_signature())
        })?;

        let transaction_configuration =
            TransactionConfiguration::try_from_sanitized_message(message, &self.feature_set)
                .ok()?;
        Some(solana_fee::calculate_fee(
            message,
            self.fee_structure().lamports_per_signature,
            transaction_configuration.priority_fee_lamports,
            self.fee_features(),
        ))
    }

    pub fn get_blockhash_last_valid_block_height(&self, blockhash: &Hash) -> Option<Slot> {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        // This calculation will need to be updated to consider epoch boundaries if BlockhashQueue
        // length is made variable by epoch
        blockhash_queue
            .get_hash_age(blockhash)
            .map(|age| self.block_height + self.max_processing_age() as u64 - age)
    }

    /// Query the alpenglow genesis certificate account.
    /// All frozen alpenglow banks will have this account populated and TowerBFT banks will not.
    ///
    /// The same is true for alpenglow banks yet to be frozen except for the first alpenglow bank:
    /// - The first alpenglow bank will contain a special marker that populates this account
    /// - If `get_alpenglow_genesis_certificate` is called before the marker is processed by replay
    ///   this account will be empty.
    /// - If `get_alpenglow_genesis_certificate` is called after the marker is processed, we return the certificate
    pub fn get_alpenglow_genesis_certificate(&self) -> Option<GenesisCert> {
        let acct = self.get_account(&GENESIS_CERTIFICATE_ACCOUNT)?;
        (!acct.data().is_empty()).then(|| {
            // The address is known in advance, so the account could already exist if it was prefunded.
            // However this account cannot be written to except by us in `set_alpenglow_genesis_certificate`,
            // so this deserialize is safe if the account is non-empty
            let cert: WireBlockCertMessage = wincode::deserialize(acct.data())
                .expect("Programmer error deserializing genesis certificate");
            GenesisCert {
                block: cert.block,
                signature: CertSignature {
                    signature: cert.signature.signature,
                    bitmap: cert.signature.bitmap,
                },
            }
        })
    }

    pub fn is_alpenglow(&self) -> bool {
        self.is_alpenglow.load(Relaxed)
    }

    fn set_is_alpenglow(&self) {
        self.is_alpenglow.store(true, Relaxed);
    }

    /// For use in the first Alpenglow block, set the genesis certificate.
    pub fn set_alpenglow_genesis_certificate(&self, cert: &GenesisCert) {
        let cert = WireBlockCertMessage {
            block: cert.block,
            signature: WireCertSignature {
                signature: cert.signature.signature,
                bitmap: cert.signature.bitmap.clone(),
            },
        };
        let data = wincode::serialize(&cert).unwrap();
        let lamports = Rent::default().minimum_balance(data.len());
        let mut cert_acct = AccountSharedData::new(lamports, data.len(), &system_program::ID);
        cert_acct.set_data_from_slice(&data);

        self.store_account_and_update_capitalization(&GENESIS_CERTIFICATE_ACCOUNT, &cert_acct);
        self.set_is_alpenglow();
    }

    /// Update the clock sysvar from a block footer's nanosecond timestamp.
    /// Also stores the nanosecond value for later retrieval via `get_nanosecond_clock`.
    pub fn update_clock_from_footer(&self, unix_timestamp_nanos: i64) {
        if !self.feature_set.snapshot().alpenglow {
            return;
        }

        // On epoch boundaries, update epoch_start_timestamp
        //
        // Note: the genesis block's bank is created via new_from_genesis, which calls update_clock
        // unconditionally. In update_clock, we have a check for whether slot == 0, and if that's
        // the case, the clock is set to self.unix_timestamp_from_genesis().
        //
        // As a result, we don't actually need the (0, _) case below, since it's never invoked.
        // However, include this for completeness in the match statement.
        let unix_timestamp_s = unix_timestamp_nanos / 1_000_000_000;
        let epoch_start_timestamp = match (self.slot, self.parent()) {
            (0, _) => self.unix_timestamp_from_genesis(),
            (_, Some(parent)) if parent.epoch() != self.epoch() => unix_timestamp_s,
            _ => self.clock().epoch_start_timestamp,
        };

        // Update clock sysvar
        // NOTE: block footer UNIX timestamps are in nanoseconds, but clock sysvar stores timestamps
        // in seconds
        let clock = sysvar::clock::Clock {
            slot: self.slot,
            epoch_start_timestamp,
            epoch: self.epoch_schedule().get_epoch(self.slot),
            leader_schedule_epoch: self.epoch_schedule().get_leader_schedule_epoch(self.slot),
            unix_timestamp: unix_timestamp_s,
        };

        self.update_sysvar_account(&sysvar::clock::id(), |account| {
            create_account(
                &clock,
                self.inherit_specially_retained_account_fields(account),
            )
        });

        // Update Alpenglow clock
        let data = wincode::serialize(&unix_timestamp_nanos).unwrap();
        let lamports = Rent::default().minimum_balance(data.len());
        let mut alpenclock_acct = AccountSharedData::new(lamports, data.len(), &system_program::ID);
        alpenclock_acct.set_data_from_slice(&data);

        self.store_account_and_update_capitalization(&NANOSECOND_CLOCK_ACCOUNT, &alpenclock_acct);

        self.transaction_processor
            .reset_and_fill_sysvar_cache_entries(self);
    }

    /// Get the nanosecond clock value. Returns `None` if the nanosecond clock has not been
    /// populated (i.e., before Alpenglow migration completes).
    pub fn get_nanosecond_clock(&self) -> Option<i64> {
        let acct = self.get_account(&NANOSECOND_CLOCK_ACCOUNT)?;
        (!acct.data().is_empty()).then(|| {
            // This address is known in advance, so the account could already exist if it was prefunded.
            // The deserialize is only safe when the account is non-empty
            wincode::deserialize(acct.data())
                .expect("Couldn't deserialize nanosecond resolution clock")
        })
    }

    pub fn confirmed_last_blockhash(&self) -> Hash {
        const NUM_BLOCKHASH_CONFIRMATIONS: usize = 3;

        let mut last_parent = None;
        for (index, parent) in self.parents_iter().enumerate() {
            if index == NUM_BLOCKHASH_CONFIRMATIONS {
                return parent.last_blockhash();
            }
            last_parent = Some(parent);
        }
        last_parent.map_or_else(|| self.last_blockhash(), |parent| parent.last_blockhash())
    }

    /// Forget all signatures. Useful for benchmarking.
    #[cfg(feature = "dev-context-only-utils")]
    pub fn clear_signatures(&self) {
        self.status_cache.write().unwrap().clear();
    }

    pub fn clear_slot_signatures(&self, slot: Slot) {
        self.status_cache.write().unwrap().clear_slot_entries(slot);
    }

    fn update_transaction_statuses(
        &self,
        sanitized_txs: &[impl TransactionWithMeta],
        processing_results: &[TransactionProcessingResult],
    ) {
        let mut status_cache = self.status_cache.write().unwrap();
        assert_eq!(sanitized_txs.len(), processing_results.len());
        for (tx, processing_result) in sanitized_txs.iter().zip(processing_results) {
            if let Ok(processed_tx) = &processing_result {
                // If this is a blockhash transaction, add the message hash to the status cache
                // to ensure that this message won't be processed again with a different signature.
                // Nonce transactions are protected from replay via the durable nonce mechanic.
                // This exclusion is necessary to support SIMD-0297 (nonce relaxation).
                if processed_tx.nonce_address().is_none() {
                    status_cache.insert(
                        tx.recent_blockhash(),
                        tx.message_hash(),
                        self.slot(),
                        processed_tx.status(),
                    );
                }

                if self.store_transaction_signatures_in_status_cache {
                    // Add the transaction signature to the status cache so that transaction
                    // status can be queried by transaction signature over RPC.
                    status_cache.insert(
                        tx.recent_blockhash(),
                        tx.signature(),
                        self.slot(),
                        processed_tx.status(),
                    );
                }
            }
        }
    }

    /// Register a new recent blockhash in the bank's recent blockhash queue. Called when a bank
    /// reaches its max tick height. Can be called by tests to get new blockhashes for transaction
    /// processing without advancing to a new bank slot.
    fn register_recent_blockhash(&self, blockhash: &Hash, scheduler: &InstalledSchedulerRwLock) {
        // This is needed because recent_blockhash updates necessitate synchronizations for
        // consistent tx check_age handling.
        BankWithScheduler::wait_for_paused_scheduler(self, scheduler);

        // Only acquire the write lock for the blockhash queue on block boundaries because
        // readers can starve this write lock acquisition and ticks would be slowed down too
        // much if the write lock is acquired for each tick.
        let mut w_blockhash_queue = self.blockhash_queue.write().unwrap();

        #[cfg(feature = "dev-context-only-utils")]
        let blockhash_override = self
            .hash_overrides
            .lock()
            .unwrap()
            .get_blockhash_override(self.slot())
            .copied()
            .inspect(|blockhash_override| {
                if blockhash_override != blockhash {
                    info!(
                        "bank: slot: {}: overrode blockhash: {} with {}",
                        self.slot(),
                        blockhash,
                        blockhash_override
                    );
                }
            });
        #[cfg(feature = "dev-context-only-utils")]
        let blockhash = blockhash_override.as_ref().unwrap_or(blockhash);

        w_blockhash_queue.register_hash(blockhash, self.fee_rate_governor.lamports_per_signature);
        self.update_recent_blockhashes_locked(&w_blockhash_queue);
    }

    // gating this under #[cfg(feature = "dev-context-only-utils")] isn't easy due to
    // solana-program-test's usage...
    pub fn register_unique_recent_blockhash_for_test(&self) {
        self.register_recent_blockhash(
            &Hash::new_unique(),
            &BankWithScheduler::no_scheduler_available(),
        )
    }

    #[cfg(feature = "dev-context-only-utils")]
    pub fn register_recent_blockhash_for_test(
        &self,
        blockhash: &Hash,
        lamports_per_signature: Option<u64>,
    ) {
        // Only acquire the write lock for the blockhash queue on block boundaries because
        // readers can starve this write lock acquisition and ticks would be slowed down too
        // much if the write lock is acquired for each tick.
        let mut w_blockhash_queue = self.blockhash_queue.write().unwrap();
        if let Some(lamports_per_signature) = lamports_per_signature {
            w_blockhash_queue.register_hash(blockhash, lamports_per_signature);
        } else {
            w_blockhash_queue
                .register_hash(blockhash, self.fee_rate_governor.lamports_per_signature);
        }
    }

    /// Tell the bank which Entry IDs exist on the ledger. This function assumes subsequent calls
    /// correspond to later entries, and will boot the oldest ones once its internal cache is full.
    /// Once boot, the bank will reject transactions using that `hash`.
    ///
    /// This is NOT thread safe because if tick height is updated by two different threads, the
    /// block boundary condition could be missed.
    pub fn register_tick(&self, hash: &Hash, scheduler: &InstalledSchedulerRwLock) {
        assert!(
            !self.freeze_started(),
            "register_tick() working on a bank that is already frozen or is undergoing freezing!"
        );

        if self.is_block_boundary(self.tick_height.load(Relaxed) + 1) {
            self.register_recent_blockhash(hash, scheduler);
        }

        // ReplayStage will start computing the accounts delta hash when it
        // detects the tick height has reached the boundary, so the system
        // needs to guarantee all account updates for the slot have been
        // committed before this tick height is incremented (like the blockhash
        // sysvar above)
        self.tick_height.fetch_add(1, Relaxed);
    }

    #[cfg(feature = "dev-context-only-utils")]
    pub fn register_tick_for_test(&self, hash: &Hash) {
        self.register_tick(hash, &BankWithScheduler::no_scheduler_available())
    }

    #[cfg(feature = "dev-context-only-utils")]
    pub fn register_default_tick_for_test(&self) {
        self.register_tick_for_test(&Hash::default())
    }

    pub fn is_complete(&self) -> bool {
        self.tick_height() == self.max_tick_height()
    }

    pub fn is_block_boundary(&self, tick_height: u64) -> bool {
        tick_height == self.max_tick_height
    }

    /// Get the max number of accounts that a transaction may lock in this block
    pub fn get_transaction_account_lock_limit(&self) -> usize {
        if let Some(transaction_account_lock_limit) = self.transaction_account_lock_limit {
            transaction_account_lock_limit
        } else if self.feature_set.snapshot().increase_tx_account_lock_limit {
            MAX_TX_ACCOUNT_LOCKS
        } else {
            64
        }
    }

    /// Prepare a transaction batch from a list of versioned transactions from
    /// an entry. Used for tests only.
    pub fn prepare_entry_batch(
        &self,
        txs: Vec<VersionedTransaction>,
    ) -> Result<TransactionBatch<'_, '_, RuntimeTransaction<SanitizedTransaction>>> {
        let sanitized_txs = txs
            .into_iter()
            .map(|tx| {
                RuntimeTransaction::try_create(
                    tx,
                    MessageHash::Compute,
                    None,
                    self,
                    self.get_reserved_account_keys(),
                )
            })
            .collect::<Result<Vec<_>>>()?;
        Ok(TransactionBatch::new(
            self.try_lock_accounts(&sanitized_txs),
            self,
            OwnedOrBorrowed::Owned(sanitized_txs),
        ))
    }

    /// Attempt to take locks on the accounts in a transaction batch
    pub fn try_lock_accounts(&self, txs: &[impl TransactionWithMeta]) -> Vec<Result<()>> {
        self.try_lock_accounts_with_results(txs, txs.iter().map(|_| Ok(())))
    }

    /// Attempt to take locks on the accounts in a transaction batch, and their cost
    /// limited packing status and duplicate transaction conflict status
    pub fn try_lock_accounts_with_results(
        &self,
        txs: &[impl TransactionWithMeta],
        tx_results: impl Iterator<Item = Result<()>>,
    ) -> Vec<Result<()>> {
        let tx_account_lock_limit = self.get_transaction_account_lock_limit();

        // we must fail transactions that duplicate a prior message hash
        let mut batch_message_hashes = AHashSet::with_capacity(txs.len());
        let tx_results = tx_results
            .enumerate()
            .map(|(i, tx_result)| match tx_result {
                Ok(()) => {
                    // `HashSet::insert()` returns `true` when the value does *not* already exist
                    if batch_message_hashes.insert(txs[i].message_hash()) {
                        Ok(())
                    } else {
                        Err(TransactionError::AlreadyProcessed)
                    }
                }
                Err(e) => Err(e),
            });

        self.rc
            .accounts
            .lock_accounts(txs.iter(), tx_results, tx_account_lock_limit)
    }

    /// Prepare a locked transaction batch from a list of sanitized transactions.
    pub fn prepare_sanitized_batch<'a, 'b, Tx: TransactionWithMeta>(
        &'a self,
        txs: &'b [Tx],
    ) -> TransactionBatch<'a, 'b, Tx> {
        self.prepare_sanitized_batch_with_results(txs, txs.iter().map(|_| Ok(())))
    }

    /// Prepare a locked transaction batch from a list of sanitized transactions, and their cost
    /// limited packing status
    pub fn prepare_sanitized_batch_with_results<'a, 'b, Tx: TransactionWithMeta>(
        &'a self,
        transactions: &'b [Tx],
        transaction_results: impl Iterator<Item = Result<()>>,
    ) -> TransactionBatch<'a, 'b, Tx> {
        // this lock_results could be: Ok, AccountInUse, WouldExceedBlockMaxLimit or WouldExceedAccountMaxLimit
        TransactionBatch::new(
            self.try_lock_accounts_with_results(transactions, transaction_results),
            self,
            OwnedOrBorrowed::Borrowed(transactions),
        )
    }

    /// Prepare a transaction batch from a single transaction without locking accounts
    pub fn prepare_unlocked_batch_from_single_tx<'a, Tx: SVMMessage>(
        &'a self,
        transaction: &'a Tx,
    ) -> TransactionBatch<'a, 'a, Tx> {
        let tx_account_lock_limit = self.get_transaction_account_lock_limit();
        let lock_result = validate_account_locks(transaction.account_keys(), tx_account_lock_limit);
        let mut batch = TransactionBatch::new(
            vec![lock_result],
            self,
            OwnedOrBorrowed::Borrowed(slice::from_ref(transaction)),
        );
        batch.set_needs_unlock(false);
        batch
    }

    /// Prepare a transaction batch from a single transaction after locking accounts
    pub fn prepare_locked_batch_from_single_tx<'a, Tx: TransactionWithMeta>(
        &'a self,
        transaction: &'a Tx,
    ) -> TransactionBatch<'a, 'a, Tx> {
        self.prepare_sanitized_batch(slice::from_ref(transaction))
    }

    pub fn resanitize_transaction_minimally(
        &self,
        transaction: &impl TransactionWithMeta,
        sanitized_epoch: Epoch,
        alt_invalidation_slot: Slot,
    ) -> Result<()> {
        if self.vote_only_bank() && !vote_parser::is_valid_vote_only_transaction(transaction) {
            return Err(TransactionError::SanitizeFailure);
        }

        // If the transaction was sanitized before this bank's epoch,
        // additional checks are necessary.
        if self.epoch() != sanitized_epoch {
            // Reserved key set may have changed, so we must verify that
            // no writable keys are reserved.
            self.check_reserved_keys(transaction)?;

            for instr in transaction.instructions_iter() {
                if instr.accounts.len() > solana_transaction_context::MAX_ACCOUNTS_PER_INSTRUCTION {
                    return Err(solana_transaction_error::TransactionError::SanitizeFailure);
                }
            }
        }

        if self.slot() > alt_invalidation_slot {
            // The address table lookup **may** have expired, but the
            // expiration is not guaranteed since there may have been
            // skipped slot.
            // If the addresses still resolve here, then the transaction is still
            // valid, and we can continue with processing.
            // If they do not, then the ATL has expired and the transaction
            // can be dropped.
            let (_addresses, _deactivation_slot) =
                self.load_addresses_from_ref(transaction.message_address_table_lookups())?;
        }

