thread.h

   1 /*    thread.h
   2  *
   3  *    Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
   4  *    by Larry Wall and others
   5  *
   6  *    You may distribute under the terms of either the GNU General Public
   7  *    License or the Artistic License, as specified in the README file.
   8  *
   9  */
  10
  11 #if defined(USE_ITHREADS)
  12
  13 #if defined(VMS)
  14 #include <builtins.h>
  15 #endif
  16
  17 #ifdef WIN32
  18 #  include <win32thread.h>
  19 #elif defined(NETWARE)
  20 #  include <nw5thread.h>
  21 #else
  22 #  ifdef OLD_PTHREADS_API /* Here be dragons. */
  23 #    define DETACH(t) \
  24     STMT_START {                                                \
  25         int _eC_;                                               \
  26         if ((_eC_ = pthread_detach(&(t)->self))) {              \
  27             MUTEX_UNLOCK(&(t)->mutex);                          \
  28             Perl_croak_nocontext("panic: DETACH (%d) [%s:%d]",  \
  29                                  _eC_, __FILE__, __LINE__);     \
  30         }                                                       \
  31     } STMT_END
  32
  33 #    define PERL_GET_CONTEXT    Perl_get_context()
  34 #    define PERL_SET_CONTEXT(t) Perl_set_context((void*)t)
  35
  36 #    define PTHREAD_GETSPECIFIC_INT
  37 #    ifdef DJGPP
  38 #      define pthread_addr_t any_t
  39 #      define NEED_PTHREAD_INIT
  40 #      define PTHREAD_CREATE_JOINABLE (1)
  41 #    endif
  42 #    ifdef OEMVS
  43 #      define pthread_addr_t void *
  44 #      define pthread_create(t,a,s,d)        pthread_create(t,&(a),s,d)
  45 #      define pthread_keycreate              pthread_key_create
  46 #    endif
  47 #    ifdef VMS
  48 #      define pthread_attr_init(a) pthread_attr_create(a)
  49 #      define PTHREAD_ATTR_SETDETACHSTATE(a,s) pthread_setdetach_np(a,s)
  50 #      define PTHREAD_CREATE(t,a,s,d) pthread_create(t,a,s,d)
  51 #      define pthread_key_create(k,d) pthread_keycreate(k,(pthread_destructor_t)(d))
  52 #      define pthread_mutexattr_init(a) pthread_mutexattr_create(a)
  53 #      define pthread_mutexattr_settype(a,t) pthread_mutexattr_setkind_np(a,t)
  54 #    endif
  55 #    if defined(__hpux) && defined(__ux_version) && __ux_version <= 1020
  56 #      define pthread_attr_init(a) pthread_attr_create(a)
  57        /* XXX pthread_setdetach_np() missing in DCE threads on HP-UX 10.20 */
  58 #      define PTHREAD_ATTR_SETDETACHSTATE(a,s)  (0)
  59 #      define PTHREAD_CREATE(t,a,s,d) pthread_create(t,a,s,d)
  60 #      define pthread_key_create(k,d) pthread_keycreate(k,(pthread_destructor_t)(d))
  61 #      define pthread_mutexattr_init(a) pthread_mutexattr_create(a)
  62 #      define pthread_mutexattr_settype(a,t) pthread_mutexattr_setkind_np(a,t)
  63 #    endif
  64 #    if defined(DJGPP) || defined(OEMVS)
  65 #      define PTHREAD_ATTR_SETDETACHSTATE(a,s) pthread_attr_setdetachstate(a,&(s))
  66 #      define YIELD pthread_yield(NULL)
  67 #    endif
  68 #  endif
  69 #  if !defined(__hpux) || !defined(__ux_version) || __ux_version > 1020
  70 #    define pthread_mutexattr_default NULL
  71 #    define pthread_condattr_default  NULL
  72 #  endif
  73 #endif
  74
  75 #ifndef PTHREAD_CREATE
  76 /* You are not supposed to pass NULL as the 2nd arg of PTHREAD_CREATE(). */
  77 #  define PTHREAD_CREATE(t,a,s,d) pthread_create(t,&(a),s,d)
  78 #endif
  79
  80 #ifndef PTHREAD_ATTR_SETDETACHSTATE
  81 #  define PTHREAD_ATTR_SETDETACHSTATE(a,s) pthread_attr_setdetachstate(a,s)
  82 #endif
  83
  84 #ifndef PTHREAD_CREATE_JOINABLE
  85 #  ifdef OLD_PTHREAD_CREATE_JOINABLE
  86 #    define PTHREAD_CREATE_JOINABLE OLD_PTHREAD_CREATE_JOINABLE
