Mercurial > sdl-ios-xcode
annotate src/thread/bsdi/SDL_syssem.c @ 673:63419da96d13
*** empty log message ***
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 08 Aug 2003 21:39:12 +0000 |
| parents | f6ffac90895c |
| children | b8d311d90021 |
| rev | line source |
|---|---|
| 256 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
297
f6ffac90895c
Updated copyright information for 2002
Sam Lantinga <slouken@libsdl.org>
parents:
271
diff
changeset
|
3 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga |
| 256 | 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 | |
| 20 slouken@devolution.com | |
| 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 SDL_USE_PTHREADS | |
| 34 | |
| 35 #include <stdio.h> | |
| 36 #include <stdlib.h> | |
| 37 #include <unistd.h> /* For getpid() */ | |
| 38 #include <pthread.h> | |
| 39 | |
| 40 | |
| 41 /* | |
| 42 * This is semaphore.h inlined here so that BSD/OS POSIX semaphore are | |
| 43 * completely selfcontained without requiring any additional include files | |
| 44 * or libraries not present in the stock system | |
| 45 */ | |
| 46 | |
| 47 /* semaphore.h: POSIX 1003.1b semaphores */ | |
| 48 | |
| 49 /*- | |
| 50 * Copyright (c) 1996, 1997 | |
| 51 * HD Associates, Inc. All rights reserved. | |
| 52 * | |
| 53 * Redistribution and use in source and binary forms, with or without | |
| 54 * modification, are permitted provided that the following conditions | |
| 55 * are met: | |
| 56 * 1. Redistributions of source code must retain the above copyright | |
| 57 * notice, this list of conditions and the following disclaimer. | |
| 58 * 2. Redistributions in binary form must reproduce the above copyright | |
| 59 * notice, this list of conditions and the following disclaimer in the | |
| 60 * documentation and/or other materials provided with the distribution. | |
| 61 * 3. All advertising materials mentioning features or use of this software | |
| 62 * must display the following acknowledgement: | |
| 63 * This product includes software developed by HD Associates, Inc | |
| 64 * 4. Neither the name of the author nor the names of any co-contributors | |
| 65 * may be used to endorse or promote products derived from this software | |
| 66 * without specific prior written permission. | |
| 67 * | |
| 68 * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND | |
| 69 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 70 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 71 * ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE | |
| 72 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 73 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 74 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 75 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 76 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 77 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 78 * SUCH DAMAGE. | |
| 79 * | |
| 80 * $FreeBSD: src/sys/posix4/semaphore.h,v 1.6 2000/01/20 07:55:42 jasone Exp $ | |
| 81 */ | |
| 82 | |
| 83 #include <machine/limits.h> | |
| 84 | |
| 85 #include <sys/types.h> | |
| 86 #include <fcntl.h> | |
| 87 | |
| 88 /* Opaque type definition. */ | |
| 89 struct sem; | |
| 90 typedef struct sem *sem_t; | |
| 91 | |
| 92 #define SEM_FAILED ((sem_t *)0) | |
| 93 #define SEM_VALUE_MAX UINT_MAX | |
| 94 | |
| 95 #include <sys/cdefs.h> | |
| 96 | |
| 97 __BEGIN_DECLS | |
| 98 int sem_init __P((sem_t *, int, unsigned int)); | |
| 99 int sem_destroy __P((sem_t *)); | |
| 100 sem_t *sem_open __P((const char *, int, ...)); | |
| 101 int sem_close __P((sem_t *)); | |
| 102 int sem_unlink __P((const char *)); | |
| 103 int sem_wait __P((sem_t *)); | |
| 104 int sem_trywait __P((sem_t *)); | |
| 105 int sem_post __P((sem_t *)); | |
