OpenCVForUnity.Extensions.SourceToMat.SourceToMatHostWait Class Reference

Host message-loop wait loop for SourceToMat grabber Open waits. More...

Static Public Member Functions
static Task< bool >	WaitUntilOnHostLoopAsync (Func< bool > predicate, InitTimeoutBudget budget, CancellationToken userToken, SynchronizationContext hostLoopContext)
	Waits until predicate is true, pumping the host message loop each tick.
static async Task	YieldHostLoopTickAsync (SynchronizationContext hostLoopContext, CancellationToken userToken)
	Yields one host-loop tick under SourceToMatSynchronizationContextScope.

Detailed Description

Host message-loop wait loop for SourceToMat grabber Open waits.

Host-loop implementation of the wait loop contract in SourceToMatWait (timeout is InitTimeoutBudget.IsExpired; user CancellationToken is cooperative cancellation only). Do not use InitTimeoutBudget.Token as a timeout signal.

Each tick restores the captured SynchronizationContext with SourceToMatSynchronizationContextScope and then calls SourceToMatHostMarshaling.YieldCapturedSynchronizationContextAsync. Nested scopes are supported, so WaitUntilOnHostLoopAsync may be called from inside an Open SourceToMatSynchronizationContextScope.

Prefer WaitUntilOnHostLoopAsync over a hand-written while around SourceToMatHostMarshaling.YieldCapturedSynchronizationContextAsync.

Event-based waits may use TaskCompletionSource<TResult> and CancellationToken.Register on the user token. Drive the outer wait with WaitUntilOnHostLoopAsync on tcs.Task.IsCompleted. When the budget expires, call TrySetCanceled on the source; do not rely on CancelAfter to unblock the wait.

Member Function Documentation

WaitUntilOnHostLoopAsync()

static Task< bool > OpenCVForUnity.Extensions.SourceToMat.SourceToMatHostWait.WaitUntilOnHostLoopAsync ( Func< bool > predicate, InitTimeoutBudget budget, CancellationToken userToken, SynchronizationContext hostLoopContext )

static

Waits until predicate is true, pumping the host message loop each tick.

Parameters

predicate	Returns true when the wait should complete. Must not be null.
budget	Shared initialization timeout budget. Must not be null.
userToken	Cooperative user cancellation token. Not a timeout signal.
hostLoopContext	Captured SynchronizationContext from SourceToMatHostMarshaling.ResolveCapturedSynchronizationContext; may be null.

Returns

true when predicate became true; false when InitTimeoutBudget.IsExpired became true.

Exceptions

ArgumentNullException	Thrown when predicate or budget is null.
OperationCanceledException	Thrown when userToken is canceled.

YieldHostLoopTickAsync()

static async Task OpenCVForUnity.Extensions.SourceToMat.SourceToMatHostWait.YieldHostLoopTickAsync ( SynchronizationContext hostLoopContext, CancellationToken userToken )

static

Yields one host-loop tick under SourceToMatSynchronizationContextScope.

Used by WaitUntilOnHostLoopAsync. Call directly only when a single host-loop tick is required (for example to resume the loop after ConfigureAwait(false)) and a predicate wait is not appropriate. Polling loops should use WaitUntilOnHostLoopAsync.

Parameters

hostLoopContext	Captured SynchronizationContext for the yield; may be null.
userToken	Cooperative user cancellation token.

Returns

A task that completes after one host-loop continuation.

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The documentation for this class was generated from the following file:

• OpenCVForUnity/Assets/OpenCVForUnity/Scripts/Extensions/SourceToMat/Core/SourceToMatHostWait.cs