Mercurial > sdl-ios-xcode
view src/timer/dc/SDL_systimer.c @ 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 | 92947e3a18db |
children | 782fd950bd46 c121d94672cb a1b03ba2fcd0 |
line wrap: on
line source
/* 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" #ifdef SDL_TIMER_DC #include <kos.h> #include "SDL_thread.h" #include "SDL_timer.h" #include "../SDL_timer_c.h" static unsigned start; /* jif = ms * HZ /1000 ms = jif * 1000/HZ */ void SDL_StartTicks(void) { /* Set first ticks value */ start = jiffies; } Uint32 SDL_GetTicks(void) { return((jiffies-start)*1000/HZ); } void SDL_Delay(Uint32 ms) { thd_sleep(ms); } /* Data to handle a single periodic alarm */ static int timer_alive = 0; static SDL_Thread *timer = NULL; static int RunTimer(void *unused) { while ( timer_alive ) { if ( SDL_timer_running ) { SDL_ThreadedTimerCheck(); } SDL_Delay(10); } return(0); } /* This is only called if the event thread is not running */ int SDL_SYS_TimerInit(void) { timer_alive = 1; timer = SDL_CreateThread(RunTimer, NULL); if ( timer == NULL ) return(-1); return(SDL_SetTimerThreaded(1)); } void SDL_SYS_TimerQuit(void) { timer_alive = 0; if ( timer ) { SDL_WaitThread(timer, NULL); timer = NULL; } } int SDL_SYS_StartTimer(void) { SDL_SetError("Internal logic error: DC uses threaded timer"); return(-1); } void SDL_SYS_StopTimer(void) { return; } #endif /* SDL_TIMER_DC */