| 106 int sem_getvalue __P((sem_t *, int *)); | |
| 107 __END_DECLS | |
| 108 | |
| 109 /* END of inlined semaphore.h */ | |
| 110 | |
| 111 /* Wrapper around POSIX 1003.1b semaphores */ | |
| 112 | |
| 113 struct SDL_semaphore { | |
| 114 sem_t *sem; | |
| 115 sem_t sem_data; | |
| 116 }; | |
| 117 | |
| 118 /* Create a semaphore, initialized with value */ | |
| 119 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 120 { | |
| 121 SDL_sem *sem = (SDL_sem *) malloc(sizeof(SDL_sem)); | |
| 122 if ( sem ) { | |
| 123 if ( sem_init(&sem->sem_data, 0, initial_value) < 0 ) { | |
| 124 SDL_SetError("sem_init() failed"); | |
| 125 free(sem); | |
| 126 sem = NULL; | |
| 127 } else { | |
| 128 sem->sem = &sem->sem_data; | |
| 129 } | |
| 130 } else { | |
| 131 SDL_OutOfMemory(); | |
| 132 } | |
| 133 return sem; | |
| 134 } | |
| 135 | |
| 136 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 137 { | |
| 138 if ( sem ) { | |
| 139 sem_destroy(sem->sem); | |
| 140 free(sem); | |
| 141 } | |
| 142 } | |
| 143 | |
| 144 int SDL_SemTryWait(SDL_sem *sem) | |
| 145 { | |
| 146 int retval; | |
| 147 | |
| 148 if ( ! sem ) { | |
| 149 SDL_SetError("Passed a NULL semaphore"); | |
| 150 return -1; | |
| 151 } | |
| 152 retval = SDL_MUTEX_TIMEDOUT; | |
| 153 if ( sem_trywait(sem->sem) == 0 ) | |
| 154 retval = 0; | |
| 155 return retval; | |
| 156 } | |
| 157 | |
| 158 int SDL_SemWait(SDL_sem *sem) | |
| 159 { | |
| 160 int retval; | |
| 161 | |
| 162 if ( ! sem ) { | |
| 163 SDL_SetError("Passed a NULL semaphore"); | |
| 164 return -1; | |
| 165 } | |
| 166 | |
| 167 retval = sem_wait(sem->sem); | |
| 168 if ( retval < 0 ) { | |
| 169 SDL_SetError("sem_wait() failed"); | |
| 170 } | |
| 171 return retval; | |
| 172 } | |
| 173 | |
| 174 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 175 { | |
| 176 int retval; | |
| 177 | |
| 178 if ( ! sem ) { | |
| 179 SDL_SetError("Passed a NULL semaphore"); | |
| 180 return -1; | |
| 181 } | |
| 182 | |
| 183 /* Try the easy cases first */ | |
| 184 if ( timeout == 0 ) { | |
| 185 return SDL_SemTryWait(sem); | |
| 186 } | |
| 187 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 188 return SDL_SemWait(sem); | |
| 189 } | |
| 190 | |
| 191 /* Ack! We have to busy wait... */ | |
| 192 timeout += SDL_GetTicks(); | |
| 193 do { | |
| 194 retval = SDL_SemTryWait(sem); | |
| 195 if ( retval == 0 ) { | |
| 196 break; | |
| 197 } | |
| 198 SDL_Delay(1); | |
| 199 } while ( SDL_GetTicks() < timeout ); | |
| 200 | |
| 201 return retval; | |
| 202 } | |
| 203 | |
| 204 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 205 { | |
| 206 int ret = 0; | |
| 207 if ( sem ) { | |
| 208 sem_getvalue(sem->sem, &ret); | |
| 209 if ( ret < 0 ) { | |
| 210 ret = 0; | |
| 211 } | |
| 212 } | |
| 213 return (Uint32)ret; | |
| 214 } | |
| 215 | |
| 216 int SDL_SemPost(SDL_sem *sem) | |
| 217 { | |
| 218 int retval; | |
| 219 | |
| 220 if ( ! sem ) { | |
| 221 SDL_SetError("Passed a NULL semaphore"); | |
| 222 return -1; | |
| 223 } | |
| 224 | |
| 225 retval = sem_post(sem->sem); | |
| 226 if ( retval < 0 ) { | |
| 227 SDL_SetError("sem_post() failed"); | |
| 228 } | |
| 229 return retval; | |
| 230 } | |
| 231 | |
| 232 /* | |
| 233 * BEGIN inlined uthread_sem.c. This is done here so that no extra libraries | |
| 234 * or include files not present in BSD/OS are required | |
| 235 */ | |
| 236 | |
| 237 /* | |
| 238 * Copyright (C) 2000 Jason Evans <jasone@freebsd.org>. | |
| 239 * All rights reserved. | |
| 240 * | |
| 241 * Redistribution and use in source and binary forms, with or without | |
| 242 * modification, are permitted provided that the following conditions | |
| 243 * are met: | |
| 244 * 1. Redistributions of source code must retain the above copyright | |