        Ok(())
    }

    /// Run transactions against a frozen bank without committing the results
    pub fn simulate_transaction(
        &self,
        transaction: &impl TransactionWithMeta,
        enable_cpi_recording: bool,
    ) -> TransactionSimulationResult {
        assert!(self.is_frozen(), "simulation bank must be frozen");

        self.simulate_transaction_unchecked(transaction, enable_cpi_recording)
    }

    /// Run transactions against a bank without committing the results; does not check if the bank
    /// is frozen, enabling use in single-Bank test frameworks
    pub fn simulate_transaction_unchecked(
        &self,
        transaction: &impl TransactionWithMeta,
        enable_cpi_recording: bool,
    ) -> TransactionSimulationResult {
        let account_keys = transaction.account_keys();
        let number_of_accounts = account_keys.len();
        let account_overrides = self.get_account_overrides_for_simulation(&account_keys);
        let batch = self.prepare_unlocked_batch_from_single_tx(transaction);
        let mut timings = ExecuteTimings::default();

        let LoadAndExecuteTransactionsOutput {
            mut processing_results,
            balance_collector,
            ..
        } = self.load_and_execute_transactions(
            &batch,
            // After simulation, transactions will need to be forwarded to the leader
            // for processing. During forwarding, the transaction could expire if the
            // delay is not accounted for.
            self.max_processing_age()
                .saturating_sub(MAX_TRANSACTION_FORWARDING_DELAY),
            &mut timings,
            &mut TransactionErrorMetrics::default(),
            TransactionProcessingConfig {
                account_overrides: Some(&account_overrides),
                log_messages_bytes_limit: None,
                limit_to_load_programs: true,
                recording_config: ExecutionRecordingConfig {
                    enable_cpi_recording,
                    enable_log_recording: true,
                    enable_return_data_recording: true,
                    enable_transaction_balance_recording: true,
                },
                drop_on_failure: false,
                all_or_nothing: false,
                strict_nonce_size_check: true,
                drop_noop_transactions: true,
            },
        );

        debug!("simulate_transaction: {timings:?}");

        let processing_result = processing_results
            .pop()
            .unwrap_or(Err(TransactionError::InvalidProgramForExecution));
        let (
            post_simulation_accounts,
            result,
            fee,
            logs,
            return_data,
            inner_instructions,
            units_consumed,
            loaded_accounts_data_size,
        ) = match processing_result {
            Ok(processed_tx) => {
                let executed_units = processed_tx.executed_units();
                let loaded_accounts_data_size = processed_tx.loaded_accounts_data_size();

                match processed_tx {
                    ProcessedTransaction::Executed(executed_tx) => {
                        let details = executed_tx.execution_details;
                        let post_simulation_accounts = executed_tx
                            .loaded_transaction
                            .accounts
                            .into_iter()
                            .take(number_of_accounts)
                            .collect::<Vec<_>>();
                        (
                            post_simulation_accounts,
                            details.status,
                            Some(executed_tx.loaded_transaction.fee_details.total_fee()),
                            details.log_messages,
                            details.return_data,
                            details.inner_instructions,
                            executed_units,
                            loaded_accounts_data_size,
                        )
                    }
                    ProcessedTransaction::FeesOnly(fees_only_tx) => (
                        vec![],
                        Err(fees_only_tx.load_error),
                        Some(fees_only_tx.fee_details.total_fee()),
                        None,
                        None,
                        None,
                        executed_units,
                        loaded_accounts_data_size,
                    ),
                    ProcessedTransaction::NoOp(no_op_tx) => (
                        vec![],
                        Err(no_op_tx.validation_error),
                        None,
                        None,
                        None,
                        None,
                        executed_units,
                        loaded_accounts_data_size,
                    ),
                }
            }
            Err(error) => (vec![], Err(error), None, None, None, None, 0, 0),
        };
        let logs = logs.unwrap_or_default();

        let (pre_balances, post_balances, pre_token_balances, post_token_balances) =
            match balance_collector {
                Some(balance_collector) => {
                    let (mut native_pre, mut native_post, mut token_pre, mut token_post) =
                        balance_collector.into_vecs();

                    (
                        native_pre.pop(),
                        native_post.pop(),
                        token_pre.pop(),
                        token_post.pop(),
                    )
                }
                None => (None, None, None, None),
            };

        TransactionSimulationResult {
            result,
            logs,
            post_simulation_accounts,
            units_consumed,
            loaded_accounts_data_size,
            return_data,
            inner_instructions,
            fee,
            pre_balances,
            post_balances,
            pre_token_balances,
            post_token_balances,
        }
    }

    fn get_account_overrides_for_simulation(&self, account_keys: &AccountKeys) -> AccountOverrides {
        let mut account_overrides = AccountOverrides::default();
        let slot_history_id = sysvar::slot_history::id();
        if account_keys.iter().any(|pubkey| *pubkey == slot_history_id) {
            let current_account = self.get_account_with_fixed_root(&slot_history_id);
            let slot_history = current_account
                .as_ref()
                .map(|account| wincode::deserialize::<SlotHistory>(account.data()).unwrap())
                .unwrap_or_default();
            if slot_history.check(self.slot()) == Check::Found {
                let ancestors = Ancestors::from(self.proper_ancestors().collect::<Vec<_>>());
                if let Some((account, _)) =
                    self.load_slow_with_fixed_root(&ancestors, &slot_history_id)
                {
                    account_overrides.set_slot_history(Some(account));
                }
            }
        }
        account_overrides
    }

    pub fn unlock_accounts<'a, Tx: SVMMessage + 'a>(
        &self,
        txs_and_results: impl Iterator<Item = (&'a Tx, &'a Result<()>)> + Clone,
    ) {
        self.rc.accounts.unlock_accounts(txs_and_results)
    }

    pub fn remove_unrooted_slots(&self, slots: &[(Slot, BankId)]) {
        self.rc.accounts.accounts_db.remove_unrooted_slots(slots)
    }

    pub fn get_hash_age(&self, hash: &Hash) -> Option<u64> {
        self.blockhash_queue.read().unwrap().get_hash_age(hash)
    }

    pub fn is_hash_valid_for_age(&self, hash: &Hash, max_age: usize) -> bool {
        self.blockhash_queue
            .read()
            .unwrap()
            .is_hash_valid_for_age(hash, max_age)
    }

    pub fn collect_balances(
        &self,
        batch: &TransactionBatch<impl SVMMessage>,
    ) -> TransactionBalances {
        let mut balances: TransactionBalances = vec![];
        for transaction in batch.sanitized_transactions() {
            let mut transaction_balances: Vec<u64> = vec![];
            for account_key in transaction.account_keys().iter() {
                transaction_balances.push(self.get_balance(account_key));
            }
            balances.push(transaction_balances);
        }
        balances
    }

    fn cancelled_load_and_execute_tx_batch(
        batch: &TransactionBatch<impl TransactionWithMeta>,
    ) -> LoadAndExecuteTransactionsOutput {
        LoadAndExecuteTransactionsOutput {
            processing_results: std::iter::repeat_with(|| Err(TransactionError::CommitCancelled))
                .take(batch.sanitized_transactions().len())
                .collect(),
            processed_counts: ProcessedTransactionCounts::default(),
            balance_collector: None,
        }
    }

    /// Loads and executes transactions after acquiring an execution token for this Bank.
    pub fn load_and_execute_transactions(
        &self,
        batch: &TransactionBatch<impl TransactionWithMeta>,
        max_age: usize,
        timings: &mut ExecuteTimings,
        error_counters: &mut TransactionErrorMetrics,
        processing_config: TransactionProcessingConfig,
    ) -> LoadAndExecuteTransactionsOutput {
        let Some(execution_guard) = self.try_enter_transaction_execution() else {
            return Self::cancelled_load_and_execute_tx_batch(batch);
        };
        execution_guard.load_and_execute_transactions(
            batch,
            max_age,
            timings,
            error_counters,
            processing_config,
        )
    }

    fn do_load_and_execute_transactions(
        &self,
        batch: &TransactionBatch<impl TransactionWithMeta>,
        max_age: usize,
        timings: &mut ExecuteTimings,
        error_counters: &mut TransactionErrorMetrics,
        processing_config: TransactionProcessingConfig,
    ) -> LoadAndExecuteTransactionsOutput {
        let sanitized_txs = batch.sanitized_transactions();

        let (check_results, check_us) = measure_us!(self.check_transactions_before_execution(
            sanitized_txs,
            batch.lock_results(),
            max_age,
            error_counters,
        ));
        timings.saturating_add_in_place(ExecuteTimingType::CheckUs, check_us);

        let (blockhash, blockhash_lamports_per_signature) =
            self.last_blockhash_and_lamports_per_signature();
        let effective_epoch_of_deployments =
            self.epoch_schedule().get_epoch(self.slot.saturating_add(
                solana_program_runtime::program_cache_entry::DELAY_VISIBILITY_SLOT_OFFSET,
            ));
        let processing_environment = TransactionProcessingEnvironment {
            blockhash,
            blockhash_lamports_per_signature,
            alpenglow_migration_succeeded: self.is_alpenglow(),
            epoch_total_stake: self.get_current_epoch_total_stake(),
            feature_set: self.feature_set.runtime_features(),
            program_runtime_environments: ProgramRuntimeEnvironments::new(
                self.transaction_processor
                    .program_runtime_environment
                    .clone(),
                self.transaction_processor
                    .program_runtime_environment_for_epoch(effective_epoch_of_deployments),
            ),
            rent: self.rent_collector.rent.clone(),
        };

        let sanitized_output = self
            .transaction_processor
            .load_and_execute_sanitized_transactions(
                self,
                sanitized_txs,
                check_results,
                &processing_environment,
                &processing_config,
            );

        // Accumulate the errors returned by the batch processor.
        error_counters.accumulate(&sanitized_output.error_metrics);

        // Accumulate the transaction batch execution timings.
        timings.accumulate(&sanitized_output.execute_timings);

        let ((), collect_logs_us) =
            measure_us!(self.collect_logs(sanitized_txs, &sanitized_output.processing_results));
        timings.saturating_add_in_place(ExecuteTimingType::CollectLogsUs, collect_logs_us);

        let mut processed_counts = ProcessedTransactionCounts::default();
        let err_count = &mut error_counters.total;

        for (processing_result, tx) in sanitized_output
            .processing_results
            .iter()
            .zip(sanitized_txs)
        {
            if let Some(debug_keys) = &self.transaction_debug_keys {
                for key in tx.account_keys().iter() {
                    if debug_keys.contains(key) {
                        let result = processing_result.flattened_result();
                        info!("slot: {} result: {:?} tx: {:?}", self.slot, result, tx);
                        break;
                    }
                }
            }

            if processing_result.was_processed() {
                // Signature count must be accumulated only if the transaction
                // is processed, otherwise a mismatched count between banking
                // and replay could occur
                processed_counts.signature_count +=
                    tx.signature_details().num_transaction_signatures();
                processed_counts.processed_transactions_count += 1;

                if !tx.is_simple_vote_transaction() {
                    processed_counts.processed_non_vote_transactions_count += 1;
                }
            }

            match processing_result.flattened_result() {
                Ok(()) => {
                    processed_counts.processed_with_successful_result_count += 1;
                }
                Err(err) => {
                    if err_count.0 == 0 {
                        debug!("tx error: {err:?} {tx:?}");
                    }
                    *err_count += 1;
                }
            }
        }

        LoadAndExecuteTransactionsOutput {
            processing_results: sanitized_output.processing_results,
            processed_counts,
            balance_collector: sanitized_output.balance_collector,
        }
    }

    fn collect_logs(
        &self,
        transactions: &[impl TransactionWithMeta],
        processing_results: &[TransactionProcessingResult],
    ) {
        let transaction_log_collector_config =
            self.transaction_log_collector_config.read().unwrap();
        if transaction_log_collector_config.filter == TransactionLogCollectorFilter::None {
            return;
        }

        let collected_logs: Vec<_> = processing_results
            .iter()
            .zip(transactions)
            .filter_map(|(processing_result, transaction)| {
                // Skip log collection for unprocessed transactions
                let processed_tx = processing_result.processed_transaction()?;
                // Skip log collection for unexecuted transactions
                let execution_details = processed_tx.execution_details()?;
                Self::collect_transaction_logs(
                    &transaction_log_collector_config,
                    transaction,
                    execution_details,
                )
            })
            .collect();

        if !collected_logs.is_empty() {
            let mut transaction_log_collector = self.transaction_log_collector.write().unwrap();
            for (log, filtered_mentioned_addresses) in collected_logs {
                let transaction_log_index = transaction_log_collector.logs.len();
                transaction_log_collector.logs.push(log);
                for key in filtered_mentioned_addresses.into_iter() {
                    transaction_log_collector
                        .mentioned_address_map
                        .entry(key)
                        .or_default()
                        .push(transaction_log_index);
                }
            }
        }
    }

    fn collect_transaction_logs(
        transaction_log_collector_config: &TransactionLogCollectorConfig,
        transaction: &impl TransactionWithMeta,
        execution_details: &TransactionExecutionDetails,
    ) -> Option<(TransactionLogInfo, Vec<Pubkey>)> {
        // Skip log collection if no log messages were recorded
        let log_messages = execution_details.log_messages.as_ref()?;

        let mut filtered_mentioned_addresses = Vec::new();
        if !transaction_log_collector_config
            .mentioned_addresses
            .is_empty()
        {
            for key in transaction.account_keys().iter() {
                if transaction_log_collector_config
                    .mentioned_addresses
                    .contains(key)
                {
                    filtered_mentioned_addresses.push(*key);
                }
            }
        }

        let is_vote = transaction.is_simple_vote_transaction();
        let store = match transaction_log_collector_config.filter {
            TransactionLogCollectorFilter::All => {
                !is_vote || !filtered_mentioned_addresses.is_empty()
            }
            TransactionLogCollectorFilter::AllWithVotes => true,
            TransactionLogCollectorFilter::None => false,
            TransactionLogCollectorFilter::OnlyMentionedAddresses => {
                !filtered_mentioned_addresses.is_empty()
            }
        };

        if store {
            Some((
                TransactionLogInfo {
                    signature: *transaction.signature(),
                    result: execution_details.status.clone(),
                    is_vote,
                    log_messages: log_messages.clone(),
                },
                filtered_mentioned_addresses,
            ))
        } else {
            None
        }
    }

    /// Load the accounts data size, in bytes
    pub fn load_accounts_data_size(&self) -> u64 {
        self.accounts_data_size_initial
            .saturating_add_signed(self.load_accounts_data_size_delta())
    }

    /// Load the change in accounts data size in this Bank, in bytes
    pub fn load_accounts_data_size_delta(&self) -> i64 {
        let delta_on_chain = self.load_accounts_data_size_delta_on_chain();
        let delta_off_chain = self.load_accounts_data_size_delta_off_chain();
        delta_on_chain.saturating_add(delta_off_chain)
    }

    /// Load the change in accounts data size in this Bank, in bytes, from on-chain events
    /// i.e. transactions
    pub fn load_accounts_data_size_delta_on_chain(&self) -> i64 {
        self.accounts_data_size_delta_on_chain.load(Acquire)
    }

    /// Load the change in accounts data size in this Bank, in bytes, from off-chain events
    /// i.e. rent collection
    pub fn load_accounts_data_size_delta_off_chain(&self) -> i64 {
        self.accounts_data_size_delta_off_chain.load(Acquire)
    }

    /// Update the accounts data size delta from on-chain events by adding `amount`.
    /// The arithmetic saturates.
    fn update_accounts_data_size_delta_on_chain(&self, amount: i64) {
        if amount == 0 {
            return;
        }

        self.accounts_data_size_delta_on_chain
            .fetch_update(AcqRel, Acquire, |accounts_data_size_delta_on_chain| {
                Some(accounts_data_size_delta_on_chain.saturating_add(amount))
            })
            // SAFETY: unwrap() is safe since our update fn always returns `Some`
            .unwrap();
    }

    /// Update the accounts data size delta from off-chain events by adding `amount`.
    /// The arithmetic saturates.
    fn update_accounts_data_size_delta_off_chain(&self, amount: i64) {
        if amount == 0 {
            return;
        }

        self.accounts_data_size_delta_off_chain
            .fetch_update(AcqRel, Acquire, |accounts_data_size_delta_off_chain| {
                Some(accounts_data_size_delta_off_chain.saturating_add(amount))
            })
            // SAFETY: unwrap() is safe since our update fn always returns `Some`
            .unwrap();
    }

