Mercurial > sdl-ios-xcode
annotate src/audio/SDL_audiomem.c @ 262:ba5363e21df8
Don't allow multiple audio opens to succeed (until SDL 1.3)
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Wed, 09 Jan 2002 16:04:58 +0000 |
| parents | e8157fcb3114 |
| children | f6ffac90895c |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
| 3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga | |
| 4 | |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 of the License, or (at your option) any later version. | |
| 9 | |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 Sam Lantinga | |
|
252
e8157fcb3114
Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
parents:
1
diff
changeset
|
20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* Functions to allocate audio buffer memory, shareable across threads | |
| 29 (necessary because SDL audio emulates threads with fork() | |
| 30 */ | |
| 31 | |
|
1
cf2af46e9e2a
Changes since SDL 1.2.0 release
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
32 #include <stdlib.h> |
| 0 | 33 #ifdef FORK_HACK |
| 34 #include <sys/types.h> | |
| 35 #include <sys/ipc.h> | |
| 36 #include <sys/shm.h> | |
| 37 #include <stddef.h> | |
| 38 #endif | |
| 39 | |
| 40 #include "SDL_audiomem.h" | |
| 41 | |
| 42 /* Allocate memory that will be shared between threads (freed on exit) */ | |
| 43 void *SDL_AllocAudioMem(int size) | |
| 44 { | |
| 45 void *chunk; | |
| 46 | |
| 47 #ifdef FORK_HACK | |
| 48 int semid; | |
| 49 | |
| 50 /* Create and get the address of a shared memory segment */ | |
| 51 semid = shmget(IPC_PRIVATE, size, (IPC_CREAT|0600)); | |
| 52 if ( semid < 0 ) { | |
| 53 return(NULL); | |
| 54 } | |
| 55 chunk = shmat(semid, NULL, 0); | |
| 56 | |
| 57 /* Set the segment for deletion when it is detatched */ | |
| 58 shmctl(semid, IPC_RMID, NULL); /* Delets semid if shmat() fails */ | |
| 59 #else | |
| 60 chunk = malloc(size); | |
| 61 #endif | |
| 62 return((void *)chunk); | |
| 63 } | |
| 64 | |
| 65 void SDL_FreeAudioMem(void *chunk) | |
| 66 { | |
| 67 #ifdef FORK_HACK | |
| 68 shmdt(chunk); | |
| 69 #else | |
| 70 free(chunk); | |
| 71 #endif | |
| 72 } |