lib/libthread_xu/thread/thr_mutex.c

   1 /*
   2  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
   3  * Copyright (c) 2006 David Xu <yfxu@corp.netease.com>.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by John Birrell.
  17  * 4. Neither the name of the author nor the names of any co-contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * $DragonFly: src/lib/libthread_xu/thread/thr_mutex.c,v 1.15 2008/05/09 16:03:27 dillon Exp $
  34  */
  35
  36 #include "namespace.h"
  37 #include <machine/tls.h>
  38
  39 #include <errno.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <sys/queue.h>
  43 #include <pthread.h>
  44 #include "un-namespace.h"
  45
  46 #include "thr_private.h"
  47
  48 #if defined(_PTHREADS_INVARIANTS)
  49 #define MUTEX_INIT_LINK(m)              do {            \
  50         (m)->m_qe.tqe_prev = NULL;                      \
  51         (m)->m_qe.tqe_next = NULL;                      \
  52 } while (0)
  53 #define MUTEX_ASSERT_IS_OWNED(m)        do {            \
  54         if ((m)->m_qe.tqe_prev == NULL)                 \
  55                 PANIC("mutex is not on list");          \
  56 } while (0)
  57 #define MUTEX_ASSERT_NOT_OWNED(m)       do {            \
  58         if (((m)->m_qe.tqe_prev != NULL) ||             \
  59             ((m)->m_qe.tqe_next != NULL))               \
  60                 PANIC("mutex is on list");              \
  61 } while (0)
  62 #define THR_ASSERT_NOT_IN_SYNCQ(thr)    do {            \
  63         THR_ASSERT(((thr)->sflags & THR_FLAGS_IN_SYNCQ) == 0, \
  64             "thread in syncq when it shouldn't be.");   \
  65 } while (0);
  66 #else
  67 #define MUTEX_INIT_LINK(m)
  68 #define MUTEX_ASSERT_IS_OWNED(m)
  69 #define MUTEX_ASSERT_NOT_OWNED(m)
  70 #define THR_ASSERT_NOT_IN_SYNCQ(thr)
  71 #endif
  72
  73 #define THR_IN_MUTEXQ(thr)      (((thr)->sflags & THR_FLAGS_IN_SYNCQ) != 0)
  74 #define MUTEX_DESTROY(m) do {           \
  75         free(m);                        \
  76 } while (0)
  77
  78 umtx_t  _mutex_static_lock;
  79
  80 /*
  81  * Prototypes
  82  */
  83 static int      mutex_self_trylock(pthread_mutex_t);
  84 static int      mutex_self_lock(pthread_mutex_t,
  85                         const struct timespec *abstime);
  86 static int      mutex_unlock_common(pthread_mutex_t *);
  87
  88 int __pthread_mutex_init(pthread_mutex_t *mutex,
  89         const pthread_mutexattr_t *mutex_attr);
  90 int __pthread_mutex_trylock(pthread_mutex_t *mutex);
  91 int __pthread_mutex_lock(pthread_mutex_t *mutex);
  92 int __pthread_mutex_timedlock(pthread_mutex_t *mutex,
  93         const struct timespec *abs_timeout);
  94
  95 static int
  96 mutex_init(pthread_mutex_t *mutex,
  97     const pthread_mutexattr_t *mutex_attr, int private)
  98 {
  99         const struct pthread_mutex_attr *attr;
 100         struct pthread_mutex *pmutex;
 101
 102         if (mutex_attr == NULL) {
 103                 attr = &_pthread_mutexattr_default;
 104         } else {
 105                 attr = *mutex_attr;
 106                 if (attr->m_type < PTHREAD_MUTEX_ERRORCHECK ||
 107                     attr->m_type >= MUTEX_TYPE_MAX)
 108                         return (EINVAL);
 109                 if (attr->m_protocol < PTHREAD_PRIO_NONE ||
 110                     attr->m_protocol > PTHREAD_PRIO_PROTECT)
