Mercurial > sdl-ios-xcode
view src/audio/baudio/SDL_beaudio.cc @ 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 | 5b5e549382b3 |
children | 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" /* Allow access to the audio stream on BeOS */ #include <SoundPlayer.h> #include "../../main/beos/SDL_BeApp.h" extern "C" { #include "SDL_audio.h" #include "../SDL_audio_c.h" #include "../SDL_sysaudio.h" #include "../../thread/beos/SDL_systhread_c.h" #include "SDL_beaudio.h" /* Audio driver functions */ static int BE_OpenAudio(_THIS, SDL_AudioSpec *spec); static void BE_WaitAudio(_THIS); static void BE_PlayAudio(_THIS); static Uint8 *BE_GetAudioBuf(_THIS); static void BE_CloseAudio(_THIS); /* Audio driver bootstrap functions */ static int Audio_Available(void) { return(1); } static void Audio_DeleteDevice(SDL_AudioDevice *device) { SDL_free(device->hidden); SDL_free(device); } static SDL_AudioDevice *Audio_CreateDevice(int devindex) { SDL_AudioDevice *device; /* Initialize all variables that we clean on shutdown */ device = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); if ( device ) { SDL_memset(device, 0, (sizeof *device)); device->hidden = (struct SDL_PrivateAudioData *) SDL_malloc((sizeof *device->hidden)); } if ( (device == NULL) || (device->hidden == NULL) ) { SDL_OutOfMemory(); if ( device ) { SDL_free(device); } return(0); } SDL_memset(device->hidden, 0, (sizeof *device->hidden)); /* Set the function pointers */ device->OpenAudio = BE_OpenAudio; device->WaitAudio = BE_WaitAudio; device->PlayAudio = BE_PlayAudio; device->GetAudioBuf = BE_GetAudioBuf; device->CloseAudio = BE_CloseAudio; device->free = Audio_DeleteDevice; return device; } AudioBootStrap BAUDIO_bootstrap = { "baudio", "BeOS BSoundPlayer", Audio_Available, Audio_CreateDevice }; /* The BeOS callback for handling the audio buffer */ static void FillSound(void *device, void *stream, size_t len, const media_raw_audio_format &format) { SDL_AudioDevice *audio = (SDL_AudioDevice *)device; /* Silence the buffer, since it's ours */ SDL_memset(stream, audio->spec.silence, len); /* Only do soemthing if audio is enabled */ if ( ! audio->enabled ) return; if ( ! audio->paused ) { if ( audio->convert.needed ) { SDL_mutexP(audio->mixer_lock); (*audio->spec.callback)(audio->spec.userdata, (Uint8 *)audio->convert.buf,audio->convert.len); SDL_mutexV(audio->mixer_lock); SDL_ConvertAudio(&audio->convert); SDL_memcpy(stream,audio->convert.buf,audio->convert.len_cvt); } else { SDL_mutexP(audio->mixer_lock); (*audio->spec.callback)(audio->spec.userdata, (Uint8 *)stream, len); SDL_mutexV(audio->mixer_lock); } } return; } /* Dummy functions -- we don't use thread-based audio */ void BE_WaitAudio(_THIS) { return; } void BE_PlayAudio(_THIS) { return; } Uint8 *BE_GetAudioBuf(_THIS) { return(NULL); } void BE_CloseAudio(_THIS) { if ( audio_obj ) { audio_obj->Stop(); delete audio_obj; audio_obj = NULL; } /* Quit the Be Application, if there's nothing left to do */ SDL_QuitBeApp(); } int BE_OpenAudio(_THIS, SDL_AudioSpec *spec) { int valid_datatype = 0; media_raw_audio_format format; Uint16 test_format = SDL_FirstAudioFormat(spec->format); /* Parse the audio format and fill the Be raw audio format */ memset(&format, '\0', sizeof (media_raw_audio_format)); format.byte_order = B_MEDIA_LITTLE_ENDIAN; format.frame_rate = (float) spec->freq; format.channel_count = spec->channels; /* !!! FIXME: support > 2? */ while ((!valid_datatype) && (test_format)) { valid_datatype = 1; spec->format = test_format; switch (test_format) { case AUDIO_S8: format.format = media_raw_audio_format::B_AUDIO_CHAR; break; case AUDIO_U8: format.format = media_raw_audio_format::B_AUDIO_UCHAR; break; case AUDIO_S16LSB: format.format = media_raw_audio_format::B_AUDIO_SHORT; break; case AUDIO_S16MSB: format.format = media_raw_audio_format::B_AUDIO_SHORT; format.byte_order = B_MEDIA_BIG_ENDIAN; break; default: valid_datatype = 0; test_format = SDL_NextAudioFormat(); break; } } if (!valid_datatype) { /* shouldn't happen, but just in case... */ SDL_SetError("Unsupported audio format"); return (-1); } /* Initialize the Be Application, if it's not already started */ if (SDL_InitBeApp() < 0) { return (-1); } format.buffer_size = spec->samples; /* Calculate the final parameters for this audio specification */ SDL_CalculateAudioSpec(spec); /* Subscribe to the audio stream (creates a new thread) */ { sigset_t omask; SDL_MaskSignals(&omask); audio_obj = new BSoundPlayer(&format, "SDL Audio", FillSound, NULL, _this); SDL_UnmaskSignals(&omask); } if ( audio_obj->Start() == B_NO_ERROR ) { audio_obj->SetHasData(true); } else { SDL_SetError("Unable to start Be audio"); return(-1); } /* We're running! */ return(1); } }; /* Extern C */