view src/thread/SDL_systhread.h @ 4158:96ce26f24b01 SDL-1.2

Date: Sun, 7 Sep 2008 15:17:00 +0200 From: c2woody@gmx.net Subject: [SDL] SDL 1.2 doube free/pointer zeroing missing Hello, this is about a crash/debug breakage for the current SDL 1.2 source tree (today's svn checkout, same problem in 1.2.13 and before as far as relevant). In some places memory is free()d but the associated pointer is not zeroed, leading to for example double free()s. For me this happened because SDL_StopEventThread() was executed twice (during restart of the subsystems), once for the close down in SDL_VideoQuit() and once at the startup, right at the beginning of SDL_StartEventLoop(). Thus the code SDL_DestroyMutex(SDL_EventQ.lock); (see SDL_events.c) was called twice and executed the SDL_free(mutex); twice as well, leading to a crash (msvc 64bit for which it was noticed). I've tried to check all other occurrences of SDL_free and similar code in msvc, see the attached patch (udiff against revision 4082). Non-windows only codepaths have neither been checked nor touched. Comments/ideas welcome. Attached patch: NULLifies some pointers after they have been free()d.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 12 Nov 2008 17:23:40 +0000
parents 9fb0eee04dd9
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* These are functions that need to be implemented by a port of SDL */

#ifndef _SDL_systhread_h
#define _SDL_systhread_h

#include "SDL_thread.h"

/* This function creates a thread, passing args to SDL_RunThread(),
   saves a system-dependent thread id in thread->id, and returns 0
   on success.
*/
#ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD
extern int SDL_SYS_CreateThread(SDL_Thread *thread, void *args, pfnSDL_CurrentBeginThread pfnBeginThread, pfnSDL_CurrentEndThread pfnEndThread);
#else
extern int SDL_SYS_CreateThread(SDL_Thread *thread, void *args);
#endif

/* This function does any necessary setup in the child thread */
extern void SDL_SYS_SetupThread(void);

/* This function waits for the thread to finish and frees any data
   allocated by SDL_SYS_CreateThread()
 */
extern void SDL_SYS_WaitThread(SDL_Thread *thread);

/* This function kills the thread and returns */
extern void SDL_SYS_KillThread(SDL_Thread *thread);

#endif /* _SDL_systhread_h */