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[official-gcc.git] / gcc / gthr-posix.h
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1 /* Threads compatibility routines for libgcc2 and libobjc. */
2 /* Compile this one with gcc. */
3 /* Copyright (C) 1997, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
23 /* As a special exception, if you link this library with other files,
24 some of which are compiled with GCC, to produce an executable,
25 this library does not by itself cause the resulting executable
26 to be covered by the GNU General Public License.
27 This exception does not however invalidate any other reasons why
28 the executable file might be covered by the GNU General Public License. */
30 #ifndef GCC_GTHR_POSIX_H
31 #define GCC_GTHR_POSIX_H
33 /* POSIX threads specific definitions.
34 Easy, since the interface is just one-to-one mapping. */
36 #define __GTHREADS 1
38 /* Some implementations of <pthread.h> require this to be defined. */
39 #if !defined(_REENTRANT) && defined(__osf__)
40 #define _REENTRANT 1
41 #endif
43 #include <pthread.h>
44 #include <unistd.h>
46 typedef pthread_key_t __gthread_key_t;
47 typedef pthread_once_t __gthread_once_t;
48 typedef pthread_mutex_t __gthread_mutex_t;
49 typedef pthread_mutex_t __gthread_recursive_mutex_t;
51 #define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER
52 #define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
53 #if defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER)
54 #define __GTHREAD_RECURSIVE_MUTEX_INIT PTHREAD_RECURSIVE_MUTEX_INITIALIZER
55 #elif defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP)
56 #define __GTHREAD_RECURSIVE_MUTEX_INIT PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
57 #else
58 #define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_recursive_mutex_init_function
59 #endif
61 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
62 # ifndef __gthrw_pragma
63 # define __gthrw_pragma(pragma)
64 # endif
65 # define __gthrw2(name,name2,type) \
66 static __typeof(type) name __attribute__ ((__weakref__(#name2))); \
67 __gthrw_pragma(weak type)
68 # define __gthrw_(name) __gthrw_ ## name
69 #else
70 # define __gthrw2(name,name2,type)
71 # define __gthrw_(name) name
72 #endif
74 /* Typically, __gthrw_foo is a weak reference to symbol foo. */
75 #define __gthrw(name) __gthrw2(__gthrw_ ## name,name,name)
77 /* On Tru64, /usr/include/pthread.h uses #pragma extern_prefix "__" to
78 map a subset of the POSIX pthread API to mangled versions of their
79 names. */
80 #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
81 #define __gthrw3(name) __gthrw2(__gthrw_ ## name, __ ## name, name)
82 __gthrw3(pthread_once)
83 __gthrw3(pthread_getspecific)
84 __gthrw3(pthread_setspecific)
85 __gthrw3(pthread_create)
86 __gthrw3(pthread_cancel)
87 __gthrw3(pthread_mutex_lock)
88 __gthrw3(pthread_mutex_trylock)
89 __gthrw3(pthread_mutex_unlock)
90 __gthrw3(pthread_mutex_init)
91 #else
92 __gthrw(pthread_once)
93 __gthrw(pthread_getspecific)
94 __gthrw(pthread_setspecific)
95 __gthrw(pthread_create)
96 __gthrw(pthread_cancel)
97 __gthrw(pthread_mutex_lock)
98 __gthrw(pthread_mutex_trylock)
99 __gthrw(pthread_mutex_unlock)
100 __gthrw(pthread_mutex_init)
101 #endif
103 __gthrw(pthread_key_create)
104 __gthrw(pthread_key_delete)
105 __gthrw(pthread_mutexattr_init)
106 __gthrw(pthread_mutexattr_settype)
107 __gthrw(pthread_mutexattr_destroy)
110 #if defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)
111 /* Objective-C. */
112 #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
113 __gthrw3(pthread_cond_broadcast)
114 __gthrw3(pthread_cond_destroy)
115 __gthrw3(pthread_cond_init)
116 __gthrw3(pthread_cond_signal)
117 __gthrw3(pthread_cond_wait)
118 __gthrw3(pthread_exit)
119 __gthrw3(pthread_mutex_destroy)
120 __gthrw3(pthread_self)
121 #else
122 __gthrw(pthread_cond_broadcast)
123 __gthrw(pthread_cond_destroy)
124 __gthrw(pthread_cond_init)
125 __gthrw(pthread_cond_signal)
126 __gthrw(pthread_cond_wait)
127 __gthrw(pthread_exit)
128 __gthrw(pthread_mutex_destroy)
129 __gthrw(pthread_self)
130 #endif /* __osf__ && _PTHREAD_USE_MANGLED_NAMES_ */
131 #ifdef _POSIX_PRIORITY_SCHEDULING
132 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
133 __gthrw(sched_get_priority_max)
134 __gthrw(sched_get_priority_min)
135 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
136 #endif /* _POSIX_PRIORITY_SCHEDULING */
137 __gthrw(sched_yield)
138 __gthrw(pthread_attr_destroy)
139 __gthrw(pthread_attr_init)
140 __gthrw(pthread_attr_setdetachstate)
141 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
142 __gthrw(pthread_getschedparam)
