ic_memory/runtime/
mod.rs

1mod admission;
2#[cfg(test)]
3mod admission_tests;
4mod adoption;
5#[cfg(test)]
6mod adoption_tests;
7mod allocations;
8mod backing;
9pub mod bootstrap;
10mod config;
11mod default;
12mod diagnostics;
13mod error;
14mod layout;
15mod policy;
16
17#[cfg(test)]
18mod allocation_tests;
19#[cfg(test)]
20mod growth_tests;
21#[cfg(test)]
22#[expect(
23    unsafe_code,
24    reason = "exercise raw reads with valid uninitialized destinations"
25)]
26mod read_tests;
27#[cfg(test)]
28mod request_tests;
29#[cfg(test)]
30mod tests;
31
32pub use admission::{BootstrapAdmission, BootstrapAdmissionError};
33pub use adoption::RuntimeAdoptionError;
34
35pub use allocations::{
36    AllocationBinding, MemoryAllocation, MemoryAllocationSummary, MemoryAllocations,
37    MemoryBindingSummary,
38};
39pub use backing::RuntimeMemory;
40pub use config::MemoryManagerConfig;
41pub use default::{
42    bootstrap_default_memory_manager, bootstrap_default_memory_manager_with_config,
43    bootstrap_default_memory_manager_with_policy, committed_allocations,
44    default_memory_manager_commit_recovery_diagnostic, default_memory_manager_diagnostic_export,
45    default_memory_manager_doctor_report, default_memory_manager_doctor_report_with_policy,
46    default_memory_manager_memory_allocation_summary, default_memory_manager_memory_allocations,
47    default_memory_manager_memory_id, is_default_memory_manager_bootstrapped,
48    open_default_memory_manager_memory, verify_default_memory_manager_authority,
49};
50pub use error::{
51    MemoryResolutionError, RuntimeBootstrapError, RuntimeConstructionError, RuntimeDiagnosticError,
52    RuntimeGrowError, RuntimeOpenError, RuntimeStateError,
53};
54pub use layout::MemoryManagerLayoutError;
55pub use policy::GenericAllocationPolicy;
56
57use crate::{
58    CommittedAllocations, PolicyIdentity, RuntimeBootstrapPolicy, STABLE_CELL_VALUE_OFFSET,
59    StableCellLedgerError, StableCellLedgerRecord,
60    requests::SealedDeclarationSnapshot,
61    slot::MEMORY_MANAGER_LEDGER_ID,
62    stable_cell::{EncodedLedgerRecord, decode_stable_cell_ledger_record_from_memory},
63};
64use ic_stable_structures::{
65    Cell, Memory,
66    memory_manager::{MemoryId, MemoryManager},
67};
68
69use std::rc::Rc;
70
71enum RuntimeLifecycle {
72    Unbootstrapped,
73    Bootstrapped {
74        committed_allocations: CommittedAllocations,
75        binding: RuntimeBootstrapBinding,
76    },
77}
78
79struct RuntimeBootstrapBinding {
80    source: SealedDeclarationSnapshot,
81    policy_identity: PolicyIdentity,
82    pool: crate::MemoryAllocationPool,
83}
84
85///
86/// MemoryRuntime
87///
88/// Canonical owner of allocation bootstrap state for one backing memory.
89///
90/// The runtime owns its `MemoryManager`, allocation-ledger persistence, bootstrap
91/// lifecycle, committed allocation capability, opens, and diagnostics. Static
92/// linked-program declarations are supplied separately as one immutable
93/// [`SealedDeclarationSnapshot`].
94///
95/// Each bootstrap attempt fallibly decodes its ledger record from persisted
96/// memory. Capacity-checked writes use `Cell`; diagnostics also read persisted
97/// memory directly.
98///
99/// `M` needs only [`Memory`]. The runtime does not require the backing memory
100/// to be `Send`, `Sync`, `Clone`, or `'static`.
101///
102
103pub struct MemoryRuntime<M: Memory> {
104    memory_manager: MemoryManager<Rc<M>>,
105    // Shared backing, immutable geometry and live accounting belong to growth.
106    // Handles reserve physical capacity; the manager owns bucket metadata.
107    growth: Rc<backing::GrowthState<M>>,
108    lifecycle: RuntimeLifecycle,
109}
110
111impl<M: Memory> MemoryRuntime<M> {
112    /// Construct an unbootstrapped runtime without overwriting foreign memory.
