Re: [Mingw-users] Re: CreateThread quirk under mingw 3.4.2

[Luke D. <cod...@ho...>]

----- Original Message ----- 
From: "Daniel Miller" <da...@im...>
To: <min...@li...>
Sent: Wednesday, April 06, 2005 4:24 AM
Subject: [Mingw-users] Re: CreateThread quirk under mingw 3.4.2


> "Luke Dunstan" <cod...@ho...> wrote in
> news:BAY...@ph...l:
>
>>
>> "-mthreads" is the equivalent switch, but I doubt it will make a
>> difference because it really only affects C++ exception handling.
>> Could you provide a small but complete example that demonstrates the
>> problem?
>>
>> I think you also need to use _beginthread() instead of CreateThread().
>>
>> Luke
>>
>
> Okay, at the risk of posting too large of a message, I'm enclosing a
> stripped-down version of my program.  It deletes all the graphics-drawing
> code, but includes everything else.

Your message is not too large. I was hoping that you could provide an 
example that compiles and runs, and visibly demonstrates the problem, but 
your example doesn't actually compile without changes so I assume you 
haven't tried running it either. By adding a small piece of drawing code to 
the thread, I can see that the thread runs normally and draws in the window 
(with no fprintf). This suggests that there is a bug in your program, and 
the fact that it works in MSVC may be accidental. Perhaps try posting again?

Luke

>
> I also switch to _beginthread() after reading the notes in msdn, but that
> has had no effect on program operation.  Again, if I compile under VC6
> with:
>
>    cl /W3 /O2 /G4 /MT rainbowt.cpp user32.lib gdi32.lib
>
> this program works fine.  If I compile under MinGW 3.4.2 with:
>
>    g++ -Wall -s -O3 -mthreads rainbowt.cpp -o rainbowt.exe -lgdi32
>
> the program runs, the main window is drawn, but no output ever appears.
> However, if I uncomment the file-printing debug code at the end of this
> code, then the g++ application runs just fine!!!  Even eliminating the
> fprintf statement, however, puts me back to nothing drawing.  I have *no*
> idea what fprintf has to do with any of this...  I had included it just
> to find out whether or not my main thread was even being executed...
>
>    Dan