  87 #  else
  88 #    define PTHREAD_CREATE_JOINABLE 0 /* Panic?  No, guess. */
  89 #  endif
  90 #endif
  91
  92 #ifdef __VMS
  93   /* Default is 1024 on VAX, 8192 otherwise */
  94 #  ifdef __ia64
  95 #    define THREAD_CREATE_NEEDS_STACK (48*1024)
  96 #  else
  97 #    define THREAD_CREATE_NEEDS_STACK (32*1024)
  98 #  endif
  99 #endif
 100
 101 #ifdef I_MACH_CTHREADS
 102
 103 /* cthreads interface */
 104
 105 /* #include <mach/cthreads.h> is in perl.h #ifdef I_MACH_CTHREADS */
 106
 107 #define MUTEX_INIT(m) \
 108     STMT_START {                                                \
 109         *m = mutex_alloc();                                     \
 110         if (*m) {                                               \
 111             mutex_init(*m);                                     \
 112         } else {                                                \
 113             Perl_croak_nocontext("panic: MUTEX_INIT [%s:%d]",   \
 114                                  __FILE__, __LINE__);           \
 115         }                                                       \
 116     } STMT_END
 117
 118 #define MUTEX_LOCK(m)                   mutex_lock(*m)
 119 #define MUTEX_UNLOCK(m)                 mutex_unlock(*m)
 120 #define MUTEX_DESTROY(m) \
 121     STMT_START {                                                \
 122         mutex_free(*m);                                         \
 123         *m = 0;                                                 \
 124     } STMT_END
 125
 126 #define COND_INIT(c) \
 127     STMT_START {                                                \
 128         *c = condition_alloc();                                 \
 129         if (*c) {                                               \
 130             condition_init(*c);                                 \
 131         }                                                       \
 132         else {                                                  \
 133             Perl_croak_nocontext("panic: COND_INIT [%s:%d]",    \
 134                                  __FILE__, __LINE__);           \
 135         }                                                       \
 136     } STMT_END
 137
 138 #define COND_SIGNAL(c)          condition_signal(*c)
 139 #define COND_BROADCAST(c)       condition_broadcast(*c)
 140 #define COND_WAIT(c, m)         condition_wait(*c, *m)
 141 #define COND_DESTROY(c) \
 142     STMT_START {                                                \
 143         condition_free(*c);                                     \
 144         *c = 0;                                                 \
 145     } STMT_END
 146
 147 #define THREAD_RET_TYPE         any_t
 148
 149 #define DETACH(t)               cthread_detach(t->self)
 150 #define JOIN(t, avp)            (*(avp) = MUTABLE_AV(cthread_join(t->self)))
 151
 152 #define PERL_SET_CONTEXT(t)     cthread_set_data(cthread_self(), t)
 153 #define PERL_GET_CONTEXT        cthread_data(cthread_self())
 154
 155 #define INIT_THREADS            cthread_init()
 156 #define YIELD                   cthread_yield()
 157 #define ALLOC_THREAD_KEY        NOOP
 158 #define FREE_THREAD_KEY         NOOP
 159 #define SET_THREAD_SELF(thr)    (thr->self = cthread_self())
 160
 161 #endif /* I_MACH_CTHREADS */
 162
 163 #ifndef YIELD
 164 #  ifdef SCHED_YIELD
 165 #    define YIELD SCHED_YIELD
 166 #  elif defined(HAS_SCHED_YIELD)
 167 #    define YIELD sched_yield()
 168 #  elif defined(HAS_PTHREAD_YIELD)
 169     /* pthread_yield(NULL) platforms are expected
 170      * to have #defined YIELD for themselves. */
 171 #    define YIELD pthread_yield()
 172 #  endif
 173 #endif
 174
 175 #ifdef __hpux