113    ///
114    /// Empty backing memory is initialized as an
115    /// `ic_stable_structures::MemoryManager`. Nonempty memory must pass bounded
116    /// validation of the current manager header, bucket table, and extents; otherwise
117    /// construction returns a typed error before the manager can
118    /// write its header or allocation table. A pre-grown blank memory is
119    /// nonempty and is therefore rejected rather than assumed disposable.
120    ///
121    /// # Errors
122    ///
123    /// Returns [`RuntimeConstructionError::ForeignMemory`] for nonempty memory
124    /// without `MemoryManager` magic, or
125    /// [`RuntimeConstructionError::UnsupportedMemoryManagerVersion`] when the
126    /// magic is recognized but the layout version is not current. Invalid
127    /// metadata returns [`RuntimeConstructionError::Layout`]. Refused fresh
128    /// metadata growth returns [`RuntimeConstructionError::Growth`] without
129    /// writes, allowing the same backing memory to be retried. Reopening honors
130    /// the actual persisted bucket size; only fresh memory uses 128 pages.
131    pub fn new(memory: M) -> Result<Self, RuntimeConstructionError> {
132        Self::construct(memory, None)
133    }
134
135    /// Construct with an explicit immutable bucket policy. Existing memory must
136    /// match exactly; mismatches fail before manager initialization or writes.
137    ///
138    /// # Errors
139    ///
140    /// Returns the construction errors described by [`Self::new`], or
141    /// [`RuntimeConstructionError::BucketSizeMismatch`] when existing geometry
142    /// differs from `config`.
143    pub fn new_with_config(
144        memory: M,
145        config: MemoryManagerConfig,
146    ) -> Result<Self, RuntimeConstructionError> {
147        Self::construct(memory, Some(config))
148    }
149
150    fn construct(
151        memory: M,
152        requested: Option<MemoryManagerConfig>,
153    ) -> Result<Self, RuntimeConstructionError> {
154        if cfg!(target_endian = "big") {
155            return Err(MemoryManagerLayoutError::UnsupportedByteOrder.into());
156        }
157        let (bucket_size_pages, allocated_buckets) = if memory.size() == 0 {
158            // Reserve the metadata page before the dependency writes its header.
159            // This fresh allocation is owned here; caller-supplied nonempty
160            // memory still passes the layout checks below before any writes.
161            if memory.grow(1) == -1 {
162                return Err(RuntimeGrowError::BackingRefused {
163                    additional_pages: 1,
164                }
165                .into());
166            }
167            (requested.unwrap_or_default().bucket_size_pages(), 0)
168        } else {
169            let measured = layout::read(&memory)?;
170            let actual = measured.bucket_pages;
171            if let Some(config) = requested {
172                check_bucket_size(actual, config)?;
173            }
174            (actual, measured.allocated_buckets)
175        };
176        let backing = Rc::new(memory);
177        let growth = Rc::new(backing::GrowthState {
178            backing: Rc::clone(&backing),
179            bucket_size_pages,
180            allocated_buckets: std::cell::RefCell::new(allocated_buckets),
181        });
182        Ok(Self {
183            memory_manager: MemoryManager::init_with_bucket_size(
184                Rc::clone(&backing),
185                bucket_size_pages,
186            ),
187            growth,
188            lifecycle: RuntimeLifecycle::Unbootstrapped,
189        })
190    }
191
192    /// Return the immutable bucket configuration bound to this runtime's manager.
193    #[must_use]
194    pub fn memory_manager_config(&self) -> MemoryManagerConfig {
195        // Construction has already validated the nonzero persisted setting.
196        MemoryManagerConfig::from_validated(self.growth.bucket_size_pages)
197    }
198
199    /// Return whether this runtime has published committed allocation authority.
200    #[must_use]
201    pub const fn is_bootstrapped(&self) -> bool {
202        matches!(self.lifecycle, RuntimeLifecycle::Bootstrapped { .. })
203    }
204
205    /// Bootstrap this backing memory from one immutable declaration snapshot.
206    ///
207    /// Recovery, metadata admission, logical resolution, policy evaluation,
208    /// staging, persistence and capability publication are local to this runtime.
209    /// A repeated call is idempotent only when the sealed declaration snapshot,
210    /// canonical host pool and [`RuntimeBootstrapPolicy::runtime_bootstrap_identity`] match the
211    /// successful bootstrap. A mismatch returns a typed error without
212    /// advancing the durable generation or re-evaluating policy.
