Mercurial > sdl-ios-xcode
view src/audio/baudio/SDL_beaudio.cc @ 3162:dc1eb82ffdaa
Von: Thomas Zimmermann
Betreff: [SDL] [PATCH] Make static variables const
Datum: Tue, 19 May 2009 19:45:37 +0200
Hi,
this is a set of simple changes which make some of SDL's internal static
arrays constant. The purpose is to shrink the number of write-able
static bytes and thus increase the number of memory pages shared between
SDL applications.
The patch set is against trunk@4513. Each of the attached patch files is
specific to a sub-system. The set is completed by a second mail, because
of the list's 40 KiB limit.
The files readelf-r4513.txt and readelf-const-patch.txt where made by
calling 'readelf -S libSDL.so'. They show the difference in ELF sections
without and with the patch. Some numbers measured on my x86-64:
Before
[13] .rodata PROGBITS 00000000000eaaa0 000eaaa0
0000000000008170 0000000000000000 A 0 0 32
[19] .data.rel.ro PROGBITS 00000000003045e0 001045e0
00000000000023d0 0000000000000000 WA 0 0 32
[23] .data PROGBITS 00000000003076e0 001076e0
0000000000004988 0000000000000000 WA 0 0 32
After
[13] .rodata PROGBITS 00000000000eaaa0 000eaaa0
0000000000009a50 0000000000000000 A 0 0 32
[19] .data.rel.ro PROGBITS 0000000000306040 00106040
0000000000002608 0000000000000000 WA 0 0 32
[23] .data PROGBITS 0000000000309360 00109360
0000000000002e88 0000000000000000 WA 0 0 32
The size of the write-able data section decreased considerably. Some
entries became const-after-relocation, while most of its content went
straight into the read-only data section.
Best regards, Thomas
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 03 Jun 2009 04:37:27 +0000 |
parents | 99210400e8b9 |
children | 4160ba33b597 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 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" } /* !!! FIXME: have the callback call the higher level to avoid code dupe. */ /* 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); } } } static void BEOSAUDIO_CloseDevice(_THIS) { if (_this->hidden != NULL) { if (_this->hidden->audio_obj) { _this->hidden->audio_obj->Stop(); delete _this->hidden->audio_obj; _this->hidden->audio_obj = NULL; } delete _this->hidden; _this->hidden = NULL; } } static int BEOSAUDIO_OpenDevice(_THIS, const char *devname, int iscapture) { int valid_datatype = 0; media_raw_audio_format format; SDL_AudioFormat test_format = SDL_FirstAudioFormat(_this->spec.format); /* Initialize all variables that we clean on shutdown */ _this->hidden = new SDL_PrivateAudioData; if (_this->hidden == NULL) { SDL_OutOfMemory(); return 0; } SDL_memset(_this->hidden, 0, (sizeof *_this->hidden)); /* Parse the audio format and fill the Be raw audio format */ SDL_memset(&format, '\0', sizeof(media_raw_audio_format)); format.byte_order = B_MEDIA_LITTLE_ENDIAN; format.frame_rate = (float) _this->spec.freq; format.channel_count = _this->spec.channels; /* !!! FIXME: support > 2? */ while ((!valid_datatype) && (test_format)) { valid_datatype = 1; _this->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; case AUDIO_S32LSB: format.format = media_raw_audio_format::B_AUDIO_INT; break; case AUDIO_S32MSB: format.format = media_raw_audio_format::B_AUDIO_INT; format.byte_order = B_MEDIA_BIG_ENDIAN; break; case AUDIO_F32LSB: format.format = media_raw_audio_format::B_AUDIO_FLOAT; break; case AUDIO_F32MSB: format.format = media_raw_audio_format::B_AUDIO_FLOAT; format.byte_order = B_MEDIA_BIG_ENDIAN; break; default: valid_datatype = 0; test_format = SDL_NextAudioFormat(); break; } } format.buffer_size = _this->spec.samples; if (!valid_datatype) { /* shouldn't happen, but just in case... */ BEOSAUDIO_CloseDevice(_this); SDL_SetError("Unsupported audio format"); return 0; } /* Calculate the final parameters for this audio specification */ SDL_CalculateAudioSpec(&_this->spec); /* Subscribe to the audio stream (creates a new thread) */ sigset_t omask; SDL_MaskSignals(&omask); _this->hidden->audio_obj = new BSoundPlayer(&format, "SDL Audio", FillSound, NULL, _this); SDL_UnmaskSignals(&omask); if (_this->hidden->audio_obj->Start() == B_NO_ERROR) { _this->hidden->audio_obj->SetHasData(true); } else { BEOSAUDIO_CloseDevice(_this); SDL_SetError("Unable to start Be audio"); return 0; } /* We're running! */ return 1; } static void BEOSAUDIO_Deinitialize(void) { SDL_QuitBeApp(); } static int BEOSAUDIO_Init(SDL_AudioDriverImpl * impl) { /* Initialize the Be Application, if it's not already started */ if (SDL_InitBeApp() < 0) { return 0; } /* Set the function pointers */ impl->OpenDevice = BEOSAUDIO_OpenDevice; impl->CloseDevice = BEOSAUDIO_CloseDevice; impl->Deinitialize = BEOSAUDIO_Deinitialize; impl->ProvidesOwnCallbackThread = 1; impl->OnlyHasDefaultOutputDevice = 1; return 1; } extern "C" { extern AudioBootStrap BEOSAUDIO_bootstrap; } AudioBootStrap BEOSAUDIO_bootstrap = { "baudio", "BeOS BSoundPlayer", BEOSAUDIO_Init, 0 }; /* vi: set ts=4 sw=4 expandtab: */