 176 #  define MUTEX_INIT_NEEDS_MUTEX_ZEROED
 177 #endif
 178
 179 #ifndef MUTEX_INIT
 180
 181 #  ifdef MUTEX_INIT_NEEDS_MUTEX_ZEROED
 182     /* Temporary workaround, true bug is deeper. --jhi 1999-02-25 */
 183 #    define MUTEX_INIT(m) \
 184     STMT_START {                                                \
 185         int _eC_;                                               \
 186         Zero((m), 1, perl_mutex);                               \
 187         if ((_eC_ = pthread_mutex_init((m), pthread_mutexattr_default)))        \
 188             Perl_croak_nocontext("panic: MUTEX_INIT (%d) [%s:%d]",      \
 189                                  _eC_, __FILE__, __LINE__);     \
 190     } STMT_END
 191 #  else
 192 #    define MUTEX_INIT(m) \
 193     STMT_START {                                                \
 194         int _eC_;                                               \
 195         if ((_eC_ = pthread_mutex_init((m), pthread_mutexattr_default)))        \
 196             Perl_croak_nocontext("panic: MUTEX_INIT (%d) [%s:%d]",      \
 197                                  _eC_, __FILE__, __LINE__);     \
 198     } STMT_END
 199 #  endif
 200
 201 #  ifdef PERL_TSA_ACTIVE
 202 #    define perl_pthread_mutex_lock(m) perl_tsa_mutex_lock(m)
 203 #    define perl_pthread_mutex_unlock(m) perl_tsa_mutex_unlock(m)
 204 #  else
 205 #    define perl_pthread_mutex_lock(m) pthread_mutex_lock(m)
 206 #    define perl_pthread_mutex_unlock(m) pthread_mutex_unlock(m)
 207 #  endif
 208
 209 #  define MUTEX_LOCK(m) \
 210     STMT_START {                                                \
 211         int _eC_;                                               \
 212         if ((_eC_ = perl_pthread_mutex_lock((m))))                      \
 213             Perl_croak_nocontext("panic: MUTEX_LOCK (%d) [%s:%d]",      \
 214                                  _eC_, __FILE__, __LINE__);     \
 215     } STMT_END
 216
 217 #  define MUTEX_UNLOCK(m) \
 218     STMT_START {                                                \
 219         int _eC_;                                               \
 220         if ((_eC_ = perl_pthread_mutex_unlock((m))))                    \
 221             Perl_croak_nocontext("panic: MUTEX_UNLOCK (%d) [%s:%d]",    \
 222                                  _eC_, __FILE__, __LINE__);     \
 223     } STMT_END
 224
 225 #  define MUTEX_DESTROY(m) \
 226     STMT_START {                                                \
 227         int _eC_;                                               \
 228         if ((_eC_ = pthread_mutex_destroy((m))))                \
 229             Perl_croak_nocontext("panic: MUTEX_DESTROY (%d) [%s:%d]",   \
 230                                  _eC_, __FILE__, __LINE__);     \
 231     } STMT_END
 232 #endif /* MUTEX_INIT */
 233
 234 #ifndef COND_INIT
 235 #  define COND_INIT(c) \
 236     STMT_START {                                                \
 237         int _eC_;                                               \
 238         if ((_eC_ = pthread_cond_init((c), pthread_condattr_default)))  \
 239             Perl_croak_nocontext("panic: COND_INIT (%d) [%s:%d]",       \
 240                                  _eC_, __FILE__, __LINE__);     \
 241     } STMT_END
 242
 243 #  define COND_SIGNAL(c) \
 244     STMT_START {                                                \
 245         int _eC_;                                               \
 246         if ((_eC_ = pthread_cond_signal((c))))                  \
 247             Perl_croak_nocontext("panic: COND_SIGNAL (%d) [%s:%d]",     \
 248                                  _eC_, __FILE__, __LINE__);     \
 249     } STMT_END
