Struct ScanOnceQueue 

pub struct ScanOnceQueue { /* private fields */ }

The scanOnce facility: one bounded ring drained by one worker thread.

Dropping it stops and joins the worker.

Implementations

impl ScanOnceQueue

pub fn new() -> Self

Build with the C default capacity (onceQueueSize, dbScan.c:64).

pub fn with_capacity(capacity: usize) -> Self

Build with an explicit ring capacity (clamped to at least 1).

pub fn start(&self)

Create the drain thread now — C initOnce (dbScan.c:768-780), which scanInit calls once the menuScan count is known and before it spawns the periodic threads (dbScan.c:201-205).

The worker otherwise appears at the first scanOnce, which is late enough that an IOC that has never run a one-shot has no scanOnce thread where C always does — visible in taskwdShow, and it defers C’s fail-at-init contract for a thread that cannot be created. Calling this at the port’s own scanInit is what removes the difference; it stays idempotent, so the lazy path is still the safety net for a scanOnce that arrives before any IOC init.

pub fn handle(&self) -> ScanOnceHandle

A cheap, clonable submission handle (see ScanOnceHandle).

pub fn scan_once(&self, cb: OnceCallback) -> Result<(), ScanOnceOverflow>

Enqueue cb for one-shot processing — convenience wrapper over ScanOnceHandle::scan_once.

pub fn overflow_count(&self) -> u64

Lifetime overflow count — C onceQOverruns (dbScan.c:67).

pub fn stats(&self, reset: bool) -> ScanOnceQueueStats

C scanOnceQueueStatus (dbScan.c:734-751): sample the ring and, when reset is set, clear the high-water mark.

Trait Implementations

impl Default for ScanOnceQueue

fn default() -> Self

Returns the “default value” for a type.

impl Drop for ScanOnceQueue

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.