public void Receive(Func <IReceiveContext, Action <IReceiveContext> > callback, TimeSpan timeout) { int messageCount = Count; bool waited = false; if (messageCount == 0) { if (!_messageReady.WaitOne(timeout, true)) { return; } waited = true; } bool monitorExitNeeded = true; if (!Monitor.TryEnter(_messageLock, timeout)) { return; } try { for (LinkedListNode <LoopbackMessage> iterator = _messages.First; iterator != null; iterator = iterator.Next) { if (iterator.Value != null) { LoopbackMessage message = iterator.Value; if (message.ExpirationTime.HasValue && message.ExpirationTime <= DateTime.UtcNow) { _messages.Remove(iterator); return; } ReceiveContext context = ReceiveContext.FromBodyStream(message.Body); context.SetMessageId(message.MessageId); context.SetContentType(message.ContentType); context.SetOriginalMessageId(message.OriginalMessageId); if (message.ExpirationTime.HasValue) { context.SetExpirationTime(message.ExpirationTime.Value); } Action <IReceiveContext> receive = callback(context); if (receive == null) { continue; } _messages.Remove(iterator); using (message) { Monitor.Exit(_messageLock); monitorExitNeeded = false; receive(context); return; } } } if (waited) { return; } // we read to the end and none were accepted, so we are going to wait until we get another in the queue _messageReady.WaitOne(timeout, true); } finally { if (monitorExitNeeded) { Monitor.Exit(_messageLock); } } }