xref: /openbsd-src/gnu/usr.bin/perl/thread.h (revision fc405d53b73a2d73393cb97f684863d17b583e38)
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         int _eC_;						\
205         if ((_eC_ = perl_pthread_mutex_lock((m))))			\
206             Perl_croak_nocontext("panic: MUTEX_LOCK (%d) [%s:%d]",	\
207                                  _eC_, __FILE__, __LINE__);	\
208     } STMT_END
209 
210 #  define MUTEX_UNLOCK(m) \
211     STMT_START {						\
212         int _eC_;						\
213         if ((_eC_ = perl_pthread_mutex_unlock((m))))			\
214             Perl_croak_nocontext("panic: MUTEX_UNLOCK (%d) [%s:%d]",	\
215                                  _eC_, __FILE__, __LINE__);	\
216     } STMT_END
217 
218 #  define MUTEX_DESTROY(m) \
219     STMT_START {						\
220         int _eC_;						\
221         if ((_eC_ = pthread_mutex_destroy((m))))		\
222             Perl_croak_nocontext("panic: MUTEX_DESTROY (%d) [%s:%d]",	\
223                                  _eC_, __FILE__, __LINE__);	\
224     } STMT_END
225 #endif /* MUTEX_INIT */
226 
227 #ifndef COND_INIT
228 #  define COND_INIT(c) \
229     STMT_START {						\
230         int _eC_;						\
231         if ((_eC_ = pthread_cond_init((c), pthread_condattr_default)))	\
232             Perl_croak_nocontext("panic: COND_INIT (%d) [%s:%d]",	\
233                                  _eC_, __FILE__, __LINE__);	\
234     } STMT_END
235 
236 #  define COND_SIGNAL(c) \
237     STMT_START {						\
238         int _eC_;						\
239         if ((_eC_ = pthread_cond_signal((c))))			\
240             Perl_croak_nocontext("panic: COND_SIGNAL (%d) [%s:%d]",	\
241                                  _eC_, __FILE__, __LINE__);	\
242     } STMT_END
243 
244 #  define COND_BROADCAST(c) \
245     STMT_START {						\
246         int _eC_;						\
247         if ((_eC_ = pthread_cond_broadcast((c))))		\
248             Perl_croak_nocontext("panic: COND_BROADCAST (%d) [%s:%d]",	\
249                                  _eC_, __FILE__, __LINE__);	\
250     } STMT_END
251 
252 #  define COND_WAIT(c, m) \
253     STMT_START {						\
254         int _eC_;						\
255         if ((_eC_ = pthread_cond_wait((c), (m))))		\
256             Perl_croak_nocontext("panic: COND_WAIT (%d) [%s:%d]",	\
257                                  _eC_, __FILE__, __LINE__);	\
258     } STMT_END
259 
260 #  define COND_DESTROY(c) \
261     STMT_START {						\
262         int _eC_;						\
263         if ((_eC_ = pthread_cond_destroy((c))))			\
264             Perl_croak_nocontext("panic: COND_DESTROY (%d) [%s:%d]",	\
265                                  _eC_, __FILE__, __LINE__);	\
266     } STMT_END
267 #endif /* COND_INIT */
268 
269 #if defined(MUTEX_LOCK) && defined(MUTEX_UNLOCK)                \
270  && defined(COND_SIGNAL) && defined(COND_WAIT)
271 
272 /* These emulate native many-reader/1-writer locks.
273  * Basically a locking reader just locks the semaphore long enough to increment
274  * a counter; and similarly decrements it when when through.  Any writer will
275  * run only when the count of readers is 0.  That is because it blocks on that
276  * semaphore (doing a COND_WAIT) until it gets control of it, which won't
277  * happen unless the count becomes 0.  ALL readers and other writers are then
278  * blocked until it releases the semaphore.  The reader whose unlocking causes
279  * the count to become 0 signals any waiting writers, and the system guarantees
280  * that only one gets control at a time */
281 
282 #  define PERL_READ_LOCK(mutex)                                     \
283     STMT_START {                                                    \
284         MUTEX_LOCK(&(mutex)->lock);                                 \
285         (mutex)->readers_count++;                                   \
286         MUTEX_UNLOCK(&(mutex)->lock);                               \
287     } STMT_END
288 
289 #  define PERL_READ_UNLOCK(mutex)                                   \
290     STMT_START {                                                    \
291         MUTEX_LOCK(&(mutex)->lock);                                 \
292         (mutex)->readers_count--;                                   \
293         if ((mutex)->readers_count <= 0) {                          \
294             assert((mutex)->readers_count == 0);                    \
295             COND_SIGNAL(&(mutex)->wakeup);                          \
296             (mutex)->readers_count = 0;                             \
297         }                                                           \
298         MUTEX_UNLOCK(&(mutex)->lock);                               \
299     } STMT_END
300 
301 #  define PERL_WRITE_LOCK(mutex)                                    \
302     STMT_START {                                                    \
303         MUTEX_LOCK(&(mutex)->lock);                                 \
304         do {                                                        \
305             if ((mutex)->readers_count <= 0) {                      \
306                 assert((mutex)->readers_count == 0);                \
307                 (mutex)->readers_count = 0;                         \
