Mercurial > sdl-ios-xcode
annotate src/thread/beos/SDL_syssem.c @ 769:b8d311d90021
Updated copyright information for 2004 (Happy New Year!)
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 04 Jan 2004 16:49:27 +0000 |
| parents | f6ffac90895c |
| children | ab0154afe938 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
769
b8d311d90021
Updated copyright information for 2004 (Happy New Year!)
Sam Lantinga <slouken@libsdl.org>
parents:
297
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changeset
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3 Copyright (C) 1997-2004 Sam Lantinga |
| 0 | 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:
0
diff
changeset
|
20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* Semaphores in the BeOS environment */ | |
| 29 | |
| 30 #include <be/kernel/OS.h> | |
| 31 | |
| 32 #include "SDL_error.h" | |
| 33 #include "SDL_thread.h" | |
| 34 | |
| 35 | |
| 36 struct SDL_semaphore { | |
| 37 sem_id id; | |
| 38 }; | |
| 39 | |
| 40 /* Create a counting semaphore */ | |
| 41 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 42 { | |
| 43 SDL_sem *sem; | |
| 44 | |
| 45 sem = (SDL_sem *)malloc(sizeof(*sem)); | |
| 46 if ( sem ) { | |
| 47 sem->id = create_sem(initial_value, "SDL semaphore"); | |
| 48 if ( sem->id < B_NO_ERROR ) { | |
| 49 SDL_SetError("create_sem() failed"); | |
| 50 free(sem); | |
| 51 sem = NULL; | |
| 52 } | |
| 53 } else { | |
| 54 SDL_OutOfMemory(); | |
| 55 } | |
| 56 return(sem); | |
| 57 } | |
| 58 | |
| 59 /* Free the semaphore */ | |
| 60 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 61 { | |
| 62 if ( sem ) { | |
| 63 if ( sem->id >= B_NO_ERROR ) { | |
| 64 delete_sem(sem->id); | |
| 65 } | |
| 66 free(sem); | |
| 67 } | |
| 68 } | |
| 69 | |
| 70 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 71 { | |
| 72 int32 val; | |
| 73 int retval; | |
| 74 | |
| 75 if ( ! sem ) { | |
| 76 SDL_SetError("Passed a NULL semaphore"); | |
| 77 return -1; | |
| 78 } | |
| 79 | |
| 80 tryagain: | |
| 81 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 82 val = acquire_sem(sem->id); | |
| 83 } else { | |
| 84 timeout *= 1000; /* BeOS uses a timeout in microseconds */ | |
| 85 val = acquire_sem_etc(sem->id, 1, B_RELATIVE_TIMEOUT, timeout); | |
| 86 } | |
| 87 switch (val) { | |
| 88 case B_INTERRUPTED: | |
| 89 goto tryagain; | |
| 90 case B_NO_ERROR: | |
| 91 retval = 0; | |
| 92 break; | |
| 93 default: | |
| 94 SDL_SetError("acquire_sem() failed"); | |
| 95 retval = -1; | |
| 96 break; | |
| 97 } | |
| 98 | |
| 99 return retval; | |
| 100 } | |
| 101 | |
| 102 int SDL_SemTryWait(SDL_sem *sem) | |
| 103 { | |
| 104 return SDL_SemWaitTimeout(sem, 0); | |
| 105 } | |
| 106 | |
| 107 int SDL_SemWait(SDL_sem *sem) | |
| 108 { | |
| 109 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); | |
| 110 } | |
| 111 | |
| 112 /* Returns the current count of the semaphore */ | |
| 113 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 114 { | |
| 115 int32 count; | |
| 116 Uint32 value; | |
| 117 | |
| 118 value = 0; | |
| 119 if ( sem ) { | |
| 120 get_sem_count(sem->id, &count); | |
| 121 if ( count > 0 ) { | |
| 122 value = (Uint32)count; | |
| 123 } | |
| 124 } | |
| 125 return value; | |
| 126 } | |
| 127 | |
| 128 /* Atomically increases the semaphore's count (not blocking) */ | |
| 129 int SDL_SemPost(SDL_sem *sem) | |
| 130 { | |
| 131 if ( ! sem ) { | |
| 132 SDL_SetError("Passed a NULL semaphore"); | |
| 133 return -1; | |
| 134 } | |
| 135 | |
| 136 if ( release_sem(sem->id) != B_NO_ERROR ) { | |
| 137 SDL_SetError("release_sem() failed"); | |
| 138 return -1; | |
| 139 } | |
| 140 return 0; | |
| 141 } |