    /// Calculate the data size delta and update the off-chain accounts data size delta
    fn calculate_and_update_accounts_data_size_delta_off_chain(
        &self,
        old_data_size: usize,
        new_data_size: usize,
    ) {
        let data_size_delta = calculate_data_size_delta(old_data_size, new_data_size);
        self.update_accounts_data_size_delta_off_chain(data_size_delta);
    }

    fn filter_program_errors_and_collect_fee_details(
        &self,
        processing_results: &[TransactionProcessingResult],
    ) {
        let mut accumulated_fee_details = FeeDetails::default();

        processing_results.iter().for_each(|processing_result| {
            if let Ok(processed_tx) = processing_result {
                accumulated_fee_details.accumulate(&processed_tx.fee_details());
            }
        });

        self.collector_fee_details
            .write()
            .unwrap()
            .accumulate(&accumulated_fee_details);
    }

    fn update_bank_hash_stats<'a>(&self, accounts: &impl StorableAccounts<'a>) {
        let mut stats = BankHashStats::default();
        (0..accounts.len()).for_each(|i| {
            accounts.account(i, |account| {
                stats.update(&account);
            })
        });
        self.bank_hash_stats.accumulate(&stats);
    }

    pub fn commit_transactions(
        &self,
        sanitized_txs: &[impl TransactionWithMeta],
        processing_results: Vec<TransactionProcessingResult>,
        processed_counts: &ProcessedTransactionCounts,
        timings: &mut ExecuteTimings,
    ) -> Vec<TransactionCommitResult> {
        assert!(
            !self.freeze_started(),
            "commit_transactions() working on a bank that is already frozen or is undergoing \
             freezing!"
        );

        let ProcessedTransactionCounts {
            processed_transactions_count,
            processed_non_vote_transactions_count,
            processed_with_successful_result_count,
            signature_count,
        } = *processed_counts;

        self.increment_transaction_count(processed_transactions_count);
        self.increment_non_vote_transaction_count_since_restart(
            processed_non_vote_transactions_count,
        );
        self.increment_signature_count(signature_count);

        let processed_with_failure_result_count =
            processed_transactions_count.saturating_sub(processed_with_successful_result_count);
        self.transaction_error_count
            .fetch_add(processed_with_failure_result_count, Relaxed);

        if processed_transactions_count > 0 {
            self.is_delta.store(true, Relaxed);
            self.transaction_entries_count.fetch_add(1, Relaxed);
            self.transactions_per_entry_max
                .fetch_max(processed_transactions_count, Relaxed);
        }

        let ((), store_accounts_us) = measure_us!({
            // If geyser is present, we must collect `SanitizedTransaction`
            // references in order to comply with that interface - until it
            // is changed.
            let maybe_transaction_refs = self
                .accounts()
                .accounts_db
                .has_accounts_update_notifier()
                .then(|| {
                    sanitized_txs
                        .iter()
                        .map(|tx| tx.as_sanitized_transaction())
                        .collect::<Vec<_>>()
                });

            let (accounts_to_store, transactions) = collect_accounts_to_store(
                sanitized_txs,
                &maybe_transaction_refs,
                &processing_results,
            );

            let to_store = (self.slot(), accounts_to_store.as_slice());
            self.update_bank_hash_stats(&to_store);
            self.enqueue_on_chain_accounts_lt_hash_updates(&to_store);
            self.rc.accounts.store_accounts(
                to_store,
                self.bank_id(),
                transactions.as_deref(),
                &self.ancestors,
            );
        });

        // Cached vote and stake accounts are synchronized with accounts-db
        // after each transaction.
        let ((), update_stakes_cache_us) =
            measure_us!(self.update_stakes_cache(sanitized_txs, &processing_results));

        let ((), update_executors_us) = measure_us!({
            let mut cache = None;
            for processing_result in &processing_results {
                if let Some(ProcessedTransaction::Executed(executed_tx)) =
                    processing_result.processed_transaction()
                {
                    let programs_modified_by_tx = &executed_tx.programs_modified_by_tx;
                    if executed_tx.was_successful() && !programs_modified_by_tx.is_empty() {
                        cache
                            .get_or_insert_with(|| {
                                self.transaction_processor
                                    .global_program_cache
                                    .write()
                                    .unwrap()
                            })
                            .merge(
                                &self.transaction_processor.program_runtime_environment,
                                self.slot,
                                programs_modified_by_tx,
                            );
                    }
                }
            }
        });

        let accounts_data_len_delta = processing_results
            .iter()
            .filter_map(|processing_result| processing_result.processed_transaction())
            .filter_map(|processed_tx| processed_tx.execution_details())
            .filter_map(|details| details.accounts_deltas.as_ref())
            .map(|deltas| {
                deltas
                    .accounts_resize_delta
                    .saturating_sub_unsigned(deltas.accounts_uninitialized_size)
            })
            .sum();
        self.update_accounts_data_size_delta_on_chain(accounts_data_len_delta);

        let ((), update_transaction_statuses_us) =
            measure_us!(self.update_transaction_statuses(sanitized_txs, &processing_results));

        self.filter_program_errors_and_collect_fee_details(&processing_results);

        timings.saturating_add_in_place(ExecuteTimingType::StoreUs, store_accounts_us);
        timings.saturating_add_in_place(
            ExecuteTimingType::UpdateStakesCacheUs,
            update_stakes_cache_us,
        );
        timings.saturating_add_in_place(ExecuteTimingType::UpdateExecutorsUs, update_executors_us);
        timings.saturating_add_in_place(
            ExecuteTimingType::UpdateTransactionStatuses,
            update_transaction_statuses_us,
        );

        Self::create_commit_results(processing_results)
    }

    fn create_commit_results(
        processing_results: Vec<TransactionProcessingResult>,
    ) -> Vec<TransactionCommitResult> {
        processing_results
            .into_iter()
            .map(|processing_result| {
                let processing_result = processing_result?;
                let executed_units = processing_result.executed_units();
                let loaded_accounts_data_size = processing_result.loaded_accounts_data_size();

                match processing_result {
                    ProcessedTransaction::Executed(executed_tx) => {
                        let successful = executed_tx.was_successful();
                        let execution_details = executed_tx.execution_details;
                        let LoadedTransaction {
                            accounts: loaded_accounts,
                            fee_details,
                            rollback_accounts,
                            ..
                        } = executed_tx.loaded_transaction;

                        // Rollback value is used for failure.
                        let fee_payer_post_balance = if successful {
                            loaded_accounts[0].1.lamports()
                        } else {
                            rollback_accounts.fee_payer().1.lamports()
                        };

                        Ok(CommittedTransaction {
                            status: execution_details.status,
                            log_messages: execution_details.log_messages,
                            inner_instructions: execution_details.inner_instructions,
                            return_data: execution_details.return_data,
                            executed_units,
                            fee_details,
                            loaded_account_stats: TransactionLoadedAccountsStats {
                                loaded_accounts_count: loaded_accounts.len(),
                                loaded_accounts_data_size,
                            },
                            fee_payer_post_balance,
                        })
                    }
                    ProcessedTransaction::FeesOnly(fees_only_tx) => Ok(CommittedTransaction {
                        status: Err(fees_only_tx.load_error),
                        log_messages: None,
                        inner_instructions: None,
                        return_data: None,
                        executed_units,
                        fee_details: fees_only_tx.fee_details,
                        loaded_account_stats: TransactionLoadedAccountsStats {
                            loaded_accounts_count: fees_only_tx.rollback_accounts.count(),
                            loaded_accounts_data_size,
                        },
                        fee_payer_post_balance: fees_only_tx
                            .rollback_accounts
                            .fee_payer()
                            .1
                            .lamports(),
                    }),
                    ProcessedTransaction::NoOp(no_op_tx) => Ok(CommittedTransaction {
                        status: Err(no_op_tx.validation_error),
                        log_messages: None,
                        inner_instructions: None,
                        return_data: None,
                        executed_units,
                        fee_details: FeeDetails::default(),
                        loaded_account_stats: TransactionLoadedAccountsStats {
                            loaded_accounts_count: 0,
                            loaded_accounts_data_size,
                        },
                        fee_payer_post_balance: no_op_tx.fee_payer_balance.unwrap_or(0),
                    }),
                }
            })
            .collect()
    }

    fn run_incinerator(&self) {
        if let Some((account, _)) =
            self.get_account_modified_since_parent_with_fixed_root(&incinerator::id())
        {
            self.capitalization.fetch_sub(account.lamports(), Relaxed);
            self.store_account(&incinerator::id(), &AccountSharedData::default());
        }
    }

    /// Returns the accounts, sorted by pubkey, that were part of accounts lt hash calculation
    /// This is used when writing a bank hash details file.
    pub(crate) fn get_accounts_for_bank_hash_details(&self) -> Vec<(Pubkey, AccountSharedData)> {
        let mut accounts = self
            .rc
            .accounts
            .accounts_db
            .get_pubkey_account_for_slot(self.slot());
        // Sort the accounts by pubkey to make diff deterministic.
        accounts.sort_unstable_by_key(|a| a.0);
        accounts
    }

    pub fn cluster_type(&self) -> ClusterType {
        // unwrap is safe; self.cluster_type is ensured to be Some() always...
        // we only using Option here for ABI compatibility...
        self.cluster_type.unwrap()
    }

    /// Process a batch of transactions.
    #[must_use]
    pub fn load_execute_and_commit_transactions(
        &self,
        batch: &TransactionBatch<impl TransactionWithMeta>,
        recording_config: ExecutionRecordingConfig,
        timings: &mut ExecuteTimings,
        log_messages_bytes_limit: Option<usize>,
    ) -> (Vec<TransactionCommitResult>, Option<BalanceCollector>) {
        self.do_load_execute_and_commit_transactions_with_pre_commit_callback(
            batch,
            recording_config,
            timings,
            log_messages_bytes_limit,
            None::<fn(&_) -> _>,
        )
        .unwrap()
    }

    pub fn load_execute_and_commit_transactions_with_pre_commit_callback(
        &self,
        batch: &TransactionBatch<impl TransactionWithMeta>,
        recording_config: ExecutionRecordingConfig,
        timings: &mut ExecuteTimings,
        log_messages_bytes_limit: Option<usize>,
        pre_commit_callback: impl FnOnce(&[TransactionProcessingResult]) -> Result<()>,
    ) -> Result<(Vec<TransactionCommitResult>, Option<BalanceCollector>)> {
        self.do_load_execute_and_commit_transactions_with_pre_commit_callback(
            batch,
            recording_config,
            timings,
            log_messages_bytes_limit,
            Some(pre_commit_callback),
        )
    }

    fn do_load_execute_and_commit_transactions_with_pre_commit_callback(
        &self,
        batch: &TransactionBatch<impl TransactionWithMeta>,
        recording_config: ExecutionRecordingConfig,
        timings: &mut ExecuteTimings,
        log_messages_bytes_limit: Option<usize>,
        pre_commit_callback: Option<impl FnOnce(&[TransactionProcessingResult]) -> Result<()>>,
    ) -> Result<(Vec<TransactionCommitResult>, Option<BalanceCollector>)> {
        let execution_guard = self.try_enter_transaction_execution();
        let LoadAndExecuteTransactionsOutput {
            processing_results,
            processed_counts,
            balance_collector,
        } = if let Some(execution_guard) = execution_guard.as_ref() {
            execution_guard.load_and_execute_transactions(
                batch,
                self.max_processing_age(),
                timings,
                &mut TransactionErrorMetrics::default(),
                TransactionProcessingConfig {
                    account_overrides: None,
                    log_messages_bytes_limit,
                    limit_to_load_programs: false,
                    recording_config,
                    drop_on_failure: false,
                    all_or_nothing: false,
                    strict_nonce_size_check: false,
                    drop_noop_transactions: false,
                },
            )
        } else {
            Self::cancelled_load_and_execute_tx_batch(batch)
        };

        if let Some(pre_commit_callback) = pre_commit_callback {
            let () = pre_commit_callback(&processing_results)?;
        }

        let commit_results = if let Some(execution_guard) = execution_guard.as_ref() {
            execution_guard.commit_transactions(
                batch.sanitized_transactions(),
                processing_results,
                &processed_counts,
                timings,
            )
        } else {
            Self::create_commit_results(processing_results)
        };
        drop(execution_guard);
        Ok((commit_results, balance_collector))
    }

    /// Process a Transaction. This is used for unit tests and simply calls the vector
    /// Bank::process_transactions method.
    pub fn process_transaction(&self, tx: &Transaction) -> Result<()> {
        self.try_process_transactions(std::iter::once(tx))?[0].clone()
    }

    /// Process a Transaction and store metadata. This is used for tests and the banks services. It
    /// replicates the vector Bank::process_transaction method with metadata recording enabled.
    pub fn process_transaction_with_metadata(
        &self,
        tx: impl Into<VersionedTransaction>,
    ) -> Result<CommittedTransaction> {
        let txs = vec![tx.into()];
        let batch = self.prepare_entry_batch(txs)?;

        let (mut commit_results, ..) = self.load_execute_and_commit_transactions(
            &batch,
            ExecutionRecordingConfig {
                enable_cpi_recording: false,
                enable_log_recording: true,
                enable_return_data_recording: true,
                enable_transaction_balance_recording: false,
            },
            &mut ExecuteTimings::default(),
            Some(1000 * 1000),
        );

        commit_results.remove(0)
    }

    /// Process multiple transaction in a single batch. This is used for benches and unit tests.
    /// Short circuits if any of the transactions do not pass sanitization checks.
    pub fn try_process_transactions<'a>(
        &self,
        txs: impl Iterator<Item = &'a Transaction>,
    ) -> Result<Vec<Result<()>>> {
        let txs = txs
            .map(|tx| VersionedTransaction::from(tx.clone()))
            .collect();
        self.try_process_entry_transactions(txs)
    }

    /// Process multiple transaction in a single batch. This is used for benches and unit tests.
    /// Short circuits if any of the transactions do not pass sanitization checks.
    pub fn try_process_entry_transactions(
        &self,
        txs: Vec<VersionedTransaction>,
    ) -> Result<Vec<Result<()>>> {
        let batch = self.prepare_entry_batch(txs)?;
        Ok(self.process_transaction_batch(&batch))
    }

    #[must_use]
    fn process_transaction_batch(
        &self,
        batch: &TransactionBatch<impl TransactionWithMeta>,
    ) -> Vec<Result<()>> {
        self.load_execute_and_commit_transactions(
            batch,
            ExecutionRecordingConfig::new_single_setting(false),
            &mut ExecuteTimings::default(),
            None,
        )
        .0
        .into_iter()
        .map(|commit_result| commit_result.and_then(|committed_tx| committed_tx.status))
        .collect()
    }

    /// Create, sign, and process a Transaction from `keypair` to `to` of
    /// `n` lamports where `blockhash` is the last Entry ID observed by the client.
    pub fn transfer(&self, n: u64, keypair: &Keypair, to: &Pubkey) -> Result<Signature> {
        let blockhash = self.last_blockhash();
        let tx = system_transaction::transfer(keypair, to, n, blockhash);
        let signature = tx.signatures[0];
        self.process_transaction(&tx).map(|_| signature)
    }

    pub fn read_balance(account: &AccountSharedData) -> u64 {
        account.lamports()
    }
    /// Each program would need to be able to introspect its own state
    /// this is hard-coded to the Budget language
    pub fn get_balance(&self, pubkey: &Pubkey) -> u64 {
        self.get_account(pubkey)
            .map(|x| Self::read_balance(&x))
            .unwrap_or(0)
    }

    /// Compute all the parents of the bank in order
    pub fn parents(&self) -> Vec<Arc<Bank>> {
        self.parents_iter().collect()
    }

    pub(crate) fn parents_iter(&self) -> impl Iterator<Item = Arc<Bank>> + '_ {
        let mut bank = self.parent();
        core::iter::from_fn(move || {
            let parent = bank.take()?;
            bank = parent.parent();
            Some(parent)
        })
    }

    /// Compute all the parents of the bank including this bank itself
    pub fn parents_inclusive(self: Arc<Self>) -> Vec<Arc<Bank>> {
        let mut parents = Vec::with_capacity(self.ancestors.len());
        parents.push(Arc::clone(&self));
        parents.extend(self.parents_iter());
        parents
    }

    /// fn store the single `account` with `pubkey`.
    /// Uses `store_accounts`, which works on a vector of accounts.
    pub fn store_account(&self, pubkey: &Pubkey, account: &AccountSharedData) {
        self.store_accounts((self.slot(), &[(pubkey, account)][..]), None)
    }

    // Store `accounts`.
    //
    // - Callers must ensure there are no duplicates in `accounts`.
    // - `thread_pool_for_loading_accounts` is used for accounts lt hashing,
    //   to load the previous version of accounts in parallel.
    pub fn store_accounts<'a>(
        &self,
        accounts: impl StorableAccounts<'a>,
        thread_pool_for_loading_accounts: Option<&ThreadPool>,
    ) {
        assert!(!self.freeze_started());
        let mut m = Measure::start("stakes_cache.check_and_store");
        let new_warmup_cooldown_rate_epoch = self.new_warmup_cooldown_rate_epoch();
        let use_fixed_point_stake_math = self.use_fixed_point_stake_math();

        (0..accounts.len()).for_each(|i| {
            accounts.account(i, |account| {
                self.stakes_cache.check_and_store(
                    account.pubkey(),
                    &account,
                    new_warmup_cooldown_rate_epoch,
                    use_fixed_point_stake_math,
                )
            })
        });
        self.store_accounts_without_stakes_cache(accounts, thread_pool_for_loading_accounts);
        m.stop();
        self.rc
            .accounts
            .accounts_db
            .stats
            .stakes_cache_check_and_store_us
            .fetch_add(m.as_us(), Relaxed);
    }

    fn store_account_without_stakes_cache(&self, pubkey: &Pubkey, account: &AccountSharedData) {
        self.store_accounts_without_stakes_cache((self.slot(), &[(pubkey, account)][..]), None)
    }

    // Store `accounts`, without updating the stakes cache.
    //
    // - Callers must ensure there are no duplicates in `accounts`.
    // - `thread_pool_for_loading_accounts` is used for accounts lt hashing,
    //   to load the previous version of accounts in parallel.
    fn store_accounts_without_stakes_cache<'a>(
        &self,
        accounts: impl StorableAccounts<'a>,
        thread_pool_for_loading_accounts: Option<&ThreadPool>,
    ) {
        assert!(!self.freeze_started());
        self.update_bank_hash_stats(&accounts);
        self.enqueue_off_chain_accounts_lt_hash_updates(
            &accounts,
            thread_pool_for_loading_accounts,
        );
        self.rc
            .accounts
            .store_accounts(accounts, self.bank_id(), None, &self.ancestors);
    }

    pub fn force_flush_accounts_cache(&self) {
        self.rc
            .accounts
            .accounts_db
            .flush_accounts_cache(true, Some(self.slot()))
    }

