No responses come through after lots of activity

[Nevetos]

Hello nikeee,

I have been using your API wrapper for a while (and made a few additions to it), and its been working like a charm. I just noticed that you started updating it again and I got really excited!

One thing that I have come across is when multiple requests occur around the same time, it will just error out with a null response.

e.g. multiple WhoAmI() requests, or GetClientInfo() requests at once.
I have gotten around this by just sending every request through a queue, so its not a major issue.

Is this something you would be willing/able to fix? As it would make things a little faster and smoother.

[nikeee]

The library uses a queue internally.

Maybe there is a race condition somewhere. I'll see if I can reproduce this.

[nikeee]

I just noticed the QueryClient uses a Queue<T> internally, which is not thread safe.
Replacing it with a ConcurrentQueue<T> may solve a problem (not sure if it would solve yours). But I think it would be better to rewrite the request/response handling entirely.

This seems to originate by the fact that this library is a port of the Node.js library. As Node.js is single-threaded, this was simply overlooked.

[cub1con]

Hi everyone, I think I know what the issue is.

Queue<T> isn't actually the problem.

If Send() is executed in quick succession or two instances at the same time, it is possible that _currentCommand is overwritten before the response is processed in ResponseProcessingLoop() and thus the task will not finish.

You are able to prove it by having multiple threads repeatedly running Send() in quick succession.

I fixed it on my fork by

• having a task with a periodic timer running CheckQueue()
• adding a check in CheckQueue() if _currentCommand != null to return
• adding in Send() d.Task.ContinueWith((o) => { this._currentCommand = null; }); to reset _currentCommand after finishing its task

Maybe not the best solution, but it works without any lockups now. https://github.com/cub1con/TeamSpeak3QueryApi/blob/master/src/TeamSpeak3QueryApi/QueryClient.cs

[nikeee]

Thanks for pointing this out, I'll have a look at this when I've got some spare time.