308                 break;                                              \
309             }                                                       \
310             COND_WAIT(&(mutex)->wakeup, &(mutex)->lock);            \
311         }                                                           \
312         while (1);                                                  \
313                                                                     \
314         /* Here, the mutex is locked, with no readers */            \
315     } STMT_END
316 
317 #  define PERL_WRITE_UNLOCK(mutex)                                  \
318     STMT_START {                                                    \
319         COND_SIGNAL(&(mutex)->wakeup);                              \
320         MUTEX_UNLOCK(&(mutex)->lock);                               \
321     } STMT_END
322 
323 #  define PERL_RW_MUTEX_INIT(mutex)                                 \
324     STMT_START {                                                    \
325         MUTEX_INIT(&(mutex)->lock);                                 \
326         COND_INIT(&(mutex)->wakeup);                                \
327         (mutex)->readers_count = 0;                                 \
328     } STMT_END
329 
330 #  define PERL_RW_MUTEX_DESTROY(mutex)                              \
331     STMT_START {                                                    \
332         COND_DESTROY(&(mutex)->wakeup);                             \
333         MUTEX_DESTROY(&(mutex)->lock);                              \
334     } STMT_END
335 
336 #endif
337 
338 /* DETACH(t) must only be called while holding t->mutex */
339 #ifndef DETACH
340 #  define DETACH(t) \
341     STMT_START {						\
342         int _eC_;						\
343         if ((_eC_ = pthread_detach((t)->self))) {		\
344             MUTEX_UNLOCK(&(t)->mutex);				\
345             Perl_croak_nocontext("panic: DETACH (%d) [%s:%d]",	\
346                                  _eC_, __FILE__, __LINE__);	\
347         }							\
348     } STMT_END
349 #endif /* DETACH */
350 
351 #ifndef JOIN
352 #  define JOIN(t, avp) \
353     STMT_START {						\
354         int _eC_;						\
355         if ((_eC_ = pthread_join((t)->self, (void**)(avp))))	\
356             Perl_croak_nocontext("panic: pthread_join (%d) [%s:%d]",	\
357                                  _eC_, __FILE__, __LINE__);	\
358     } STMT_END
359 #endif /* JOIN */
360 
361 /* Use an unchecked fetch of thread-specific data instead of a checked one.
362  * It would fail if the key were bogus, but if the key were bogus then
363  * Really Bad Things would be happening anyway. --dan */
364 #if (defined(__ALPHA) && (__VMS_VER >= 70000000)) || \
365     (defined(__alpha) && defined(__osf__) && !defined(__GNUC__)) /* Available only on >= 4.0 */
366 #  define HAS_PTHREAD_UNCHECKED_GETSPECIFIC_NP /* Configure test needed */
367 #endif
368 
369 #ifdef HAS_PTHREAD_UNCHECKED_GETSPECIFIC_NP
370 #  define PTHREAD_GETSPECIFIC(key) pthread_unchecked_getspecific_np(key)
371 #else
372 #    define PTHREAD_GETSPECIFIC(key) pthread_getspecific(key)
373 #endif
374 
375 #if defined(PERL_THREAD_LOCAL) && !defined(PERL_GET_CONTEXT) && !defined(PERL_SET_CONTEXT) && !defined(__cplusplus)
376 /* Use C11 thread-local storage, where possible.
377  * Frustratingly we can't use it for C++ extensions, C++ and C disagree on the
378  * syntax used for thread local storage, meaning that the working token that
379  * Configure probed for C turns out to be a compiler error on C++. Great.
380  * (Well, unless one or both is supporting non-standard syntax as an extension)
381  * As Configure doesn't have a way to probe for C++ dialects, we just take the
382  * safe option and do the same as 5.34.0 and earlier - use pthreads on C++.
383  * Of course, if C++ XS extensions really want to avoid *all* this overhead,
384  * they should #define PERL_NO_GET_CONTEXT and pass aTHX/aTHX_ explicitly) */
385 #  define PERL_USE_THREAD_LOCAL
386 extern PERL_THREAD_LOCAL void *PL_current_context;
387 
388 #  define PERL_GET_CONTEXT        PL_current_context
389 
390 /* We must also call pthread_setspecific() always, as C++ code has to read it
391  * with pthreads (the #else side just below) */
392 
393 #  define PERL_SET_CONTEXT(t)                                           \
394     STMT_START {                                                        \
395         int _eC_;                                                       \
396         if ((_eC_ = pthread_setspecific(PL_thr_key, PL_current_context = (void *)(t)))) \
397             Perl_croak_nocontext("panic: pthread_setspecific (%d) [%s:%d]", \
398                                  _eC_, __FILE__, __LINE__);             \
399     } STMT_END
400 
401 #else
402 /* else fall back to pthreads */
403 
404 #  ifndef PERL_GET_CONTEXT
405 #    define PERL_GET_CONTEXT	PTHREAD_GETSPECIFIC(PL_thr_key)
406 #  endif
407 
408 /* For C++ extensions built on a system where the C compiler provides thread
409  * local storage that call PERL_SET_CONTEXT() also need to set
410  * PL_current_context, so need to call into C code to do this.