    /// Technically this issues (or even burns!) new lamports,
    /// so be extra careful for its usage
    pub(crate) fn store_account_and_update_capitalization(
        &self,
        pubkey: &Pubkey,
        new_account: &AccountSharedData,
    ) {
        let old_account_data_size = if let Some(old_account) =
            self.get_account_with_fixed_root_no_cache(pubkey)
        {
            match new_account.lamports().cmp(&old_account.lamports()) {
                std::cmp::Ordering::Greater => {
                    let diff = new_account.lamports() - old_account.lamports();
                    trace!("store_account_and_update_capitalization: increased: {pubkey} {diff}");
                    self.capitalization.fetch_add(diff, Relaxed);
                }
                std::cmp::Ordering::Less => {
                    let diff = old_account.lamports() - new_account.lamports();
                    trace!("store_account_and_update_capitalization: decreased: {pubkey} {diff}");
                    self.capitalization.fetch_sub(diff, Relaxed);
                }
                std::cmp::Ordering::Equal => {}
            }
            old_account.data().len()
        } else {
            trace!(
                "store_account_and_update_capitalization: created: {pubkey} {}",
                new_account.lamports()
            );
            self.capitalization
                .fetch_add(new_account.lamports(), Relaxed);
            0
        };

        self.store_account(pubkey, new_account);

        // If the new account has zero lamports, that means it is being closed.
        let new_account_data_size = if new_account.lamports() == 0 {
            0
        } else {
            new_account.data().len()
        };
        self.calculate_and_update_accounts_data_size_delta_off_chain(
            old_account_data_size,
            new_account_data_size,
        );
    }

    pub fn accounts(&self) -> Arc<Accounts> {
        self.rc.accounts.clone()
    }

    /// Recomputes cost tracker limits from active feature state.
    fn apply_cost_tracker_limits_for_active_features(&mut self) {
        let params = self.current_slot_params();
        let cost_limits =
            params.cost_limits(self.feature_set.snapshot().raise_block_limits_to_100m);

        let mut cost_tracker = self.write_cost_tracker().unwrap();
        cost_tracker.set_limits(cost_limits);
    }

    /// Recomputes this bank's effective partitioned-reward write budget.
    fn apply_partitioned_epoch_rewards_config_for_active_features(&mut self) {
        self.partitioned_rewards_stake_account_stores_per_block = self
            .current_slot_params()
            .partitioned_epoch_rewards_stake_account_stores_per_block();
    }

    /// Applies slot-time changes for fields serialized into snapshots.
    fn apply_slot_time_persistent_changes(&mut self) {
        let params = self.current_slot_params();
        self.ns_per_slot = params.ns_per_slot();
        self.slots_per_year = params.slots_per_year();
        self.rent_collector.slots_per_year = params.slots_per_year();
        if !self.feature_set.is_active(&feature_set::alpenglow::id())
            && self.hashes_per_tick().is_some()
        {
            self.set_hashes_per_tick(params.hashes_per_tick());
        }
    }

    /// Verifies bank fields are consistent with current slot params.
    fn assert_bank_matches_slot_params(&self) {
        let params = self.current_slot_params();
        assert_eq!(
            self.ns_per_slot,
            params.ns_per_slot(),
            "snapshot slot-time ns_per_slot mismatch"
        );
        assert_eq!(
            self.slots_per_year.to_bits(),
            params.slots_per_year().to_bits(),
            "snapshot slot-time slots_per_year mismatch"
        );
        assert_eq!(
            self.rent_collector.slots_per_year.to_bits(),
            params.slots_per_year().to_bits(),
            "snapshot slot-time rent_collector.slots_per_year mismatch"
        );
        let hashes_per_tick = self.hashes_per_tick();
        if !self.feature_set.is_active(&feature_set::alpenglow::id()) && hashes_per_tick.is_some() {
            assert_eq!(
                hashes_per_tick,
                params.hashes_per_tick(),
                "snapshot slot-time hashes_per_tick mismatch"
            );
        }
        assert_eq!(
            self.entry_bytes_budget().slot_limit(),
            params.max_entry_bytes_per_slot(),
            "snapshot slot-time entry byte budget mismatch"
        );
    }

    /// Applies slot-time changes for runtime-only fields. This function is
    /// expected to be idempotent.
    fn apply_slot_time_runtime_changes(&mut self) {
        self.entry_bytes_consumed =
            EntryBytesBudget::new(self.current_slot_params().max_entry_bytes_per_slot());
        self.apply_cost_tracker_limits_for_active_features();
        self.apply_partitioned_epoch_rewards_config_for_active_features();
    }

    fn apply_simd_0339_invoke_cost_changes(&mut self) {
        let simd_0268_active = self.feature_set.snapshot().raise_cpi_nesting_limit_to_8;
        let compute_budget = self
            .compute_budget()
            .as_ref()
            .unwrap_or(&ComputeBudget::new_with_defaults(simd_0268_active))
            .to_cost();

        self.transaction_processor
            .set_execution_cost(compute_budget);
    }

    /// This is called from genesis and snapshot restore
    fn apply_activated_features(&mut self) {
        // Update active set of reserved account keys which are not allowed to be write locked
        self.reserved_account_keys = {
            let mut reserved_keys = ReservedAccountKeys::clone(&self.reserved_account_keys);
            reserved_keys.update_active_set(&self.feature_set);
            Arc::new(reserved_keys)
        };

        // Many fields are not serialized in snapshot or any configs. Rebuild
        // them from the feature set so the initial bank state is consistent.
        self.refresh_slot_params();
        self.apply_slot_time_runtime_changes();
        self.apply_simd_0339_invoke_cost_changes();

        let program_runtime_environment =
            self.create_program_runtime_environment(&self.feature_set);
        self.transaction_processor
            .global_program_cache
            .write()
            .unwrap()
            .latest_root_slot = self.slot;
        self.transaction_processor
            .epoch_boundary_preparation
            .write()
            .unwrap()
            .upcoming_epoch = self.epoch;
        self.transaction_processor.program_runtime_environment = program_runtime_environment;

        // Load all active built-in programs after the program runtime environment has been initialized
        self.add_active_builtin_programs();
    }

    fn create_program_runtime_environment(
        &self,
        feature_set: &FeatureSet,
    ) -> ProgramRuntimeEnvironment {
        let simd_0268_active = feature_set.snapshot().raise_cpi_nesting_limit_to_8;
        let compute_budget = self
            .compute_budget()
            .as_ref()
            .unwrap_or(&ComputeBudget::new_with_defaults(simd_0268_active))
            .to_budget();
        create_program_runtime_environment(
            &feature_set.runtime_features(),
            &compute_budget,
            false, /* deployment */
            false, /* debugging_features */
        )
        .unwrap()
    }

    pub fn set_tick_height(&self, tick_height: u64) {
        self.tick_height.store(tick_height, Relaxed)
    }

    pub fn set_inflation(&self, inflation: Inflation) {
        *self.inflation.write().unwrap() = inflation;
    }

    /// Get a snapshot of the current set of hard forks
    pub fn hard_forks(&self) -> HardForks {
        self.hard_forks.read().unwrap().clone()
    }

    pub fn register_hard_fork(&self, new_hard_fork_slot: Slot) {
        let bank_slot = self.slot();

        let lock = self.freeze_lock();
        let bank_frozen = *lock != Hash::default();
        if new_hard_fork_slot < bank_slot {
            warn!(
                "Hard fork at slot {new_hard_fork_slot} ignored, the hard fork is older than the \
                 bank at slot {bank_slot} that attempted to register it."
            );
        } else if (new_hard_fork_slot == bank_slot) && bank_frozen {
            warn!(
                "Hard fork at slot {new_hard_fork_slot} ignored, the hard fork is the same slot \
                 as the bank at slot {bank_slot} that attempted to register it, but that bank is \
                 already frozen."
            );
        } else {
            self.hard_forks
                .write()
                .unwrap()
                .register(new_hard_fork_slot);
        }
    }

    pub fn register_hard_forks(&self, new_hard_fork_slots: Option<&Vec<Slot>>) {
        if let Some(slots) = new_hard_fork_slots {
            slots
                .iter()
                .for_each(|hard_fork_slot| self.register_hard_fork(*hard_fork_slot));
        }
    }

    pub fn get_account_with_fixed_root_no_cache(
        &self,
        pubkey: &Pubkey,
    ) -> Option<AccountSharedData> {
        self.rc
            .accounts
            .load_with_fixed_root_do_not_populate_read_cache(&self.ancestors, pubkey)
            .map(|(acc, _slot)| acc)
    }

    // Hi! leaky abstraction here....
    // try to use get_account_with_fixed_root() if it's called ONLY from on-chain runtime account
    // processing. That alternative fn provides more safety.
    pub fn get_account(&self, pubkey: &Pubkey) -> Option<AccountSharedData> {
        self.get_account_modified_slot(pubkey)
            .map(|(acc, _slot)| acc)
    }

    // Hi! leaky abstraction here....
    // use this over get_account() if it's called ONLY from on-chain runtime account
    // processing (i.e. from in-band replay/banking stage; that ensures root is *fixed* while
    // running).
    // pro: safer assertion can be enabled inside AccountsDb
    // con: panics!() if called from off-chain processing
    pub fn get_account_with_fixed_root(&self, pubkey: &Pubkey) -> Option<AccountSharedData> {
        self.get_account_modified_slot_with_fixed_root(pubkey)
            .map(|(acc, _slot)| acc)
    }

    // See note above get_account_with_fixed_root() about when to prefer this function
    pub fn get_account_modified_slot_with_fixed_root(
        &self,
        pubkey: &Pubkey,
    ) -> Option<(AccountSharedData, Slot)> {
        self.load_slow_with_fixed_root(&self.ancestors, pubkey)
    }

    // See note above get_account_with_fixed_root() about when to prefer this function.
    //
    // `load_filter` is a predicate over an account's lamports, owner, and data length,
    // which AccountsDb uses to avoid loading the full data. Callers should regard
    // the predicate as a performance hint, not a validation function, and perform
    // all necessary validation on the returned account themselves.
    pub fn get_account_with_fixed_root_if(
        &self,
        pubkey: &Pubkey,
        load_filter: impl Fn(u64, &Pubkey, usize) -> bool,
    ) -> Option<AccountSharedData> {
        self.rc
            .accounts
            .load_with_fixed_root(&self.ancestors, pubkey, Some(load_filter))
            .map(|(acc, _slot)| acc)
    }

    pub fn get_account_modified_slot(&self, pubkey: &Pubkey) -> Option<(AccountSharedData, Slot)> {
        self.load_slow(&self.ancestors, pubkey)
    }

    fn load_slow(
        &self,
        ancestors: &Ancestors,
        pubkey: &Pubkey,
    ) -> Option<(AccountSharedData, Slot)> {
        // get_account (= primary this fn caller) may be called from on-chain Bank code even if we
        // try hard to use get_account_with_fixed_root for that purpose...
        // so pass safer LoadHint:Unspecified here as a fallback
        self.rc.accounts.load_without_fixed_root(ancestors, pubkey)
    }

    fn load_slow_with_fixed_root(
        &self,
        ancestors: &Ancestors,
        pubkey: &Pubkey,
    ) -> Option<(AccountSharedData, Slot)> {
        self.rc
            .accounts
            .load_with_fixed_root(ancestors, pubkey, None::<fn(_, &_, _) -> _>)
    }

    pub fn get_program_accounts(
        &self,
        program_id: &Pubkey,
    ) -> ScanResult<Vec<KeyedAccountSharedData>> {
        self.rc
            .accounts
            .load_by_program(&self.ancestors, self.bank_id, program_id)
    }

    pub fn get_filtered_program_accounts<F: Fn(&AccountSharedData) -> bool>(
        &self,
        program_id: &Pubkey,
        filter: F,
    ) -> ScanResult<Vec<KeyedAccountSharedData>> {
        self.rc.accounts.load_by_program_with_filter(
            &self.ancestors,
            self.bank_id,
            program_id,
            filter,
        )
    }

    pub fn get_filtered_indexed_accounts<F: Fn(&AccountSharedData) -> bool>(
        &self,
        index_key: &IndexKey,
        filter: F,
        byte_limit_for_scan: Option<usize>,
    ) -> ScanResult<Vec<KeyedAccountSharedData>> {
        self.rc.accounts.load_by_index_key_with_filter(
            &self.ancestors,
            self.bank_id,
            index_key,
            filter,
            byte_limit_for_scan,
        )
    }

    pub fn account_indexes_include_key(&self, key: &Pubkey) -> bool {
        self.rc.accounts.account_indexes_include_key(key)
    }

    // Scans all the accounts this bank can load, applying `scan_func`
    pub fn scan_all_accounts<F>(&self, scan_func: F) -> ScanResult<()>
    where
        F: FnMut(Option<(&Pubkey, AccountSharedData, Slot)>),
    {
        self.rc
            .accounts
            .scan_all(&self.ancestors, self.bank_id, scan_func)
    }

    pub fn get_program_accounts_modified_since_parent(
        &self,
        program_id: &Pubkey,
    ) -> Vec<KeyedAccountSharedData> {
        self.rc
            .accounts
            .load_by_program_slot(self.slot(), Some(program_id))
    }

    pub fn get_transaction_logs(
        &self,
        address: Option<&Pubkey>,
    ) -> Option<Vec<TransactionLogInfo>> {
        self.transaction_log_collector
            .read()
            .unwrap()
            .get_logs_for_address(address)
    }

    /// Returns all the accounts stored in this slot
    pub fn get_all_accounts_modified_since_parent(&self) -> Vec<KeyedAccountSharedData> {
        self.rc.accounts.load_by_program_slot(self.slot(), None)
    }

    // if you want get_account_modified_since_parent without fixed_root, please define so...
    fn get_account_modified_since_parent_with_fixed_root(
        &self,
        pubkey: &Pubkey,
    ) -> Option<(AccountSharedData, Slot)> {
        let just_self: Ancestors = Ancestors::from(vec![self.slot()]);
        if let Some((account, slot)) = self.load_slow_with_fixed_root(&just_self, pubkey)
            && slot == self.slot()
        {
            return Some((account, slot));
        }
        None
    }

    pub fn get_largest_accounts(
        &self,
        num: usize,
        filter_by_address: &HashSet<Pubkey>,
        filter: AccountAddressFilter,
    ) -> ScanResult<Vec<(Pubkey, u64)>> {
        self.rc.accounts.load_largest_accounts(
            &self.ancestors,
            self.bank_id,
            num,
            filter_by_address,
            filter,
        )
    }

    /// Return the accumulated executed transaction count
    pub fn transaction_count(&self) -> u64 {
        self.transaction_count.load(Relaxed)
    }

    /// Returns the number of non-vote transactions processed without error
    /// since the most recent boot from snapshot or genesis.
    /// This value is not shared though the network, nor retained
    /// within snapshots, but is preserved in `Bank::new_from_parent`.
    pub fn non_vote_transaction_count_since_restart(&self) -> u64 {
        self.non_vote_transaction_count_since_restart.load(Relaxed)
    }

    /// Return the transaction count executed only in this bank
    pub fn executed_transaction_count(&self) -> u64 {
        self.transaction_count()
            .saturating_sub(self.parent().map_or(0, |parent| parent.transaction_count()))
    }

    pub fn transaction_error_count(&self) -> u64 {
        self.transaction_error_count.load(Relaxed)
    }

    pub fn transaction_entries_count(&self) -> u64 {
        self.transaction_entries_count.load(Relaxed)
    }

    pub fn transactions_per_entry_max(&self) -> u64 {
        self.transactions_per_entry_max.load(Relaxed)
    }

    pub fn max_data_shreds_per_slot(&self) -> u32 {
        self.max_data_shreds_per_slot_for_slot(self.slot())
    }

    pub fn max_code_shreds_per_slot(&self) -> u32 {
        self.max_code_shreds_per_slot_for_slot(self.slot())
    }

    /// Returns the data shred limit applicable to `slot`.
    ///
    /// Limit changes are delayed by an epoch, so a root bank can derive the
    /// limit for any slot inside the shred intake window.
    pub fn max_data_shreds_per_slot_for_slot(&self, slot: Slot) -> u32 {
        self.slot_params_at_slot(slot).max_data_shreds_per_slot()
    }

    /// Returns the code shred limit applicable to `slot`.
    ///
    /// Limit changes are delayed by an epoch, so a root bank can derive the
    /// limit for any slot inside the shred intake window.
    pub fn max_code_shreds_per_slot_for_slot(&self, slot: Slot) -> u32 {
        self.slot_params_at_slot(slot).max_code_shreds_per_slot()
    }

    pub fn max_entry_bytes_per_slot(&self) -> u64 {
        self.entry_bytes_budget().slot_limit()
    }

    pub fn entry_bytes_budget(&self) -> &EntryBytesBudget {
        &self.entry_bytes_consumed
    }

    fn increment_transaction_count(&self, tx_count: u64) {
        self.transaction_count.fetch_add(tx_count, Relaxed);
    }

    fn increment_non_vote_transaction_count_since_restart(&self, tx_count: u64) {
        self.non_vote_transaction_count_since_restart
            .fetch_add(tx_count, Relaxed);
    }

    pub fn signature_count(&self) -> u64 {
        self.signature_count.load(Relaxed)
    }

    fn increment_signature_count(&self, signature_count: u64) {
        self.signature_count.fetch_add(signature_count, Relaxed);
    }

    pub fn get_signature_status_processed_since_parent(
        &self,
        signature: &Signature,
    ) -> Option<Result<()>> {
        if let Some((slot, status)) = self.get_signature_status_slot(signature)
            && slot <= self.slot()
        {
            return Some(status);
        }
        None
    }

    pub fn get_signature_status_with_blockhash(
        &self,
        signature: &Signature,
        blockhash: &Hash,
    ) -> Option<Result<()>> {
        let rcache = self.status_cache.read().unwrap();
        rcache
            .get_status(signature, blockhash, &self.ancestors)
            .map(|v| v.1)
    }

    pub fn get_transaction_status_and_slot_from_status_cache(
        &self,
        message_hash: &Hash,
        transaction_blockhash: &Hash,
    ) -> Option<(Slot, bool)> {
        let rcache = self.status_cache.read().unwrap();
        rcache
            .get_status(message_hash, transaction_blockhash, &self.ancestors)
            .map(|(slot, status)| (slot, status.is_ok()))
    }

    pub fn get_signature_status_slot(&self, signature: &Signature) -> Option<(Slot, Result<()>)> {
        let rcache = self.status_cache.read().unwrap();
        rcache.get_status_any_blockhash(signature, &self.ancestors)
    }

    pub fn get_signature_status(&self, signature: &Signature) -> Option<Result<()>> {
        self.get_signature_status_slot(signature).map(|v| v.1)
    }

    pub fn has_signature(&self, signature: &Signature) -> bool {
        self.get_signature_status_slot(signature).is_some()
    }

