view docs/man3/SDL_CreateSemaphore.3 @ 717:42ed44b2c8b6

Date: Sun, 14 Sep 2003 17:04:55 -0400 From: Philip D.S. Thoren <pthoren@cs.uml.edu> Reply-To: "sdl@libsdl.org" <sdl@libsdl.org> To: "sdl@libsdl.org" <sdl@libsdl.org> Subject: [SDL] BUG in src/video/windx5/SDL_dx5events.c I tracked down a bug that crashed my program on Windows *all* the time. FILE: src/video/windx5/SDL_dx5events.c FUNCTION: handle_mouse BUG: SDL_PublicSurface is being dereferenced when it is NULL. I added the following to the very begining of handle_mouse and it solved my crashing problems: if (SDL_PublicSurface == NULL) return; ~ Philip D.S. Thoren
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 15 Sep 2003 13:51:25 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.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