Mercurial > sdl-ios-xcode
view docs/man3/SDL_SemTryWait.3 @ 1120:8e1fde455471
Patch by me to fix crash described below.
--ryan.
To: sdl@libsdl.org
From: Rainer Deyke <rainerd@eldwood.com>
Date: Tue, 16 Aug 2005 01:08:18 -0600
Subject: [SDL] Bug report: SDL_CreateRGBSurface with SDL_HWSURFACE crashes
If SDL is in full-screen mode with a hardware video surface on OS X,
SDL_CreateRGBSurface with SDL_HWSURFACE crashes. The crash occurs on
line 109 of SDL_Surface.c. This was tested on OS X 10.3.9 with both SDL
1.2.8 and the latest CVS. Here is a small C++ program that demonstrates
the problem:
#include "SDL.h"
#include <stdio.h>
namespace {
void wait_for_key()
{
SDL_Event e;
printf("%d\n", SDL_GetAppState());
while (SDL_WaitEvent(&e)) {
if (e.type == SDL_KEYDOWN || e.type == SDL_QUIT) return;
}
}
}
int main(int, char *[])
{
SDL_Init(SDL_INIT_VIDEO);
SDL_Surface *screen
= SDL_SetVideoMode(640, 480, 32, SDL_FULLSCREEN | SDL_HWSURFACE);
SDL_Surface *s = SDL_CreateRGBSurface(SDL_HWSURFACE, 640, 480, 32,
screen->format->Rmask, screen->format->Gmask,
screen->format->Bmask, screen->format->Amask);
wait_for_key();
if (s) SDL_FreeSurface(s);
SDL_Quit();
printf("Success!\n");
return 0;
}
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Thu, 18 Aug 2005 06:46:32 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
line wrap: on
line source
.TH "SDL_SemTryWait" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_SemTryWait\- Attempt to lock a semaphore but don\&'t suspend the thread\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" #include "SDL_thread\&.h" .sp \fBint \fBSDL_SemTryWait\fP\fR(\fBSDL_sem *sem\fR); .SH "DESCRIPTION" .PP \fBSDL_SemTryWait\fP is a non-blocking varient of \fI\fBSDL_SemWait\fP\fR\&. If the value of the semaphore pointed to by \fBsem\fR is positive it will atomically decrement the semaphore value and return 0, otherwise it will return \fBSDL_MUTEX_TIMEOUT\fR instead of suspending the thread\&. .PP After \fBSDL_SemTryWait\fP is successful, the semaphore can be released and its count atomically incremented by a successful call to \fISDL_SemPost\fR\&. .SH "RETURN VALUE" .PP Returns \fB0\fR if the semaphore was successfully locked or either \fBSDL_MUTEX_TIMEOUT\fR or \fB-1\fR if the thread would have suspended or there was an error, respectivly\&. .PP If the semaphore was not successfully locked, the semaphore will be unchanged\&. .SH "EXAMPLES" .PP .PP .nf \f(CWres = SDL_SemTryWait(my_sem); if (res == SDL_MUTEX_TIMEOUT) { return TRY_AGAIN; } if (res == -1) { return WAIT_ERROR; } \&.\&.\&. SDL_SemPost(my_sem);\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_CreateSemaphore\fP\fR, \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemWait\fP\fR, \fI\fBSDL_SemWaitTimeout\fP\fR, \fI\fBSDL_SemPost\fP\fR, \fI\fBSDL_SemValue\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00