How to interrupt an IO bound thread.

Question

I am opening a System.Diagnostic.Process to read the stdout from a process and I would like to be able to interrupt it after a certain elapsed time.

try
{
    output = outputStream.ReadToEnd();
}
catch (ThreadInterruptedException e)
{
    return;
}

That doesn't work since the thread is in the ReadToEnd() method. I attempted to close the stream from the main thread, hoping that'd EOF the Read method, but that didn't work either.

Answer 1

I would hazard aborting

try 
{ 
    Timer watchdog = new Timer(abortMe, Thread.CurrentThread, timeout, Timeout.Infinite);
    output = outputStream.ReadToEnd(); 
    watchdog.Dispose();
} 
catch (ThreadAbortException e) 
{ 
    return; 
} 

private void abortMe(object state)
{
    ((Thread)state).Abort()
}

Actually I succeed in closing the stream when I work with TCP and UDP sockets: it triggers a SocketException and the thread gets successfully interrupted.

By the way, should your stream be an input stream? You're not supposed to read an output stream...

Answer 2

You could try calling Dispose() on the Process object as well as on the stream. I imagine outputStream is linked to the Process instance via Process.StandardOutput so this ought to have the desired effect.

EDIT - see my answer to this question - this area of .Net I/O is prone to deadlocking, prefer async I/O if that is an option.