Re: why UI gets hangs

From:

"Tom Serface" <tom.nospam@camaswood.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 21 Mar 2008 13:04:27 -0700

Message-ID:

<5D225C74-EF6D-431E-8A47-274646E33C80@microsoft.com>

Hi David,

I think what Aditya is saying is that the OS is checking the program and if
it has not processed messages for some time it puts Not Responding in the
title bar and hangs it up until it starts processing messages again. I
think he was causing the problem, but the symptom is the same as many other
times Vista (or XP but not as often) thinks a program is not doing what it
is supposed to be doing. For sure sleeping for 60 seconds would make it
look like it's not responding.

Tom

"David Wilkinson" <no-reply@effisols.com> wrote in message
news:uSe5E$3iIHA.4320@TK2MSFTNGP06.phx.gbl...

Aditya:

I think you are still confused. The main thread does not check the message
queue of other threads. It checks its own message queue. And it cannot do
that if it is busy or sleeping.

Personally, I usually use worker threads, not UI threads. Then there are
no message queues outside the main thread. It's very simple:

1. The main thread just waits for messages and updates the GUI as
appropriate, but does not do any significant work.

2. The worker thread just works, and uses PostMessage() or SendMessage()
to transmit results back to the main thread.

--
David Wilkinson
Visual C++ MVP