Mercurial > sdl-ios-xcode
annotate src/thread/linux/SDL_syssem.c @ 1300:fd068ab116ee
Removed some old Mac OS X cruft.
Fixes Bugzilla #64.
--ryan.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Mon, 30 Jan 2006 18:56:30 +0000 |
| parents | b8d311d90021 |
| children | c9b51268668f |
| 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
|
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:
94
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changeset
|
20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 #include <stdlib.h> | |
| 29 #include "SDL_error.h" | |
| 30 #include "SDL_thread.h" | |
| 31 #include "SDL_timer.h" | |
| 32 | |
| 33 #ifdef linux | |
| 34 /* Look to see if glibc is available, and if so, what version */ | |
| 35 #include <features.h> | |
| 36 | |
| 37 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0) | |
| 38 #warning Working around a bug in glibc 2.0 pthreads | |
| 39 #undef SDL_USE_PTHREADS | |
| 40 /* The bug is actually a problem where threads are suspended, but don't | |
| 41 wake up when the thread manager sends them a signal. This is a problem | |
| 42 with thread creation too, but it happens less often. :-/ | |
| 43 We avoid this by using System V IPC for semaphores. | |
| 44 */ | |
| 45 #endif /* glibc 2.0 */ | |
| 46 #endif /* linux */ | |
| 47 | |
| 48 #ifdef SDL_USE_PTHREADS | |
| 49 | |
| 50 #ifdef SDL_NO_PTHREAD_SEMAPHORES | |
|
94
ae6e6b73333f
Cleaned up the OpenBSD port, thanks to Peter Valchev
Sam Lantinga <slouken@lokigames.com>
parents:
18
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|
51 #include "generic/SDL_syssem.c" |
| 0 | 52 #else |
| 53 | |
| 54 #include <stdio.h> | |
| 55 #include <stdlib.h> | |
| 56 #include <unistd.h> /* For getpid() */ | |
|
18
d9e3595b63d5
Added pthread.h - necessary on some configurations
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
57 #include <pthread.h> |
| 0 | 58 #include <semaphore.h> |
| 59 | |
| 60 /* Wrapper around POSIX 1003.1b semaphores */ | |
| 61 | |
| 62 #ifdef MACOSX | |
| 63 #define USE_NAMED_SEMAPHORES | |
| 64 #endif /* MACOSX */ | |
| 65 | |
| 66 struct SDL_semaphore { | |
| 67 sem_t *sem; | |
| 68 #ifndef USE_NAMED_SEMAPHORES | |
| 69 sem_t sem_data; | |
| 70 #endif | |
| 71 }; | |
| 72 | |
| 73 /* Create a semaphore, initialized with value */ | |
| 74 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 75 { | |
| 76 SDL_sem *sem = (SDL_sem *) malloc(sizeof(SDL_sem)); | |
| 77 if ( sem ) { | |
| 78 #ifdef USE_NAMED_SEMAPHORES | |
| 79 static int semnum = 0; | |
| 80 char name[32]; | |
| 81 | |
| 82 sprintf(name, "/SDL_sem-%d-%4.4d", getpid(), semnum++); | |
| 83 sem->sem = sem_open(name, O_CREAT, 0600, initial_value); | |
| 84 if ( sem->sem == (sem_t *)SEM_FAILED ) { | |
| 85 SDL_SetError("sem_open(%s) failed", name); | |
| 86 free(sem); | |
| 87 sem = NULL; | |
| 88 } else { | |
| 89 sem_unlink(name); | |
