Mercurial > sdl-ios-xcode
annotate src/thread/linux/SDL_syssem.c @ 1358:c71e05b4dc2e
More header massaging... works great on Windows. ;-)
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 10 Feb 2006 06:48:43 +0000 |
| parents | 604d73db6802 |
| children |
| 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>
parents:
94
diff
changeset
|
20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #include "SDL_thread.h" | |
| 24 #include "SDL_timer.h" | |
| 25 | |
| 26 #ifdef linux | |
| 27 /* Look to see if glibc is available, and if so, what version */ | |
| 28 #include <features.h> | |
| 29 | |
| 30 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0) | |
| 31 #warning Working around a bug in glibc 2.0 pthreads | |
| 32 #undef SDL_USE_PTHREADS | |
| 33 /* The bug is actually a problem where threads are suspended, but don't | |
| 34 wake up when the thread manager sends them a signal. This is a problem | |
| 35 with thread creation too, but it happens less often. :-/ | |
| 36 We avoid this by using System V IPC for semaphores. | |
| 37 */ | |
| 38 #endif /* glibc 2.0 */ | |
| 39 #endif /* linux */ | |
| 40 | |
| 41 #ifdef SDL_USE_PTHREADS | |
| 42 | |
| 43 #ifdef SDL_NO_PTHREAD_SEMAPHORES | |
|
94
ae6e6b73333f
Cleaned up the OpenBSD port, thanks to Peter Valchev
Sam Lantinga <slouken@lokigames.com>
parents:
18
diff
changeset
|
44 #include "generic/SDL_syssem.c" |
| 0 | 45 #else |
| 46 | |
|
18
d9e3595b63d5
Added pthread.h - necessary on some configurations
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
47 #include <pthread.h> |
| 0 | 48 #include <semaphore.h> |
| 49 | |
| 50 /* Wrapper around POSIX 1003.1b semaphores */ | |
| 51 | |
| 52 #ifdef MACOSX | |
| 53 #define USE_NAMED_SEMAPHORES | |
| 54 #endif /* MACOSX */ | |
| 55 | |
| 56 struct SDL_semaphore { | |
| 57 sem_t *sem; | |
| 58 #ifndef USE_NAMED_SEMAPHORES | |
| 59 sem_t sem_data; | |
| 60 #endif | |
| 61 }; | |
| 62 | |
| 63 /* Create a semaphore, initialized with value */ | |
| 64 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 65 { | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
66 SDL_sem *sem = (SDL_sem *) SDL_malloc(sizeof(SDL_sem)); |
| 0 | 67 if ( sem ) { |
| 68 #ifdef USE_NAMED_SEMAPHORES | |
| 69 static int semnum = 0; | |
| 70 char name[32]; | |
| 71 | |
|
1338
604d73db6802
Removed uses of stdlib.h and string.h
Sam Lantinga <slouken@libsdl.org>
parents:
1336
diff
changeset
|
72 SDL_snprintf(name, SDL_arraysize(name), "/SDL_sem-%d-%4.4d", getpid(), semnum++); |
| 0 | 73 sem->sem = sem_open(name, O_CREAT, 0600, initial_value); |
| 74 if ( sem->sem == (sem_t *)SEM_FAILED ) { | |
| 75 SDL_SetError("sem_open(%s) failed", name); | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
76 SDL_free(sem); |
| 0 | 77 sem = NULL; |
| 78 } else { | |
| 79 sem_unlink(name); | |
| 80 } | |
| 81 #else | |
| 82 if ( sem_init(&sem->sem_data, 0, initial_value) < 0 ) { | |
