Akka.Dispatch.ConcurrentQueueMailbox.Run C# (CSharp) Method

        private void Run()
        {
            if (_isClosed)
            {
                return;
            }

            var throughputDeadlineTime = dispatcher.ThroughputDeadlineTime;
            ActorCell.UseThreadContext(() =>
            {
                //if ThroughputDeadlineTime is enabled, start a stopwatch
                if (throughputDeadlineTime.HasValue && throughputDeadlineTime.Value > 0)
                {
                    if (_deadLineTimer != null)
                    {
                        _deadLineTimer.Restart();
                    }
                    else
                    {
                        _deadLineTimer = Stopwatch.StartNew();
                    }
                }

                //we are about to process all enqueued messages
                hasUnscheduledMessages = false;
                Envelope envelope;

                //start with system messages, they have the highest priority
                while (_systemMessages.TryDequeue(out envelope))
                {
                    Mailbox.DebugPrint(ActorCell.Self + " processing system message " + envelope);
                    // TODO: Add + " with " + ActorCell.GetChildren());
                    dispatcher.SystemDispatch(ActorCell, envelope);
                }

                //we should process x messages in this run
                var left = dispatcher.Throughput;

                //try dequeue a user message
                while (!IsSuspended && !_isClosed && _userMessages.TryDequeue(out envelope))
                {
                    Mailbox.DebugPrint(ActorCell.Self + " processing message " + envelope);

                    //run the receive handler
                    dispatcher.Dispatch(ActorCell, envelope);

                    //check if any system message have arrived while processing user messages
                    if (_systemMessages.TryDequeue(out envelope))
                    {
                        //handle system message
                        Mailbox.DebugPrint(ActorCell.Self + " processing system message " + envelope);
                        // TODO: Add + " with " + ActorCell.GetChildren());
                        dispatcher.SystemDispatch(ActorCell, envelope);
                        break;
                    }
                    left--;
                    if (_isClosed)
                        return;

                    //if deadline time have expired, stop and break
                    if (throughputDeadlineTime.HasValue && throughputDeadlineTime.Value > 0 &&
                        _deadLineTimer.Elapsed.Ticks > throughputDeadlineTime.Value)
                    {
                        _deadLineTimer.Stop();
                        break;
                    }

                    //we are done processing messages for this run
                    if (left == 0)
                    {
                        break;
                    }
                }

                Interlocked.Exchange(ref status, MailboxStatus.Idle);

                //there are still messages that needs to be processed
                if (_systemMessages.Count > 0 || (!IsSuspended && _userMessages.Count > 0))
                {
                    //we still need has unscheduled messages for external info.
                    //e.g. repointable actor ref uses it
                    //TODO: will this be enough for external parties to work?
                    hasUnscheduledMessages = true;

                    //this is subject of a race condition
                    //but that doesn't matter, since if the above "if" misses
                    //the "Post" that adds the new message will still schedule
                    //this specific call is just to deal with existing messages
                    //that wasn't scheduled due to dispatcher throughput being reached
                    //or system messages arriving during user message processing
                    Schedule();
                }
            });
        }