| 1 | .TH "SDL_CreateSemaphore" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" |
| 2 | .SH "NAME" |
| 3 | SDL_CreateSemaphore \- Creates a new semaphore and assigns an initial value to it\&. |
| 4 | .SH "SYNOPSIS" |
| 5 | .PP |
| 6 | \fB#include "SDL\&.h" |
| 7 | #include "SDL_thread\&.h" |
| 8 | .sp |
| 9 | \fBSDL_sem *\fBSDL_CreateSemaphore\fP\fR(\fBUint32 initial_value\fR); |
| 10 | .SH "DESCRIPTION" |
| 11 | .PP |
| 12 | \fBSDL_CreateSemaphore()\fP creates a new semaphore and initializes it with the value \fBinitial_value\fR\&. Each locking operation on the semaphore by \fISDL_SemWait\fR, \fISDL_SemTryWait\fR or \fISDL_SemWaitTimeout\fR will atomically decrement the semaphore value\&. The locking operation will be blocked if the semaphore value is not positive (greater than zero)\&. Each unlock operation by \fISDL_SemPost\fR will atomically increment the semaphore value\&. |
| 13 | .SH "RETURN VALUE" |
| 14 | .PP |
| 15 | Returns a pointer to an initialized semaphore or \fBNULL\fR if there was an error\&. |
| 16 | .SH "EXAMPLES" |
| 17 | .PP |
| 18 | .PP |
| 19 | .nf |
| 20 | \f(CWSDL_sem *my_sem; |
| 21 | |
| 22 | my_sem = SDL_CreateSemaphore(INITIAL_SEM_VALUE); |
| 23 | |
| 24 | if (my_sem == NULL) { |
| 25 | return CREATE_SEM_FAILED; |
| 26 | }\fR |
| 27 | .fi |
| 28 | .PP |
| 29 | .SH "SEE ALSO" |
| 30 | .PP |
| 31 | \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemWait\fP\fR, \fI\fBSDL_SemTryWait\fP\fR, \fI\fBSDL_SemWaitTimeout\fP\fR, \fI\fBSDL_SemPost\fP\fR, \fI\fBSDL_SemValue\fP\fR |
| 32 | .\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00 |