xref: /openbsd-src/gnu/usr.bin/perl/thread.h (revision e068048151d29f2562a32185e21a8ba885482260)
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 #else
20 #  ifdef OLD_PTHREADS_API /* Here be dragons. */
21 #    define DETACH(t) \
22     STMT_START {						\
23         int _eC_;						\
24         if ((_eC_ = pthread_detach(&(t)->self))) {		\
25             MUTEX_UNLOCK(&(t)->mutex);				\
26             Perl_croak_nocontext("panic: DETACH (%d) [%s:%d]",	\
27                                  _eC_, __FILE__, __LINE__);	\
28         }							\
29     } STMT_END
30 
31 #    define PERL_GET_CONTEXT	Perl_get_context()
32 #    define PERL_SET_CONTEXT(t)	Perl_set_context((void*)t)
33 
34 #    define PTHREAD_GETSPECIFIC_INT
35 #    ifdef OEMVS
36 #      define pthread_addr_t void *
37 #      define pthread_create(t,a,s,d)        pthread_create(t,&(a),s,d)
38 #      define pthread_keycreate              pthread_key_create
39 #    endif
40 #    ifdef VMS
41 #      define pthread_attr_init(a) pthread_attr_create(a)
42 #      define PTHREAD_ATTR_SETDETACHSTATE(a,s) pthread_setdetach_np(a,s)
43 #      define PTHREAD_CREATE(t,a,s,d) pthread_create(t,a,s,d)
44 #      define pthread_key_create(k,d) pthread_keycreate(k,(pthread_destructor_t)(d))
45 #      define pthread_mutexattr_init(a) pthread_mutexattr_create(a)
46 #      define pthread_mutexattr_settype(a,t) pthread_mutexattr_setkind_np(a,t)
47 #    endif
48 #    if defined(__hpux) && defined(__ux_version) && __ux_version <= 1020
49 #      define pthread_attr_init(a) pthread_attr_create(a)
50        /* XXX pthread_setdetach_np() missing in DCE threads on HP-UX 10.20 */
51 #      define PTHREAD_ATTR_SETDETACHSTATE(a,s)	(0)
52 #      define PTHREAD_CREATE(t,a,s,d) pthread_create(t,a,s,d)
53 #      define pthread_key_create(k,d) pthread_keycreate(k,(pthread_destructor_t)(d))
54 #      define pthread_mutexattr_init(a) pthread_mutexattr_create(a)
55 #      define pthread_mutexattr_settype(a,t) pthread_mutexattr_setkind_np(a,t)
56 #    endif
57 #    if defined(OEMVS)
58 #      define PTHREAD_ATTR_SETDETACHSTATE(a,s) pthread_attr_setdetachstate(a,&(s))
59 #      define YIELD pthread_yield(NULL)
60 #    endif
61 #  endif
62 #  if !defined(__hpux) || !defined(__ux_version) || __ux_version > 1020
63 #    define pthread_mutexattr_default NULL
64 #    define pthread_condattr_default  NULL
65 #  endif
66 #endif
67 
68 #ifndef PTHREAD_CREATE
69 /* You are not supposed to pass NULL as the 2nd arg of PTHREAD_CREATE(). */
70 #  define PTHREAD_CREATE(t,a,s,d) pthread_create(t,&(a),s,d)
71 #endif
72 
73 #ifndef PTHREAD_ATTR_SETDETACHSTATE
74 #  define PTHREAD_ATTR_SETDETACHSTATE(a,s) pthread_attr_setdetachstate(a,s)
75 #endif
76 
77 #ifndef PTHREAD_CREATE_JOINABLE
78 #  ifdef OLD_PTHREAD_CREATE_JOINABLE
79 #    define PTHREAD_CREATE_JOINABLE OLD_PTHREAD_CREATE_JOINABLE
80 #  else
81 #    define PTHREAD_CREATE_JOINABLE 0 /* Panic?  No, guess. */
82 #  endif
83 #endif
84 
85 #ifdef __VMS
86   /* Default is 1024 on VAX, 8192 otherwise */
87 #  ifdef __ia64
88 #    define THREAD_CREATE_NEEDS_STACK (48*1024)
89 #  else
90 #    define THREAD_CREATE_NEEDS_STACK (32*1024)
91 #  endif
92 #endif
93 
94 #ifdef I_MACH_CTHREADS
95 
96 /* cthreads interface */
97 
98 /* #include <mach/cthreads.h> is in perl.h #ifdef I_MACH_CTHREADS */
99 
100 #define MUTEX_INIT(m) \
101     STMT_START {						\
102         *m = mutex_alloc();					\
103         if (*m) {						\
104             mutex_init(*m);					\
105         } else {						\
106             Perl_croak_nocontext("panic: MUTEX_INIT [%s:%d]",	\
107                                  __FILE__, __LINE__);		\
108         }							\
109     } STMT_END
110 
