Re: C++ COM STA model

From:
"Igor Tandetnik" <itandetnik@mvps.org>
Newsgroups:
microsoft.public.vc.language
Date:
Mon, 24 Mar 2008 08:29:21 -0400
Message-ID:
<ujlu0qajIHA.5208@TK2MSFTNGP04.phx.gbl>
"George" <George@discussions.microsoft.com> wrote in message
news:568AFEA1-D919-4EE8-95C1-92FC7BDC5684@microsoft.com

I think the function call through public method of interface
(retrieved from QueryInterface) is translated into message pump. Is
that correct?


Like I said, if you make an out-of-apartment COM call from STA thread,
COM does run a modal message pump while waiting for the call to return.
See also IMessageFilter

How does message pump work?


Read about GetMessage, DispatchMessage in your favorite Windows
programming textbook.

Like enqueue a message into a double ended
queue, one end is the function call, the other end is the component
itself?


It's a queue of window messages, not of COM calls. In some cases, COM
sends a message to that special hidden window to notify it that an
incoming COM call has arrived and is waiting to be processed.

See also

http://support.microsoft.com/kb/q150777/
http://msdn2.microsoft.com/en-us/library/ms809971.aspx

--
With best wishes,
    Igor Tandetnik

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