09cd73f1b5
--HG-- extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401342
67 lines
1.8 KiB
C
67 lines
1.8 KiB
C
/*
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SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
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slouken@libsdl.org
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*/
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/* Functions to allocate audio buffer memory, shareable across threads
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(necessary because SDL audio emulates threads with fork()
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*/
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#ifdef FORK_HACK
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#include <sys/types.h>
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#include <sys/ipc.h>
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#include <sys/shm.h>
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#include <stddef.h>
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#endif
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#include "SDL_stdlib.h"
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#include "SDL_audiomem.h"
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/* Allocate memory that will be shared between threads (freed on exit) */
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void *SDL_AllocAudioMem(int size)
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{
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void *chunk;
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#ifdef FORK_HACK
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int semid;
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/* Create and get the address of a shared memory segment */
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semid = shmget(IPC_PRIVATE, size, (IPC_CREAT|0600));
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if ( semid < 0 ) {
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return(NULL);
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}
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chunk = shmat(semid, NULL, 0);
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/* Set the segment for deletion when it is detatched */
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shmctl(semid, IPC_RMID, NULL); /* Delets semid if shmat() fails */
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#else
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chunk = SDL_malloc(size);
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#endif
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return((void *)chunk);
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}
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void SDL_FreeAudioMem(void *chunk)
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{
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#ifdef FORK_HACK
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shmdt(chunk);
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#else
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SDL_free(chunk);
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#endif
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}
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