213    /// Independently sealed snapshots match when their canonical contents are equal.
214    ///
215    /// # Panics
216    ///
217    /// Panics if a private runtime or encoding invariant is broken, or backing
218    /// memory or a policy callback panics.
219    pub fn bootstrap<P: RuntimeBootstrapPolicy>(
220        &mut self,
221        declarations: &SealedDeclarationSnapshot,
222        pool: &crate::MemoryAllocationPool,
223        policy: &P,
224    ) -> Result<&CommittedAllocations, RuntimeBootstrapError<P::Error>> {
225        let policy_identity = policy.runtime_bootstrap_identity()?;
226        match &self.lifecycle {
227            RuntimeLifecycle::Unbootstrapped => {
228                self.bootstrap_unbootstrapped(declarations, pool, policy, policy_identity)?;
229            }
230            RuntimeLifecycle::Bootstrapped { binding, .. } => {
231                binding.validate(declarations, pool, &policy_identity)?;
232            }
233        }
234        match &self.lifecycle {
235            RuntimeLifecycle::Bootstrapped {
236                committed_allocations,
237                ..
238            } => Ok(committed_allocations),
239            RuntimeLifecycle::Unbootstrapped => {
240                unreachable!("successful bootstrap publishes committed allocations")
241            }
242        }
243    }
244
245    fn validate_pool_custody(
246        &self,
247        occupied: &[bool; crate::constants::MAX_ALLOCATIONS],
248        pool: &crate::MemoryAllocationPool,
249    ) -> Result<(), super::MemoryResolutionError> {
250        for id in 0..crate::MEMORY_MANAGER_INVALID_ID {
251            if pool.contains(id) && self.memory_size_pages(id) != 0 && !occupied[usize::from(id)] {
252                return Err(super::MemoryResolutionError::UnmanagedAllocation { id });
253            }
254        }
255        Ok(())
256    }
257
258    fn bootstrap_unbootstrapped<P: RuntimeBootstrapPolicy>(
259        &mut self,
260        declarations: &SealedDeclarationSnapshot,
261        pool: &crate::MemoryAllocationPool,
262        policy: &P,
263        policy_identity: PolicyIdentity,
264    ) -> Result<(), RuntimeBootstrapError<P::Error>> {
265        let memory = self.memory(MEMORY_MANAGER_LEDGER_ID);
266        let mut record = decode_stable_cell_ledger_record_from_memory(&memory)?;
267        let recovered = record.store().recover_or_genesis()?;
268        let occupied = recovered.ledger().occupied_slots();
269        self.validate_pool_custody(&occupied, pool)?;
270        if memory.size() == 0 {
271            // Empty memory decodes to an uninitialized record. Preserve fresh
272            // cell acquisition before admission without persisting genesis.
273            write_ledger_cell(memory.clone(), &StableCellLedgerRecord::default())?;
274        }
275        let mut admission = BootstrapAdmission::new(recovered.ledger(), declarations, pool);
276        let preparation = policy.prepare_bootstrap(&mut admission);
277        let historical = admission.complete()?;
278        preparation.map_err(RuntimeBootstrapError::AdmissionPolicy)?;
279        let resolved = declarations.resolve(recovered.ledger(), &occupied, historical, pool)?;
280        let commit = crate::runtime::bootstrap::prepare_commit(
281            record.store_mut(),
282            recovered,
283            resolved,
284            policy,
285        )?;
286        write_ledger_cell(memory, &record)?;
287        let committed = commit.confirm_persisted();
288        self.lifecycle = RuntimeLifecycle::Bootstrapped {
289            committed_allocations: committed,
290            binding: RuntimeBootstrapBinding {
291                source: declarations.clone(),
292                policy_identity,
293                pool: pool.clone(),
294            },
295        };
296        Ok(())
297    }
298
299    /// Borrow this runtime's committed allocation-open capability.
300    pub const fn committed_allocations(&self) -> Result<&CommittedAllocations, RuntimeOpenError> {
301        match &self.lifecycle {
302            RuntimeLifecycle::Unbootstrapped => Err(RuntimeOpenError::NotBootstrapped),
303            RuntimeLifecycle::Bootstrapped {
304                committed_allocations,
305                ..