 250
 251 #  define COND_BROADCAST(c) \
 252     STMT_START {                                                \
 253         int _eC_;                                               \
 254         if ((_eC_ = pthread_cond_broadcast((c))))               \
 255             Perl_croak_nocontext("panic: COND_BROADCAST (%d) [%s:%d]",  \
 256                                  _eC_, __FILE__, __LINE__);     \
 257     } STMT_END
 258
 259 #  define COND_WAIT(c, m) \
 260     STMT_START {                                                \
 261         int _eC_;                                               \
 262         if ((_eC_ = pthread_cond_wait((c), (m))))               \
 263             Perl_croak_nocontext("panic: COND_WAIT (%d) [%s:%d]",       \
 264                                  _eC_, __FILE__, __LINE__);     \
 265     } STMT_END
 266
 267 #  define COND_DESTROY(c) \
 268     STMT_START {                                                \
 269         int _eC_;                                               \
 270         if ((_eC_ = pthread_cond_destroy((c))))                 \
 271             Perl_croak_nocontext("panic: COND_DESTROY (%d) [%s:%d]",    \
 272                                  _eC_, __FILE__, __LINE__);     \
 273     } STMT_END
 274 #endif /* COND_INIT */
 275
 276 #if defined(MUTEX_LOCK) && defined(MUTEX_UNLOCK)                \
 277  && defined(COND_SIGNAL) && defined(COND_WAIT)
 278
 279 /* These emulate native many-reader/1-writer locks.
 280  * Basically a locking reader just locks the semaphore long enough to increment
 281  * a counter; and similarly decrements it when when through.  Any writer will
 282  * run only when the count of readers is 0.  That is because it blocks on that
 283  * semaphore (doing a COND_WAIT) until it gets control of it, which won't
 284  * happen unless the count becomes 0.  ALL readers and other writers are then
 285  * blocked until it releases the semaphore.  The reader whose unlocking causes
 286  * the count to become 0 signals any waiting writers, and the system guarantees
 287  * that only one gets control at a time */
 288
 289 #  define PERL_READ_LOCK(mutex)                                     \
 290     STMT_START {                                                    \
 291         MUTEX_LOCK(&(mutex)->lock);                                 \
 292         (mutex)->readers_count++;                                   \
 293         MUTEX_UNLOCK(&(mutex)->lock);                               \
 294     } STMT_END
 295
 296 #  define PERL_READ_UNLOCK(mutex)                                   \
 297     STMT_START {                                                    \
 298         MUTEX_LOCK(&(mutex)->lock);                                 \
 299         (mutex)->readers_count--;                                   \
 300         if ((mutex)->readers_count <= 0) {                          \
 301             assert((mutex)->readers_count == 0);                    \
 302             COND_SIGNAL(&(mutex)->wakeup);                          \
 303             (mutex)->readers_count = 0;                             \
 304         }                                                           \
 305         MUTEX_UNLOCK(&(mutex)->lock);                               \
 306     } STMT_END
 307
 308 #  define PERL_WRITE_LOCK(mutex)                                    \
 309     STMT_START {                                                    \
 310         MUTEX_LOCK(&(mutex)->lock);                                 \
 311         do {                                                        \
 312             if ((mutex)->readers_count <= 0) {                      \