| 83 SDL_SetError("sem_init() failed"); | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
84 SDL_free(sem); |
| 0 | 85 sem = NULL; |
| 86 } else { | |
| 87 sem->sem = &sem->sem_data; | |
| 88 } | |
| 89 #endif /* USE_NAMED_SEMAPHORES */ | |
| 90 } else { | |
| 91 SDL_OutOfMemory(); | |
| 92 } | |
| 93 return sem; | |
| 94 } | |
| 95 | |
| 96 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 97 { | |
| 98 if ( sem ) { | |
| 99 #ifdef USE_NAMED_SEMAPHORES | |
| 100 sem_close(sem->sem); | |
| 101 #else | |
| 102 sem_destroy(sem->sem); | |
| 103 #endif | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
104 SDL_free(sem); |
| 0 | 105 } |
| 106 } | |
| 107 | |
| 108 int SDL_SemTryWait(SDL_sem *sem) | |
| 109 { | |
| 110 int retval; | |
| 111 | |
| 112 if ( ! sem ) { | |
| 113 SDL_SetError("Passed a NULL semaphore"); | |
| 114 return -1; | |
| 115 } | |
| 116 retval = SDL_MUTEX_TIMEDOUT; | |
| 117 if ( sem_trywait(sem->sem) == 0 ) { | |
| 118 retval = 0; | |
| 119 } | |
| 120 return retval; | |
| 121 } | |
| 122 | |
| 123 int SDL_SemWait(SDL_sem *sem) | |
| 124 { | |
| 125 int retval; | |
| 126 | |
| 127 if ( ! sem ) { | |
| 128 SDL_SetError("Passed a NULL semaphore"); | |
| 129 return -1; | |
| 130 } | |
| 131 | |
| 132 retval = sem_wait(sem->sem); | |
| 133 if ( retval < 0 ) { | |
| 134 SDL_SetError("sem_wait() failed"); | |
| 135 } | |
| 136 return retval; | |
| 137 } | |
| 138 | |
| 139 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 140 { | |
| 141 int retval; | |
| 142 | |
| 143 if ( ! sem ) { | |
| 144 SDL_SetError("Passed a NULL semaphore"); | |
| 145 return -1; | |
| 146 } | |
| 147 | |
| 148 /* Try the easy cases first */ | |
| 149 if ( timeout == 0 ) { | |
| 150 return SDL_SemTryWait(sem); | |
| 151 } | |
| 152 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 153 return SDL_SemWait(sem); | |
| 154 } | |
| 155 | |
| 156 /* Ack! We have to busy wait... */ | |
| 157 timeout += SDL_GetTicks(); | |
| 158 do { | |
| 159 retval = SDL_SemTryWait(sem); | |
| 160 if ( retval == 0 ) { | |
| 161 break; | |
| 162 } | |
| 163 SDL_Delay(1); | |
| 164 } while ( SDL_GetTicks() < timeout ); | |
| 165 | |
| 166 return retval; | |
| 167 } | |
| 168 | |
| 169 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 170 { | |
| 171 int ret = 0; | |
| 172 if ( sem ) { | |
| 173 sem_getvalue(sem->sem, &ret); | |
| 174 if ( ret < 0 ) { | |
| 175 ret = 0; | |
| 176 } | |
| 177 } | |
| 178 return (Uint32)ret; | |
| 179 } | |
| 180 | |
| 181 int SDL_SemPost(SDL_sem *sem) | |
| 182 { | |
| 183 int retval; | |
| 184 | |
| 185 if ( ! sem ) { | |
| 186 SDL_SetError("Passed a NULL semaphore"); | |
| 187 return -1; | |
| 188 } | |
| 189 | |
| 190 retval = sem_post(sem->sem); | |
| 191 if ( retval < 0 ) { | |
| 192 SDL_SetError("sem_post() failed"); | |
| 193 } | |
| 194 return retval; | |
| 195 } | |
| 196 | |
| 197 #endif /* NO_PTHREAD_SEMAPHORES */ | |
| 198 | |
| 199 #else /* System V IPC implementation */ | |
