public Task <bool> WaitToReadAsync(CancellationToken cancellationToken)
{
if (cancellationToken.IsCancellationRequested)
{
return(Task.FromCanceled <bool>(cancellationToken));
}
switch (_task.Status)
{
case TaskStatus.Faulted:
case TaskStatus.Canceled:
return(s_falseTask);
case TaskStatus.RanToCompletion:
return(_completion.Task.IsCompleted ? s_falseTask : s_trueTask);
default:
return(_task.ContinueWith((_, s) =>
{
TaskChannel <T> thisRef = (TaskChannel <T>)s;
return
thisRef._task.Status == TaskStatus.RanToCompletion &&
!thisRef._completion.Task.IsCompleted;
}, this, CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default));
}
}
public ValueTask <T> ReadAsync(CancellationToken cancellationToken)
{
if (cancellationToken.IsCancellationRequested)
{
return(new ValueTask <T>(Task.FromCanceled <T>(cancellationToken)));
}
switch (_task.Status)
{
case TaskStatus.Faulted:
return(new ValueTask <T>(_task));
case TaskStatus.Canceled:
return(new ValueTask <T>(Task.FromException <T>(CreateInvalidCompletionException())));
case TaskStatus.RanToCompletion:
return(new ValueTask <T>(TransitionRead() ?
_task :
Task.FromException <T>(CreateInvalidCompletionException())));
default:
return(new ValueTask <T>(_task.ContinueWith((_, s) =>
{
TaskChannel <T> thisRef = (TaskChannel <T>)s;
return thisRef.ReadAsync(CancellationToken.None).GetAwaiter().GetResult();
}, this, CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default)));
}
}
