.TH "SDL_CreateSemaphore" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 

.SH "NAME"

SDL_CreateSemaphore \- Creates a new semaphore and assigns an initial value to it\&.

.SH "SYNOPSIS"

.PP

\fB#include "SDL\&.h"

#include "SDL_thread\&.h"

.sp

\fBSDL_sem *\fBSDL_CreateSemaphore\fP\fR(\fBUint32 initial_value\fR);

.SH "DESCRIPTION"

.PP

\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\&.

.SH "RETURN VALUE"

.PP

Returns a pointer to an initialized semaphore or \fBNULL\fR if there was an error\&.

.SH "EXAMPLES"

.PP

.PP

.nf

\f(CWSDL_sem *my_sem;

my_sem = SDL_CreateSemaphore(INITIAL_SEM_VALUE);

if (my_sem == NULL) {

        return CREATE_SEM_FAILED;

}\fR

.fi

.PP

.SH "SEE ALSO"

.PP

\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

...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00