143 __gthrw(pthread_setschedparam)
144 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
145 #endif /* _LIBOBJC || _LIBOBJC_WEAK */
147 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
149 /* On Solaris 2.6 up to 9, the libc exposes a POSIX threads interface even if
150 -pthreads is not specified. The functions are dummies and most return an
151 error value. However pthread_once returns 0 without invoking the routine
152 it is passed so we cannot pretend that the interface is active if -pthreads
153 is not specified. On Solaris 2.5.1, the interface is not exposed at all so
154 we need to play the usual game with weak symbols. On Solaris 10 and up, a
155 working interface is always exposed. */
157 #if defined(__sun) && defined(__svr4__)
159 static volatile int __gthread_active = -1;
161 static void
162 __gthread_trigger (void)
164 __gthread_active = 1;
167 static inline int
168 __gthread_active_p (void)
170 static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
171 static pthread_once_t __gthread_active_once = PTHREAD_ONCE_INIT;
173 /* Avoid reading __gthread_active twice on the main code path. */
174 int __gthread_active_latest_value = __gthread_active;
176 /* This test is not protected to avoid taking a lock on the main code
177 path so every update of __gthread_active in a threaded program must
178 be atomic with regard to the result of the test. */
179 if (__builtin_expect (__gthread_active_latest_value < 0, 0))
181 if (__gthrw_(pthread_once))
183 /* If this really is a threaded program, then we must ensure that
184 __gthread_active has been set to 1 before exiting this block. */
185 __gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
186 __gthrw_(pthread_once) (&__gthread_active_once, __gthread_trigger);
187 __gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
190 /* Make sure we'll never enter this block again. */
191 if (__gthread_active < 0)
192 __gthread_active = 0;
194 __gthread_active_latest_value = __gthread_active;
197 return __gthread_active_latest_value != 0;
200 #else /* not Solaris */
202 static inline int
203 __gthread_active_p (void)
205 static void *const __gthread_active_ptr
206 = __extension__ (void *) &__gthrw_(pthread_cancel);
207 return __gthread_active_ptr != 0;
210 #endif /* Solaris */
212 #else /* not SUPPORTS_WEAK */
214 /* Similar to Solaris, HP-UX 11 for PA-RISC provides stubs for pthread
215 calls in shared flavors of the HP-UX C library. Most of the stubs
216 have no functionality. The details are described in the "libc cumulative
217 patch" for each subversion of HP-UX 11. There are two special interfaces
218 provided for checking whether an application is linked to a pthread
219 library or not. However, these interfaces aren't available in early
220 libc versions. We also can't use pthread_once as some libc versions
221 call the init function. So, we use pthread_create to check whether it
222 is possible to create a thread or not. The stub implementation returns
223 the error number ENOSYS. */
225 #if defined(__hppa__) && defined(__hpux__)
227 #include <errno.h>
229 static volatile int __gthread_active = -1;
231 static void *
232 __gthread_start (void *arg __attribute__((unused)))
234 return NULL;
237 static void __gthread_active_init (void) __attribute__((noinline));
238 static void
239 __gthread_active_init (void)
241 static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
242 pthread_t t;
243 int result;
245 __gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
246 if (__gthread_active < 0)
248 result = __gthrw_(pthread_create) (&t, NULL, __gthread_start, NULL);
249 if (result != ENOSYS)
251 __gthread_active = 1;
252 if (!result)
253 __gthrw_(pthread_join) (t, NULL);
255 else
256 __gthread_active = 0;
258 __gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
261 static inline int
262 __gthread_active_p (void)
264 /* Avoid reading __gthread_active twice on the main code path. */
265 int __gthread_active_latest_value = __gthread_active;
267 /* This test is not protected to avoid taking a lock on the main code
268 path so every update of __gthread_active in a threaded program must
269 be atomic with regard to the result of the test. */
270 if (__builtin_expect (__gthread_active_latest_value < 0, 0))
272 __gthread_active_init ();
273 __gthread_active_latest_value = __gthread_active;
276 return __gthread_active_latest_value != 0;
279 #else /* not hppa-hpux */
281 static inline int
282 __gthread_active_p (void)
284 return 1;
287 #endif /* hppa-hpux */
289 #endif /* SUPPORTS_WEAK */
291 #ifdef _LIBOBJC
293 /* This is the config.h file in libobjc/ */
294 #include <config.h>
296 #ifdef HAVE_SCHED_H
297 # include <sched.h>