| 200 | |
| 201 #include <stdio.h> | |
| 202 #include <stdlib.h> | |
| 203 #include <sys/types.h> | |
| 204 #include <sys/ipc.h> | |
| 205 #include <sys/sem.h> | |
| 206 #include <errno.h> | |
| 207 | |
| 208 #include "SDL_error.h" | |
| 209 #include "SDL_thread.h" | |
| 210 | |
| 211 | |
| 212 struct SDL_semaphore { | |
| 213 int id; | |
| 214 }; | |
| 215 | |
| 216 /* Not defined by many operating systems, use configure to detect */ | |
| 217 #if !defined(HAVE_SEMUN) | |
| 218 union semun { | |
| 219 int val; | |
| 220 struct semid_ds *buf; | |
| 221 ushort *array; | |
| 222 }; | |
| 223 #endif | |
| 224 | |
| 225 static struct sembuf op_trywait[2] = { | |
| 226 { 0, -1, (IPC_NOWAIT|SEM_UNDO) } /* Decrement semaphore, no block */ | |
| 227 }; | |
| 228 static struct sembuf op_wait[2] = { | |
| 229 { 0, -1, SEM_UNDO } /* Decrement semaphore */ | |
| 230 }; | |
| 231 static struct sembuf op_post[1] = { | |
| 232 { 0, 1, (IPC_NOWAIT|SEM_UNDO) } /* Increment semaphore */ | |
| 233 }; | |
| 234 | |
| 235 /* Create a blockable semaphore */ | |
| 236 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 237 { | |
| 238 extern int _creating_thread_lock; /* SDL_threads.c */ | |
| 239 SDL_sem *sem; | |
| 240 union semun init; | |
| 241 key_t key; | |
| 242 | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
243 sem = (SDL_sem *)SDL_malloc(sizeof(*sem)); |
| 0 | 244 if ( sem == NULL ) { |
| 245 SDL_OutOfMemory(); | |
| 246 return(NULL); | |
| 247 } | |
| 248 /* This flag is true if we are creating the thread manager sem, | |
| 249 which is never freed. This allows us to reuse the same sem. | |
| 250 */ | |
| 251 if ( _creating_thread_lock ) { | |
| 252 key = 'S'+'D'+'L'; | |
| 253 } else { | |
| 254 key = IPC_PRIVATE; | |
| 255 } | |
| 256 /* Keep trying to create sem while we don't own the requested key */ | |
| 257 do { | |
| 258 if ( key != IPC_PRIVATE ) { | |
| 259 ++key; | |
| 260 } | |
| 261 sem->id = semget(key, 1, (0600|IPC_CREAT)); | |
| 262 } while ((sem->id < 0) && (key != IPC_PRIVATE) && (errno == EACCES)); | |
| 263 | |
| 264 /* Report the error if we eventually failed */ | |
| 265 if ( sem->id < 0 ) { | |
| 266 SDL_SetError("Couldn't create semaphore"); | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
267 SDL_free(sem); |
| 0 | 268 return(NULL); |
| 269 } | |
| 270 init.val = initial_value; /* Initialize semaphore */ | |
| 271 semctl(sem->id, 0, SETVAL, init); | |
| 272 return(sem); | |
| 273 } | |
| 274 | |
| 275 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 276 { | |
| 277 if ( sem ) { | |
| 278 #ifdef _SGI_SOURCE | |
| 279 semctl(sem->id, 0, IPC_RMID); | |
| 280 #else | |
| 281 union semun dummy; | |
| 282 dummy.val = 0; | |
| 283 semctl(sem->id, 0, IPC_RMID, dummy); | |
| 284 #endif | |
|
1336
3692456e7b0f
Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents:
1312
diff
changeset
|
285 SDL_free(sem); |
| 0 | 286 } |
| 287 } | |
| 288 | |
