view docs/man3/SDL_SemWait.3 @ 2226:0e70b4b8cf84

Date: Sat, 11 Aug 2007 02:03:16 +0200 (CEST) From: couriersud arcor.de To: slouken@libsdl.org Subject: Directfb driver for SDL1.3 Hi, the attachment contains a patch for a SDL1.3 directfb driver. It supports: - Renderer "directfb": Hardware acceleration as supported by the underlying directfb driver. With a radeon X850, testsprite2 runs at 50% to 70% of OpenGL (X11, dri) performance. Also supports hardware accelerated yuv overlays. This must be enabled by sett ing: export SDL_DIRECTFB_YUV_DIRECT=1 - Renderer "opengl" Supports software opengl using mesa opengl (make linux-directfb). Some more information may be found in README.DirectFB There will certainly still be some bugs, and there is some debug code around. When I find some time, I will compile against directfb-0.9.25 as distributed with ubuntu 7.04. The diff also contains a fix for SDL_LockYUVOverlay fixing a bug in *pixels and pitches initialization. Kind regards, couriersud
author Sam Lantinga <slouken@libsdl.org>
date Sat, 11 Aug 2007 21:51:19 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.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