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[perl5.git] / 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  */