private void ExitLockAndTryRunContinuations()
{
var c1 = _continuation;
_continuation = null;
_lock.Exit();
if (c1 is Action action)
{
ContinuationRunner.Run(action);
}
}
static void CallbackImpl(IAsyncResult ar)
{
var thiz = ar.AsyncState as BeginEndAwaiter;
thiz._ar = ar;
var r = Interlocked.Exchange(ref thiz._continuation, COMPLETED);
if (r != null)
{
// continuation is registered before completed, run it now.
ContinuationRunner.Run(r);
}
else
{
// completed before continuation registered.
}
}
public void OnCompleted(Action continuation)
{
var r = Interlocked.CompareExchange(ref _continuation, continuation, null);
if (r == null)
{
// it havn't completed, continuation registered.
}
else if (r == COMPLETED)
{
// it have completed, run the continuation now.
ContinuationRunner.Run(continuation);
}
else
{
throw new Exception("a continuation was already registered");
}
}
public void UnsafeOnCompleted(Action continuation)
{
if (awaitable == COMPLETED)
{
ContinuationRunner.Run(continuation);
}
else if (awaitable is Task <T> task)
{
GetTaskAwaiter(task).UnsafeOnCompleted(continuation);
}
else if (awaitable is ReusableAwaiter <T> ra)
{
ra.UnsafeOnCompleted(continuation);
}
else if (awaitable is IAwaiter <T> ia)
{
ia.UnsafeOnCompleted(continuation);
}
else
{
throw WrongAwaitableType();
}
}
/// <summary>
/// Attempts to transition the exception state.
/// </summary>
/// <param name="result"></param>
/// <returns></returns>
public bool TrySetException(Exception exception)
{
bool lt = false;
if (!this.IsCompleted)
{
_lock.Enter(ref lt);
if (this.IsCompleted)
{
_lock.Exit();
return(false);
}
var c1 = _continuation;
this._continuation = exception;
this.state = State.Completed;
_lock.Exit();
if (c1 is Action action)
{
ContinuationRunner.Run(action);
}
return(true);
}
return(false);
}
private static void RunContinuation(Action c)
{
ContinuationRunner.Run(c);
}
