What is a good way to shutdown Threads blocked on NamedPipeServer#WaitForConnection?

Solution 1:

This is cheesy, but it is the only method I have gotten to work. Create a 'fake' client and connect to your named pipe to move past the WaitForConnection. Works every time.

Also, even Thread.Abort() did not fix this issue for me.

_pipeserver.Dispose();
_pipeserver = null;

using (NamedPipeClientStream npcs = new NamedPipeClientStream("pipename")) 
{
    npcs.Connect(100);
}

Solution 2:

Switch to the asynchronous version: BeginWaitForConnection.

If it does ever complete, you'll need a flag so the completion handler can just call EndWaitForConnection absorbing any exceptions and exiting (call End... to ensure any resources are able to be cleaned up).

Solution 3:

You can use the following extension method. Note the inclusion of 'ManualResetEvent cancelEvent' - you can set this event from another thread to signal that the waiting connect method should abort now and close the pipe. Include cancelEvent.Set() when setting m_bShutdownRequested and the shutdown should be relatively graceful.

    public static void WaitForConnectionEx(this NamedPipeServerStream stream, ManualResetEvent cancelEvent)
    {
        Exception e = null;
        AutoResetEvent connectEvent = new AutoResetEvent(false);
        stream.BeginWaitForConnection(ar =>
        {
            try
            {
                stream.EndWaitForConnection(ar);
            }
            catch (Exception er)
            {
                e = er;
            }
            connectEvent.Set();
        }, null);
        if (WaitHandle.WaitAny(new WaitHandle[] { connectEvent, cancelEvent }) == 1)
            stream.Close();
        if (e != null)
            throw e; // rethrow exception
    }