| 289 int SDL_SemTryWait(SDL_sem *sem) | |
| 290 { | |
| 291 int retval; | |
| 292 | |
| 293 if ( ! sem ) { | |
| 294 SDL_SetError("Passed a NULL semaphore"); | |
| 295 return -1; | |
| 296 } | |
| 297 | |
| 298 retval = 0; | |
| 299 tryagain: | |
| 300 if ( semop(sem->id, op_trywait, 1) < 0 ) { | |
| 301 if ( errno == EINTR ) { | |
| 302 goto tryagain; | |
| 303 } | |
| 304 retval = SDL_MUTEX_TIMEDOUT; | |
| 305 } | |
| 306 return retval; | |
| 307 } | |
| 308 | |
| 309 int SDL_SemWait(SDL_sem *sem) | |
| 310 { | |
| 311 int retval; | |
| 312 | |
| 313 if ( ! sem ) { | |
| 314 SDL_SetError("Passed a NULL semaphore"); | |
| 315 return -1; | |
| 316 } | |
| 317 | |
| 318 retval = 0; | |
| 319 tryagain: | |
| 320 if ( semop(sem->id, op_wait, 1) < 0 ) { | |
| 321 if ( errno == EINTR ) { | |
| 322 goto tryagain; | |
| 323 } | |
| 324 SDL_SetError("Semaphore operation error"); | |
| 325 retval = -1; | |
| 326 } | |
| 327 return retval; | |
| 328 } | |
| 329 | |
| 330 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 331 { | |
| 332 int retval; | |
| 333 | |
| 334 if ( ! sem ) { | |
| 335 SDL_SetError("Passed a NULL semaphore"); | |
| 336 return -1; | |
| 337 } | |
| 338 | |
| 339 /* Try the easy cases first */ | |
| 340 if ( timeout == 0 ) { | |
| 341 return SDL_SemTryWait(sem); | |
| 342 } | |
| 343 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 344 return SDL_SemWait(sem); | |
| 345 } | |
| 346 | |
| 347 /* Ack! We have to busy wait... */ | |
| 348 timeout += SDL_GetTicks(); | |
| 349 do { | |
| 350 retval = SDL_SemTryWait(sem); | |
| 351 if ( retval == 0 ) { | |
| 352 break; | |
| 353 } | |
| 354 SDL_Delay(1); | |
| 355 } while ( SDL_GetTicks() < timeout ); | |
| 356 | |
| 357 return retval; | |
| 358 } | |
| 359 | |
| 360 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 361 { | |
| 362 int semval; | |
| 363 Uint32 value; | |
| 364 | |
| 365 value = 0; | |
| 366 if ( sem ) { | |
| 367 tryagain: | |
| 368 #ifdef _SGI_SOURCE | |
| 369 semval = semctl(sem->id, 0, GETVAL); | |
| 370 #else | |
| 371 { | |
| 372 union semun arg; | |
| 373 arg.val = 0; | |
| 374 semval = semctl(sem->id, 0, GETVAL, arg); | |
| 375 } | |
| 376 #endif | |
| 377 if ( semval < 0 ) { | |
| 378 if ( errno == EINTR ) { | |
| 379 goto tryagain; | |
| 380 } | |
| 381 } else { | |
| 382 value = (Uint32)semval; | |
| 383 } | |
| 384 } | |
| 385 return value; | |
| 386 } | |
| 387 | |
| 388 int SDL_SemPost(SDL_sem *sem) | |
| 389 { | |
| 390 int retval; | |
| 391 | |
| 392 if ( ! sem ) { | |
| 393 SDL_SetError("Passed a NULL semaphore"); | |
| 394 return -1; | |
| 395 } | |
| 396 | |
| 397 retval = 0; | |
| 398 tryagain: | |
| 399 if ( semop(sem->id, op_post, 1) < 0 ) { | |
| 400 if ( errno == EINTR ) { | |
| 401 goto tryagain; | |
| 402 } | |
| 403 SDL_SetError("Semaphore operation error"); | |
| 404 retval = -1; | |
| 405 } | |
| 406 return retval; | |
| 407 } | |
| 408 | |
| 409 #endif /* SDL_USE_PTHREADS */ |