306            } => Ok(committed_allocations),
307        }
308    }
309
310    /// Open by durable key using only this runtime's persisted current capability.
311    pub fn open_memory(&self, stable_key: &str) -> Result<RuntimeMemory<M>, RuntimeOpenError> {
312        Ok(self.memory(self.memory_id(stable_key)?))
313    }
314
315    /// Resolve an application key's committed ID without opening memory,
316    /// reading history, or changing the host's policy or bucket configuration.
317    pub fn memory_id(&self, stable_key: &str) -> Result<u8, RuntimeOpenError> {
318        crate::key::validate(stable_key)?;
319        if crate::is_ic_memory_stable_key(stable_key) {
320            return Err(RuntimeOpenError::ReservedStableKey {
321                stable_key: stable_key.to_string(),
322            });
323        }
324        let declaration = crate::capability::declaration_for_key(
325            self.committed_allocations()?.declarations(),
326            stable_key,
327        )
328        .ok_or_else(|| RuntimeOpenError::StableKeyNotCommitted(stable_key.to_string()))?;
329        Ok(declaration.slot().id())
330    }
331
332    fn memory(&self, id: u8) -> RuntimeMemory<M> {
333        RuntimeMemory {
334            memory: self.memory_manager.get(MemoryId::new(id)),
335            growth: Rc::clone(&self.growth),
336        }
337    }
338
339    // Size-only observations need no handle carrying runtime growth authority.
340    fn memory_size_pages(&self, id: u8) -> u64 {
341        self.memory_manager.get(MemoryId::new(id)).size()
342    }
343
344    fn ledger_record_from_memory(&self) -> Result<StableCellLedgerRecord, StableCellLedgerError> {
345        // Decoding only reads; the manager handle retains backing lifetime
346        // without carrying the growth owner needed by writable runtime handles.
347        let memory = self
348            .memory_manager
349            .get(MemoryId::new(MEMORY_MANAGER_LEDGER_ID));
350        decode_stable_cell_ledger_record_from_memory(&memory)
351    }
352}
353
354impl RuntimeBootstrapBinding {
355    fn validate<P>(
356        &self,
357        declarations: &SealedDeclarationSnapshot,
358        pool: &crate::MemoryAllocationPool,
359        policy_identity: &PolicyIdentity,
360    ) -> Result<(), RuntimeBootstrapError<P>> {
361        if &self.source != declarations {
362            return Err(RuntimeBootstrapError::DeclarationSnapshotMismatch);
363        }
364        if &self.pool != pool {
365            return Err(RuntimeBootstrapError::AllocationPoolMismatch);
366        }
367        if &self.policy_identity != policy_identity {
368            return Err(RuntimeBootstrapError::PolicyIdentityMismatch {
369                established: self.policy_identity.clone(),
370                requested: policy_identity.clone(),
371            });
372        }
373        Ok(())
374    }
375}
376
377fn write_ledger_cell<M: Memory, P>(
378    memory: RuntimeMemory<M>,
379    record: &StableCellLedgerRecord,
380) -> Result<(), RuntimeBootstrapError<P>> {
381    let encoded = EncodedLedgerRecord::new(record).map_err(|value_size| {
382        RuntimeBootstrapError::StableCellLedgerWriteTooLarge { value_size }
383    })?;
384    let value_size = encoded.len();
385    // The record limit is below u32::MAX, including the eight-byte cell header.
386    let required_bytes = STABLE_CELL_VALUE_OFFSET + value_size as u64;
387    let available_bytes = memory.size().saturating_mul(crate::WASM_PAGE_SIZE_BYTES);
388    if required_bytes > available_bytes {
389        let grow_by = (required_bytes - available_bytes).div_ceil(crate::WASM_PAGE_SIZE_BYTES);
390        memory.grow(grow_by)?;
391    }
392    drop(Cell::new(memory, encoded));
393    Ok(())
394}
395
396const fn check_bucket_size(
397    actual: u16,
398    requested: MemoryManagerConfig,
399) -> Result<(), RuntimeConstructionError> {
400    if actual != requested.bucket_size_pages() {
401        return Err(RuntimeConstructionError::BucketSizeMismatch {
402            persisted: actual,
403            requested: requested.bucket_size_pages(),
404        });
405    }
406    Ok(())
407}
ic_memory/runtime/mod.rs

ic_memory/runtime/
mod.rs