 111                         return (EINVAL);
 112         }
 113
 114         if ((pmutex = (pthread_mutex_t)
 115                 malloc(sizeof(struct pthread_mutex))) == NULL)
 116                 return (ENOMEM);
 117
 118         _thr_umtx_init(&pmutex->m_lock);
 119         pmutex->m_type = attr->m_type;
 120         pmutex->m_protocol = attr->m_protocol;
 121         TAILQ_INIT(&pmutex->m_queue);
 122         pmutex->m_owner = NULL;
 123         pmutex->m_flags = attr->m_flags | MUTEX_FLAGS_INITED;
 124         if (private)
 125                 pmutex->m_flags |= MUTEX_FLAGS_PRIVATE;
 126         pmutex->m_count = 0;
 127         pmutex->m_refcount = 0;
 128         if (attr->m_protocol == PTHREAD_PRIO_PROTECT)
 129                 pmutex->m_prio = attr->m_ceiling;
 130         else
 131                 pmutex->m_prio = -1;
 132         pmutex->m_saved_prio = 0;
 133         MUTEX_INIT_LINK(pmutex);
 134         *mutex = pmutex;
 135         return (0);
 136 }
 137
 138 static int
 139 init_static(struct pthread *thread, pthread_mutex_t *mutex)
 140 {
 141         int ret;
 142
 143         THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
 144
 145         if (*mutex == NULL)
 146                 ret = mutex_init(mutex, NULL, 0);
 147         else
 148                 ret = 0;
 149
 150         THR_LOCK_RELEASE(thread, &_mutex_static_lock);
 151
 152         return (ret);
 153 }
 154
 155 static int
 156 init_static_private(struct pthread *thread, pthread_mutex_t *mutex)
 157 {
 158         int ret;
 159
 160         THR_LOCK_ACQUIRE(thread, &_mutex_static_lock);
 161
 162         if (*mutex == NULL)
 163                 ret = mutex_init(mutex, NULL, 1);
 164         else
 165                 ret = 0;
 166
 167         THR_LOCK_RELEASE(thread, &_mutex_static_lock);
 168
 169         return (ret);
 170 }
 171
 172 int
 173 _pthread_mutex_init(pthread_mutex_t *mutex,
 174     const pthread_mutexattr_t *mutex_attr)
 175 {
 176         return mutex_init(mutex, mutex_attr, 1);
 177 }
 178
 179 int
 180 __pthread_mutex_init(pthread_mutex_t *mutex,
 181     const pthread_mutexattr_t *mutex_attr)
 182 {
 183         return mutex_init(mutex, mutex_attr, 0);
 184 }
 185
 186 int
 187 _mutex_reinit(pthread_mutex_t *mutex)
 188 {
 189         _thr_umtx_init(&(*mutex)->m_lock);
 190         TAILQ_INIT(&(*mutex)->m_queue);
 191         MUTEX_INIT_LINK(*mutex);
 192         (*mutex)->m_owner = NULL;
 193         (*mutex)->m_count = 0;
 194         (*mutex)->m_refcount = 0;
 195         (*mutex)->m_prio = 0;
 196         (*mutex)->m_saved_prio = 0;
 197         return (0);
 198 }
 199
 200 void
 201 _mutex_fork(struct pthread *curthread)
 202 {
 203         struct pthread_mutex *m;
 204
 205         TAILQ_FOREACH(m, &curthread->mutexq, m_qe)
 206                 m->m_lock = UMTX_LOCKED;
 207 }
 208
 209 int
 210 _pthread_mutex_destroy(pthread_mutex_t *mutex)
 211 {
 212         struct pthread *curthread = tls_get_curthread();
 213         pthread_mutex_t m;
 214         int ret = 0;
 215
 216         if (mutex == NULL || *mutex == NULL)
 217                 ret = EINVAL;
 218         else {
 219                 /*
 220                  * Try to lock the mutex structure, we only need to
 221                  * try once, if failed, the mutex is in used.
