view docs/man3/SDL_CreateSemaphore.3 @ 614:0b4c3f5ff63d

Date: Wed, 9 Apr 2003 18:21:33 -0230 From: Stephen Anthony <stephena@roadrunner.nf.net> Subject: [SDL] First patch concerning 4.3 and refresh rates OK, here's my first draft of the patch for the above subject. A short explanation: X 4.3 introduces many more modelines than older versions. This would be fine, except it introduces many modes with the *same* resolution but different refresh rates. And SDL won't necessarily pick the one with the highest refresh rate. So this patch restores SDL to X 4.2 functionality. That is, there is only ever one refresh rate *per* resolution, and it is the highest possible. This functionality can be totally disabled by using the environment variable 'SDL_VIDEO_X11_USE_ALL_MODES' set equal to 1.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 20 Apr 2003 05:36:52 +0000
parents e5bc29de3f0a
children 546f7c1eb755
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.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