111 #define MUTEX_LOCK(m)			mutex_lock(*m)
112 #define MUTEX_UNLOCK(m)			mutex_unlock(*m)
113 #define MUTEX_DESTROY(m) \
114     STMT_START {						\
115         mutex_free(*m);						\
116         *m = 0;							\
117     } STMT_END
118 
119 #define COND_INIT(c) \
120     STMT_START {						\
121         *c = condition_alloc();					\
122         if (*c) {						\
123             condition_init(*c);					\
124         }							\
125         else {							\
126             Perl_croak_nocontext("panic: COND_INIT [%s:%d]",	\
127                                  __FILE__, __LINE__);		\
128         }							\
129     } STMT_END
130 
131 #define COND_SIGNAL(c)		condition_signal(*c)
132 #define COND_BROADCAST(c)	condition_broadcast(*c)
133 #define COND_WAIT(c, m)		condition_wait(*c, *m)
134 #define COND_DESTROY(c) \
135     STMT_START {						\
136         condition_free(*c);					\
137         *c = 0;							\
138     } STMT_END
139 
140 #define THREAD_RET_TYPE		any_t
141 
142 #define DETACH(t)		cthread_detach(t->self)
143 #define JOIN(t, avp)		(*(avp) = MUTABLE_AV(cthread_join(t->self)))
144 
145 #define PERL_SET_CONTEXT(t)	cthread_set_data(cthread_self(), t)
146 #define PERL_GET_CONTEXT	cthread_data(cthread_self())
147 
148 #define INIT_THREADS		cthread_init()
149 #define YIELD			cthread_yield()
150 #define ALLOC_THREAD_KEY	NOOP
151 #define FREE_THREAD_KEY		NOOP
152 #define SET_THREAD_SELF(thr)	(thr->self = cthread_self())
153 
154 #endif /* I_MACH_CTHREADS */
155 
156 #ifndef YIELD
157 #  ifdef SCHED_YIELD
158 #    define YIELD SCHED_YIELD
159 #  elif defined(HAS_SCHED_YIELD)
160 #    define YIELD sched_yield()
161 #  elif defined(HAS_PTHREAD_YIELD)
162     /* pthread_yield(NULL) platforms are expected
163      * to have #defined YIELD for themselves. */
164 #    define YIELD pthread_yield()
165 #  endif
166 #endif
167 
168 #ifdef __hpux
169 #  define MUTEX_INIT_NEEDS_MUTEX_ZEROED
170 #endif
171 
172 #ifndef MUTEX_INIT
173 
174 #  ifdef MUTEX_INIT_NEEDS_MUTEX_ZEROED
175     /* Temporary workaround, true bug is deeper. --jhi 1999-02-25 */
176 #    define MUTEX_INIT(m) \
177     STMT_START {                                                    \
178         int _eC_;                                                   \
179         Zero((m), 1, perl_mutex);                                   \
180         if ((_eC_ = pthread_mutex_init((m), pthread_mutexattr_default)))\
181             Perl_croak_nocontext("panic: MUTEX_INIT (%d) [%s:%d]",  \
182                                  _eC_, __FILE__, __LINE__);         \
183     } STMT_END
184 #  else
185 #    define MUTEX_INIT(m) \
186     STMT_START {						\
187         int _eC_;						\
188         if ((_eC_ = pthread_mutex_init((m), pthread_mutexattr_default))) \
189             Perl_croak_nocontext("panic: MUTEX_INIT (%d) [%s:%d]", \
190                                  _eC_, __FILE__, __LINE__);     \
191     } STMT_END
192 #  endif
193 
194 #  ifdef PERL_TSA_ACTIVE
195 #    define perl_pthread_mutex_lock(m) perl_tsa_mutex_lock(m)
196 #    define perl_pthread_mutex_unlock(m) perl_tsa_mutex_unlock(m)
197 #  else
198 #    define perl_pthread_mutex_lock(m) pthread_mutex_lock(m)
199 #    define perl_pthread_mutex_unlock(m) pthread_mutex_unlock(m)
200 #  endif
201 
202 #  define MUTEX_LOCK(m)                                         \
203     STMT_START {						\
204         dSAVE_ERRNO;                                            \
205         int _eC_;						\
206         if ((_eC_ = perl_pthread_mutex_lock((m))))		\
207             Perl_croak_nocontext("panic: MUTEX_LOCK (%d) [%s:%d]",\
208                                  _eC_, __FILE__, __LINE__);	\
209         RESTORE_ERRNO;                                          \