 222                  */
 223                 ret = THR_UMTX_TRYLOCK(curthread, &(*mutex)->m_lock);
 224                 if (ret)
 225                         return (ret);
 226
 227                 /*
 228                  * Check mutex other fields to see if this mutex is
 229                  * in use. Mostly for prority mutex types, or there
 230                  * are condition variables referencing it.
 231                  */
 232                 if (((*mutex)->m_owner != NULL) ||
 233                     (TAILQ_FIRST(&(*mutex)->m_queue) != NULL) ||
 234                     ((*mutex)->m_refcount != 0)) {
 235                         THR_UMTX_UNLOCK(curthread, &(*mutex)->m_lock);
 236                         ret = EBUSY;
 237                 } else {
 238                         /*
 239                          * Save a pointer to the mutex so it can be free'd
 240                          * and set the caller's pointer to NULL:
 241                          */
 242                         m = *mutex;
 243                         *mutex = NULL;
 244
 245                         /* Unlock the mutex structure: */
 246                         THR_UMTX_UNLOCK(curthread, &m->m_lock);
 247
 248                         /*
 249                          * Free the memory allocated for the mutex
 250                          * structure:
 251                          */
 252                         MUTEX_ASSERT_NOT_OWNED(m);
 253                         MUTEX_DESTROY(m);
 254                 }
 255         }
 256
 257         /* Return the completion status: */
 258         return (ret);
 259 }
 260
 261 static int
 262 mutex_trylock_common(struct pthread *curthread, pthread_mutex_t *mutex)
 263 {
 264         struct pthread_mutex *m;
 265         int ret;
 266
 267         m = *mutex;
 268         ret = THR_UMTX_TRYLOCK(curthread, &m->m_lock);
 269         if (ret == 0) {
 270                 m->m_owner = curthread;
 271                 /* Add to the list of owned mutexes: */
 272                 MUTEX_ASSERT_NOT_OWNED(m);
 273                 TAILQ_INSERT_TAIL(&curthread->mutexq,
 274                     m, m_qe);
 275         } else if (m->m_owner == curthread) {
 276                 ret = mutex_self_trylock(m);
 277         } /* else {} */
 278
 279         return (ret);
 280 }
 281
 282 int
 283 __pthread_mutex_trylock(pthread_mutex_t *m)
 284 {
 285         struct pthread *curthread = tls_get_curthread();
 286         int ret;
 287
 288         if (__predict_false(m == NULL))
 289                 return(EINVAL);
 290         /*
 291          * If the mutex is statically initialized, perform the dynamic
 292          * initialization:
 293          */
 294         if (__predict_false(*m == NULL)) {
 295                 ret = init_static(curthread, m);
 296                 if (__predict_false(ret != 0))
 297                         return (ret);
 298         }
 299         return (mutex_trylock_common(curthread, m));
 300 }
 301
 302 int
 303 _pthread_mutex_trylock(pthread_mutex_t *m)
 304 {
 305         struct pthread  *curthread = tls_get_curthread();
 306         int     ret = 0;
 307
 308         /*
 309          * If the mutex is statically initialized, perform the dynamic
 310          * initialization marking the mutex private (delete safe):
 311          */
 312         if (__predict_false(*m == NULL)) {
 313                 ret = init_static_private(curthread, m);
 314                 if (__predict_false(ret != 0))
 315                         return (ret);
 316         }
 317         return (mutex_trylock_common(curthread, m));
 318 }
 319
 320 static int
 321 mutex_lock_common(struct pthread *curthread, pthread_mutex_t *mutex,
 322         const struct timespec * abstime)
 323 {
 324         struct  timespec ts, ts2;
 325         struct  pthread_mutex *m;
 326         int     ret = 0;
 327
 328         m = *mutex;
 329         ret = THR_UMTX_TRYLOCK(curthread, &m->m_lock);
 330         if (ret == 0) {
 331                 m->m_owner = curthread;
 332                 /* Add to the list of owned mutexes: */
 333                 MUTEX_ASSERT_NOT_OWNED(m);
 334                 TAILQ_INSERT_TAIL(&curthread->mutexq,
 335                     m, m_qe);
 336         } else if (m->m_owner == curthread) {
