74 lines
1.8 KiB
C
74 lines
1.8 KiB
C
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/*
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SDL - Simple DirectMedia Layer
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Copyright (C) 1997, 1998, 1999, 2000, 2001 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 Library General Public
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License as published by the Free Software Foundation; either
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version 2 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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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with this library; if not, write to the Free
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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Sam Lantinga
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slouken@devolution.com
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*/
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#ifdef SAVE_RCSID
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static char rcsid =
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"@(#) $Id$";
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#endif
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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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#else
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#include <stdlib.h>
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#endif
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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 = 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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free(chunk);
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#endif
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}
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