    /// Hash the `accounts` HashMap. This represents a validator's interpretation
    ///  of the delta of the ledger since the last vote and up to now
    fn hash_internal_state(&self) -> Hash {
        let measure_total = Measure::start("");
        let slot = self.slot();

        let mut hash = hashv(&[
            self.parent_hash.as_ref(),
            &self.signature_count().to_le_bytes(),
            self.last_blockhash().as_ref(),
        ]);

        let accounts_lt_hash_checksum = {
            let accounts_lt_hash = &*self.accounts_lt_hash.lock().unwrap();
            let lt_hash_bytes = bytemuck::must_cast_slice(&accounts_lt_hash.0.0);
            hash = hashv(&[hash.as_ref(), lt_hash_bytes]);
            accounts_lt_hash.0.checksum()
        };

        let buf = self
            .hard_forks
            .read()
            .unwrap()
            .get_hash_data(slot, self.parent_slot());
        if let Some(buf) = buf {
            let hard_forked_hash = hashv(&[hash.as_ref(), &buf]);
            warn!("hard fork at slot {slot} by hashing {buf:?}: {hash} => {hard_forked_hash}");
            hash = hard_forked_hash;
        }

        #[cfg(feature = "dev-context-only-utils")]
        let hash_override = self
            .hash_overrides
            .lock()
            .unwrap()
            .get_bank_hash_override(slot)
            .copied()
            .inspect(|&hash_override| {
                if hash_override != hash {
                    info!(
                        "bank: slot: {}: overrode bank hash: {} with {}",
                        self.slot(),
                        hash,
                        hash_override
                    );
                }
            });
        // Avoid to optimize out `hash` along with the whole computation by super smart rustc.
        // hash_override is used by ledger-tool's simulate-block-production, which prefers
        // the actual bank freezing processing for accurate simulation.
        #[cfg(feature = "dev-context-only-utils")]
        let hash = hash_override.unwrap_or(std::hint::black_box(hash));

        let bank_hash_stats = self.bank_hash_stats.load();

        let total_us = measure_total.end_as_us();

        datapoint_info!(
            "bank-hash_internal_state",
            ("slot", slot, i64),
            ("total_us", total_us, i64),
        );
        info!(
            "bank frozen: {slot} hash: {hash} signature_count: {} last_blockhash: {} \
             capitalization: {}, accounts_lt_hash checksum: {accounts_lt_hash_checksum}, stats: \
             {bank_hash_stats:?}",
            self.signature_count(),
            self.last_blockhash(),
            self.capitalization(),
        );
        hash
    }

    /// Used by ledger tool to run a final hash calculation once all ledger replay has completed.
    /// This should not be called by validator code.
    pub fn run_final_hash_calc(&self) {
        self.force_flush_accounts_cache();
        // note that this slot may not be a root
        _ = self.verify_accounts(None);
    }

    /// Verify the account state as part of startup, typically from a snapshot.
    ///
    /// This fn compares the calculated accounts lt hash against the stored value in the bank.
    ///
    /// Normal validator operation will calculate the accounts lt hash during index generation.
    /// Tests/ledger-tool may not have the calculated value from index generation (or the bank
    /// being verified is different from the snapshot/startup bank), and thus will be calculated in
    /// this function, using the accounts index for input, running in the foreground.
    ///
    /// Returns true if all is good.
    ///
    /// Only intended to be called at startup, or from tests/ledger-tool.
    #[must_use]
    fn verify_accounts(&self, calculated_accounts_lt_hash: Option<&AccountsLtHash>) -> bool {
        let accounts_db = &self.rc.accounts.accounts_db;

        fn check_lt_hash(
            expected_accounts_lt_hash: &AccountsLtHash,
            calculated_accounts_lt_hash: &AccountsLtHash,
        ) -> bool {
            let is_ok = calculated_accounts_lt_hash == expected_accounts_lt_hash;
            if !is_ok {
                let expected = expected_accounts_lt_hash.0.checksum();
                let calculated = calculated_accounts_lt_hash.0.checksum();
                error!(
                    "Verifying accounts failed: accounts lattice hashes do not match, expected: \
                     {expected}, calculated: {calculated}",
                );
            }
            is_ok
        }

        info!("Verifying accounts...");
        let start = Instant::now();
        let expected_accounts_lt_hash = self.accounts_lt_hash.lock().unwrap().clone();
        let is_ok = if let Some(calculated_accounts_lt_hash) = calculated_accounts_lt_hash {
            check_lt_hash(&expected_accounts_lt_hash, calculated_accounts_lt_hash)
        } else {
            let calculated_accounts_lt_hash =
                accounts_db.calculate_accounts_lt_hash_at_startup_from_index(&self.ancestors);
            check_lt_hash(&expected_accounts_lt_hash, &calculated_accounts_lt_hash)
        };
        info!("Verifying accounts... Done in {:?}", start.elapsed());
        is_ok
    }

    /// Get this bank's storages to use for snapshots.
    ///
    /// If a base slot is provided, return only the storages that are *higher* than this slot.
    pub fn get_snapshot_storages(&self, base_slot: Option<Slot>) -> Vec<Arc<AccountStorageEntry>> {
        // if a base slot is provided, request storages starting at the slot *after*
        let start_slot = base_slot.map_or(0, |slot| slot.saturating_add(1));
        // we want to *include* the storage at our slot
        let requested_slots = start_slot..=self.slot();

        self.rc.accounts.accounts_db.get_storages(requested_slots).0
    }

    #[must_use]
    fn verify_hash(&self) -> bool {
        assert!(self.is_frozen());
        let calculated_hash = self.hash_internal_state();
        let expected_hash = self.hash();

        if calculated_hash == expected_hash {
            true
        } else {
            warn!(
                "verify failed: slot: {}, {} (calculated) != {} (expected)",
                self.slot(),
                calculated_hash,
                expected_hash
            );
            false
        }
    }

    /// Verify the transaction signatures, hash and other metadata.
    pub fn verify_transaction<D>(
        &self,
        tx: UnsanitizedTransactionView<D>,
        verification_mode: TransactionVerificationMode,
    ) -> Result<RuntimeTransaction<ResolvedTransactionView<D>>>
    where
        D: TransactionData,
    {
        // Discard v1 transactions until feature gate is activated.
        let enable_tx_v1 = self.feature_set.snapshot().enable_tx_v1;
        if !enable_tx_v1 && matches!(tx.version(), TransactionVersion::V1) {
            return Err(TransactionError::UnsupportedVersion);
        }
        let max_transaction_size = match tx.version() {
            TransactionVersion::V1 if enable_tx_v1 => solana_message::v1::MAX_TRANSACTION_SIZE,
            _ => PACKET_DATA_SIZE,
        };

        // WARNING: Any pending features added here most likely must also be checked in
        //          `Bank::resanitize_transaction_minimally`.
        let sanitized_tx = {
            let size = tx.data().len();
            if size > max_transaction_size {
                return Err(TransactionError::SanitizeFailure);
            }

            let sanitized_tx = tx
                .sanitize(&solana_runtime_transaction::sanitize_config::sanitize_config())
                .map_err(|_| TransactionError::SanitizeFailure)?;

            if verification_mode == TransactionVerificationMode::FullVerification {
                let message_data = sanitized_tx.message_data();
                let keys = sanitized_tx.static_account_keys().iter();
                let signatures = sanitized_tx.signatures().iter();

                for (key, signature) in keys.zip(signatures) {
                    let valid_signature = signature.verify(key.as_ref(), message_data);
                    if !valid_signature {
                        return Err(TransactionError::SignatureFailure);
                    }
                }
            };

            let sanitized_tx = RuntimeTransaction::<SanitizedTransactionView<_>>::try_new(
                sanitized_tx,
                MessageHash::Compute,
                None,
            )?;

            let (loaded_addresses, _) = self.load_addresses_for_view(&sanitized_tx)?;

            RuntimeTransaction::<ResolvedTransactionView<_>>::try_new(
                sanitized_tx,
                loaded_addresses,
                self.get_reserved_account_keys(),
            )
        }?;

        Ok(sanitized_tx)
    }

    /// Load addresses from ALTs (if necessary) and return the
    /// [`LoadedAddresses`] with the minimum deactivation slot.
    pub fn load_addresses_for_view<D: TransactionData>(
        &self,
        view: &SanitizedTransactionView<D>,
    ) -> std::result::Result<(Option<LoadedAddresses>, Slot), AddressLoaderError> {
        match view.version() {
            TransactionVersion::Legacy | TransactionVersion::V1 => Ok((None, u64::MAX)),
            TransactionVersion::V0 => self
                .load_addresses_from_ref(view.address_table_lookup_iter())
                .map(|(loaded_addresses, deactivation_slot)| {
                    (Some(loaded_addresses), deactivation_slot)
                }),
        }
    }

    /// Checks if the transaction violates the bank's reserved keys.
    /// This needs to be checked upon epoch boundary crosses because the
    /// reserved key set may have changed since the initial sanitization.
    pub fn check_reserved_keys(&self, tx: &impl SVMMessage) -> Result<()> {
        // Check keys against the reserved set - these failures simply require us
        // to re-sanitize the transaction. We do not need to drop the transaction.
        let reserved_keys = self.get_reserved_account_keys();
        for (index, key) in tx.account_keys().iter().enumerate() {
            if tx.is_writable(index) && reserved_keys.contains(key) {
                return Err(TransactionError::ResanitizationNeeded);
            }
        }

        Ok(())
    }

    /// Calculates and returns the capitalization.
    ///
    /// Panics if capitalization overflows a u64.
    ///
    /// Note, this is *very* expensive!  It walks the whole accounts index,
    /// account-by-account, summing each account's balance.
    ///
    /// Only intended to be called at startup by ledger-tool or tests.
    /// (cannot be made DCOU due to solana-program-test)
    pub fn calculate_capitalization_for_tests(&self) -> u64 {
        self.rc
            .accounts
            .accounts_db
            .calculate_capitalization_at_startup_from_index(&self.ancestors)
    }

    /// Sets the capitalization.
    ///
    /// Only intended to be called by ledger-tool or tests.
    /// (cannot be made DCOU due to solana-program-test)
    pub fn set_capitalization_for_tests(&self, capitalization: u64) {
        self.capitalization.store(capitalization, Relaxed);
    }

    /// Returns the `SnapshotHash` for this bank's slot
    ///
    /// This fn is used at startup to verify the bank was rebuilt correctly.
    pub fn get_snapshot_hash(&self) -> SnapshotHash {
        SnapshotHash::new(self.accounts_lt_hash.lock().unwrap().0.checksum())
    }

    /// A snapshot bank should be purged of 0 lamport accounts which are not part of the hash
    /// calculation and could shield other real accounts.
    pub fn verify_snapshot_bank(
        &self,
        skip_shrink: bool,
        force_clean: bool,
        latest_full_snapshot_slot: Slot,
        calculated_accounts_lt_hash: Option<&AccountsLtHash>,
    ) -> bool {
        let (verified_accounts, verify_accounts_time_us) = measure_us!({
            let should_verify_accounts = !self.rc.accounts.accounts_db.skip_initial_hash_calc;
            if should_verify_accounts {
                self.verify_accounts(calculated_accounts_lt_hash)
            } else {
                info!("Verifying accounts... Skipped.");
                true
            }
        });

        let (_, clean_time_us) = measure_us!({
            let should_clean = force_clean || (!skip_shrink && self.slot() > 0);
            if should_clean {
                info!("Cleaning...");
                // We cannot clean past the latest full snapshot's slot because we are about to
                // perform an accounts hash calculation *up to that slot*.  If we cleaned *past*
                // that slot, then accounts could be removed from older storages, which would
                // change the accounts hash.
                self.rc
                    .accounts
                    .accounts_db
                    .clean_accounts(latest_full_snapshot_slot, true);
                info!("Cleaning... Done.");
            } else {
                info!("Cleaning... Skipped.");
            }
        });

        let (_, shrink_time_us) = measure_us!({
            let should_shrink = !skip_shrink && self.slot() > 0;
            if should_shrink {
                info!("Shrinking...");
                self.rc.accounts.accounts_db.shrink_all_slots(
                    true,
                    // we cannot allow the snapshot slot to be shrunk
                    Some(self.slot()),
                );
                info!("Shrinking... Done.");
            } else {
                info!("Shrinking... Skipped.");
            }
        });

        info!("Verifying bank...");
        let (verified_bank, verify_bank_time_us) = measure_us!(self.verify_hash());
        info!("Verifying bank... Done.");

        datapoint_info!(
            "verify_snapshot_bank",
            ("clean_us", clean_time_us, i64),
            ("shrink_us", shrink_time_us, i64),
            ("verify_accounts_us", verify_accounts_time_us, i64),
            ("verify_bank_us", verify_bank_time_us, i64),
        );

        verified_accounts && verified_bank
    }

    /// Return the number of hashes per tick
    pub fn hashes_per_tick(&self) -> Option<u64> {
        *self.hashes_per_tick.read().unwrap()
    }

    /// Return the number of ticks per slot
    pub fn ticks_per_slot(&self) -> u64 {
        self.ticks_per_slot
    }

    /// Return the target number of ticks per second for this bank.
    pub fn ticks_per_second(&self) -> u64 {
        let ticks_per_slot = u128::from(self.ticks_per_slot.max(1));
        let ns_per_tick = self.ns_per_slot.saturating_div(ticks_per_slot).max(1);
        u64::try_from(1_000_000_000u128.saturating_div(ns_per_tick))
            .expect("ticks per second must fit in u64")
    }

    /// Return the number of slots per year
    pub fn slots_per_year(&self) -> f64 {
        self.slots_per_year
    }

    /// Return the number of ticks since genesis.
    pub fn tick_height(&self) -> u64 {
        self.tick_height.load(Relaxed)
    }

    /// Return the inflation parameters of the Bank
    pub fn inflation(&self) -> Inflation {
        *self.inflation.read().unwrap()
    }

    /// Return the rent collector for this Bank
    pub fn rent_collector(&self) -> &RentCollector {
        &self.rent_collector
    }

    /// Return the total capitalization of the Bank
    pub fn capitalization(&self) -> u64 {
        self.capitalization.load(Relaxed)
    }

    /// Return this bank's max_tick_height
    pub fn max_tick_height(&self) -> u64 {
        self.max_tick_height
    }

    /// Return the block_height of this bank
    pub fn block_height(&self) -> u64 {
        self.block_height
    }

    /// Return the number of slots per epoch for the given epoch
    pub fn get_slots_in_epoch(&self, epoch: Epoch) -> u64 {
        self.epoch_schedule().get_slots_in_epoch(epoch)
    }

    /// returns the epoch for which this bank's leader_schedule_slot_offset and slot would
    ///  need to cache leader_schedule
    pub fn get_leader_schedule_epoch(&self, slot: Slot) -> Epoch {
        self.epoch_schedule().get_leader_schedule_epoch(slot)
    }

    /// a bank-level cache of vote accounts and stake delegation info
    fn update_stakes_cache(
        &self,
        txs: &[impl SVMMessage],
        processing_results: &[TransactionProcessingResult],
    ) {
        debug_assert_eq!(txs.len(), processing_results.len());
        let new_warmup_cooldown_rate_epoch = self.new_warmup_cooldown_rate_epoch();
        let use_fixed_point_stake_math = self.use_fixed_point_stake_math();
        txs.iter()
            .zip(processing_results)
            .filter_map(|(tx, processing_result)| {
                processing_result
                    .processed_transaction()
                    .map(|processed_tx| (tx, processed_tx))
            })
            .filter_map(|(tx, processed_tx)| {
                processed_tx
                    .executed_transaction()
                    .map(|executed_tx| (tx, executed_tx))
            })
            .filter(|(_, executed_tx)| executed_tx.was_successful())
            .flat_map(|(tx, executed_tx)| {
                let num_account_keys = tx.account_keys().len();
                let loaded_tx = &executed_tx.loaded_transaction;
                loaded_tx.accounts.iter().take(num_account_keys)
            })
            .for_each(|(pubkey, account)| {
                // note that this could get timed to: self.rc.accounts.accounts_db.stats.stakes_cache_check_and_store_us,
                //  but this code path is captured separately in ExecuteTimingType::UpdateStakesCacheUs
                self.stakes_cache.check_and_store(
                    pubkey,
                    account,
                    new_warmup_cooldown_rate_epoch,
                    use_fixed_point_stake_math,
                );
            });
    }

    /// current vote accounts for this bank along with the stake
    ///   attributed to each account
    pub fn vote_accounts(&self) -> Arc<VoteAccountsHashMap> {
        let stakes = self.stakes_cache.stakes();
        Arc::from(stakes.vote_accounts())
    }

    /// Vote account for the given vote account pubkey.
    pub fn get_vote_account(&self, vote_account: &Pubkey) -> Option<VoteAccount> {
        let stakes = self.stakes_cache.stakes();
        let vote_account = stakes.vote_accounts().get(vote_account)?;
        Some(vote_account.clone())
    }

    /// Get the EpochStakes for the current Bank::epoch
    pub fn current_epoch_stakes(&self) -> &VersionedEpochStakes {
        // The stakes for a given epoch (E) in self.epoch_stakes are keyed by leader schedule epoch
        // (E + 1) so the stakes for the current epoch are stored at self.epoch_stakes[E + 1]
        self.epoch_stakes
            .get(&self.epoch.saturating_add(1))
            .expect("Current epoch stakes must exist")
    }

    /// Get the EpochStakes for a given epoch
    pub fn epoch_stakes(&self, epoch: Epoch) -> Option<&VersionedEpochStakes> {
        self.epoch_stakes.get(&epoch)
    }

