Mercurial > sdl-ios-xcode
annotate src/thread/linux/SDL_syssem.c @ 1312:c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
I batch edited these files, so please let me know if I've accidentally removed anybody's
credit here.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Wed, 01 Feb 2006 06:32:25 +0000 |
| parents | fd068ab116ee |
| children | 3692456e7b0f |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
1312
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1300
diff
changeset
|
3 Copyright (C) 1997-2006 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
|
1312
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1300
diff
changeset
|
6 modify it under the terms of the GNU Lesser General Public |
| 0 | 7 License as published by the Free Software Foundation; either |
|
1312
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1300
diff
changeset
|
8 version 2.1 of the License, or (at your option) any later version. |
| 0 | 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 | |
|
1312
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1300
diff
changeset
|
13 Lesser General Public License for more details. |
| 0 | 14 |
|
1312
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1300
diff
changeset
|
15 You should have received a copy of the GNU Lesser General Public |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1300
diff
changeset
|
16 License along with this library; if not, write to the Free Software |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1300
diff
changeset
|
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 0 | 18 |
| 19 Sam Lantinga | |
|
252
e8157fcb3114
Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
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20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #include <stdlib.h> | |
| 24 #include "SDL_error.h" | |
| 25 #include "SDL_thread.h" | |
| 26 #include "SDL_timer.h" | |
| 27 | |
| 28 #ifdef linux | |
| 29 /* Look to see if glibc is available, and if so, what version */ | |
| 30 #include <features.h> | |
| 31 | |
| 32 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0) | |
| 33 #warning Working around a bug in glibc 2.0 pthreads | |
| 34 #undef SDL_USE_PTHREADS | |
| 35 /* The bug is actually a problem where threads are suspended, but don't | |
| 36 wake up when the thread manager sends them a signal. This is a problem | |
| 37 with thread creation too, but it happens less often. :-/ | |
| 38 We avoid this by using System V IPC for semaphores. | |
| 39 */ | |
| 40 #endif /* glibc 2.0 */ | |
| 41 #endif /* linux */ | |
| 42 | |
| 43 #ifdef SDL_USE_PTHREADS | |
| 44 | |
| 45 #ifdef SDL_NO_PTHREAD_SEMAPHORES | |
|
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ae6e6b73333f
Cleaned up the OpenBSD port, thanks to Peter Valchev
Sam Lantinga <slouken@lokigames.com>
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diff
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46 #include "generic/SDL_syssem.c" |
| 0 | 47 #else |
| 48 | |
| 49 #include <stdio.h> | |
| 50 #include <stdlib.h> | |
| 51 #include <unistd.h> /* For getpid() */ | |
|
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Added pthread.h - necessary on some configurations
Sam Lantinga <slouken@lokigames.com>
