/// <summary>
/// Schedules the continuation onto the <see cref="Task" /> associated with this <see cref="TaskAwaiter" /> .
/// </summary>
/// <param name="task"> The awaited task. </param>
/// <param name="continuation"> The action to invoke when the await operation completes. </param>
/// <param name="continueOnCapturedContext"> Whether to capture and marshal back to the current context. </param>
/// <exception cref="ArgumentNullException">
/// The
/// <paramref name="continuation" />
/// argument is null (Nothing in Visual Basic).
/// </exception>
/// <exception cref="NullReferenceException">The awaiter was not properly initialized.</exception>
/// <remarks>
/// This method is intended for compiler user rather than use directly in code.
/// </remarks>
internal static void OnCompletedInternal(Task task, Action continuation, bool continueOnCapturedContext)
{
if (continuation == null)
{
throw new ArgumentNullException(nameof(continuation));
}
var syncContext = continueOnCapturedContext ? SynchronizationContext.Current : null;
if (syncContext != null && syncContext.GetType() != typeof(SynchronizationContext))
{
task.ContinueWith
(
_ =>
{
try
{
syncContext.Post(state => ((Action)state)(), continuation);
}
catch (Exception ex)
{
AsyncMethodBuilderCore.ThrowOnContext(ex, null);
}
},
CancellationToken.None,
TaskContinuationOptions.ExecuteSynchronously,
TaskScheduler.Default
);
}
else
{
OnCompletedWithoutSyncContext(task, continuation, continueOnCapturedContext);
}
}
/// <summary>
/// Notifies the current synchronization context that the operation completed.
/// </summary>
private void NotifySynchronizationContextOfCompletion()
{
try
{
_synchronizationContext.OperationCompleted();
}
catch (Exception ex)
{
AsyncMethodBuilderCore.ThrowOnContext(ex, null);
}
}
/// <summary>
/// Schedules the continuation onto the <see cref="Task" /> associated with this <see cref="TaskAwaiter" /> .
/// </summary>
/// <param name="task"> The awaited task. </param>
/// <param name="continuation"> The action to invoke when the await operation completes. </param>
/// <param name="continueOnCapturedContext"> Whether to capture and marshal back to the current context. </param>
/// <exception cref="ArgumentNullException">The
/// <paramref name="continuation" />
/// argument is null (Nothing in Visual Basic).</exception>
/// <exception cref="NullReferenceException">The awaiter was not properly initialized.</exception>
/// <remarks>
/// This method is intended for compiler user rather than use directly in code.
/// </remarks>
internal static void OnCompletedInternal(Task task, Action continuation, bool continueOnCapturedContext)
{
if (continuation == null)
{
throw new ArgumentNullException(nameof(continuation));
}
var syncContext = continueOnCapturedContext ? SynchronizationContext.Current : null;
if (syncContext != null && syncContext.GetType() != typeof(SynchronizationContext))
{
task.ContinueWith(result =>
{
try
{
syncContext.Post(state => ((Action)state)(), continuation);
}
catch (Exception ex)
{
AsyncMethodBuilderCore.ThrowOnContext(ex, null);
}
}, CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);
}
else
{
var scheduler = continueOnCapturedContext ? TaskScheduler.Current : TaskScheduler.Default;
if (task.IsCompleted)
{
Task.Factory.StartNew(state => ((Action)state)(), continuation, CancellationToken.None,
TaskCreationOptions.None, scheduler);
}
else if (scheduler != TaskScheduler.Default)
{
task.ContinueWith(_ => RunNoException(continuation), CancellationToken.None,
TaskContinuationOptions.ExecuteSynchronously, scheduler);
}
else
{
task.ContinueWith(result =>
{
if (IsValidLocationForInlining)
{
RunNoException(continuation);
}
else
{
Task.Factory.StartNew(state => RunNoException((Action)state), continuation,
CancellationToken.None, TaskCreationOptions.None,
TaskScheduler.Default);
}
}, CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);
}
}
}
public void AwaitUnsafeOnCompleted <TAwaiter, TStateMachine>(ref TAwaiter awaiter, ref TStateMachine stateMachine)
where TAwaiter : ICriticalNotifyCompletion
where TStateMachine : IAsyncStateMachine
{
try
{
var completionAction = _coreState.GetCompletionAction(ref this, ref stateMachine);
awaiter.UnsafeOnCompleted(completionAction);
}
catch (Exception ex)
{
AsyncMethodBuilderCore.ThrowOnContext(ex, null);
}
}
private static void RunNoException(Action continuation)
{
if (continuation == null)
{
return;
}
try
{
continuation();
}
catch (Exception ex)
{
AsyncMethodBuilderCore.ThrowOnContext(ex, null);
}
}
/// <summary>
/// Faults the method builder with an exception.
/// </summary>
/// <param name="exception">The exception that is the cause of this fault.</param>
/// <exception cref="ArgumentNullException">
/// The <paramref name="exception" /> argument is null (Nothing in Visual
/// Basic).
/// </exception>
/// <exception cref="InvalidOperationException">The builder is not initialized.</exception>
public void SetException(Exception exception)
{
if (exception == null)
{
throw new ArgumentNullException(nameof(exception));
}
if (_synchronizationContext != null)
{
try
{
AsyncMethodBuilderCore.ThrowOnContext(exception, _synchronizationContext);
}
finally
{
NotifySynchronizationContextOfCompletion();
}
}
else
{
AsyncMethodBuilderCore.ThrowOnContext(exception, null);
}
}