    /// Verify a BLS certificate's signature using this bank's epoch stakes.
    pub fn verify_certificate(
        &self,
        cert: UnverifiedCertificate,
    ) -> std::result::Result<Certificate, CertVerifyError> {
        let slot = cert.cert_type.slot();
        let epoch_stakes = self
            .epoch_stakes_from_slot(slot)
            .ok_or(CertVerifyError::MissingRankMap)?;
        let key_to_rank_map = epoch_stakes.bls_pubkey_to_rank_map();
        let total_stake = key_to_rank_map.total_stake();

        let cert =
            cert_verify::verify_certificate(cert, key_to_rank_map.len(), total_stake, |rank| {
                key_to_rank_map
                    .get_pubkey_stake_entry(rank)
                    .map(|entry| (entry.stake, entry.bls_pubkey))
            })?;

        Ok(cert)
    }

    pub fn epoch_stakes_map(&self) -> &HashMap<Epoch, VersionedEpochStakes> {
        &self.epoch_stakes
    }

    /// Returns a mapping from validator [`Pubkey`] to stake in Lamports for the current Bank::epoch.
    pub fn current_epoch_staked_nodes(&self) -> Arc<HashMap<Pubkey, u64>> {
        self.current_epoch_stakes().stakes().staked_nodes()
    }

    /// Returns a mapping from validator [`Pubkey`] to stake in Lamports for the given epoch.
    pub fn epoch_staked_nodes(&self, epoch: Epoch) -> Option<Arc<HashMap<Pubkey, u64>>> {
        Some(self.epoch_stakes.get(&epoch)?.stakes().staked_nodes())
    }

    /// Returns the total stake in Lamports for the given epoch.
    pub fn epoch_total_stake(&self, epoch: Epoch) -> Option<u64> {
        self.epoch_stakes
            .get(&epoch)
            .map(|epoch_stakes| epoch_stakes.total_stake())
    }

    /// Returns the total stake in Lamports for the current Bank::epoch.
    pub fn get_current_epoch_total_stake(&self) -> u64 {
        self.current_epoch_stakes().total_stake()
    }

    /// Returns a mapping from [`Pubkey`] to (stake in Lamports and [`VoteAccount`]) for the given epoch.
    pub fn epoch_vote_accounts(&self, epoch: Epoch) -> Option<&VoteAccountsHashMap> {
        let epoch_stakes = self.epoch_stakes.get(&epoch)?.stakes();
        Some(epoch_stakes.vote_accounts().as_ref())
    }

    /// Returns a mapping from [`Pubkey`] to (stake in Lamports and [`VoteAccount`]) for the current Bank::epoch.
    pub fn get_current_epoch_vote_accounts(&self) -> &VoteAccountsHashMap {
        self.current_epoch_stakes()
            .stakes()
            .vote_accounts()
            .as_ref()
    }

    /// Get the fixed authorized voter for the given vote account for the
    /// current epoch
    pub fn epoch_authorized_voter(&self, vote_account: &Pubkey) -> Option<&Pubkey> {
        self.epoch_stakes
            .get(&self.epoch)
            .expect("Epoch stakes for bank's own epoch must exist")
            .epoch_authorized_voters()
            .get(vote_account)
    }

    /// Get the fixed set of vote accounts for the given node id for the
    /// current epoch
    pub fn epoch_vote_accounts_for_node_id(&self, node_id: &Pubkey) -> Option<&NodeVoteAccounts> {
        self.epoch_stakes
            .get(&self.epoch)
            .expect("Epoch stakes for bank's own epoch must exist")
            .node_id_to_vote_accounts()
            .get(node_id)
    }

    /// Returns the total stake in Lamports belonging to vote accounts associated with the given node_id for the given epoch.
    pub fn epoch_node_id_to_stake(&self, epoch: Epoch, node_id: &Pubkey) -> Option<u64> {
        self.epoch_stakes(epoch)
            .and_then(|epoch_stakes| epoch_stakes.node_id_to_stake(node_id))
    }

    /// Returns the total stake in Lamports of all vote accounts for current Bank::epoch.
    pub fn total_epoch_stake(&self) -> u64 {
        self.epoch_stakes
            .get(&self.epoch)
            .expect("Epoch stakes for bank's own epoch must exist")
            .total_stake()
    }

    /// Get the fixed stake of the given vote account for the current epoch
    pub fn epoch_vote_account_stake(&self, vote_account: &Pubkey) -> u64 {
        *self
            .epoch_vote_accounts(self.epoch())
            .expect("Bank epoch vote accounts must contain entry for the bank's own epoch")
            .get(vote_account)
            .map(|(stake, _)| stake)
            .unwrap_or(&0)
    }

    /// given a slot, return the epoch and offset into the epoch this slot falls
    /// e.g. with a fixed number for slots_per_epoch, the calculation is simply:
    ///
    ///  ( slot/slots_per_epoch, slot % slots_per_epoch )
    ///
    pub fn get_epoch_and_slot_index(&self, slot: Slot) -> (Epoch, SlotIndex) {
        self.epoch_schedule().get_epoch_and_slot_index(slot)
    }

    pub fn get_epoch_info(&self) -> EpochInfo {
        let absolute_slot = self.slot();
        let block_height = self.block_height();
        let (epoch, slot_index) = self.get_epoch_and_slot_index(absolute_slot);
        let slots_in_epoch = self.get_slots_in_epoch(epoch);
        let transaction_count = Some(self.transaction_count());
        EpochInfo {
            epoch,
            slot_index,
            slots_in_epoch,
            absolute_slot,
            block_height,
            transaction_count,
        }
    }

    pub fn is_empty(&self) -> bool {
        !self.is_delta.load(Relaxed)
    }

    pub fn add_mockup_builtin(&mut self, program_id: Pubkey, builtin: BuiltinFunctionRegisterer) {
        self.add_builtin(
            program_id,
            "mockup",
            ProgramCacheEntry::new_builtin(builtin),
        );
    }

    pub fn add_precompile(&mut self, program_id: &Pubkey) {
        debug!("Adding precompiled program {program_id}");
        self.add_precompiled_account(program_id);
        debug!("Added precompiled program {program_id:?}");
    }

    // Call AccountsDb::clean_accounts()
    //
    // This fn is meant to be called by the snapshot handler in Accounts Background Service.  If
    // calling from elsewhere, ensure the same invariants hold/expectations are met.
    pub(crate) fn clean_accounts(&self) {
        // Don't clean the slot we're snapshotting because it may have zero-lamport
        // accounts that were included in the bank delta hash when the bank was frozen,
        // and if we clean them here, any newly created snapshot's hash for this bank
        // may not match the frozen hash.
        //
        // So when we're snapshotting, the highest slot to clean is lowered by one.
        let highest_slot_to_clean = self.slot().saturating_sub(1);

        self.rc
            .accounts
            .accounts_db
            .clean_accounts(highest_slot_to_clean, false);
    }

    pub fn print_accounts_stats(&self) {
        self.rc.accounts.accounts_db.print_accounts_stats("");
    }

    pub fn shrink_candidate_slots(&self) -> usize {
        self.rc
            .accounts
            .accounts_db
            .shrink_candidate_slots(self.epoch_schedule())
    }

    pub(crate) fn shrink_ancient_slots(&self) {
        self.rc
            .accounts
            .accounts_db
            .shrink_ancient_slots(self.epoch_schedule())
    }

    pub fn read_cost_tracker(&self) -> LockResult<RwLockReadGuard<'_, CostTracker>> {
        self.cost_tracker.read()
    }

    pub fn write_cost_tracker(&self) -> LockResult<RwLockWriteGuard<'_, CostTracker>> {
        self.cost_tracker.write()
    }

    // Check if the wallclock time from bank creation to now has exceeded the allotted
    // time for transaction processing
    pub fn should_bank_still_be_processing_txs(
        bank_creation_time: &Instant,
        max_tx_ingestion_nanos: u128,
    ) -> bool {
        // Do this check outside of the PoH lock, hence not a method on PohRecorder
        bank_creation_time.elapsed().as_nanos() <= max_tx_ingestion_nanos
    }

    pub fn deactivate_feature(&mut self, id: &Pubkey) {
        let mut feature_set = Arc::make_mut(&mut self.feature_set).clone();
        feature_set.deactivate(id);
        self.feature_set = Arc::new(feature_set);
        self.refresh_slot_params();
    }

    pub fn activate_feature(&mut self, id: &Pubkey) {
        let mut feature_set = Arc::make_mut(&mut self.feature_set).clone();
        feature_set.activate(id, 0);
        self.feature_set = Arc::new(feature_set);
        self.refresh_slot_params();
    }

    pub fn fill_bank_with_ticks_for_tests(&self) {
        self.do_fill_bank_with_ticks_for_tests(&BankWithScheduler::no_scheduler_available())
    }

    pub(crate) fn do_fill_bank_with_ticks_for_tests(&self, scheduler: &InstalledSchedulerRwLock) {
        if self.tick_height.load(Relaxed) < self.max_tick_height {
            let last_blockhash = self.last_blockhash();
            while self.last_blockhash() == last_blockhash {
                self.register_tick(&Hash::new_unique(), scheduler)
            }
        } else {
            warn!("Bank already reached max tick height, cannot fill it with more ticks");
        }
    }

    /// Get a set of all actively reserved account keys that are not allowed to
    /// be write-locked during transaction processing.
    pub fn get_reserved_account_keys(&self) -> &HashSet<Pubkey> {
        &self.reserved_account_keys.active
    }

    /// Compute and apply all activated features, initialize the transaction
    /// processor, and recalculate partitioned rewards if needed
    fn initialize_after_snapshot_restore<F, TP>(&mut self, rewards_thread_pool_builder: F)
    where
        F: FnOnce() -> TP,
        TP: std::borrow::Borrow<ThreadPool>,
    {
        self.transaction_processor =
            TransactionBatchProcessor::new_uninitialized(self.slot, self.epoch);
        if let Some(compute_budget) = &self.compute_budget {
            self.transaction_processor
                .set_execution_cost(compute_budget.to_cost());
        }

        self.compute_and_apply_features_after_snapshot_restore();
        self.stakes_cache.refresh_delegated_stakes(
            self.new_warmup_cooldown_rate_epoch(),
            self.use_fixed_point_stake_math(),
        );

        self.recalculate_partitioned_rewards_if_active(rewards_thread_pool_builder);

        self.transaction_processor
            .fill_missing_sysvar_cache_entries(self);
    }

    /// Compute and apply all activated features and also add accounts for builtins
    fn compute_and_apply_genesis_features(&mut self) {
        // Update the feature set to include all features active at this slot
        let feature_set = self.compute_active_feature_set(false).0;
        self.feature_set = Arc::new(feature_set);

        // Apply rent deprecation feature if it's active at genesis
        // After feature cleanup, assert that rent exemption threshold is 1.0
        if self
            .feature_set
            .snapshot()
            .deprecate_rent_exemption_threshold
        {
            self.rent_collector.deprecate_rent_exemption_threshold();
        }

        // Apply the doubled disinflation rate if it's active at genesis (the
        // re-anchor is a no-op for `initial` at year zero). Not needed on
        // snapshot restore: the serialized bank fields carry the result.
        if self
            .feature_set
            .is_active(&feature_set::double_disinflation_rate::id())
        {
            self.apply_double_disinflation_rate();
        }

        // Add built-in program accounts to the bank if they don't already exist
        self.add_builtin_program_accounts();

        self.apply_activated_features();
    }

    /// SIMD-0550: double the taper, re-anchoring `initial` so the inflation
    /// rate stays continuous at the point of activation.
    fn apply_double_disinflation_rate(&mut self) {
        let year = self.slot_in_year_for_inflation();
        let mut inflation = *self.inflation.read().unwrap();
        let anchor_rate = inflation.total(year);
        let taper = feature_set::double_disinflation_rate::TAPER;
        inflation.taper = taper;
        inflation.initial = anchor_rate / (1.0 - taper).powf(year);
        // The lock is shared with parent and sibling banks; replace it instead
        // of writing through it so every boundary bank anchors off the
        // pre-activation schedule and other forks never observe the change.
        self.inflation = Arc::new(RwLock::new(inflation));
    }

    /// Compute and apply all activated features but do not add built-in
    /// accounts because we shouldn't modify accounts db for a completed bank
    fn compute_and_apply_features_after_snapshot_restore(&mut self) {
        // Update the feature set to include all features active at this slot
        let feature_set = self.compute_active_feature_set(false).0;
        self.feature_set = Arc::new(feature_set);

        self.apply_activated_features();
        self.assert_bank_matches_slot_params();
    }

    /// This is called from each epoch boundary
    fn compute_and_apply_new_feature_activations(&mut self) {
        let include_pending = true;
        let (feature_set, new_feature_activations) =
            self.compute_active_feature_set(include_pending);
        self.feature_set = Arc::new(feature_set);
        self.refresh_slot_params();

        // Update activation slot of features in `new_feature_activations`
        for feature_id in new_feature_activations.iter() {
            if let Some(mut account) = self.get_account_with_fixed_root(feature_id)
                && let Some(mut feature) = feature::state::from_account(&account)
            {
                feature.activated_at = Some(self.slot());
                if feature::state::to_account(&feature, &mut account).is_some() {
                    self.store_account(feature_id, &account);
                }
                info!("Feature {} activated at slot {}", feature_id, self.slot());
            }
        }

        // Update active set of reserved account keys which are not allowed to be write locked
        self.reserved_account_keys = {
            let mut reserved_keys = ReservedAccountKeys::clone(&self.reserved_account_keys);
            reserved_keys.update_active_set(&self.feature_set);
            Arc::new(reserved_keys)
        };

        if new_feature_activations.contains(&feature_set::deprecate_rent_exemption_threshold::id())
        {
            self.rent_collector.deprecate_rent_exemption_threshold();
            self.update_rent();
        }

        // SIMD-0437 feature gates: all assume rent exemption threshold has been deprecated
        // (SIMD-0194), so rent.lamports_per_byte can be set directly. These gates are
        // expected to activate in order; if multiple activate in one epoch, the lowest
        // activated lamports_per_byte value will be used. If features are activated out of
        // order, the most recently activated value will be used.
        let rent_feature_gates = [
            (
                feature_set::set_lamports_per_byte_to_6333::id(),
                feature_set::set_lamports_per_byte_to_6333::LAMPORTS_PER_BYTE,
            ),
            (
                feature_set::set_lamports_per_byte_to_5080::id(),
                feature_set::set_lamports_per_byte_to_5080::LAMPORTS_PER_BYTE,
            ),
            (
                feature_set::set_lamports_per_byte_to_2575::id(),
                feature_set::set_lamports_per_byte_to_2575::LAMPORTS_PER_BYTE,
            ),
            (
                feature_set::set_lamports_per_byte_to_1322::id(),
                feature_set::set_lamports_per_byte_to_1322::LAMPORTS_PER_BYTE,
            ),
            (
                feature_set::set_lamports_per_byte_to_696::id(),
                feature_set::set_lamports_per_byte_to_696::LAMPORTS_PER_BYTE,
            ),
        ];
        for (feature_id, lamports_per_byte) in rent_feature_gates {
            if new_feature_activations.contains(&feature_id) {
                self.rent_collector.rent.lamports_per_byte = lamports_per_byte;
                self.update_rent();
            }
        }

        // SIMD-0438 feature gate: reset lamports per byte to legacy value of 6960. Safeguard
        // intended to be activated if rent reduction causes issues in the cluster.
        // Note: if this is activated in the same epoch as a 437 feature gate (above), the
        // safeguard must override it.
        if new_feature_activations.contains(&feature_set::set_lamports_per_byte_to_6960::id()) {
            self.rent_collector.rent.lamports_per_byte =
                feature_set::set_lamports_per_byte_to_6960::LAMPORTS_PER_BYTE;
            self.update_rent();
        }

        if new_feature_activations.contains(&feature_set::pico_inflation::id()) {
            *self.inflation.write().unwrap() = Inflation::pico();
            self.fee_rate_governor.burn_percent = solana_fee_calculator::DEFAULT_BURN_PERCENT;
        }

        if !new_feature_activations.is_disjoint(&self.feature_set.full_inflation_features_enabled())
        {
            *self.inflation.write().unwrap() = Inflation::full();
            self.fee_rate_governor.burn_percent = solana_fee_calculator::DEFAULT_BURN_PERCENT;
        }

        if new_feature_activations.contains(&feature_set::double_disinflation_rate::id()) {
            self.apply_double_disinflation_rate();
        }

