Mercurial > sdl-ios-xcode
annotate src/thread/os2/SDL_sysmutex.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 | d910939febfa |
| children | 782fd950bd46 c121d94672cb a1b03ba2fcd0 |
| rev | line source |
|---|---|
| 1190 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
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Sam Lantinga <slouken@libsdl.org>
parents:
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changeset
|
3 Copyright (C) 1997-2006 Sam Lantinga |
| 1190 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
|
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6 modify it under the terms of the GNU Lesser General Public |
| 1190 | 7 License as published by the Free Software Foundation; either |
|
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Sam Lantinga <slouken@libsdl.org>
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|
8 version 2.1 of the License, or (at your option) any later version. |
| 1190 | 9 |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
|
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Sam Lantinga <slouken@libsdl.org>
parents:
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13 Lesser General Public License for more details. |
| 1190 | 14 |
|
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Sam Lantinga <slouken@libsdl.org>
parents:
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15 You should have received a copy of the GNU Lesser General Public |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1190
diff
changeset
|
16 License along with this library; if not, write to the Free Software |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
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diff
changeset
|
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 1190 | 18 |
| 19 Sam Lantinga | |
| 20 slouken@libsdl.org | |
| 21 */ | |
|
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22 #include "SDL_config.h" |
| 1190 | 23 |
| 24 /* Mutex functions using the OS/2 API */ | |
| 25 | |
| 26 #define INCL_DOSERRORS | |
| 27 #define INCL_DOSSEMAPHORES | |
| 28 #include <os2.h> | |
| 29 | |
| 30 #include "SDL_mutex.h" | |
| 31 | |
| 32 | |
| 33 struct SDL_mutex { | |
| 34 HMTX hmtxID; | |
| 35 }; | |
| 36 | |
| 37 /* Create a mutex */ | |
| 38 DECLSPEC SDL_mutex * SDLCALL SDL_CreateMutex(void) | |
| 39 { | |
| 40 SDL_mutex *mutex; | |
| 41 APIRET ulrc; | |
| 42 | |
| 43 /* Allocate mutex memory */ | |
|
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44 mutex = (SDL_mutex *)SDL_malloc(sizeof(*mutex)); |
| 1190 | 45 if (mutex) |
| 46 { | |
| 47 /* Create the mutex, with initial value signaled */ | |
| 48 ulrc = DosCreateMutexSem(NULL, // Create unnamed semaphore | |
| 49 &(mutex->hmtxID), // Pointer to handle | |
| 50 0L, // Flags: create it private (not shared) | |
| 51 FALSE); // Initial value: unowned | |
| 52 if (ulrc!=NO_ERROR) | |
| 53 { | |
| 54 SDL_SetError("Couldn't create mutex"); | |
|
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3692456e7b0f
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Sam Lantinga <slouken@libsdl.org>
parents:
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diff
changeset
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55 SDL_free(mutex); |
| 1190 | 56 mutex = NULL; |
| 57 } | |
| 58 } else { | |
| 59 SDL_OutOfMemory(); | |
| 60 } | |
| 61 return(mutex); | |
| 62 } | |
| 63 | |
| 64 /* Free the mutex */ | |
| 65 DECLSPEC void SDLCALL SDL_DestroyMutex(SDL_mutex *mutex) | |
| 66 { | |
| 67 if ( mutex ) | |
| 68 { | |
| 69 if ( mutex->hmtxID ) | |
| 70 { | |
| 71 DosCloseMutexSem(mutex->hmtxID); | |
| 72 mutex->hmtxID = 0; | |
| 73 } | |
|
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3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
74 SDL_free(mutex); |
| 1190 | 75 } |
| 76 } | |
| 77 | |
| 78 /* Lock the mutex */ | |
| 79 DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex *mutex) | |
| 80 { | |
| 81 if ( mutex == NULL ) | |
| 82 { | |
| 83 SDL_SetError("Passed a NULL mutex"); | |
| 84 return -1; | |
| 85 } | |
| 86 if ( DosRequestMutexSem(mutex->hmtxID, SEM_INDEFINITE_WAIT) != NO_ERROR ) | |
| 87 { | |
| 88 SDL_SetError("Couldn't wait on mutex"); | |
| 89 return -1; | |
| 90 } | |
| 91 return(0); | |
| 92 } | |
| 93 | |
| 94 /* Unlock the mutex */ | |
| 95 DECLSPEC int SDLCALL SDL_mutexV(SDL_mutex *mutex) | |
| 96 { | |
| 97 if ( mutex == NULL ) | |
| 98 { | |
| 99 SDL_SetError("Passed a NULL mutex"); | |
| 100 return -1; | |
| 101 } | |
| 102 if ( DosReleaseMutexSem(mutex->hmtxID) != NO_ERROR ) | |
| 103 { | |
| 104 SDL_SetError("Couldn't release mutex"); | |
| 105 return -1; | |
| 106 } | |
| 107 return(0); | |
| 108 } |