| 245 * notice(s), this list of conditions and the following disclaimer as | |
| 246 * the first lines of this file unmodified other than the possible | |
| 247 * addition of one or more copyright notices. | |
| 248 * 2. Redistributions in binary form must reproduce the above copyright | |
| 249 * notice(s), this list of conditions and the following disclaimer in | |
| 250 * the documentation and/or other materials provided with the | |
| 251 * distribution. | |
| 252 * | |
| 253 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY | |
| 254 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 255 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| 256 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE | |
| 257 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| 258 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| 259 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR | |
| 260 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, | |
| 261 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE | |
| 262 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, | |
| 263 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 264 * | |
| 265 * $FreeBSD: src/lib/libc_r/uthread/uthread_sem.c,v 1.3.2.1 2000/07/18 02:05:57 jasone Exp $ | |
| 266 */ | |
| 267 | |
| 268 #include <errno.h> | |
| 269 #include <pthread.h> | |
| 270 | |
| 271 /* Begin thread_private.h kluge */ | |
| 272 /* | |
| 273 * These come out of (or should go into) thread_private.h - rather than have | |
| 274 * to copy (or symlink) the files from the source tree these definitions are | |
| 275 * inlined here. Obviously these go away when this module is part of libc. | |
| 276 */ | |
| 277 struct sem { | |
| 278 #define SEM_MAGIC ((u_int32_t) 0x09fa4012) | |
| 279 u_int32_t magic; | |
| 280 pthread_mutex_t lock; | |
| 281 pthread_cond_t gtzero; | |
| 282 u_int32_t count; | |
| 283 u_int32_t nwaiters; | |
| 284 }; | |
| 285 | |
| 286 extern pthread_once_t _thread_init_once; | |
| 287 extern int _threads_initialized; | |
| 288 extern void _thread_init __P((void)); | |
| 289 #define THREAD_INIT() \ | |
| 290 (void) pthread_once(&_thread_init_once, _thread_init) | |
| 291 #define THREAD_SAFE() \ | |
| 292 (_threads_initialized != 0) | |
| 293 | |
| 294 #define _SEM_CHECK_VALIDITY(sem) \ | |
| 295 if ((*(sem))->magic != SEM_MAGIC) { \ | |
| 296 errno = EINVAL; \ | |
| 297 retval = -1; \ | |
| 298 goto RETURN; \ | |
| 299 } | |
| 300 /* End thread_private.h kluge */ | |
| 301 | |
| 302 int | |
| 303 sem_init(sem_t *sem, int pshared, unsigned int value) | |
| 304 { | |
| 305 int retval; | |
| 306 | |
| 307 if (!THREAD_SAFE()) | |
| 308 THREAD_INIT(); | |
| 309 | |
| 310 /* | |
| 311 * Range check the arguments. | |
| 312 */ | |
| 313 if (pshared != 0) { | |
| 314 /* | |
| 315 * The user wants a semaphore that can be shared among | |
| 316 * processes, which this implementation can't do. Sounds like a | |
| 317 * permissions problem to me (yeah right). | |
| 318 */ | |
| 319 errno = EPERM; | |
| 320 retval = -1; | |
| 321 goto RETURN; | |
| 322 } | |
| 323 | |
| 324 if (value > SEM_VALUE_MAX) { | |
| 325 errno = EINVAL; | |
| 326 retval = -1; | |
| 327 goto RETURN; | |
| 328 } | |
| 329 | |
| 330 *sem = (sem_t)malloc(sizeof(struct sem)); | |
| 331 if (*sem == NULL) { | |
| 332 errno = ENOSPC; | |
| 333 retval = -1; | |
| 334 goto RETURN; | |
| 335 } | |
| 336 | |
| 337 /* | |
| 338 * Initialize the semaphore. | |
| 339 */ | |
| 340 if (pthread_mutex_init(&(*sem)->lock, NULL) != 0) { | |
| 341 free(*sem); | |
| 342 errno = ENOSPC; | |
| 343 retval = -1; | |
| 344 goto RETURN; | |
| 345 } | |
| 346 | |
| 347 if (pthread_cond_init(&(*sem)->gtzero, NULL) != 0) { | |
| 348 pthread_mutex_destroy(&(*sem)->lock); | |
| 349 free(*sem); | |