210     } STMT_END
211 
212 #  define MUTEX_UNLOCK(m)                                       \
213     STMT_START {						\
214         dSAVE_ERRNO; /* Shouldn't be necessary as panics if fails */\
215         int _eC_;						\
216         if ((_eC_ = perl_pthread_mutex_unlock((m)))) {          \
217             Perl_croak_nocontext(                               \
218                             "panic: MUTEX_UNLOCK (%d) [%s:%d]", \
219                                  _eC_, __FILE__, __LINE__);	\
220         }                                                       \
221         RESTORE_ERRNO;                                          \
222     } STMT_END
223 
224 #  define MUTEX_DESTROY(m)                                                  \
225     STMT_START {						            \
226         int _eC_;						            \
227         if ((_eC_ = pthread_mutex_destroy((m)))) {                          \
228             dTHX;                                                           \
229             if (PL_phase != PERL_PHASE_DESTRUCT) {                          \
230                 Perl_croak_nocontext("panic: MUTEX_DESTROY (%d) [%s:%d]",   \
231                                     _eC_, __FILE__, __LINE__);	            \
232             }                                                               \
233         }                                                                   \
234     } STMT_END
235 #endif /* MUTEX_INIT */
236 
237 #ifndef COND_INIT
238 #  define COND_INIT(c) \
239     STMT_START {						\
240         int _eC_;						\
241         if ((_eC_ = pthread_cond_init((c), pthread_condattr_default)))	\
242             Perl_croak_nocontext("panic: COND_INIT (%d) [%s:%d]",	\
243                                  _eC_, __FILE__, __LINE__);	\
244     } STMT_END
245 
246 #  define COND_SIGNAL(c) \
247     STMT_START {						\
248         int _eC_;						\
249         if ((_eC_ = pthread_cond_signal((c))))			\
250             Perl_croak_nocontext("panic: COND_SIGNAL (%d) [%s:%d]",	\
251                                  _eC_, __FILE__, __LINE__);	\
252     } STMT_END
253 
254 #  define COND_BROADCAST(c) \
255     STMT_START {						\
256         int _eC_;						\
257         if ((_eC_ = pthread_cond_broadcast((c))))		\
258             Perl_croak_nocontext("panic: COND_BROADCAST (%d) [%s:%d]",	\
259                                  _eC_, __FILE__, __LINE__);	\
260     } STMT_END
261 
262 #  define COND_WAIT(c, m) \
263     STMT_START {						\
264         int _eC_;						\
265         if ((_eC_ = pthread_cond_wait((c), (m))))		\
266             Perl_croak_nocontext("panic: COND_WAIT (%d) [%s:%d]",	\
267                                  _eC_, __FILE__, __LINE__);	\
268     } STMT_END
269 
270 #  define COND_DESTROY(c) \
271     STMT_START {						            \
272         int _eC_;						            \
273         if ((_eC_ = pthread_cond_destroy((c)))) {                           \
274             dTHX;                                                           \
275             if (PL_phase != PERL_PHASE_DESTRUCT) {                          \
276                 Perl_croak_nocontext("panic: COND_DESTROY (%d) [%s:%d]",    \
277                                     _eC_, __FILE__, __LINE__);	            \
278             }                                                               \
279         }                                                                   \
280     } STMT_END
281 #endif /* COND_INIT */
282 
283 #if defined(MUTEX_LOCK) && defined(MUTEX_UNLOCK)                \
284  && defined(COND_SIGNAL) && defined(COND_WAIT)
285 
286 /* These emulate native many-reader/1-writer locks.
