internal void Complete(OperationCompletionFlags completionFlags)
{
bool cancelled = (completionFlags & OperationCompletionFlags.OperationCancelled) != 0;
if (cancelled)
{
SocketError = SocketError.OperationAborted;
}
// Reset state.
ExecutionContext?context = _context;
_context = null;
CurrentSocket = null;
CurrentOperation = System.Net.Sockets.SocketAsyncOperation.None;
// Call OnCompleted only when completed async.
bool completedAsync = (completionFlags & OperationCompletionFlags.CompletedSync) == 0;
if (completedAsync)
{
if (context == null)
{
OnCompleted(this);
}
else
{
ExecutionContext.Run(context, s_executionCallback, this);
}
}
}
// Requests the operation to be marked as cancelled.
// Returns CancellationRequestResult.Cancelled when the operation was cancelled synchronously.
// Returns CancellationRequestResult.Requested when the operation is marked for async cancellation.
public CancellationRequestResult RequestCancellationAsync(OperationCompletionFlags flags)
{
Debug.Assert((CompletionFlags & (OperationCompletionFlags.OperationFinished | OperationCompletionFlags.OperationCancelled)) == 0);
CompletionFlags = OperationCompletionFlags.CompletedCanceled | flags;
return(IsExecuting ? CancellationRequestResult.Requested : CancellationRequestResult.Cancelled);
}
// Requests operation to be cancelled.
public void TryCancelAndComplete(OperationCompletionFlags completionFlags = OperationCompletionFlags.None)
{
AsyncContext?context = CurrentAsyncContext;
// When context is null, the operation completed already.
if (context != null)
{
context.TryCancelAndComplete(this, completionFlags);
}
}
internal override void TryCancelAndComplete(AsyncOperation operation, OperationCompletionFlags flags)
{
if (operation.IsReadNotWrite)
{
_readQueue.TryCancelAndComplete(operation, flags);
}
else
{
_writeQueue.TryCancelAndComplete(operation, flags);
}
}
public void GetResult(short token)
{
// Capture values.
SocketError socketError = Saea.SocketError;
OperationCompletionFlags completionFlags = CompletionFlags;
// Reset this object and allow it to be reused.
ResetAndReturnThis();
ThrowForSocketError(socketError, completionFlags);
}
void IThreadPoolWorkItem.Execute()
{
// Capture state.
OperationCompletionFlags completionStatus = CompletionFlags;
// Reset state.
CompletionFlags = OperationCompletionFlags.None;
CurrentAsyncContext = null;
// Complete.
_saea.Complete(completionStatus);
}
public void SetResult(T result, SocketError socketError, OperationCompletionFlags completionFlags)
{
_vts.SetResult(result);
_socketError = socketError;
_completionFlags = completionFlags;
ManualResetEventSlim?mre = Interlocked.Exchange(ref _mre, s_completedSentinel);
// This ManualResetEventSlim is used to wait until the operation completed.
// After that a direct call is made to get the result.
mre?.Set();
}
int IValueTaskSource <int> .GetResult(short token)
{
// Capture values.
int bytesTransferred = Saea.BytesTransferred;
SocketError socketError = Saea.SocketError;
OperationCompletionFlags completionFlags = CompletionFlags;
// Reset this object and allow it to be reused.
ResetAndReturnThis();
ThrowForSocketError(socketError, completionFlags);
return(bytesTransferred);
}
Socket IValueTaskSource <Socket> .GetResult(short token)
{
// Capture values.
Socket?socket = Saea.AcceptSocket;
Saea.AcceptSocket = null; // Don't hold a reference.
SocketError socketError = Saea.SocketError;
OperationCompletionFlags completionFlags = CompletionFlags;
// Reset this object and allow it to be reused.
ResetAndReturnThis();
ThrowForSocketError(socketError, completionFlags);
return(socket !);
}
protected void ReturnThis()
{
AsyncContext asyncContext = CurrentAsyncContext !;
CurrentAsyncContext = null;
CompletionFlags = OperationCompletionFlags.None;
if (IsReadNotWrite)
{
asyncContext.ReturnReadOperation(this);
}
else
{
asyncContext.ReturnWriteOperation(this);
}
}
private static void ThrowForSocketError(SocketError socketError, OperationCompletionFlags completionFlags)
{
if (socketError != System.Net.Sockets.SocketError.Success)
{
bool cancelledByToken = (completionFlags & OperationCompletionFlags.CancelledByToken) != 0;
if (cancelledByToken)
{
throw new OperationCanceledException();
}
bool cancelledByTimeout = (completionFlags & OperationCompletionFlags.CancelledByTimeout) != 0;
if (cancelledByTimeout)
{
socketError = SocketError.TimedOut;
}
throw new SocketException((int)socketError);
}
}
public Result(T value, SocketError socketError, OperationCompletionFlags completionFlags)
{
_value = value;
_socketError = socketError;
_completionFlags = completionFlags;
}
// Cancel AsyncOperation. internal abstract void TryCancelAndComplete(AsyncOperation asyncOperation, OperationCompletionFlags completionFlags);
// Requests cancellation of a queued operation.
// If the operation is not on the queue (because it already completed), NotFound is returned.
// If the operation is not executing, it is removed from the queue and Cancelled is returned.
// If the operation is executing, it stays on the queue, the operation gets marked as cancellation requested,
// and Requested is returned.
protected CancellationRequestResult RequestCancellationAsync(AsyncOperation operation, OperationCompletionFlags flags)
{
CancellationRequestResult result = CancellationRequestResult.NotFound;
if (_tail == operation) // We're the last operation
{
result = operation.RequestCancellationAsync(flags);
if (result == CancellationRequestResult.Cancelled)
{
if (operation.Next == operation) // We're the only operation.
{
_tail = null;
}
else
{
// Update tail
do
{
_tail = _tail.Next;
} while (_tail !.Next != operation);
// Update head
_tail.Next = operation.Next;
}
operation.Next = null;
}
}
else if (_tail != null) // The list is multiple operations and we're not the last
{
ref AsyncOperation nextOperation = ref _tail.Next !;
do
{
if (nextOperation == operation)
{
result = operation.RequestCancellationAsync(flags);
if (result == CancellationRequestResult.Cancelled)
{
nextOperation = operation.Next !;
operation.Next = null;
}
break;
}
nextOperation = ref nextOperation.Next !;
} while (nextOperation != _tail);
}