 313                 assert((mutex)->readers_count == 0);                \
 314                 (mutex)->readers_count = 0;                         \
 315                 break;                                              \
 316             }                                                       \
 317             COND_WAIT(&(mutex)->wakeup, &(mutex)->lock);            \
 318         }                                                           \
 319         while (1);                                                  \
 320                                                                     \
 321         /* Here, the mutex is locked, with no readers */            \
 322     } STMT_END
 323
 324 #  define PERL_WRITE_UNLOCK(mutex)                                  \
 325     STMT_START {                                                    \
 326         COND_SIGNAL(&(mutex)->wakeup);                              \
 327         MUTEX_UNLOCK(&(mutex)->lock);                               \
 328     } STMT_END
 329
 330 #  define PERL_RW_MUTEX_INIT(mutex)                                 \
 331     STMT_START {                                                    \
 332         MUTEX_INIT(&(mutex)->lock);                                 \
 333         COND_INIT(&(mutex)->wakeup);                                \
 334         (mutex)->readers_count = 0;                                 \
 335     } STMT_END
 336
 337 #  define PERL_RW_MUTEX_DESTROY(mutex)                              \
 338     STMT_START {                                                    \
 339         COND_DESTROY(&(mutex)->wakeup);                             \
 340         MUTEX_DESTROY(&(mutex)->lock);                              \
 341     } STMT_END
 342
 343 #endif
 344
 345 /* DETACH(t) must only be called while holding t->mutex */
 346 #ifndef DETACH
 347 #  define DETACH(t) \
 348     STMT_START {                                                \
 349         int _eC_;                                               \
 350         if ((_eC_ = pthread_detach((t)->self))) {               \
 351             MUTEX_UNLOCK(&(t)->mutex);                          \
 352             Perl_croak_nocontext("panic: DETACH (%d) [%s:%d]",  \
 353                                  _eC_, __FILE__, __LINE__);     \
 354         }                                                       \
 355     } STMT_END
 356 #endif /* DETACH */
 357
 358 #ifndef JOIN
 359 #  define JOIN(t, avp) \
 360     STMT_START {                                                \
 361         int _eC_;                                               \
 362         if ((_eC_ = pthread_join((t)->self, (void**)(avp))))    \
 363             Perl_croak_nocontext("panic: pthread_join (%d) [%s:%d]",    \
 364                                  _eC_, __FILE__, __LINE__);     \
 365     } STMT_END
 366 #endif /* JOIN */
 367
 368 /* Use an unchecked fetch of thread-specific data instead of a checked one.
 369  * It would fail if the key were bogus, but if the key were bogus then
 370  * Really Bad Things would be happening anyway. --dan */
 371 #if (defined(__ALPHA) && (__VMS_VER >= 70000000)) || \
 372     (defined(__alpha) && defined(__osf__) && !defined(__GNUC__)) /* Available only on >= 4.0 */
 373 #  define HAS_PTHREAD_UNCHECKED_GETSPECIFIC_NP /* Configure test needed */
 374 #endif
 375
 376 #ifdef HAS_PTHREAD_UNCHECKED_GETSPECIFIC_NP
 377 #  define PTHREAD_GETSPECIFIC(key) pthread_unchecked_getspecific_np(key)
 378 #else
 379 #    define PTHREAD_GETSPECIFIC(key) pthread_getspecific(key)
 380 #endif
 381
 382 #ifndef PERL_GET_CONTEXT
 383 #  define PERL_GET_CONTEXT      PTHREAD_GETSPECIFIC(PL_thr_key)
 384 #endif
 385
