Mercurial > sdl-ios-xcode
view test/testtimer.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 | 290b5baf2fca |
children | 782fd950bd46 c121d94672cb |
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/* Test program to check the resolution of the SDL timer on the current platform */ #include <stdlib.h> #include <stdio.h> #include "SDL.h" #define DEFAULT_RESOLUTION 1 static int ticks = 0; static Uint32 SDLCALL ticktock(Uint32 interval) { ++ticks; return(interval); } static Uint32 SDLCALL callback(Uint32 interval, void *param) { printf("Timer %d : param = %d\n", interval, (int)(uintptr_t)param); return interval; } int main(int argc, char *argv[]) { int desired; SDL_TimerID t1, t2, t3; if ( SDL_Init(SDL_INIT_TIMER) < 0 ) { fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError()); return(1); } /* Start the timer */ desired = 0; if ( argv[1] ) { desired = atoi(argv[1]); } if ( desired == 0 ) { desired = DEFAULT_RESOLUTION; } SDL_SetTimer(desired, ticktock); /* Wait 10 seconds */ printf("Waiting 10 seconds\n"); SDL_Delay(10*1000); /* Stop the timer */ SDL_SetTimer(0, NULL); /* Print the results */ if ( ticks ) { fprintf(stderr, "Timer resolution: desired = %d ms, actual = %f ms\n", desired, (double)(10*1000)/ticks); } /* Test multiple timers */ printf("Testing multiple timers...\n"); t1 = SDL_AddTimer(100, callback, (void*)1); if(!t1) fprintf(stderr,"Could not create timer 1: %s\n", SDL_GetError()); t2 = SDL_AddTimer(50, callback, (void*)2); if(!t2) fprintf(stderr,"Could not create timer 2: %s\n", SDL_GetError()); t3 = SDL_AddTimer(233, callback, (void*)3); if(!t3) fprintf(stderr,"Could not create timer 3: %s\n", SDL_GetError()); /* Wait 10 seconds */ printf("Waiting 10 seconds\n"); SDL_Delay(10*1000); printf("Removing timer 1 and waiting 5 more seconds\n"); SDL_RemoveTimer(t1); SDL_Delay(5*1000); SDL_RemoveTimer(t2); SDL_RemoveTimer(t3); SDL_Quit(); return(0); }