internal static void WaitForResponse (HttpRequestMessage request, ExpectedResponse arrival, TimeSpan requestTimeout, AmqpModelContainer model, bool closeModel, CancellationToken cancellationToken, TaskCompletionSource<HttpResponseMessage> taskSource, Action cleanup)
{
//Spawning a new task to wait on the MRESlim is slower than using ThreadPool.RegisterWaitForSingleObject
//
//TODO: Test task vs RegisterWaitForSingleObject modes in a super fast network environment with 40, 100, 200 all the way to 1000 threads to see what method has fastest throughput.
#if WAIT_FOR_RESPONSE_IN_TASK_MODE
//Wait for response arrival event on a new task
Task.Factory.StartNew(() =>
{
bool succeeded = arrival.ReceivedEvent.Wait(
requestTimeout.TotalMilliseconds > Int32.MaxValue ? TimeSpan.FromMilliseconds(Int32.MaxValue) : requestTimeout /* Covers InfiniteTimeSpan */,
cancellationToken);
Thread.MemoryBarrier(); //Ensure non-cached versions of arrival are read
//It failed either because it timed out or was cancelled
//HttpClient treats both scenarios the same way.
try
{
if (closeModel) model.Close();
SetResponseResult(request, !succeeded, arrival, taskSource);
}
catch
{
//TODO: Log this:
// the code in the try block should be safe so this catch block should never be called,
// hoewever, this delegate is called on a separate thread and should be protected.
}
finally
{
CleanupMessagingResources(correlationId, arrival);
}
}, cancellationToken);
#else
//Wait for response arrival event on the ThreadPool:
var localVariableInitLock = new object();
lock (localVariableInitLock)
{
//TODO: Have cancellationToken signal WaitHandle so that threadpool stops waiting.
RegisteredWaitHandle callbackHandle = null;
callbackHandle = ThreadPool.RegisterWaitForSingleObject(arrival.ReceivedEvent.WaitHandle,
(state, timedOut) =>
{
//TODO: Investigate, this memorybarrier might be unnecessary since the thread is released from the threadpool
//after deserializationException and responsePacket is set.
Thread.MemoryBarrier(); //Ensure non-cached versions of arrival are read
try
{
//TODO: Check Cancelation Token when it's implemented
if (closeModel) model.Close();
SetResponseResult(request, timedOut, arrival, taskSource);
lock (localVariableInitLock)
{
callbackHandle.Unregister(null);
}
}
catch
{
//TODO: Log this:
// the code in the try block should be safe so this catch block should never be called,
// hoewever, this delegate is called on a separate thread and should be protected.
}
finally
{
cleanup();
}
},
null,
requestTimeout == System.Threading.Timeout.InfiniteTimeSpan ? System.Threading.Timeout.Infinite : (long)requestTimeout.TotalMilliseconds,
true);
}
#endif
}
private void CloseAmqpModel(AmqpModelContainer model)
{
if (model != null)
{
model.Close();
}
}