 386 #ifndef PERL_SET_CONTEXT
 387 #  define PERL_SET_CONTEXT(t) \
 388     STMT_START {                                                \
 389         int _eC_;                                               \
 390         if ((_eC_ = pthread_setspecific(PL_thr_key, (void *)(t))))      \
 391             Perl_croak_nocontext("panic: pthread_setspecific (%d) [%s:%d]",     \
 392                                  _eC_, __FILE__, __LINE__);     \
 393     } STMT_END
 394 #endif /* PERL_SET_CONTEXT */
 395
 396 #ifndef INIT_THREADS
 397 #  ifdef NEED_PTHREAD_INIT
 398 #    define INIT_THREADS pthread_init()
 399 #  endif
 400 #endif
 401
 402 #ifndef ALLOC_THREAD_KEY
 403 #  define ALLOC_THREAD_KEY \
 404     STMT_START {                                                \
 405         if (pthread_key_create(&PL_thr_key, 0)) {               \
 406             PERL_UNUSED_RESULT(write(2, STR_WITH_LEN("panic: pthread_key_create failed\n"))); \
 407             exit(1);                                            \
 408         }                                                       \
 409     } STMT_END
 410 #endif
 411
 412 #ifndef FREE_THREAD_KEY
 413 #  define FREE_THREAD_KEY \
 414     STMT_START {                                                \
 415         pthread_key_delete(PL_thr_key);                         \
 416     } STMT_END
 417 #endif
 418
 419 #ifndef PTHREAD_ATFORK
 420 #  ifdef HAS_PTHREAD_ATFORK
 421 #    define PTHREAD_ATFORK(prepare,parent,child)                \
 422         pthread_atfork(prepare,parent,child)
 423 #  else
 424 #    define PTHREAD_ATFORK(prepare,parent,child)                \
 425         NOOP
 426 #  endif
 427 #endif
 428
 429 #ifndef THREAD_RET_TYPE
 430 #  define THREAD_RET_TYPE       void *
 431 #endif /* THREAD_RET */
 432
 433 #  define LOCK_DOLLARZERO_MUTEX         MUTEX_LOCK(&PL_dollarzero_mutex)
 434 #  define UNLOCK_DOLLARZERO_MUTEX       MUTEX_UNLOCK(&PL_dollarzero_mutex)
 435
 436 #endif /* USE_ITHREADS */
 437
 438 #ifndef MUTEX_LOCK
 439 #  define MUTEX_LOCK(m)           NOOP
 440 #endif
 441
 442 #ifndef MUTEX_UNLOCK
 443 #  define MUTEX_UNLOCK(m)         NOOP
 444 #endif
 445
 446 #ifndef MUTEX_INIT
 447 #  define MUTEX_INIT(m)           NOOP
 448 #endif
 449
 450 #ifndef MUTEX_DESTROY
 451 #  define MUTEX_DESTROY(m)        NOOP
 452 #endif
 453
 454 #ifndef COND_INIT
 455 #  define COND_INIT(c)            NOOP
 456 #endif
 457
 458 #ifndef COND_SIGNAL
 459 #  define COND_SIGNAL(c)          NOOP
 460 #endif
 461
 462 #ifndef COND_BROADCAST
 463 #  define COND_BROADCAST(c)       NOOP
 464 #endif
 465
 466 #ifndef COND_WAIT
 467 #  define COND_WAIT(c, m)         NOOP
 468 #endif
 469
 470 #ifndef COND_DESTROY
 471 #  define COND_DESTROY(c)         NOOP
 472 #endif
 473
 474 #ifndef PERL_READ_LOCK
 475 #  define PERL_READ_LOCK          NOOP
 476 #  define PERL_READ_UNLOCK        NOOP
 477 #  define PERL_WRITE_LOCK         NOOP
 478 #  define PERL_WRITE_UNLOCK       NOOP
 479 #  define PERL_RW_MUTEX_INIT      NOOP
 480 #  define PERL_RW_MUTEX_DESTROY   NOOP
 481 #endif
 482
 483 #ifndef LOCK_DOLLARZERO_MUTEX
 484 #  define LOCK_DOLLARZERO_MUTEX   NOOP
 485 #endif
 486
 487 #ifndef UNLOCK_DOLLARZERO_MUTEX
 488 #  define UNLOCK_DOLLARZERO_MUTEX NOOP
 489 #endif
 490
 491 /* THR, SET_THR, and dTHR are there for compatibility with old versions */
 492 #ifndef THR
 493 #  define THR           PERL_GET_THX
 494 #endif
 495
 496 #ifndef SET_THR
 497 #  define SET_THR(t)    PERL_SET_THX(t)
 498 #endif
 499
 500 #ifndef dTHR
 501 #  define dTHR dNOOP
 502 #endif
 503
 504 #ifndef INIT_THREADS
 505 #  define INIT_THREADS NOOP
 506 #endif
 507
 508 /*
 509  * ex: set ts=8 sts=4 sw=4 et:
 510  */