| 90 } | |
| 91 #else | |
| 92 if ( sem_init(&sem->sem_data, 0, initial_value) < 0 ) { | |
| 93 SDL_SetError("sem_init() failed"); | |
| 94 free(sem); | |
| 95 sem = NULL; | |
| 96 } else { | |
| 97 sem->sem = &sem->sem_data; | |
| 98 } | |
| 99 #endif /* USE_NAMED_SEMAPHORES */ | |
| 100 } else { | |
| 101 SDL_OutOfMemory(); | |
| 102 } | |
| 103 return sem; | |
| 104 } | |
| 105 | |
| 106 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 107 { | |
| 108 if ( sem ) { | |
| 109 #ifdef USE_NAMED_SEMAPHORES | |
| 110 sem_close(sem->sem); | |
| 111 #else | |
| 112 sem_destroy(sem->sem); | |
| 113 #endif | |
| 114 free(sem); | |
| 115 } | |
| 116 } | |
| 117 | |
| 118 int SDL_SemTryWait(SDL_sem *sem) | |
| 119 { | |
| 120 int retval; | |
| 121 | |
| 122 if ( ! sem ) { | |
| 123 SDL_SetError("Passed a NULL semaphore"); | |
| 124 return -1; | |
| 125 } | |
| 126 retval = SDL_MUTEX_TIMEDOUT; | |
| 127 if ( sem_trywait(sem->sem) == 0 ) { | |
| 128 retval = 0; | |
| 129 } | |
| 130 return retval; | |
| 131 } | |
| 132 | |
| 133 int SDL_SemWait(SDL_sem *sem) | |
| 134 { | |
| 135 int retval; | |
| 136 | |
| 137 if ( ! sem ) { | |
| 138 SDL_SetError("Passed a NULL semaphore"); | |
| 139 return -1; | |
| 140 } | |
| 141 | |
| 142 retval = sem_wait(sem->sem); | |
| 143 if ( retval < 0 ) { | |
| 144 SDL_SetError("sem_wait() failed"); | |
| 145 } | |
| 146 return retval; | |
| 147 } | |
| 148 | |
| 149 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 150 { | |
| 151 int retval; | |
| 152 | |
| 153 if ( ! sem ) { | |
| 154 SDL_SetError("Passed a NULL semaphore"); | |
| 155 return -1; | |
| 156 } | |
| 157 | |
| 158 /* Try the easy cases first */ | |
| 159 if ( timeout == 0 ) { | |
| 160 return SDL_SemTryWait(sem); | |
| 161 } | |
| 162 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 163 return SDL_SemWait(sem); | |
| 164 } | |
| 165 | |
| 166 /* Ack! We have to busy wait... */ | |
| 167 timeout += SDL_GetTicks(); | |
| 168 do { | |
| 169 retval = SDL_SemTryWait(sem); | |
| 170 if ( retval == 0 ) { | |
| 171 break; | |
| 172 } | |
| 173 SDL_Delay(1); | |
| 174 } while ( SDL_GetTicks() < timeout ); | |
| 175 | |
| 176 return retval; | |
| 177 } | |
| 178 | |
| 179 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 180 { | |
| 181 int ret = 0; | |
| 182 if ( sem ) { | |
| 183 sem_getvalue(sem->sem, &ret); | |
| 184 if ( ret < 0 ) { | |
| 185 ret = 0; | |
| 186 } | |
| 187 } | |
| 188 return (Uint32)ret; | |
| 189 } | |
| 190 | |
| 191 int SDL_SemPost(SDL_sem *sem) | |
| 192 { | |
| 193 int retval; | |
| 194 | |
| 195 if ( ! sem ) { | |
| 196 SDL_SetError("Passed a NULL semaphore"); | |
| 197 return -1; | |
| 198 } | |
| 199 | |
| 200 retval = sem_post(sem->sem); | |
| 201 if ( retval < 0 ) { | |
| 202 SDL_SetError("sem_post() failed"); | |
| 203 } | |
| 204 return retval; | |
| 205 } | |
| 206 | |
