| .TH "SDL_SemWait" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" |
| .SH "NAME" |
| SDL_SemWait \- Lock a semaphore and suspend the thread if the semaphore value is zero\&. |
| .SH "SYNOPSIS" |
| .PP |
| \fB#include "SDL\&.h" |
| #include "SDL_thread\&.h" |
| .sp |
| \fBint \fBSDL_SemWait\fP\fR(\fBSDL_sem *sem\fR); |
| .SH "DESCRIPTION" |
| .PP |
| \fBSDL_SemWait()\fP suspends the calling thread until either the semaphore pointed to by \fBsem\fR has a positive value, the call is interrupted by a signal or error\&. If the call is successful it will atomically decrement the semaphore value\&. |
| .PP |
| After \fBSDL_SemWait()\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 successful or \fB-1\fR if there was an error (leaving the semaphore unchanged)\&. |
| .SH "EXAMPLES" |
| .PP |
| .PP |
| .nf |
| \f(CWif (SDL_SemWait(my_sem) == -1) { |
| return WAIT_FAILED; |
| } |
| |
| \&.\&.\&. |
| |
| SDL_SemPost(my_sem);\fR |
| .fi |
| .PP |
| .SH "SEE ALSO" |
| .PP |
| \fI\fBSDL_CreateSemaphore\fP\fR, \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemTryWait\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 |
