Struct AsyncDbHandle 

pub struct AsyncDbHandle { /* private fields */ }

A cycle-free handle for driving async-side database updates from OUTSIDE a record’s process() cycle.

Wraps a std::sync::Weak reference to the database: a record stashes it (via crate::server::record::Record::set_async_context) without creating an ownership cycle — the database owns the record, so a strong Arc<PvDatabaseInner> stored on the record would leak the whole database. Every call upgrades the Weak to a temporary PvDatabase; once the last strong owner drops, the upgrade fails and the call is a no-op (nothing is stranded).

This is the out-of-band counterpart to the in-band re-entry crate::server::record::ProcessActions: a driver / callback thread (asyn TRACE post, AQR cancel, motor intermediate readback) holds the handle and pushes field updates or wires a completion-driven re-entry without going through process(). It exposes exactly the c401e2f0 PACT primitive surface, each call guarded by the live-database check.

Implementations

impl AsyncDbHandle

pub fn is_alive(&self) -> bool

True while the backing database is still alive.

pub fn post_fields( &self, name: &str, fields: Vec<(String, EpicsValue)>, ) -> CaResult<Vec<String>>

Out-of-band field post — see PvDatabase::post_fields. Returns an empty Vec (no-op) if the database has been dropped.

pub fn link_target_field_type(&self, link: &str) -> Option<DbFieldType>

Resolve a link’s target field type for the sseq link-status diagnostics — see PvDatabase::link_target_field_type. None if the link is constant / external / unresolvable, or the database is gone. (Distinct from the free server::record::link_field_type, which returns the link class LinkType, not the target’s type.)

pub fn schedule_record_init( &self, record: &str, init: impl Future<Output = ()> + Send + 'static, )

Schedule a record’s link-status classification — see PvDatabase::schedule_record_init. This is the ONE owner every record’s refresh_link_status goes through: during the LOAD phase the classification is queued for iocInit (so it never reads a half-built database, and its result is final when iocInit returns), and on a complete database it is spawned at once. Dropped, unrun, if the database is gone.

pub async fn read_link_value(&self, link: &str) -> Option<EpicsValue>

Read a link’s value WITHOUT processing its source record — the C dbGetLink semantics. Parses link and reads it via PvDatabase::read_link_value_no_process; None if the link is constant-less / external-unresolvable or the database has been dropped. Used by module-crate records (e.g. std throttle SYNC → SINP→VAL) that must pull an input link from special() without triggering a process cycle.

pub async fn put_pv(&self, name: &str, value: EpicsValue) -> CaResult<()>

Out-of-band dbPutField on any record field, common fields included — see PvDatabase::put_pv. Ok(()) (no-op) if the database has been dropped.

Unlike Self::post_fields (which writes through put_field_internal and only posts), this is the full put path: a SCAN write moves the record between scan buckets and fires the get_ioint_info hook. C records call dbPutField on their own fields exactly this way — asynRecord’s cancelIOInterruptScan does dbPutField(&scanAddr, DBR_LONG, &passiveScan, 1) on its own .SCAN (asynRecord.c:794-806).

pub fn mint_async_token(&self, name: &str) -> Option<AsyncToken>

Mint an async re-entry token — see PvDatabase::mint_async_token. None if the record is absent or the database has been dropped.

pub fn cancel_async_reentry(&self, name: &str)

Cancel an outstanding async re-entry — see PvDatabase::cancel_async_reentry. No-op if the database is gone.

pub fn new_put_notify() -> (Arc<NotifyWaitSet>, Receiver<()>)

Arm a put-notify wait-set — see PvDatabase::new_put_notify. Database-independent (re-exported associated fn).

pub fn reprocess_on_notify( &self, token: AsyncToken, completion: Receiver<()>, ) -> Option<TaskHandle<()>>

Wire a completion oneshot to an async re-entry — see PvDatabase::reprocess_on_notify. None if the database is gone (the completion receiver is dropped, stranding nothing).

pub async fn put_link_notify( &self, record_name: &str, link_field: &str, link_str: &str, value: EpicsValue, ) -> Option<Receiver<()>>

Issue a non-blocking put-with-completion to an OUT link — see PvDatabase::put_link_notify. None if the database is gone or the source record is missing.

Trait Implementations

impl Clone for AsyncDbHandle

fn clone(&self) -> AsyncDbHandle

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.