Clarify threading model

Hello,
I use the following code under Mono JIT compiler version 4.0.2, ubuntu 14.04:

public static void OnMessageReceived(object sender, EventArgs e)
{
Console.WriteLine ("thread pool id {0}",System.Threading.Thread.CurrentThread.ManagedThreadId);
/*
var evt = (WebSocketSharp.MessageEventArgs)e;
//We push the message to the ui thread to process all message in a single thread to avoid multithreading issues
Gtk.Application.Invoke(delegate {
ProcessMessage (evt.RawData);
});*/
}

Later in main :
ws = new WebSocket (uri);
ws.OnMessage += OnMessageReceived;

It seems I receive varying threadIds.
It is problematic because It means I lose the order of message that websockets (being over TCP) should guarantee.
It may happen that the first thread is executed after the second thread, which result in frames delivered in the wrong order.

Thank you

Start by tracing the WebSocket.OnMessage subscription and the OnMessageReceived callback shown in the issue, including the reported Thread.CurrentThread.ManagedThreadId behavior. Document which threading and message-ordering guarantees the library provides, and clarify whether callers must marshal processing to another thread.