        // Apply unconditionally: this is relatively cheap and idempotent.
        self.apply_slot_time_persistent_changes();
        self.apply_slot_time_runtime_changes();

        self.apply_new_builtin_program_feature_transitions(&new_feature_activations);

        if new_feature_activations.contains(&feature_set::replace_spl_token_with_p_token::id())
            && let Err(e) = self.upgrade_loader_v2_program_with_loader_v3_program(
                &feature_set::replace_spl_token_with_p_token::SPL_TOKEN_PROGRAM_ID,
                &feature_set::replace_spl_token_with_p_token::PTOKEN_PROGRAM_BUFFER,
                self.feature_set
                    .snapshot()
                    .relax_programdata_account_check_migration,
                "replace_spl_token_with_p_token",
            )
        {
            warn!(
                "Failed to replace SPL Token with p-token buffer '{}': {e}",
                feature_set::replace_spl_token_with_p_token::PTOKEN_PROGRAM_BUFFER,
            );
        }

        if new_feature_activations.contains(&feature_set::upgrade_bpf_stake_program_to_v5::id())
            && let Err(e) = self.upgrade_core_bpf_program(
                &solana_sdk_ids::stake::id(),
                &feature_set::upgrade_bpf_stake_program_to_v5::buffer::id(),
                "upgrade_stake_program_to_v5",
            )
        {
            error!("Failed to upgrade Core BPF Stake program: {e}");
        }

        if new_feature_activations.contains(&feature_set::upgrade_bpf_stake_program_to_v5_1::id())
            && let Err(e) = self.upgrade_core_bpf_program(
                &solana_sdk_ids::stake::id(),
                &feature_set::upgrade_bpf_stake_program_to_v5_1::buffer::id(),
                "upgrade_stake_program_to_v5_1",
            )
        {
            error!("Failed to upgrade Core BPF Stake program: {e}");
        }
    }

    fn apply_new_builtin_program_feature_transitions(
        &mut self,
        new_feature_activations: &AHashSet<Pubkey>,
    ) {
        for builtin in BUILTINS.iter() {
            if let Some(feature_id) = builtin.enable_feature_id
                && new_feature_activations.contains(&feature_id)
            {
                self.add_builtin(
                    builtin.program_id,
                    builtin.name,
                    ProgramCacheEntry::new_builtin(builtin.register_fn),
                );
            }

            if let Some(core_bpf_migration_config) = &builtin.core_bpf_migration_config {
                // If the builtin is set to be migrated to Core BPF on feature
                // activation, perform the migration which will remove it from
                // the builtins list and the cache.
                if new_feature_activations.contains(&core_bpf_migration_config.feature_id)
                    && let Err(e) = self.migrate_builtin_to_core_bpf(
                        &builtin.program_id,
                        core_bpf_migration_config,
                        self.feature_set
                            .snapshot()
                            .relax_programdata_account_check_migration,
                    )
                {
                    warn!(
                        "Failed to migrate builtin {} to Core BPF: {}",
                        builtin.name, e
                    );
                }
            };
        }

        // Migrate any necessary stateless builtins to core BPF.
        // Stateless builtins do not have an `enable_feature_id` since they
        // do not exist on-chain.
        for stateless_builtin in STATELESS_BUILTINS.iter() {
            if let Some(core_bpf_migration_config) = &stateless_builtin.core_bpf_migration_config
                && new_feature_activations.contains(&core_bpf_migration_config.feature_id)
                && let Err(e) = self.migrate_builtin_to_core_bpf(
                    &stateless_builtin.program_id,
                    core_bpf_migration_config,
                    self.feature_set
                        .snapshot()
                        .relax_programdata_account_check_migration,
                )
            {
                warn!(
                    "Failed to migrate stateless builtin {} to Core BPF: {}",
                    stateless_builtin.name, e
                );
            }
        }

        for precompile in get_precompiles() {
            if let Some(feature_id) = &precompile.feature
                && new_feature_activations.contains(feature_id)
            {
                self.add_precompile(&precompile.program_id);
            }
        }
    }

    fn adjust_sysvar_balance_for_rent(&self, account: &mut AccountSharedData) {
        account.set_lamports(
            self.get_minimum_balance_for_rent_exemption(account.data().len())
                .max(account.lamports()),
        );
    }

    /// Compute the active feature set based on the current bank state,
    /// and return it together with the set of newly activated features.
    fn compute_active_feature_set(&self, include_pending: bool) -> (FeatureSet, AHashSet<Pubkey>) {
        let mut active = self.feature_set.active().clone();
        let mut inactive = AHashSet::new();
        let mut pending = AHashSet::new();
        let slot = self.slot();

        for feature_id in self.feature_set.inactive() {
            let mut activated = None;
            if let Some(account) = self.get_account_with_fixed_root(feature_id)
                && let Some(feature) = feature::state::from_account(&account)
            {
                match feature.activated_at {
                    None if include_pending => {
                        // Feature activation is pending
                        pending.insert(*feature_id);
                        activated = Some(slot);
                    }
                    Some(activation_slot) if slot >= activation_slot => {
                        // Feature has been activated already
                        activated = Some(activation_slot);
                    }
                    _ => {}
                }
            }
            if let Some(slot) = activated {
                active.insert(*feature_id, slot);
            } else {
                inactive.insert(*feature_id);
            }
        }

        (FeatureSet::new(active, inactive), pending)
    }

    /// If `feature_id` is pending to be activated at the next epoch boundary, return
    /// the first slot at which it will be active (the epoch boundary).
    pub fn compute_pending_activation_slot(&self, feature_id: &Pubkey) -> Option<Slot> {
        let account = self.get_account_with_fixed_root(feature_id)?;
        let feature = feature::from_account(&account)?;
        if feature.activated_at.is_some() {
            // Feature is already active
            return None;
        }
        // Feature will be active at the next epoch boundary
        let active_epoch = self.epoch + 1;
        Some(self.epoch_schedule.get_first_slot_in_epoch(active_epoch))
    }

    fn add_active_builtin_programs(&mut self) {
        for builtin in BUILTINS.iter() {
            // The `builtin_is_bpf` flag is used to handle the case where a
            // builtin is scheduled to be enabled by one feature gate and
            // later migrated to Core BPF by another.
            //
            // There should never be a case where a builtin is set to be
            // migrated to Core BPF and is also set to be enabled on feature
            // activation on the same feature gate. However, the
            // `builtin_is_bpf` flag will handle this case as well, electing
            // to first attempt the migration to Core BPF.
            //
            // The migration to Core BPF will fail gracefully because the
            // program account will not exist. The builtin will subsequently
            // be enabled, but it will never be migrated to Core BPF.
            //
            // Using the same feature gate for both enabling and migrating a
            // builtin to Core BPF should be strictly avoided.
            let builtin_is_bpf = builtin.core_bpf_migration_config.is_some() && {
                self.get_account(&builtin.program_id)
                    .map(|a| a.owner() == &bpf_loader_upgradeable::id())
                    .unwrap_or(false)
            };

            // If the builtin has already been migrated to Core BPF, do not
            // add it to the bank's builtins.
            if builtin_is_bpf {
                continue;
            }

            let builtin_is_active = builtin
                .enable_feature_id
                .map(|feature_id| self.feature_set.is_active(&feature_id))
                .unwrap_or(true);

            if builtin_is_active {
                self.transaction_processor.add_builtin(
                    builtin.program_id,
                    ProgramCacheEntry::new_builtin(builtin.register_fn),
                );
            }
        }
    }

    fn add_builtin_program_accounts(&mut self) {
        for builtin in BUILTINS.iter() {
            // The `builtin_is_bpf` flag is used to handle the case where a
            // builtin is scheduled to be enabled by one feature gate and
            // later migrated to Core BPF by another.
            //
            // There should never be a case where a builtin is set to be
            // migrated to Core BPF and is also set to be enabled on feature
            // activation on the same feature gate. However, the
            // `builtin_is_bpf` flag will handle this case as well, electing
            // to first attempt the migration to Core BPF.
            //
            // The migration to Core BPF will fail gracefully because the
            // program account will not exist. The builtin will subsequently
            // be enabled, but it will never be migrated to Core BPF.
            //
            // Using the same feature gate for both enabling and migrating a
            // builtin to Core BPF should be strictly avoided.
            let builtin_is_bpf = builtin.core_bpf_migration_config.is_some() && {
                self.get_account(&builtin.program_id)
                    .map(|a| a.owner() == &bpf_loader_upgradeable::id())
                    .unwrap_or(false)
            };

            // If the builtin has already been migrated to Core BPF, do not
            // add it to the bank's builtins.
            if builtin_is_bpf {
                continue;
            }

            let builtin_is_active = builtin
                .enable_feature_id
                .map(|feature_id| self.feature_set.is_active(&feature_id))
                .unwrap_or(true);

            if builtin_is_active {
                self.add_builtin_account(builtin.name, &builtin.program_id);
            }
        }

        for precompile in get_precompiles() {
            let precompile_is_active = precompile
                .feature
                .as_ref()
                .map(|feature_id| self.feature_set.is_active(feature_id))
                .unwrap_or(true);

            if precompile_is_active {
                self.add_precompile(&precompile.program_id);
            }
        }
    }

    /// Calculates the accounts data size of all accounts
    ///
    /// Panics if total overflows a u64.
    ///
    /// Note, this may be *very* expensive, as *all* accounts are accessed.
    ///
    /// Only intended to be called by tests or when the number of accounts is small.
    pub fn calculate_accounts_data_size(&self) -> ScanResult<u64> {
        let mut accounts_data_size: u64 = 0;
        self.scan_all_accounts(|address_account_slot| {
            let Some((_address, account, _slot)) = address_account_slot else {
                return;
            };
            accounts_data_size = accounts_data_size
                .checked_add(account.data().len() as u64)
                .expect("accounts data size cannot overflow");
        })?;
        Ok(accounts_data_size)
    }

    pub fn is_in_slot_hashes_history(&self, slot: &Slot) -> bool {
        if slot < &self.slot
            && let Ok(slot_hashes) = self.transaction_processor.sysvar_cache().get_slot_hashes()
        {
            return slot_hashes.get(slot).is_some();
        }
        false
    }

    pub fn fee_structure(&self) -> &FeeStructure {
        &self.fee_structure
    }

    pub fn parent_block_id(&self) -> Option<Hash> {
        self.parent().and_then(|p| p.block_id())
    }

    pub fn block_id(&self) -> Option<Hash> {
        *self.block_id.read().unwrap()
    }

    pub fn set_block_id(&self, block_id: Option<Hash>) {
        let mut block_id_w = self.block_id.write().unwrap();
        debug_assert!(block_id_w.is_none() || *block_id_w == block_id);
        *block_id_w = block_id
    }

    pub fn compute_budget(&self) -> Option<ComputeBudget> {
        self.compute_budget
    }

    pub fn add_builtin(&self, program_id: Pubkey, name: &str, builtin: ProgramCacheEntry) {
        debug!("Adding program {name} under {program_id:?}");
        self.add_builtin_account(name, &program_id);
        self.transaction_processor.add_builtin(program_id, builtin);
        debug!("Added program {name} under {program_id:?}");
    }

    // NOTE: must hold idempotent for the same set of arguments
    /// Add a builtin program account
    fn add_builtin_account(&self, name: &str, program_id: &Pubkey) {
        let existing_genuine_program =
            self.get_account_with_fixed_root(program_id)
                .and_then(|account| {
                    // it's very unlikely to be squatted at program_id as non-system account because of burden to
                    // find victim's pubkey/hash. So, when account.owner is indeed native_loader's, it's
                    // safe to assume it's a genuine program.
                    if native_loader::check_id(account.owner()) {
                        Some(account)
                    } else {
                        // malicious account is pre-occupying at program_id
                        self.burn_and_purge_account(program_id, account);
                        None
                    }
                });

        // introducing builtin program
        if existing_genuine_program.is_some() {
            // The existing account is sufficient
            return;
        }

        assert!(
            !self.freeze_started(),
            "Can't change frozen bank by adding not-existing new builtin program ({name}, \
             {program_id}). Maybe, inconsistent program activation is detected on snapshot \
             restore?"
        );

        // Add a bogus executable builtin account, which will be loaded and ignored.
        let (lamports, rent_epoch) =
            self.inherit_specially_retained_account_fields(&existing_genuine_program);
        let account: AccountSharedData = AccountSharedData::from(Account {
            lamports,
            data: name.as_bytes().to_vec(),
            owner: solana_sdk_ids::native_loader::id(),
            executable: true,
            rent_epoch,
        });
        self.store_account_and_update_capitalization(program_id, &account);
    }

    pub fn get_bank_hash_stats(&self) -> BankHashStats {
        self.bank_hash_stats.load()
    }

    pub fn clear_epoch_rewards_cache(&self) {
        self.epoch_rewards_calculation_cache.lock().unwrap().clear();
    }

    /// Sets the accounts lt hash, only to be used by SnapshotMinimizer
    pub fn set_accounts_lt_hash_for_snapshot_minimizer(&self, accounts_lt_hash: AccountsLtHash) {
        *self.accounts_lt_hash.lock().unwrap() = accounts_lt_hash;
    }

    /// Return total transaction fee collected
    pub fn get_collector_fee_details(&self) -> CollectorFeeDetails {
        self.collector_fee_details.read().unwrap().clone()
    }

    /// Minimum balance a vote account must hold to survive SIMD-0357 filtering
    /// under the current feature set. When `alpenglow` is active the threshold
    /// also includes one epoch's worth of VAT burn.
    pub fn minimum_vote_account_balance_for_vat(&self) -> u64 {
        let vote_account_rent_exempt_minimum = self
            .rent_collector
            .rent
            .minimum_balance(VoteStateV4::size_of());
        if self.feature_set.snapshot().alpenglow {
            vote_account_rent_exempt_minimum + self.vat_to_burn_per_epoch()
        } else {
            vote_account_rent_exempt_minimum
        }
    }

    /// Returns the `Stakes` as filtered by SIMD-0357
    /// See `VoteAccounts::clone_and_filter_for_vat` for the full criteria
    pub fn get_top_epoch_stakes(&self) -> Stakes<StakeAccount<Delegation>> {
        self.stakes_cache.stakes().clone_and_filter_for_vat(
            MAX_ALPENGLOW_VOTE_ACCOUNTS,
            self.minimum_vote_account_balance_for_vat(),
        )
    }

    /// Calculates and sets block id for `bank`.
    ///
    /// This fn operates recursively. Since calculating the block id requires
    /// the bank's parent's block id, if the bank's parent's block id is unset,
    /// it will be calculated and set first.
    ///
    /// Note this fn will also freeze `bank`.
    ///
    /// Only to be called from dev contexts.
    /// Couldn't make the fn actually DCOU, since it is called by
    /// Validator::new() when warping a slot.
    pub fn calculate_and_set_block_id_for_dcou(bank: &Bank) {
        if bank.block_id().is_some() {
            // done!
            return;
        }

        let Some(parent) = bank.parent() else {
            // If bank doesn't have a parent, then use bank hash for block id,
            // as parent's block id is not available for the calculation below.
            // Must freeze() to ensure bank hash has been calculated.
            bank.freeze();
            bank.set_block_id(Some(bank.hash()));
            return;
        };

        let parent_block_id = parent.block_id().unwrap_or_else(|| {
            // if the parent's block id isn't set, we recurse so it gets set
            Self::calculate_and_set_block_id_for_dcou(&parent);
            parent.block_id().unwrap()
        });

        // must freeze() to ensure bank hash has been calculated
        bank.freeze();
        let block_id =
            solana_sha256_hasher::hashv(&[parent_block_id.as_ref(), bank.hash().as_ref()]);
        bank.set_block_id(Some(block_id));
    }

    pub(crate) fn get_alpenglow_migration_slot(&self) -> Option<Slot> {
        let genesis_cert = self.get_alpenglow_genesis_certificate()?;
        Some(genesis_cert.block.slot)
    }

    /// Signals to the accounts lt hash manager that this bank has reached the end
    /// of its slot and needs all of its account updates as soon as possible.
    pub fn set_accounts_lt_hash_async_progress_is_at_end(&self) {
        self.accounts_lt_hash_async_progress.set_is_at_end_of_slot();
    }

    /// Clears the bank-is-at-end-of-slot from `set_accounts_lt_hash_async_progress_is_at_end()`.
    ///
    /// To be called when a bank is EOL. Either during Bank::freeze(), or being discarded.
    pub fn clear_accounts_lt_hash_async_progress_is_at_end(&self) {
        self.accounts_lt_hash_async_progress
            .clear_is_at_end_of_slot();
    }
}

impl InvokeContextCallback for Bank {
    fn get_epoch_stake(&self) -> u64 {
        self.get_current_epoch_total_stake()
    }

    fn get_epoch_stake_for_vote_account(&self, vote_address: &Pubkey) -> u64 {
        self.get_current_epoch_vote_accounts()
            .get(vote_address)
            .map(|(stake, _)| *stake)
            .unwrap_or(0)
    }

    fn is_precompile(&self, program_id: &Pubkey) -> bool {
        is_precompile(program_id, |feature_id: &Pubkey| {
            self.feature_set.is_active(feature_id)
        })
    }

    fn process_precompile(
        &self,
        program_id: &Pubkey,
        data: &[u8],
        instruction_datas: Vec<&[u8]>,
    ) -> std::result::Result<(), PrecompileError> {
        if let Some(precompile) = get_precompile(program_id, |feature_id: &Pubkey| {
            self.feature_set.is_active(feature_id)
        }) {
            precompile.verify(data, &instruction_datas, &self.feature_set)
        } else {
            Err(PrecompileError::InvalidPublicKey)
        }
    }
}

impl TransactionProcessingCallback for Bank {
    fn get_account_shared_data(&self, pubkey: &Pubkey) -> Option<AccountSharedData> {
        self.rc
            .accounts
            .load_with_fixed_root(&self.ancestors, pubkey, None::<fn(_, &_, _) -> _>)
            .map(|(account, _slot)| account)
    }

    fn inspect_account(&self, _address: &Pubkey, _account_state: AccountState, _is_writable: bool) {
        // nothing to do here
    }
}

impl fmt::Debug for Bank {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Bank")
            .field("slot", &self.slot)
            .field("bank_id", &self.bank_id)
            .field("block_height", &self.block_height)
            .field("parent_slot", &self.parent_slot)
            .field("capitalization", &self.capitalization())
            .finish_non_exhaustive()
    }
}

