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