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diff
changeset
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52 #include <pthread.h> |
| 0 | 53 #include <semaphore.h> |
| 54 | |
| 55 /* Wrapper around POSIX 1003.1b semaphores */ | |
| 56 | |
| 57 #ifdef MACOSX | |
| 58 #define USE_NAMED_SEMAPHORES | |
| 59 #endif /* MACOSX */ | |
| 60 | |
| 61 struct SDL_semaphore { | |
| 62 sem_t *sem; | |
| 63 #ifndef USE_NAMED_SEMAPHORES | |
| 64 sem_t sem_data; | |
| 65 #endif | |
| 66 }; | |
| 67 | |
| 68 /* Create a semaphore, initialized with value */ | |
| 69 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 70 { | |
| 71 SDL_sem *sem = (SDL_sem *) malloc(sizeof(SDL_sem)); | |
| 72 if ( sem ) { | |
| 73 #ifdef USE_NAMED_SEMAPHORES | |
| 74 static int semnum = 0; | |
| 75 char name[32]; | |
| 76 | |
| 77 sprintf(name, "/SDL_sem-%d-%4.4d", getpid(), semnum++); | |
| 78 sem->sem = sem_open(name, O_CREAT, 0600, initial_value); | |
| 79 if ( sem->sem == (sem_t *)SEM_FAILED ) { | |
| 80 SDL_SetError("sem_open(%s) failed", name); | |
| 81 free(sem); | |
| 82 sem = NULL; | |
| 83 } else { | |
| 84 sem_unlink(name); | |
| 85 } | |
| 86 #else | |
| 87 if ( sem_init(&sem->sem_data, 0, initial_value) < 0 ) { | |
| 88 SDL_SetError("sem_init() failed"); | |
| 89 free(sem); | |
| 90 sem = NULL; | |
| 91 } else { | |
| 92 sem->sem = &sem->sem_data; | |
| 93 } | |
| 94 #endif /* USE_NAMED_SEMAPHORES */ | |
| 95 } else { | |
| 96 SDL_OutOfMemory(); | |
| 97 } | |
| 98 return sem; | |
| 99 } | |
| 100 | |
| 101 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 102 { | |
| 103 if ( sem ) { | |
| 104 #ifdef USE_NAMED_SEMAPHORES | |
| 105 sem_close(sem->sem); | |
| 106 #else | |
| 107 sem_destroy(sem->sem); | |
| 108 #endif | |
| 109 free(sem); | |
| 110 } | |
| 111 } | |
| 112 | |
| 113 int SDL_SemTryWait(SDL_sem *sem) | |
| 114 { | |
| 115 int retval; | |
| 116 | |
| 117 if ( ! sem ) { | |
| 118 SDL_SetError("Passed a NULL semaphore"); | |
| 119 return -1; | |
| 120 } | |
| 121 retval = SDL_MUTEX_TIMEDOUT; | |
| 122 if ( sem_trywait(sem->sem) == 0 ) { | |
| 123 retval = 0; | |
| 124 } | |
| 125 return retval; | |
| 126 } | |
| 127 | |
| 128 int SDL_SemWait(SDL_sem *sem) | |
| 129 { | |
| 130 int retval; | |
| 131 | |
| 132 if ( ! sem ) { | |
| 133 SDL_SetError("Passed a NULL semaphore"); | |
| 134 return -1; | |
| 135 } | |
| 136 | |
| 137 retval = sem_wait(sem->sem); | |
| 138 if ( retval < 0 ) { | |
| 139 SDL_SetError("sem_wait() failed"); | |
| 140 } | |
| 141 return retval; | |
| 142 } | |
| 143 | |
| 144 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 145 { | |
| 146 int retval; | |
| 147 | |
| 148 if ( ! sem ) { | |
| 149 SDL_SetError("Passed a NULL semaphore"); | |
| 150 return -1; | |
| 151 } | |
| 152 | |
| 153 /* Try the easy cases first */ | |
| 154 if ( timeout == 0 ) { | |
| 155 return SDL_SemTryWait(sem); | |
| 156 } | |
| 157 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 158 return SDL_SemWait(sem); | |
| 159 } | |
| 160 | |
| 161 /* Ack! We have to busy wait... */ | |
| 162 timeout += SDL_GetTicks(); | |
| 163 do { | |
| 164 retval = SDL_SemTryWait(sem); | |
| 165 if ( retval == 0 ) { | |
| 166 break; | |
| 167 } | |
| 168 SDL_Delay(1); | |
