public async Task <CFHTTPMessage> Open(WorkerThread worker,
CancellationToken cancellationToken)
{
this.worker = worker;
openTcs = new TaskCompletionSource <CFHTTPMessage> ();
openCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
openCts.Token.Register(() => OnCanceled());
mainThread = Thread.CurrentThread;
try {
if (worker != null)
{
await worker.Post(c => DoOpen(), openCts.Token);
}
else
{
DoOpen();
}
var result = await openTcs.Task;
return(result);
} finally {
openCts.Dispose();
openCts = null;
}
}
/*
* Under normal circumstances, we're running on the main thread,
* so we could do without all the locking.
*
* However, we're exposing a System.IO.Stream to the user, who
* might be using ConfigureAwait (false).
*
* Ideally, consumers of the API should either only access the
* stream from the main thread or use a 'WorkerThread'.
*
*/
void StartOperation(IOperation operation)
{
bool isCrossThread;
lock (syncRoot) {
if (!open || (currentOperation != null))
{
throw new InvalidOperationException();
}
if (canceled)
{
operation.SetCanceled();
return;
}
if (lastError != null)
{
operation.SetException(lastError);
return;
}
if (completed)
{
operation.SetCompleted();
return;
}
currentOperation = operation;
isCrossThread = CheckCrossThreadAccess();
if (!bytesAvailable)
{
return;
}
}
/*
* The server already sent us the OnBytesAvailable() event
* before the operation started.
*
* If we have a worker thread, we simply handle it there and
* don't have to worry about any locking or anything.
*
*/
if ((worker != null) && !Thread.CurrentThread.Equals(workerThread))
{
worker.Post(() => {
if (bytesAvailable)
{
OnBytesAvailable(false);
}
}
);
return;
}
/*
* We're on the main / worker thread, so we don't need any locking.
*/
if (!isCrossThread)
{
OnBytesAvailable(false);
return;
}
/*
* Ok, now it's getting complicated: we're neither on the main nor on
* the worker thread, so we need to do some locking here.
*
*/
Monitor.Enter(syncRoot);
if (!bytesAvailable)
{
Monitor.Exit(syncRoot);
return;
}
OnBytesAvailable(true);
}
public override void Send(SendOrPostCallback d, object state)
{
worker.Post(() => d(state)).Wait();
}
