Mercurial > sdl-ios-xcode
view README @ 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 | 8582c6a5ca16 |
| children |
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Simple DirectMedia Layer (SDL) Version 1.2 --- http://www.libsdl.org/ This is the Simple DirectMedia Layer, a general API that provides low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D framebuffer across multiple platforms. The current version supports Linux, Windows CE/95/98/ME/XP/Vista, BeOS, MacOS Classic, Mac OS X, FreeBSD, NetBSD, OpenBSD, BSD/OS, Solaris, IRIX, and QNX. The code contains support for Dreamcast, Atari, AIX, OSF/Tru64, RISC OS, SymbianOS, Nintendo DS, and OS/2, but these are not officially supported. SDL is written in C, but works with C++ natively, and has bindings to several other languages, including Ada, C#, Eiffel, Erlang, Euphoria, Guile, Haskell, Java, Lisp, Lua, ML, Objective C, Pascal, Perl, PHP, Pike, Pliant, Python, Ruby, and Smalltalk. This library is distributed under GNU LGPL version 2, which can be found in the file "COPYING". This license allows you to use SDL freely in commercial programs as long as you link with the dynamic library. The best way to learn how to use SDL is to check out the header files in the "include" subdirectory and the programs in the "test" subdirectory. The header files and test programs are well commented and always up to date. More documentation is available in HTML format in "docs/index.html", and a documentation wiki is available online at: http://www.libsdl.org/cgi/docwiki.cgi The test programs in the "test" subdirectory are in the public domain. Frequently asked questions are answered online: http://www.libsdl.org/faq.php If you need help with the library, or just want to discuss SDL related issues, you can join the developers mailing list: http://www.libsdl.org/mailing-list.php Enjoy! Sam Lantinga (slouken@libsdl.org)