为什么异步C＃套接字代码中的异常在没有堆栈跟踪的情况下终止程序？

Question

I have a C# Windows UI program, with a Window1 : Window in whose constructor I start an asynchronous socket server that while (true) { /* BeginAccept */ } and streams data to any client that connects using BeginSend and EndSend .

If one of the clients is forcibly disconnected Socket.EndSend throws an exception (a bit surprisingly ObjectDisposedException instead of SocketException , but whatever).

That exception terminates my whole program (closing the window) but does not print a stack trace!

Instead, I only get an innocent

A first chance exception of type 'System.ObjectDisposedException' occurred in System.dll

message in the Ouput panel.

If exceptions are silenced like this but still crash my program without stack trace, how am I supposed to find where the exception is thrown?

Answer 1

Well, it depends on what version of .NET you are using. But, that's generally what's documented will happen.

If you don't want that to happen, use top-level exception handlers in your thread entry points and "swallow" the exception--logging it or whatever else you want to do before exiting the thread.

In terms of methods like BeginSend , the method given to BeginSend (or BeginAccept for that matter) is effectively the thread entry-point. eg

listener.BeginAcceptTcpClient(OnAccept, null);
//...

private static void OnAccept(IAsyncResult ar)
{
    try {
        var tcpClient = listener.EndAcceptTcpClient(ar);
        //...
    } catch(Exception ex)
    {
        Dump(ex);
        return;
    }
}