| 169 } while ( SDL_GetTicks() < timeout ); | |
| 170 | |
| 171 return retval; | |
| 172 } | |
| 173 | |
| 174 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 175 { | |
| 176 int ret = 0; | |
| 177 if ( sem ) { | |
| 178 sem_getvalue(sem->sem, &ret); | |
| 179 if ( ret < 0 ) { | |
| 180 ret = 0; | |
| 181 } | |
| 182 } | |
| 183 return (Uint32)ret; | |
| 184 } | |
| 185 | |
| 186 int SDL_SemPost(SDL_sem *sem) | |
| 187 { | |
| 188 int retval; | |
| 189 | |
| 190 if ( ! sem ) { | |
| 191 SDL_SetError("Passed a NULL semaphore"); | |
| 192 return -1; | |
| 193 } | |
| 194 | |
| 195 retval = sem_post(sem->sem); | |
| 196 if ( retval < 0 ) { | |
| 197 SDL_SetError("sem_post() failed"); | |
| 198 } | |
| 199 return retval; | |
| 200 } | |
| 201 | |
| 202 #endif /* NO_PTHREAD_SEMAPHORES */ | |
| 203 | |
| 204 #else /* System V IPC implementation */ | |
| 205 | |
| 206 #include <stdio.h> | |
| 207 #include <stdlib.h> | |
| 208 #include <sys/types.h> | |
| 209 #include <sys/ipc.h> | |
| 210 #include <sys/sem.h> | |
| 211 #include <errno.h> | |
| 212 | |
| 213 #include "SDL_error.h" | |
| 214 #include "SDL_thread.h" | |
| 215 | |
| 216 | |
| 217 struct SDL_semaphore { | |
| 218 int id; | |
| 219 }; | |
| 220 | |
| 221 /* Not defined by many operating systems, use configure to detect */ | |
| 222 #if !defined(HAVE_SEMUN) | |
| 223 union semun { | |
| 224 int val; | |
| 225 struct semid_ds *buf; | |
| 226 ushort *array; | |
| 227 }; | |
| 228 #endif | |
| 229 | |
| 230 static struct sembuf op_trywait[2] = { | |
| 231 { 0, -1, (IPC_NOWAIT|SEM_UNDO) } /* Decrement semaphore, no block */ | |
| 232 }; | |
| 233 static struct sembuf op_wait[2] = { | |
| 234 { 0, -1, SEM_UNDO } /* Decrement semaphore */ | |
| 235 }; | |
| 236 static struct sembuf op_post[1] = { | |
| 237 { 0, 1, (IPC_NOWAIT|SEM_UNDO) } /* Increment semaphore */ | |
| 238 }; | |
| 239 | |
| 240 /* Create a blockable semaphore */ | |
| 241 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 242 { | |
| 243 extern int _creating_thread_lock; /* SDL_threads.c */ | |
| 244 SDL_sem *sem; | |
| 245 union semun init; | |
| 246 key_t key; | |
| 247 | |
| 248 sem = (SDL_sem *)malloc(sizeof(*sem)); | |
| 249 if ( sem == NULL ) { | |
| 250 SDL_OutOfMemory(); | |
| 251 return(NULL); | |
| 252 } | |
| 253 /* This flag is true if we are creating the thread manager sem, | |
| 254 which is never freed. This allows us to reuse the same sem. | |
| 255 */ | |
| 256 if ( _creating_thread_lock ) { | |
| 257 key = 'S'+'D'+'L'; | |
| 258 } else { | |
| 259 key = IPC_PRIVATE; | |
| 260 } | |
| 261 /* Keep trying to create sem while we don't own the requested key */ | |
| 262 do { | |
| 263 if ( key != IPC_PRIVATE ) { | |
| 264 ++key; | |
| 265 } | |
| 266 sem->id = semget(key, 1, (0600|IPC_CREAT)); | |
| 267 } while ((sem->id < 0) && (key != IPC_PRIVATE) && (errno == EACCES)); | |
| 268 | |
| 269 /* Report the error if we eventually failed */ | |
| 270 if ( sem->id < 0 ) { | |
| 271 SDL_SetError("Couldn't create semaphore"); | |
| 272 free(sem); | |
| 273 return(NULL); | |
| 274 } | |
| 275 init.val = initial_value; /* Initialize semaphore */ | |
| 276 semctl(sem->id, 0, SETVAL, init); | |
| 277 return(sem); | |
| 278 } | |
| 279 | |
| 280 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 281 { | |