#[cfg(feature = "dev-context-only-utils")]
impl Bank {
    /// Shared bank constructor used by `new_for_txn_tests` and
    /// `new_for_block_tests`. Builds only the `Bank` struct from deserialized
    /// fields with the supplied `leader`, `stakes_cache`, and
    /// `accounts_data_size_initial`. All post-init (feature application,
    /// sysvar cache fill, partitioned rewards recalc,
    /// `prepare_for_block_execution`, etc.) is the caller's responsibility.
    fn new_from_fields_for_tests(
        bank_rc: BankRc,
        fields: BankFieldsToDeserialize,
        feature_set: FeatureSet,
        epoch_stakes: HashMap<Epoch, VersionedEpochStakes>,
        leader: SlotLeader,
        stakes_cache: StakesCache,
        accounts_data_size_initial: u64,
    ) -> Self {
        let slot = fields.slot;
        let epoch = fields.epoch_schedule.get_epoch(slot);
        let ancestors = Ancestors::from(vec![slot]);
        let rent = Self::load_rent_from_account_for_snapshot_load(&bank_rc.accounts, &ancestors);

        let accounts = Accounts::new(Arc::clone(&bank_rc.accounts.accounts_db));
        let mut bank = Self::default_with_accounts(accounts);

        bank.rc = bank_rc;
        bank.blockhash_queue = RwLock::new(fields.blockhash_queue);
        bank.ancestors = ancestors;
        bank.hash = RwLock::new(fields.hash);
        bank.parent_hash = fields.parent_hash;
        bank.parent_slot = fields.parent_slot;
        bank.hard_forks = Arc::new(RwLock::new(fields.hard_forks));
        bank.transaction_count = AtomicU64::new(fields.transaction_count);
        bank.tick_height = AtomicU64::new(fields.tick_height);
        bank.signature_count = AtomicU64::new(fields.signature_count);
        bank.capitalization = AtomicU64::new(fields.capitalization);
        bank.max_tick_height = fields.max_tick_height;
        bank.hashes_per_tick = RwLock::new(fields.hashes_per_tick);
        bank.ticks_per_slot = fields.ticks_per_slot;
        bank.ns_per_slot = fields.ns_per_slot;
        bank.genesis_creation_time = fields.genesis_creation_time;
        bank.slots_per_year = fields.slots_per_year;
        bank.slot = slot;
        bank.epoch = epoch;
        bank.block_height = fields.block_height;
        bank.leader = leader;
        bank.fee_rate_governor = fields.fee_rate_governor;
        bank.rent_collector = RentCollector::new(
            epoch,
            fields.epoch_schedule.clone(),
            fields.slots_per_year,
            rent,
        );
        bank.epoch_schedule = fields.epoch_schedule;
        bank.inflation = Arc::new(RwLock::new(fields.inflation));
        bank.stakes_cache = stakes_cache;
        bank.epoch_stakes = epoch_stakes;
        bank.is_delta = AtomicBool::new(fields.is_delta);
        bank.cluster_type = Some(ClusterType::Development);
        bank.feature_set = Arc::new(feature_set);
        bank.freeze_started = AtomicBool::new(fields.hash != Hash::default());
        bank.accounts_data_size_initial = accounts_data_size_initial;
        bank.transaction_processor = TransactionBatchProcessor::new_uninitialized(slot, epoch);
        bank.accounts_lt_hash = Mutex::new(fields.accounts_lt_hash);
        bank.bank_hash_stats = AtomicBankHashStats::new(&fields.bank_hash_stats);
        bank.refresh_slot_params_with_baseline(SlotParams::genesis_baseline(
            bank.ns_per_slot,
            bank.slots_per_year,
            bank.hashes_per_tick(),
            bank.partitioned_rewards_stake_account_stores_per_block,
        ));

        bank
    }

    /// Create a bank for transaction testing. Constructs the bank struct,
    /// applies activated features, and fills missing sysvar cache entries.
    /// Skips block-level setup (`prepare_for_block_execution`, partitioned
    /// rewards recalc) and snapshot fields (stakes loading, debug keys,
    /// accounts data size) that are irrelevant to individual transaction
    /// execution.
    ///
    /// **Important:** The returned bank must be inserted into a
    /// [`BankForks`] before calling `load_and_execute_transactions`,
    /// because the program cache requires a `ForkGraph` to be present.
    pub fn new_for_txn_tests(
        bank_rc: BankRc,
        fields: BankFieldsToDeserialize,
        feature_set: FeatureSet,
        epoch_stakes: HashMap<Epoch, VersionedEpochStakes>,
    ) -> Self {
        let leader = SlotLeader {
            id: fields.leader_id,
            vote_address: Pubkey::default(),
        };
        let mut bank = Self::new_from_fields_for_tests(
            bank_rc,
            fields,
            feature_set,
            epoch_stakes,
            leader,
            StakesCache::default(), /* Irrelevant for txn tests */
            0,                      /* Irrelevant to txn execution */
        );

        bank.apply_activated_features();
        bank.transaction_processor
            .fill_missing_sysvar_cache_entries(&bank);

        bank
    }

    /// Create a bank for block testing. Constructs the bank struct,
    /// applies activated features, recalculates partitioned rewards if
    /// mid-distribution, and runs `prepare_for_block_execution` to
    /// complete the `_new_from_parent`-equivalent initialization
    /// (epoch processing, sysvar updates, LT hash cache).
    ///
    /// **Important:** The returned bank must be inserted into a
    /// [`BankForks`] before calling `load_and_execute_transactions`,
    /// because the program cache requires a `ForkGraph` to be present.
    pub fn new_for_block_tests(
        bank_rc: BankRc,
        fields: BankFieldsToDeserialize,
        feature_set: FeatureSet,
        epoch_stakes: HashMap<Epoch, VersionedEpochStakes>,
        stakes: Stakes<StakeAccount<Delegation>>,
        accounts_data_size_initial: u64,
    ) -> Self {
        let parent_epoch = fields.epoch_schedule.get_epoch(fields.parent_slot);
        let parent_capitalization = fields.capitalization;
        let leader =
            Self::slot_leader_from_epoch_stakes(fields.slot, &fields.epoch_schedule, &epoch_stakes);

        let mut bank = Self::new_from_fields_for_tests(
            bank_rc,
            fields,
            feature_set,
            epoch_stakes,
            leader,
            StakesCache::new(stakes),
            accounts_data_size_initial,
        );

        bank.apply_activated_features();
        bank.stakes_cache.refresh_delegated_stakes(
            bank.new_warmup_cooldown_rate_epoch(),
            bank.use_fixed_point_stake_math(),
        );

        // If booting mid-distribution, recalculate reward partitions from the
        // EpochRewards sysvar (mirrors initialize_after_snapshot_restore).
        bank.recalculate_partitioned_rewards_if_active(|| {
            rayon::ThreadPoolBuilder::new()
                .num_threads(1)
                .build()
                .expect("single-threaded rayon pool")
        });

        bank.prepare_for_block_execution(
            parent_epoch,
            bank.parent_slot,
            parent_capitalization,
            bank.block_height.saturating_sub(1),
            null_tracer(),
        );

        bank
    }

    pub fn wrap_with_bank_forks_for_tests(self) -> (Arc<Self>, Arc<RwLock<BankForks>>) {
        let bank_forks = BankForks::new_rw_arc(self);
        let bank = bank_forks.read().unwrap().root_bank();
        (bank, bank_forks)
    }

    pub fn default_for_tests() -> Self {
        let accounts_db = AccountsDb::default_for_tests();
        let accounts = Accounts::new(Arc::new(accounts_db));
        Self::default_with_accounts(accounts)
    }

    pub fn new_with_bank_forks_for_tests(
        genesis_config: &GenesisConfig,
    ) -> (Arc<Self>, Arc<RwLock<BankForks>>) {
        let bank = Self::new_for_tests(genesis_config);
        bank.wrap_with_bank_forks_for_tests()
    }

    pub fn new_for_tests(genesis_config: &GenesisConfig) -> Self {
        Self::new_with_paths_for_tests(genesis_config, None, vec![], None)
    }

    pub fn new_with_mockup_builtin_for_tests(
        genesis_config: &GenesisConfig,
        program_id: Pubkey,
        builtin: BuiltinFunctionRegisterer,
    ) -> (Arc<Self>, Arc<RwLock<BankForks>>) {
        let mut bank = Self::new_for_tests(genesis_config);
        bank.add_mockup_builtin(program_id, builtin);
        bank.wrap_with_bank_forks_for_tests()
    }

    pub fn new_with_paths_for_tests(
        genesis_config: &GenesisConfig,
        test_config: Option<BankTestConfig>,
        paths: Vec<PathBuf>,
        leader: Option<SlotLeader>,
    ) -> Self {
        let test_config = test_config.unwrap_or_default();
        let mut bank = Self::new_from_genesis(
            genesis_config,
            Arc::new(RuntimeConfig::default()),
            paths,
            None,
            test_config.accounts_db_config,
            None,
            leader,
            Arc::default(),
            None,
            None,
        );
        // Keep test-bank fee structure aligned with the genesis fee configuration.
        bank.set_fee_structure(&FeeStructure {
            lamports_per_signature: genesis_config.fee_rate_governor.lamports_per_signature,
            ..FeeStructure::default()
        });
        bank
    }

    pub fn new_for_benches(genesis_config: &GenesisConfig) -> Self {
        Self::new_with_paths_for_benches(genesis_config, Vec::new())
    }

    /// Intended for use by benches only.
    /// create new bank with the given config and paths.
    pub fn new_with_paths_for_benches(genesis_config: &GenesisConfig, paths: Vec<PathBuf>) -> Self {
        Self::new_from_genesis(
            genesis_config,
            Arc::<RuntimeConfig>::default(),
            paths,
            None,
            ACCOUNTS_DB_CONFIG_FOR_BENCHMARKS,
            None,
            Some(SlotLeader::new_unique()),
            Arc::default(),
            None,
            None,
        )
    }

    pub fn new_from_parent_with_bank_forks(
        bank_forks: &RwLock<BankForks>,
        parent: Arc<Bank>,
        leader: SlotLeader,
        slot: Slot,
    ) -> Arc<Self> {
        let bank = Bank::new_from_parent(parent, leader, slot);
        bank_forks
            .write()
            .unwrap()
            .insert(bank)
            .clone_without_scheduler()
    }

    /// Prepare a transaction batch from a list of legacy transactions. Used for tests only.
    pub fn prepare_batch_for_tests(
        &self,
        txs: Vec<Transaction>,
    ) -> TransactionBatch<'_, '_, RuntimeTransaction<SanitizedTransaction>> {
        let sanitized_txs = txs
            .into_iter()
            .map(RuntimeTransaction::from_transaction_for_tests)
            .collect::<Vec<_>>();
        TransactionBatch::new(
            self.try_lock_accounts(&sanitized_txs),
            self,
            OwnedOrBorrowed::Owned(sanitized_txs),
        )
    }

    /// Set the initial accounts data size
    /// NOTE: This fn is *ONLY FOR TESTS*
    pub fn set_accounts_data_size_initial_for_tests(&mut self, amount: u64) {
        self.accounts_data_size_initial = amount;
    }

    /// Update the accounts data size off-chain delta
    /// NOTE: This fn is *ONLY FOR TESTS*
    pub fn update_accounts_data_size_delta_off_chain_for_tests(&self, amount: i64) {
        self.update_accounts_data_size_delta_off_chain(amount)
    }

    /// Process multiple transaction in a single batch. This is used for benches and unit tests.
    ///
    /// # Panics
    ///
    /// Panics if any of the transactions do not pass sanitization checks.
    #[must_use]
    pub fn process_transactions<'a>(
        &self,
        txs: impl Iterator<Item = &'a Transaction>,
    ) -> Vec<Result<()>> {
        self.try_process_transactions(txs).unwrap()
    }

    /// Process entry transactions in a single batch. This is used for benches and unit tests.
    ///
    /// # Panics
    ///
    /// Panics if any of the transactions do not pass sanitization checks.
    #[must_use]
    pub fn process_entry_transactions(&self, txs: Vec<VersionedTransaction>) -> Vec<Result<()>> {
        self.try_process_entry_transactions(txs).unwrap()
    }

    pub fn get_sysvar_cache_for_tests(&self) -> SysvarCache {
        self.transaction_processor.get_sysvar_cache_for_tests()
    }

    pub fn calculate_accounts_lt_hash_for_tests(&self) -> AccountsLtHash {
        self.rc
            .accounts
            .accounts_db
            .calculate_accounts_lt_hash_at_startup_from_index(&self.ancestors)
    }

    pub fn get_transaction_processor(&self) -> &TransactionBatchProcessor<BankForks> {
        &self.transaction_processor
    }

    pub fn set_fee_structure(&mut self, fee_structure: &FeeStructure) {
        self.fee_structure = fee_structure.clone();
    }

    pub fn load_program(
        &self,
        pubkey: &Pubkey,
        effective_epoch: Epoch,
    ) -> Option<Arc<ProgramCacheEntry>> {
        let environments = self
            .transaction_processor
            .program_runtime_environment_for_epoch(effective_epoch);
        load_program_with_pubkey(
            self,
            &environments,
            pubkey,
            self.slot(),
            &mut ExecuteTimings::default(), // Called by ledger-tool, metrics not accumulated.
        )
    }

    pub fn withdraw(&self, pubkey: &Pubkey, lamports: u64) -> Result<()> {
        match self.get_account_with_fixed_root(pubkey) {
            Some(mut account) => {
                let min_balance = match get_system_account_kind(&account) {
                    Some(SystemAccountKind::Nonce) => self
                        .rent_collector
                        .rent
                        .minimum_balance(nonce::state::State::size()),
                    _ => 0,
                };

                lamports
                    .checked_add(min_balance)
                    .filter(|required_balance| *required_balance <= account.lamports())
                    .ok_or(TransactionError::InsufficientFundsForFee)?;
                account
                    .checked_sub_lamports(lamports)
                    .map_err(|_| TransactionError::InsufficientFundsForFee)?;
                self.store_account(pubkey, &account);

                Ok(())
            }
            None => Err(TransactionError::AccountNotFound),
        }
    }

    pub fn set_hash_overrides(&self, hash_overrides: HashOverrides) {
        *self.hash_overrides.lock().unwrap() = hash_overrides;
    }

    /// Get stake and stake node accounts
    pub(crate) fn get_stake_accounts(&self, minimized_account_set: &DashSet<Pubkey>) {
        self.stakes_cache
            .stakes()
            .stake_delegations()
            .iter()
            .for_each(|(pubkey, _)| {
                minimized_account_set.insert(*pubkey);
            });

        self.stakes_cache
            .stakes()
            .staked_nodes()
            .par_iter()
            .for_each(|(pubkey, _)| {
                minimized_account_set.insert(*pubkey);
            });
    }

    /// Returns true when this bank is using slot params beyond its genesis baseline.
    pub fn slot_time_reduction_active(&self) -> bool {
        self.ns_per_slot != self.slot_params.baseline_params().ns_per_slot()
    }
}

/// Returns a thread pool intended to be used for reward calculation. This
/// includes both crossing an epoch boundary and loading banks from snapshots.
///
/// # Performance
///
/// Initializing the thread pool takes 10ms. The first call to this function
/// initializes the thread pool, and subsequent calls re-use it. Make sure this
/// function is not called for the first time on a hot path, especially at an
/// epoch boundary.
pub(crate) fn rewards_calculation_thread_pool() -> &'static ThreadPool {
    static NEW_EPOCH_THREAD_POOL: OnceLock<ThreadPool> = OnceLock::new();
    NEW_EPOCH_THREAD_POOL.get_or_init(|| {
        rayon::ThreadPoolBuilder::new()
            .thread_name(|i| format!("solBnkClcRwds{i:02}"))
            .build()
            .expect("new epoch boundary rayon threadpool")
    })
}

/// Compute how much an account has changed size.  This function is useful when the data size delta
/// needs to be computed and passed to an `update_accounts_data_size_delta` function.
fn calculate_data_size_delta(old_data_size: usize, new_data_size: usize) -> i64 {
    assert!(old_data_size <= i64::MAX as usize);
    assert!(new_data_size <= i64::MAX as usize);
    let old_data_size = old_data_size as i64;
    let new_data_size = new_data_size as i64;

    new_data_size.saturating_sub(old_data_size)
}

impl Drop for Bank {
    fn drop(&mut self) {
        self.clear_accounts_lt_hash_async_progress_is_at_end();
        if let Some(drop_callback) = self.drop_callback.read().unwrap().0.as_ref() {
            drop_callback.callback(self);
        } else {
            // Default case for tests
            self.rc
                .accounts
                .accounts_db
                .purge_slot(self.slot(), self.bank_id(), false);
        }
    }
}

/// utility function used for testing and benchmarking.
pub mod test_utils {
    use {
        super::Bank,
        crate::installed_scheduler_pool::BankWithScheduler,
        solana_account::{ReadableAccount, WritableAccount, state_traits::StateMutWincode as _},
        solana_instruction::error::LamportsError,
        solana_pubkey::Pubkey,
        solana_sha256_hasher::hashv,
        solana_vote_interface::state::VoteStateV4,
        solana_vote_program::vote_state::{BlockTimestamp, VoteStateVersions},
        std::sync::Arc,
    };
    pub fn goto_end_of_slot(bank: Arc<Bank>) {
        goto_end_of_slot_with_scheduler(&BankWithScheduler::new_without_scheduler(bank))
    }

    pub fn goto_end_of_slot_with_scheduler(bank: &BankWithScheduler) {
        let mut tick_hash = bank.last_blockhash();
        loop {
            tick_hash = hashv(&[tick_hash.as_ref(), &[42]]);
            bank.register_tick(&tick_hash);
            if tick_hash == bank.last_blockhash() {
                bank.freeze();
                return;
            }
        }
    }

    pub fn update_vote_account_timestamp(
        timestamp: BlockTimestamp,
        bank: &Bank,
        vote_pubkey: &Pubkey,
    ) {
        let mut vote_account = bank.get_account(vote_pubkey).unwrap_or_default();
        let mut vote_state = VoteStateV4::deserialize(vote_account.data(), vote_pubkey)
            .ok()
            .unwrap_or_default();
        vote_state.last_timestamp = timestamp;
        let versioned = VoteStateVersions::new_v4(vote_state);
        vote_account.set_state(&versioned).unwrap();
        bank.store_account(vote_pubkey, &vote_account);
    }

    pub fn deposit(
        bank: &Bank,
        pubkey: &Pubkey,
        lamports: u64,
    ) -> std::result::Result<u64, LamportsError> {
        // This doesn't collect rents intentionally.
        // Rents should only be applied to actual TXes
        let mut account = bank
            .get_account_with_fixed_root_no_cache(pubkey)
            .unwrap_or_default();
        account.checked_add_lamports(lamports)?;
        bank.store_account(pubkey, &account);
        Ok(account.lamports())
    }
}