287  * Basically a locking reader just locks the semaphore long enough to increment
288  * a counter; and similarly decrements it when when through.  Any writer will
289  * run only when the count of readers is 0.  That is because it blocks on that
290  * semaphore (doing a COND_WAIT) until it gets control of it, which won't
291  * happen unless the count becomes 0.  ALL readers and other writers are then
292  * blocked until it releases the semaphore.  The reader whose unlocking causes
293  * the count to become 0 signals any waiting writers, and the system guarantees
294  * that only one gets control at a time */
295 
296 #  define PERL_READ_LOCK(mutex)                                     \
297     STMT_START {                                                    \
298         MUTEX_LOCK(&(mutex)->lock);                                 \
299         (mutex)->readers_count++;                                   \
300         MUTEX_UNLOCK(&(mutex)->lock);                               \
301     } STMT_END
302 
303 #  define PERL_READ_UNLOCK(mutex)                                   \
304     STMT_START {                                                    \
305         MUTEX_LOCK(&(mutex)->lock);                                 \
306         (mutex)->readers_count--;                                   \
307         if ((mutex)->readers_count <= 0) {                          \
308             assert((mutex)->readers_count == 0);                    \
309             COND_SIGNAL(&(mutex)->wakeup);                          \
310             (mutex)->readers_count = 0;                             \
311         }                                                           \
312         MUTEX_UNLOCK(&(mutex)->lock);                               \
313     } STMT_END
314 
315 #  define PERL_WRITE_LOCK(mutex)                                    \
316     STMT_START {                                                    \
317         MUTEX_LOCK(&(mutex)->lock);                                 \
318         do {                                                        \
319             if ((mutex)->readers_count <= 0) {                      \
320                 assert((mutex)->readers_count == 0);                \
321                 (mutex)->readers_count = 0;                         \
322                 break;                                              \
323             }                                                       \
324             COND_WAIT(&(mutex)->wakeup, &(mutex)->lock);            \
325         }                                                           \
326         while (1);                                                  \
327                                                                     \
328         /* Here, the mutex is locked, with no readers */            \
329     } STMT_END
330 
331 #  define PERL_WRITE_UNLOCK(mutex)                                  \
332     STMT_START {                                                    \
333         COND_SIGNAL(&(mutex)->wakeup);                              \
334         MUTEX_UNLOCK(&(mutex)->lock);                               \
335     } STMT_END
336 
337 #  define PERL_RW_MUTEX_INIT(mutex)                                 \
338     STMT_START {                                                    \
339         MUTEX_INIT(&(mutex)->lock);                                 \
340         COND_INIT(&(mutex)->wakeup);                                \
341         (mutex)->readers_count = 0;                                 \
342     } STMT_END
343 
344 #  define PERL_RW_MUTEX_DESTROY(mutex)                              \
345     STMT_START {                                                    \
346         COND_DESTROY(&(mutex)->wakeup);                             \
347         MUTEX_DESTROY(&(mutex)->lock);                              \
348     } STMT_END
349 
350 #endif
351 
352 /* DETACH(t) must only be called while holding t->mutex */
353 #ifndef DETACH
354 #  define DETACH(t) \
355     STMT_START {						\
356         int _eC_;						\
357         if ((_eC_ = pthread_detach((t)->self))) {		\
358             MUTEX_UNLOCK(&(t)->mutex);				\
359             Perl_croak_nocontext("panic: DETACH (%d) [%s:%d]",	\
360                                  _eC_, __FILE__, __LINE__);	\
361         }							\
362     } STMT_END
363 #endif /* DETACH */
364 
365 #ifndef JOIN
366 #  define JOIN(t, avp) \
367     STMT_START {						\
368         int _eC_;						\
369         if ((_eC_ = pthread_join((t)->self, (void**)(avp))))	\
370             Perl_croak_nocontext("panic: pthread_join (%d) [%s:%d]",	\
371                                  _eC_, __FILE__, __LINE__);	\
372     } STMT_END
373 #endif /* JOIN */
374 
375 /* Use an unchecked fetch of thread-specific data instead of a checked one.
