Mercurial > sdl-ios-xcode
view README.Qtopia @ 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 | 2c5d4c22a2ac |
children |
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============================================================================== Using the Simple DirectMedia Layer with Qtopia/OPIE ============================================================================== ============================================================================== I. Setting up the Qtopia development environment. This document will not explain how to setup the Qtopia development environment. That is outside the scope of the document. You can read more on this subject in this excellent howto: http://www.zauruszone.com/howtos/linux_compiler_setup_howto.html ============================================================================== II. Building the Simple DirectMedia Layer libraries using the arm cross-compiler This is somewhat tricky since the name of the compiler binaries differ from the standard. Also you should disable features not needed. The command below works for me. Note that it's all one line. You can also set the NM, LD etc environment variables separately. NM=arm-linux-nm LD=arm-linux-ld CC=arm-linux-gcc CXX=arm-linux-g++ RANLIB=arm-linux-ranlib AR=arm-linux-ar ./configure --enable-video-qtopia --disable-video-dummy --disable-video-fbcon --disable-video-dga --disable-arts --disable-esd --disable-alsa --disable-cdrom --disable-video-x11 --disable-nasm --prefix=/opt/Qtopia/sharp/ arm-unknown-linux-gnu One thing to note is that the above configure will include joystick support, even though you can't have joysticks on the Zaurus. The reason for this is to avoid link / compile / runtime errors with applications that have joystick support. ============================================================================== III. Building the Simple DirectMedia Layer test programs: After installing, making sure the correct sdl-config is in your path, run configure like this: NM=arm-linux-nm LD=arm-linux-ld CC=arm-linux-gcc CXX=arm-linux-g++ AR=arm-linux-ar ./configure arm-unknown-linux-gnu ============================================================================== IV. Application porting notes One thing I have noticed is that applications sometimes don't exit correctly. Their icon remains in the taskbar and they tend to relaunch themselves automatically. I believe this problem doesn't occur if you exit your application using the exit() method. However, if you end main() with 'return 0;' or so, this seems to happen. Also note that when running in landscape mode - i.e requesting a window that is HEIGHT pixels wide and WIDTH pixels high, where WIDTH and HEIGHT normally is 240 and 320 - the image is blitted so that the hardware buttons are on the left side of the display. This might not always be desirable but such is the code today. ============================================================================== V. Enjoy! :) If you have a project you'd like me to know about, or want to ask questions, go ahead and join the SDL developer's mailing list by sending e-mail to: sdl-request@libsdl.org and put "subscribe" into the subject of the message. Or alternatively you can use the web interface: http://www.libsdl.org/mailman/listinfo/sdl ============================================================================== VI. What is supported: Keyboard (Sharp Zaurus) Hardware buttons Stylus input (mouse) Video. Allows fullscreen both in portrait mode (up to WIDTHxHEIGHT size window) and in landscape mode (up to HEIGHTxWIDTH). All other SDL functionality works like a normal Linux system (threads, audio etc). -- David Hedbor <david@hedbor.org> http://david.hedbor.org/ http://eongames.com/