| 350 errno = ENOSPC; | |
| 351 retval = -1; | |
| 352 goto RETURN; | |
| 353 } | |
| 354 | |
| 355 (*sem)->count = (u_int32_t)value; | |
| 356 (*sem)->nwaiters = 0; | |
| 357 (*sem)->magic = SEM_MAGIC; | |
| 358 | |
| 359 retval = 0; | |
| 360 RETURN: | |
| 361 return retval; | |
| 362 } | |
| 363 | |
| 364 int | |
| 365 sem_destroy(sem_t *sem) | |
| 366 { | |
| 367 int retval; | |
| 368 | |
| 369 _SEM_CHECK_VALIDITY(sem); | |
| 370 | |
| 371 /* Make sure there are no waiters. */ | |
| 372 pthread_mutex_lock(&(*sem)->lock); | |
| 373 if ((*sem)->nwaiters > 0) { | |
| 374 pthread_mutex_unlock(&(*sem)->lock); | |
| 375 errno = EBUSY; | |
| 376 retval = -1; | |
| 377 goto RETURN; | |
| 378 } | |
| 379 pthread_mutex_unlock(&(*sem)->lock); | |
| 380 | |
| 381 pthread_mutex_destroy(&(*sem)->lock); | |
| 382 pthread_cond_destroy(&(*sem)->gtzero); | |
| 383 (*sem)->magic = 0; | |
| 384 | |
| 385 free(*sem); | |
| 386 | |
| 387 retval = 0; | |
| 388 RETURN: | |
| 389 return retval; | |
| 390 } | |
| 391 | |
| 392 sem_t * | |
| 393 sem_open(const char *name, int oflag, ...) | |
| 394 { | |
| 395 errno = ENOSYS; | |
| 396 return SEM_FAILED; | |
| 397 } | |
| 398 | |
| 399 int | |
| 400 sem_close(sem_t *sem) | |
| 401 { | |
| 402 errno = ENOSYS; | |
| 403 return -1; | |
| 404 } | |
| 405 | |
| 406 int | |
| 407 sem_unlink(const char *name) | |
| 408 { | |
| 409 errno = ENOSYS; | |
| 410 return -1; | |
| 411 } | |
| 412 | |
| 413 int | |
| 414 sem_wait(sem_t *sem) | |
| 415 { | |
| 416 int retval; | |
| 417 | |
| 418 pthread_testcancel(); | |
| 419 | |
| 420 _SEM_CHECK_VALIDITY(sem); | |
| 421 | |
| 422 pthread_mutex_lock(&(*sem)->lock); | |
| 423 | |
| 424 while ((*sem)->count == 0) { | |
| 425 (*sem)->nwaiters++; | |
| 426 pthread_cond_wait(&(*sem)->gtzero, &(*sem)->lock); | |
| 427 (*sem)->nwaiters--; | |
| 428 } | |
| 429 (*sem)->count--; | |
| 430 | |
| 431 pthread_mutex_unlock(&(*sem)->lock); | |
| 432 | |
| 433 retval = 0; | |
| 434 RETURN: | |
| 435 | |
| 436 pthread_testcancel(); | |
| 437 return retval; | |
| 438 } | |
| 439 | |
| 440 int | |
| 441 sem_trywait(sem_t *sem) | |
| 442 { | |
| 443 int retval; | |
| 444 | |
| 445 _SEM_CHECK_VALIDITY(sem); | |
| 446 | |
| 447 pthread_mutex_lock(&(*sem)->lock); | |
| 448 | |
| 449 if ((*sem)->count > 0) { | |
| 450 (*sem)->count--; | |
| 451 retval = 0; | |
| 452 } else { | |
| 453 errno = EAGAIN; | |
| 454 retval = -1; | |
| 455 } | |
| 456 | |
| 457 pthread_mutex_unlock(&(*sem)->lock); | |
| 458 | |
| 459 RETURN: | |
| 460 return retval; | |
| 461 } | |
| 462 | |
| 463 int | |
| 464 sem_post(sem_t *sem) | |
| 465 { | |
| 466 int retval; | |
| 467 | |
| 468 _SEM_CHECK_VALIDITY(sem); | |
| 469 | |
| 470 pthread_mutex_lock(&(*sem)->lock); | |
| 471 | |
| 472 (*sem)->count++; | |
| 473 if ((*sem)->nwaiters > 0) { | |
| 474 /* | |
| 475 * We must use pthread_cond_broadcast() rather than | |
| 476 * pthread_cond_signal() in order to assure that the highest | |
| 477 * priority thread is run by the scheduler, since | |
| 478 * pthread_cond_signal() signals waiting threads in FIFO order. | |
| 479 */ | |
| 480 pthread_cond_broadcast(&(*sem)->gtzero); | |
| 481 } | |
| 482 | |
| 483 pthread_mutex_unlock(&(*sem)->lock); | |
| 484 | |
| 485 retval = 0; | |
| 486 RETURN: | |
| 487 return retval; | |
| 488 } | |
| 489 | |
| 490 int | |
| 491 sem_getvalue(sem_t *sem, int *sval) | |
| 492 { | |
| 493 int retval; | |
| 494 | |
| 495 _SEM_CHECK_VALIDITY(sem); | |
| 496 | |
| 497 pthread_mutex_lock(&(*sem)->lock); | |
| 498 *sval = (int)(*sem)->count; | |
| 499 pthread_mutex_unlock(&(*sem)->lock); | |
| 500 | |
| 501 retval = 0; | |
| 502 RETURN: | |
| 503 return retval; | |
| 504 } | |
| 505 | |
| 506 /* END of inlined uthread_sem.c */ | |
| 507 #endif /* SDL_USE_PTHREADS */ |