376  * It would fail if the key were bogus, but if the key were bogus then
377  * Really Bad Things would be happening anyway. --dan */
378 #if (defined(__ALPHA) && (__VMS_VER >= 70000000)) || \
379     (defined(__alpha) && defined(__osf__) && !defined(__GNUC__)) /* Available only on >= 4.0 */
380 #  define HAS_PTHREAD_UNCHECKED_GETSPECIFIC_NP /* Configure test needed */
381 #endif
382 
383 #ifdef HAS_PTHREAD_UNCHECKED_GETSPECIFIC_NP
384 #  define PTHREAD_GETSPECIFIC(key) pthread_unchecked_getspecific_np(key)
385 #else
386 #    define PTHREAD_GETSPECIFIC(key) pthread_getspecific(key)
387 #endif
388 
389 #if defined(PERL_THREAD_LOCAL) && !defined(PERL_GET_CONTEXT) && !defined(PERL_SET_CONTEXT) && !defined(__cplusplus)
390 /* Use C11 thread-local storage, where possible.
391  * Frustratingly we can't use it for C++ extensions, C++ and C disagree on the
392  * syntax used for thread local storage, meaning that the working token that
393  * Configure probed for C turns out to be a compiler error on C++. Great.
394  * (Well, unless one or both is supporting non-standard syntax as an extension)
395  * As Configure doesn't have a way to probe for C++ dialects, we just take the
396  * safe option and do the same as 5.34.0 and earlier - use pthreads on C++.
397  * Of course, if C++ XS extensions really want to avoid *all* this overhead,
398  * they should #define PERL_NO_GET_CONTEXT and pass aTHX/aTHX_ explicitly) */
399 #  define PERL_USE_THREAD_LOCAL
400 extern PERL_THREAD_LOCAL void *PL_current_context;
401 
402 #  define PERL_GET_CONTEXT        PL_current_context
403 
404 /* We must also call pthread_setspecific() always, as C++ code has to read it
405  * with pthreads (the #else side just below) */
406 
407 #  define PERL_SET_CONTEXT(t)                                               \
408     STMT_START {                                                            \
409         int _eC_;                                                           \
410         if ((_eC_ = pthread_setspecific(PL_thr_key,                         \
411                                         PL_current_context = (void *)(t)))) \
412             Perl_croak_nocontext("panic: pthread_setspecific (%d) [%s:%d]", \
413                                  _eC_, __FILE__, __LINE__);                 \
414         PERL_SET_NON_tTHX_CONTEXT(t);                                       \
415     } STMT_END
416 
417 #else
418 /* else fall back to pthreads */
419 
420 #  ifndef PERL_GET_CONTEXT
421 #    define PERL_GET_CONTEXT	PTHREAD_GETSPECIFIC(PL_thr_key)
422 #  endif
423 
424 /* For C++ extensions built on a system where the C compiler provides thread
425  * local storage that call PERL_SET_CONTEXT() also need to set
426  * PL_current_context, so need to call into C code to do this.