| 207 #endif /* NO_PTHREAD_SEMAPHORES */ | |
| 208 | |
| 209 #else /* System V IPC implementation */ | |
| 210 | |
| 211 #include <stdio.h> | |
| 212 #include <stdlib.h> | |
| 213 #include <sys/types.h> | |
| 214 #include <sys/ipc.h> | |
| 215 #include <sys/sem.h> | |
| 216 #include <errno.h> | |
| 217 | |
| 218 #include "SDL_error.h" | |
| 219 #include "SDL_thread.h" | |
| 220 | |
| 221 | |
| 222 struct SDL_semaphore { | |
| 223 int id; | |
| 224 }; | |
| 225 | |
| 226 /* Not defined by many operating systems, use configure to detect */ | |
| 227 #if !defined(HAVE_SEMUN) | |
| 228 union semun { | |
| 229 int val; | |
| 230 struct semid_ds *buf; | |
| 231 ushort *array; | |
| 232 }; | |
| 233 #endif | |
| 234 | |
| 235 static struct sembuf op_trywait[2] = { | |
| 236 { 0, -1, (IPC_NOWAIT|SEM_UNDO) } /* Decrement semaphore, no block */ | |
| 237 }; | |
| 238 static struct sembuf op_wait[2] = { | |
| 239 { 0, -1, SEM_UNDO } /* Decrement semaphore */ | |
| 240 }; | |
| 241 static struct sembuf op_post[1] = { | |
| 242 { 0, 1, (IPC_NOWAIT|SEM_UNDO) } /* Increment semaphore */ | |
| 243 }; | |
| 244 | |
| 245 /* Create a blockable semaphore */ | |
| 246 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 247 { | |
| 248 extern int _creating_thread_lock; /* SDL_threads.c */ | |
| 249 SDL_sem *sem; | |
| 250 union semun init; | |
| 251 key_t key; | |
| 252 | |
| 253 sem = (SDL_sem *)malloc(sizeof(*sem)); | |
| 254 if ( sem == NULL ) { | |
| 255 SDL_OutOfMemory(); | |
| 256 return(NULL); | |
| 257 } | |
| 258 /* This flag is true if we are creating the thread manager sem, | |
| 259 which is never freed. This allows us to reuse the same sem. | |
| 260 */ | |
| 261 if ( _creating_thread_lock ) { | |
| 262 key = 'S'+'D'+'L'; | |
| 263 } else { | |
| 264 key = IPC_PRIVATE; | |
| 265 } | |
| 266 /* Keep trying to create sem while we don't own the requested key */ | |
| 267 do { | |
| 268 if ( key != IPC_PRIVATE ) { | |
| 269 ++key; | |
| 270 } | |
| 271 sem->id = semget(key, 1, (0600|IPC_CREAT)); | |
| 272 } while ((sem->id < 0) && (key != IPC_PRIVATE) && (errno == EACCES)); | |
| 273 | |
| 274 /* Report the error if we eventually failed */ | |
| 275 if ( sem->id < 0 ) { | |
| 276 SDL_SetError("Couldn't create semaphore"); | |
| 277 free(sem); | |
| 278 return(NULL); | |
| 279 } | |
| 280 init.val = initial_value; /* Initialize semaphore */ | |
| 281 semctl(sem->id, 0, SETVAL, init); | |
| 282 return(sem); | |
| 283 } | |
| 284 | |
| 285 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 286 { | |
| 287 if ( sem ) { | |
| 288 #ifdef _SGI_SOURCE | |
| 289 semctl(sem->id, 0, IPC_RMID); | |
| 290 #else | |
| 291 union semun dummy; | |
| 292 dummy.val = 0; | |
| 293 semctl(sem->id, 0, IPC_RMID, dummy); | |
| 294 #endif | |
| 295 free(sem); | |
| 296 } | |
| 297 } | |
| 298 | |
| 299 int SDL_SemTryWait(SDL_sem *sem) | |
| 300 { | |
| 301 int retval; | |
