Mercurial > sdl-ios-xcode
view docs/man3/SDL_SemTryWait.3 @ 4204:976bc19f8f6b SDL-1.2
1.2 Quartz video: Ripped out QuickDraw and QuickTime.
Now we use the software path for YUV, and CoreGraphics for 2D stuff.
There are several other 10.6 fixes in here, too...now we can build a 64-bit
SDL for Snow Leopard!
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Mon, 21 Sep 2009 06:08:23 +0000 |
parents | 4e3b250c950e |
children | 1238da4a7112 |
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.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