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Diffstat (limited to 'distrib/sdl-1.2.15/docs/man3/SDL_SemTryWait.3')
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diff --git a/distrib/sdl-1.2.15/docs/man3/SDL_SemTryWait.3 b/distrib/sdl-1.2.15/docs/man3/SDL_SemTryWait.3 new file mode 100644 index 0000000..aee9aff --- /dev/null +++ b/distrib/sdl-1.2.15/docs/man3/SDL_SemTryWait.3 @@ -0,0 +1,41 @@ +.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 |