427  * To avoid exploding code complexity, do this also on C platforms that don't
428  * support thread local storage. PERL_SET_CONTEXT is not called that often. */
429 
430 #  ifndef PERL_SET_CONTEXT
431 #    define PERL_SET_CONTEXT(t) Perl_set_context((void*)t)
432 #  endif /* PERL_SET_CONTEXT */
433 #endif /* PERL_THREAD_LOCAL */
434 
435 #ifndef INIT_THREADS
436 #  ifdef NEED_PTHREAD_INIT
437 #    define INIT_THREADS pthread_init()
438 #  endif
439 #endif
440 
441 #ifndef ALLOC_THREAD_KEY
442 #  define ALLOC_THREAD_KEY \
443     STMT_START {						\
444         if (pthread_key_create(&PL_thr_key, 0)) {		\
445             PERL_UNUSED_RESULT(write(2, STR_WITH_LEN("panic: pthread_key_create failed\n"))); \
446             exit(1);						\
447         }							\
448     } STMT_END
449 #endif
450 
451 #ifndef FREE_THREAD_KEY
452 #  define FREE_THREAD_KEY \
453     STMT_START {						\
454         pthread_key_delete(PL_thr_key);				\
455     } STMT_END
456 #endif
457 
458 #ifndef PTHREAD_ATFORK
459 #  ifdef HAS_PTHREAD_ATFORK
460 #    define PTHREAD_ATFORK(prepare,parent,child)		\
461         pthread_atfork(prepare,parent,child)
462 #  else
463 #    define PTHREAD_ATFORK(prepare,parent,child)		\
464         NOOP
465 #  endif
466 #endif
467 
468 #ifndef THREAD_RET_TYPE
469 #  define THREAD_RET_TYPE	void *
470 #endif /* THREAD_RET */
471 
472 #  define LOCK_DOLLARZERO_MUTEX		MUTEX_LOCK(&PL_dollarzero_mutex)
473 #  define UNLOCK_DOLLARZERO_MUTEX	MUTEX_UNLOCK(&PL_dollarzero_mutex)
474 
475 #endif /* USE_ITHREADS */
476 
477 #ifndef MUTEX_LOCK
478 #  define MUTEX_LOCK(m)           NOOP
479 #endif
480 
481 #ifndef MUTEX_UNLOCK
482 #  define MUTEX_UNLOCK(m)         NOOP
483 #endif
484 
485 #ifndef MUTEX_INIT
486 #  define MUTEX_INIT(m)           NOOP
487 #endif
488 
489 #ifndef MUTEX_DESTROY
490 #  define MUTEX_DESTROY(m)        NOOP
491 #endif
492 
493 #ifndef COND_INIT
494 #  define COND_INIT(c)            NOOP
495 #endif
496 
497 #ifndef COND_SIGNAL
498 #  define COND_SIGNAL(c)          NOOP
499 #endif
500 
501 #ifndef COND_BROADCAST
502 #  define COND_BROADCAST(c)       NOOP
503 #endif
504 
505 #ifndef COND_WAIT
506 #  define COND_WAIT(c, m)         NOOP
507 #endif
508 
509 #ifndef COND_DESTROY
510 #  define COND_DESTROY(c)         NOOP
511 #endif
512 
513 #ifndef PERL_READ_LOCK
514 #  define PERL_READ_LOCK          NOOP
515 #  define PERL_READ_UNLOCK        NOOP
516 #  define PERL_WRITE_LOCK         NOOP
517 #  define PERL_WRITE_UNLOCK       NOOP
518 #  define PERL_RW_MUTEX_INIT      NOOP
519 #  define PERL_RW_MUTEX_DESTROY   NOOP
520 #endif
521 
522 #ifndef LOCK_DOLLARZERO_MUTEX
523 #  define LOCK_DOLLARZERO_MUTEX   NOOP
524 #endif
525 
526 #ifndef UNLOCK_DOLLARZERO_MUTEX
527 #  define UNLOCK_DOLLARZERO_MUTEX NOOP
528 #endif
529 
530 /* THR, SET_THR, and dTHR are there for compatibility with old versions */
531 #ifndef THR
532 #  define THR		PERL_GET_THX
533 #endif
534 
535 #ifndef SET_THR
536 #  define SET_THR(t)	PERL_SET_THX(t)
537 #endif
538 
539 #ifndef dTHR
540 #  define dTHR dNOOP
541 #endif
542 
543 #ifndef INIT_THREADS
544 #  define INIT_THREADS NOOP
545 #endif
546 
547 /*
548  * ex: set ts=8 sts=4 sw=4 et:
549  */
550