 337                 ret = mutex_self_lock(m, abstime);
 338         } else {
 339                 if (abstime == NULL) {
 340                         THR_UMTX_LOCK(curthread, &m->m_lock);
 341                         ret = 0;
 342                 } else if (__predict_false(
 343                         abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
 344                         abstime->tv_nsec >= 1000000000)) {
 345                                 ret = EINVAL;
 346                 } else {
 347                         clock_gettime(CLOCK_REALTIME, &ts);
 348                         TIMESPEC_SUB(&ts2, abstime, &ts);
 349                         ret = THR_UMTX_TIMEDLOCK(curthread,
 350                                 &m->m_lock, &ts2);
 351                         /*
 352                          * Timed out wait is not restarted if
 353                          * it was interrupted, not worth to do it.
 354                          */
 355                         if (ret == EINTR)
 356                                 ret = ETIMEDOUT;
 357                 }
 358                 if (ret == 0) {
 359                         m->m_owner = curthread;
 360                         /* Add to the list of owned mutexes: */
 361                         MUTEX_ASSERT_NOT_OWNED(m);
 362                         TAILQ_INSERT_TAIL(&curthread->mutexq,
 363                             m, m_qe);
 364                 }
 365         }
 366         return (ret);
 367 }
 368
 369 int
 370 __pthread_mutex_lock(pthread_mutex_t *m)
 371 {
 372         struct pthread *curthread;
 373         int     ret;
 374
 375         _thr_check_init();
 376
 377         if (__predict_false(m == NULL))
 378                 return(EINVAL);
 379
 380         /*
 381          * If the mutex is statically initialized, perform the dynamic
 382          * initialization:
 383          */
 384         curthread = tls_get_curthread();
 385         if (__predict_false(*m == NULL)) {
 386                 ret = init_static(curthread, m);
 387                 if (__predict_false(ret))
 388                         return (ret);
 389         }
 390         return (mutex_lock_common(curthread, m, NULL));
 391 }
 392
 393 int
 394 _pthread_mutex_lock(pthread_mutex_t *m)
 395 {
 396         struct pthread *curthread;
 397         int     ret;
 398
 399         _thr_check_init();
 400
 401         if (__predict_false(m == NULL))
 402                 return(EINVAL);
 403
 404         /*
 405          * If the mutex is statically initialized, perform the dynamic
 406          * initialization marking it private (delete safe):
 407          */
 408         curthread = tls_get_curthread();
 409         if (__predict_false(*m == NULL)) {
 410                 ret = init_static_private(curthread, m);
 411                 if (__predict_false(ret))
 412                         return (ret);
 413         }
 414         return (mutex_lock_common(curthread, m, NULL));
 415 }
 416
 417 int
 418 __pthread_mutex_timedlock(pthread_mutex_t *m,
 419         const struct timespec *abs_timeout)
 420 {
 421         struct pthread *curthread;
 422         int     ret;
 423
 424         _thr_check_init();
 425
 426         if (__predict_false(m == NULL))
 427                 return(EINVAL);
 428
 429         /*
 430          * If the mutex is statically initialized, perform the dynamic
 431          * initialization:
 432          */
 433         curthread = tls_get_curthread();
 434         if (__predict_false(*m == NULL)) {
 435                 ret = init_static(curthread, m);
 436                 if (__predict_false(ret))
 437                         return (ret);
 438         }
 439         return (mutex_lock_common(curthread, m, abs_timeout));
 440 }
 441
 442 int
 443 _pthread_mutex_timedlock(pthread_mutex_t *m,
 444         const struct timespec *abs_timeout)
 445 {
 446         struct pthread *curthread;
 447         int     ret;
 448
 449         _thr_check_init();
 450
 451         if (__predict_false(m == NULL))
 452                 return(EINVAL);
 453
 454         curthread = tls_get_curthread();
 455
 456         /*
 457          * If the mutex is statically initialized, perform the dynamic
