// The message pump.
// When we start listening for the next request on one thread, we may need to be sure that the
// completion continues on another thread as to not block the current request processing.
// The awaits will manage stack depth for us.
private async Task ProcessRequestsWorker()
{
Debug.Assert(RequestContextFactory != null);
// Allocate and accept context per loop and reuse it for all accepts
using var acceptContext = new AsyncAcceptContext(Listener, RequestContextFactory);
int workerIndex = Interlocked.Increment(ref _acceptorCounts);
while (!Stopping && workerIndex <= _maxAccepts)
{
// Receive a request
RequestContext requestContext;
try
{
requestContext = await Listener.AcceptAsync(acceptContext);
if (!Listener.ValidateRequest(requestContext))
{
// Dispose the request
requestContext.ReleasePins();
requestContext.Dispose();
// If either of these is false then a response has already been sent to the client, so we can accept the next request
continue;
}
}
catch (Exception exception)
{
Debug.Assert(Stopping);
if (Stopping)
{
Log.AcceptErrorStopping(_logger, exception);
}
else
{
Log.AcceptError(_logger, exception);
}
continue;
}
try
{
if (_options.UnsafePreferInlineScheduling)
{
await requestContext.ExecuteAsync();
}
else
{
ThreadPool.UnsafeQueueUserWorkItem(requestContext, preferLocal: false);
}
}
catch (Exception ex)
{
// Request processing failed
// Log the error message, release throttle and move on
Log.RequestListenerProcessError(_logger, ex);
}
}
Interlocked.Decrement(ref _acceptorCounts);
}