| 282 if ( sem ) { | |
| 283 #ifdef _SGI_SOURCE | |
| 284 semctl(sem->id, 0, IPC_RMID); | |
| 285 #else | |
| 286 union semun dummy; | |
| 287 dummy.val = 0; | |
| 288 semctl(sem->id, 0, IPC_RMID, dummy); | |
| 289 #endif | |
| 290 free(sem); | |
| 291 } | |
| 292 } | |
| 293 | |
| 294 int SDL_SemTryWait(SDL_sem *sem) | |
| 295 { | |
| 296 int retval; | |
| 297 | |
| 298 if ( ! sem ) { | |
| 299 SDL_SetError("Passed a NULL semaphore"); | |
| 300 return -1; | |
| 301 } | |
| 302 | |
| 303 retval = 0; | |
| 304 tryagain: | |
| 305 if ( semop(sem->id, op_trywait, 1) < 0 ) { | |
| 306 if ( errno == EINTR ) { | |
| 307 goto tryagain; | |
| 308 } | |
| 309 retval = SDL_MUTEX_TIMEDOUT; | |
| 310 } | |
| 311 return retval; | |
| 312 } | |
| 313 | |
| 314 int SDL_SemWait(SDL_sem *sem) | |
| 315 { | |
| 316 int retval; | |
| 317 | |
| 318 if ( ! sem ) { | |
| 319 SDL_SetError("Passed a NULL semaphore"); | |
| 320 return -1; | |
| 321 } | |
| 322 | |
| 323 retval = 0; | |
| 324 tryagain: | |
| 325 if ( semop(sem->id, op_wait, 1) < 0 ) { | |
| 326 if ( errno == EINTR ) { | |
| 327 goto tryagain; | |
| 328 } | |
| 329 SDL_SetError("Semaphore operation error"); | |
| 330 retval = -1; | |
| 331 } | |
| 332 return retval; | |
| 333 } | |
| 334 | |
| 335 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 336 { | |
| 337 int retval; | |
| 338 | |
| 339 if ( ! sem ) { | |
| 340 SDL_SetError("Passed a NULL semaphore"); | |
| 341 return -1; | |
| 342 } | |
| 343 | |
| 344 /* Try the easy cases first */ | |
| 345 if ( timeout == 0 ) { | |
| 346 return SDL_SemTryWait(sem); | |
| 347 } | |
| 348 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 349 return SDL_SemWait(sem); | |
| 350 } | |
| 351 | |
| 352 /* Ack! We have to busy wait... */ | |
| 353 timeout += SDL_GetTicks(); | |
| 354 do { | |
| 355 retval = SDL_SemTryWait(sem); | |
| 356 if ( retval == 0 ) { | |
| 357 break; | |
| 358 } | |
| 359 SDL_Delay(1); | |
| 360 } while ( SDL_GetTicks() < timeout ); | |
| 361 | |
| 362 return retval; | |
| 363 } | |
| 364 | |
| 365 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 366 { | |
| 367 int semval; | |
| 368 Uint32 value; | |
| 369 | |
| 370 value = 0; | |
| 371 if ( sem ) { | |
| 372 tryagain: | |
| 373 #ifdef _SGI_SOURCE | |
| 374 semval = semctl(sem->id, 0, GETVAL); | |
| 375 #else | |
| 376 { | |
| 377 union semun arg; | |
| 378 arg.val = 0; | |
| 379 semval = semctl(sem->id, 0, GETVAL, arg); | |
| 380 } | |
| 381 #endif | |
| 382 if ( semval < 0 ) { | |
| 383 if ( errno == EINTR ) { | |
| 384 goto tryagain; | |
| 385 } | |
| 386 } else { | |
| 387 value = (Uint32)semval; | |
| 388 } | |
| 389 } | |
| 390 return value; | |
| 391 } | |
| 392 | |
| 393 int SDL_SemPost(SDL_sem *sem) | |
| 394 { | |
| 395 int retval; | |
| 396 | |
| 397 if ( ! sem ) { | |
| 398 SDL_SetError("Passed a NULL semaphore"); | |
| 399 return -1; | |
| 400 } | |
| 401 | |
| 402 retval = 0; | |
| 403 tryagain: | |
| 404 if ( semop(sem->id, op_post, 1) < 0 ) { | |
| 405 if ( errno == EINTR ) { | |
| 406 goto tryagain; | |
| 407 } | |
| 408 SDL_SetError("Semaphore operation error"); | |
| 409 retval = -1; | |
| 410 } | |
| 411 return retval; | |
| 412 } | |
| 413 | |
| 414 #endif /* SDL_USE_PTHREADS */ |