 458          * initialization marking it private (delete safe):
 459          */
 460         if (__predict_false(*m == NULL)) {
 461                 ret = init_static_private(curthread, m);
 462                 if (__predict_false(ret))
 463                         return (ret);
 464         }
 465         return (mutex_lock_common(curthread, m, abs_timeout));
 466 }
 467
 468 int
 469 _pthread_mutex_unlock(pthread_mutex_t *m)
 470 {
 471         if (__predict_false(m == NULL))
 472                 return(EINVAL);
 473         return (mutex_unlock_common(m));
 474 }
 475
 476 static int
 477 mutex_self_trylock(pthread_mutex_t m)
 478 {
 479         int     ret;
 480
 481         switch (m->m_type) {
 482         /* case PTHREAD_MUTEX_DEFAULT: */
 483         case PTHREAD_MUTEX_ERRORCHECK:
 484         case PTHREAD_MUTEX_NORMAL:
 485                 ret = EBUSY;
 486                 break;
 487
 488         case PTHREAD_MUTEX_RECURSIVE:
 489                 /* Increment the lock count: */
 490                 if (m->m_count + 1 > 0) {
 491                         m->m_count++;
 492                         ret = 0;
 493                 } else
 494                         ret = EAGAIN;
 495                 break;
 496
 497         default:
 498                 /* Trap invalid mutex types; */
 499                 ret = EINVAL;
 500         }
 501
 502         return (ret);
 503 }
 504
 505 static int
 506 mutex_self_lock(pthread_mutex_t m, const struct timespec *abstime)
 507 {
 508         struct timespec ts1, ts2;
 509         int ret;
 510
 511         switch (m->m_type) {
 512         /* case PTHREAD_MUTEX_DEFAULT: */
 513         case PTHREAD_MUTEX_ERRORCHECK:
 514                 if (abstime) {
 515                         clock_gettime(CLOCK_REALTIME, &ts1);
 516                         TIMESPEC_SUB(&ts2, abstime, &ts1);
 517                         __sys_nanosleep(&ts2, NULL);
 518                         ret = ETIMEDOUT;
 519                 } else {
 520                         /*
 521                          * POSIX specifies that mutexes should return
 522                          * EDEADLK if a recursive lock is detected.
 523                          */
 524                         ret = EDEADLK;
 525                 }
 526                 break;
 527
 528         case PTHREAD_MUTEX_NORMAL:
 529                 /*
 530                  * What SS2 define as a 'normal' mutex.  Intentionally
 531                  * deadlock on attempts to get a lock you already own.
 532                  */
 533                 ret = 0;
 534                 if (abstime) {
 535                         clock_gettime(CLOCK_REALTIME, &ts1);
 536                         TIMESPEC_SUB(&ts2, abstime, &ts1);
 537                         __sys_nanosleep(&ts2, NULL);
 538                         ret = ETIMEDOUT;
 539                 } else {
 540                         ts1.tv_sec = 30;
 541                         ts1.tv_nsec = 0;
 542                         for (;;)
 543                                 __sys_nanosleep(&ts1, NULL);
 544                 }
 545                 break;
 546
 547         case PTHREAD_MUTEX_RECURSIVE:
 548                 /* Increment the lock count: */
 549                 if (m->m_count + 1 > 0) {
 550                         m->m_count++;
 551                         ret = 0;
 552                 } else
 553                         ret = EAGAIN;
 554                 break;
 555
 556         default:
 557                 /* Trap invalid mutex types; */
 558                 ret = EINVAL;
 559         }
 560
 561         return (ret);
 562 }
 563
 564 static int
 565 mutex_unlock_common(pthread_mutex_t *mutex)
 566 {
 567         struct pthread *curthread = tls_get_curthread();
 568         struct pthread_mutex *m;
 569
 570         if (__predict_false((m = *mutex)== NULL))
 571                 return (EINVAL);
 572         if (__predict_false(m->m_owner != curthread))
 573                 return (EPERM);
 574
 575         if (__predict_false(
 576                 m->m_type == PTHREAD_MUTEX_RECURSIVE &&
 577                 m->m_count > 0)) {
 578                 m->m_count--;
 579         } else {
 580                 /*
 581                  * Clear the count in case this is a recursive mutex.