411  * To avoid exploding code complexity, do this also on C platforms that don't
412  * support thread local storage. PERL_SET_CONTEXT is not called that often. */
413 
414 #  ifndef PERL_SET_CONTEXT
415 #    define PERL_SET_CONTEXT(t) Perl_set_context((void*)t)
416 #  endif /* PERL_SET_CONTEXT */
417 #endif /* PERL_THREAD_LOCAL */
418 
419 #ifndef INIT_THREADS
420 #  ifdef NEED_PTHREAD_INIT
421 #    define INIT_THREADS pthread_init()
422 #  endif
423 #endif
424 
425 #ifndef ALLOC_THREAD_KEY
426 #  define ALLOC_THREAD_KEY \
427     STMT_START {						\
428         if (pthread_key_create(&PL_thr_key, 0)) {		\
429             PERL_UNUSED_RESULT(write(2, STR_WITH_LEN("panic: pthread_key_create failed\n"))); \
430             exit(1);						\
431         }							\
432     } STMT_END
433 #endif
434 
435 #ifndef FREE_THREAD_KEY
436 #  define FREE_THREAD_KEY \
437     STMT_START {						\
438         pthread_key_delete(PL_thr_key);				\
439     } STMT_END
440 #endif
441 
442 #ifndef PTHREAD_ATFORK
443 #  ifdef HAS_PTHREAD_ATFORK
444 #    define PTHREAD_ATFORK(prepare,parent,child)		\
445         pthread_atfork(prepare,parent,child)
446 #  else
447 #    define PTHREAD_ATFORK(prepare,parent,child)		\
448         NOOP
449 #  endif
450 #endif
451 
452 #ifndef THREAD_RET_TYPE
453 #  define THREAD_RET_TYPE	void *
454 #endif /* THREAD_RET */
455 
456 #  define LOCK_DOLLARZERO_MUTEX		MUTEX_LOCK(&PL_dollarzero_mutex)
457 #  define UNLOCK_DOLLARZERO_MUTEX	MUTEX_UNLOCK(&PL_dollarzero_mutex)
458 
459 #endif /* USE_ITHREADS */
460 
461 #ifndef MUTEX_LOCK
462 #  define MUTEX_LOCK(m)           NOOP
463 #endif
464 
465 #ifndef MUTEX_UNLOCK
466 #  define MUTEX_UNLOCK(m)         NOOP
467 #endif
468 
469 #ifndef MUTEX_INIT
470 #  define MUTEX_INIT(m)           NOOP
471 #endif
472 
473 #ifndef MUTEX_DESTROY
474 #  define MUTEX_DESTROY(m)        NOOP
475 #endif
476 
477 #ifndef COND_INIT
478 #  define COND_INIT(c)            NOOP
479 #endif
480 
481 #ifndef COND_SIGNAL
482 #  define COND_SIGNAL(c)          NOOP
483 #endif
484 
485 #ifndef COND_BROADCAST
486 #  define COND_BROADCAST(c)       NOOP
487 #endif
488 
489 #ifndef COND_WAIT
490 #  define COND_WAIT(c, m)         NOOP
491 #endif
492 
493 #ifndef COND_DESTROY
494 #  define COND_DESTROY(c)         NOOP
495 #endif
496 
497 #ifndef PERL_READ_LOCK
498 #  define PERL_READ_LOCK          NOOP
499 #  define PERL_READ_UNLOCK        NOOP
500 #  define PERL_WRITE_LOCK         NOOP
501 #  define PERL_WRITE_UNLOCK       NOOP
502 #  define PERL_RW_MUTEX_INIT      NOOP
503 #  define PERL_RW_MUTEX_DESTROY   NOOP
504 #endif
505 
506 #ifndef LOCK_DOLLARZERO_MUTEX
507 #  define LOCK_DOLLARZERO_MUTEX   NOOP
508 #endif
509 
510 #ifndef UNLOCK_DOLLARZERO_MUTEX
511 #  define UNLOCK_DOLLARZERO_MUTEX NOOP
512 #endif
513 
514 /* THR, SET_THR, and dTHR are there for compatibility with old versions */
515 #ifndef THR
516 #  define THR		PERL_GET_THX
517 #endif
518 
519 #ifndef SET_THR
520 #  define SET_THR(t)	PERL_SET_THX(t)
521 #endif
522 
523 #ifndef dTHR
524 #  define dTHR dNOOP
525 #endif
526 
527 #ifndef INIT_THREADS
528 #  define INIT_THREADS NOOP
529 #endif
530 
531 /*
532  * ex: set ts=8 sts=4 sw=4 et:
533  */
534