| 302 | |
| 303 if ( ! sem ) { | |
| 304 SDL_SetError("Passed a NULL semaphore"); | |
| 305 return -1; | |
| 306 } | |
| 307 | |
| 308 retval = 0; | |
| 309 tryagain: | |
| 310 if ( semop(sem->id, op_trywait, 1) < 0 ) { | |
| 311 if ( errno == EINTR ) { | |
| 312 goto tryagain; | |
| 313 } | |
| 314 retval = SDL_MUTEX_TIMEDOUT; | |
| 315 } | |
| 316 return retval; | |
| 317 } | |
| 318 | |
| 319 int SDL_SemWait(SDL_sem *sem) | |
| 320 { | |
| 321 int retval; | |
| 322 | |
| 323 if ( ! sem ) { | |
| 324 SDL_SetError("Passed a NULL semaphore"); | |
| 325 return -1; | |
| 326 } | |
| 327 | |
| 328 retval = 0; | |
| 329 tryagain: | |
| 330 if ( semop(sem->id, op_wait, 1) < 0 ) { | |
| 331 if ( errno == EINTR ) { | |
| 332 goto tryagain; | |
| 333 } | |
| 334 SDL_SetError("Semaphore operation error"); | |
| 335 retval = -1; | |
| 336 } | |
| 337 return retval; | |
| 338 } | |
| 339 | |
| 340 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 341 { | |
| 342 int retval; | |
| 343 | |
| 344 if ( ! sem ) { | |
| 345 SDL_SetError("Passed a NULL semaphore"); | |
| 346 return -1; | |
| 347 } | |
| 348 | |
| 349 /* Try the easy cases first */ | |
| 350 if ( timeout == 0 ) { | |
| 351 return SDL_SemTryWait(sem); | |
| 352 } | |
| 353 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 354 return SDL_SemWait(sem); | |
| 355 } | |
| 356 | |
| 357 /* Ack! We have to busy wait... */ | |
| 358 timeout += SDL_GetTicks(); | |
| 359 do { | |
| 360 retval = SDL_SemTryWait(sem); | |
| 361 if ( retval == 0 ) { | |
| 362 break; | |
| 363 } | |
| 364 SDL_Delay(1); | |
| 365 } while ( SDL_GetTicks() < timeout ); | |
| 366 | |
| 367 return retval; | |
| 368 } | |
| 369 | |
| 370 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 371 { | |
| 372 int semval; | |
| 373 Uint32 value; | |
| 374 | |
| 375 value = 0; | |
| 376 if ( sem ) { | |
| 377 tryagain: | |
| 378 #ifdef _SGI_SOURCE | |
| 379 semval = semctl(sem->id, 0, GETVAL); | |
| 380 #else | |
| 381 { | |
| 382 union semun arg; | |
| 383 arg.val = 0; | |
| 384 semval = semctl(sem->id, 0, GETVAL, arg); | |
| 385 } | |
| 386 #endif | |
| 387 if ( semval < 0 ) { | |
| 388 if ( errno == EINTR ) { | |
| 389 goto tryagain; | |
| 390 } | |
| 391 } else { | |
| 392 value = (Uint32)semval; | |
| 393 } | |
| 394 } | |
| 395 return value; | |
| 396 } | |
| 397 | |
| 398 int SDL_SemPost(SDL_sem *sem) | |
| 399 { | |
| 400 int retval; | |
| 401 | |
| 402 if ( ! sem ) { | |
| 403 SDL_SetError("Passed a NULL semaphore"); | |
| 404 return -1; | |
| 405 } | |
| 406 | |
| 407 retval = 0; | |
| 408 tryagain: | |
| 409 if ( semop(sem->id, op_post, 1) < 0 ) { | |
| 410 if ( errno == EINTR ) { | |
| 411 goto tryagain; | |
| 412 } | |
| 413 SDL_SetError("Semaphore operation error"); | |
| 414 retval = -1; | |
| 415 } | |
| 416 return retval; | |
| 417 } | |
| 418 | |
| 419 #endif /* SDL_USE_PTHREADS */ |