 582                  */
 583                 m->m_count = 0;
 584                 m->m_owner = NULL;
 585                 /* Remove the mutex from the threads queue. */
 586                 MUTEX_ASSERT_IS_OWNED(m);
 587                 TAILQ_REMOVE(&curthread->mutexq, m, m_qe);
 588                 MUTEX_INIT_LINK(m);
 589                 /*
 590                  * Hand off the mutex to the next waiting thread.
 591                  */
 592                 THR_UMTX_UNLOCK(curthread, &m->m_lock);
 593         }
 594         return (0);
 595 }
 596
 597 int
 598 _mutex_cv_lock(pthread_mutex_t *m, int count)
 599 {
 600         int     ret;
 601
 602         if ((ret = _pthread_mutex_lock(m)) == 0) {
 603                 (*m)->m_refcount--;
 604                 (*m)->m_count += count;
 605         }
 606         return (ret);
 607 }
 608
 609 int
 610 _mutex_cv_unlock(pthread_mutex_t *mutex, int *count)
 611 {
 612         struct pthread *curthread = tls_get_curthread();
 613         struct pthread_mutex *m;
 614
 615         if (__predict_false(mutex == NULL))
 616                 return (EINVAL);
 617         if (__predict_false((m = *mutex) == NULL))
 618                 return (EINVAL);
 619         if (__predict_false(m->m_owner != curthread))
 620                 return (EPERM);
 621
 622         *count = m->m_count;
 623         m->m_count = 0;
 624         m->m_refcount++;
 625         m->m_owner = NULL;
 626         /* Remove the mutex from the threads queue. */
 627         MUTEX_ASSERT_IS_OWNED(m);
 628         TAILQ_REMOVE(&curthread->mutexq, m, m_qe);
 629         MUTEX_INIT_LINK(m);
 630         THR_UMTX_UNLOCK(curthread, &m->m_lock);
 631         return (0);
 632 }
 633
 634 void
 635 _mutex_unlock_private(pthread_t pthread)
 636 {
 637         struct pthread_mutex    *m, *m_next;
 638
 639         for (m = TAILQ_FIRST(&pthread->mutexq); m != NULL; m = m_next) {
 640                 m_next = TAILQ_NEXT(m, m_qe);
 641                 if ((m->m_flags & MUTEX_FLAGS_PRIVATE) != 0)
 642                         _pthread_mutex_unlock(&m);
 643         }
 644 }
 645
 646 __strong_reference(__pthread_mutex_init, pthread_mutex_init);
 647 __strong_reference(__pthread_mutex_lock, pthread_mutex_lock);
 648 __strong_reference(__pthread_mutex_timedlock, pthread_mutex_timedlock);
 649 __strong_reference(__pthread_mutex_trylock, pthread_mutex_trylock);
 650
 651 /* Single underscore versions provided for libc internal usage: */
 652 /* No difference between libc and application usage of these: */
 653 __strong_reference(_pthread_mutex_destroy, pthread_mutex_destroy);
 654 __strong_reference(_pthread_mutex_unlock, pthread_mutex_unlock);