298 #endif
300 /* Key structure for maintaining thread specific storage */
301 static pthread_key_t _objc_thread_storage;
302 static pthread_attr_t _objc_thread_attribs;
304 /* Thread local storage for a single thread */
305 static void *thread_local_storage = NULL;
307 /* Backend initialization functions */
309 /* Initialize the threads subsystem. */
310 static inline int
311 __gthread_objc_init_thread_system (void)
313 if (__gthread_active_p ())
315 /* Initialize the thread storage key. */
316 if (__gthrw_(pthread_key_create) (&_objc_thread_storage, NULL) == 0)
318 /* The normal default detach state for threads is
319 * PTHREAD_CREATE_JOINABLE which causes threads to not die
320 * when you think they should. */
321 if (__gthrw_(pthread_attr_init) (&_objc_thread_attribs) == 0
322 && __gthrw_(pthread_attr_setdetachstate) (&_objc_thread_attribs,
323 PTHREAD_CREATE_DETACHED) == 0)
324 return 0;
328 return -1;
331 /* Close the threads subsystem. */
332 static inline int
333 __gthread_objc_close_thread_system (void)
335 if (__gthread_active_p ()
336 && __gthrw_(pthread_key_delete) (_objc_thread_storage) == 0
337 && __gthrw_(pthread_attr_destroy) (&_objc_thread_attribs) == 0)
338 return 0;
340 return -1;
343 /* Backend thread functions */
345 /* Create a new thread of execution. */
346 static inline objc_thread_t
347 __gthread_objc_thread_detach (void (*func)(void *), void *arg)
349 objc_thread_t thread_id;
350 pthread_t new_thread_handle;
352 if (!__gthread_active_p ())
353 return NULL;
355 if (!(__gthrw_(pthread_create) (&new_thread_handle, NULL, (void *) func, arg)))
356 thread_id = (objc_thread_t) new_thread_handle;
357 else
358 thread_id = NULL;
360 return thread_id;
363 /* Set the current thread's priority. */
364 static inline int
365 __gthread_objc_thread_set_priority (int priority)
367 if (!__gthread_active_p ())
368 return -1;
369 else
371 #ifdef _POSIX_PRIORITY_SCHEDULING
372 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
373 pthread_t thread_id = __gthrw_(pthread_self) ();
374 int policy;
375 struct sched_param params;
376 int priority_min, priority_max;
378 if (__gthrw_(pthread_getschedparam) (thread_id, &policy, &params) == 0)
380 if ((priority_max = __gthrw_(sched_get_priority_max) (policy)) == -1)
381 return -1;
383 if ((priority_min = __gthrw_(sched_get_priority_min) (policy)) == -1)
384 return -1;
386 if (priority > priority_max)
387 priority = priority_max;
388 else if (priority < priority_min)
389 priority = priority_min;
390 params.sched_priority = priority;
393 * The solaris 7 and several other man pages incorrectly state that
394 * this should be a pointer to policy but pthread.h is universally
395 * at odds with this.
397 if (__gthrw_(pthread_setschedparam) (thread_id, policy, &params) == 0)
398 return 0;
400 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
401 #endif /* _POSIX_PRIORITY_SCHEDULING */
402 return -1;
406 /* Return the current thread's priority. */
407 static inline int
408 __gthread_objc_thread_get_priority (void)
410 #ifdef _POSIX_PRIORITY_SCHEDULING
411 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
412 if (__gthread_active_p ())
414 int policy;
415 struct sched_param params;
417 if (__gthrw_(pthread_getschedparam) (__gthrw_(pthread_self) (), &policy, &params) == 0)
418 return params.sched_priority;
419 else
420 return -1;
422 else
423 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
424 #endif /* _POSIX_PRIORITY_SCHEDULING */
425 return OBJC_THREAD_INTERACTIVE_PRIORITY;
428 /* Yield our process time to another thread. */
429 static inline void
430 __gthread_objc_thread_yield (void)
432 if (__gthread_active_p ())
433 __gthrw_(sched_yield) ();
436 /* Terminate the current thread. */
437 static inline int
438 __gthread_objc_thread_exit (void)
440 if (__gthread_active_p ())
441 /* exit the thread */
442 __gthrw_(pthread_exit) (&__objc_thread_exit_status);
444 /* Failed if we reached here */
445 return -1;
448 /* Returns an integer value which uniquely describes a thread. */
449 static inline objc_thread_t
450 __gthread_objc_thread_id (void)
452 if (__gthread_active_p ())
453 return (objc_thread_t) __gthrw_(pthread_self) ();
454 else
455 return (objc_thread_t) 1;
458 /* Sets the thread's local storage pointer. */
459 static inline int
460 __gthread_objc_thread_set_data (void *value)
462 if (__gthread_active_p ())
463 return __gthrw_(pthread_setspecific) (_objc_thread_storage, value);
464 else
466 thread_local_storage = value;
467 return 0;
471 /* Returns the thread's local storage pointer. */
472 static inline void *
473 __gthread_objc_thread_get_data (void)
475 if (__gthread_active_p ())
476 return __gthrw_(pthread_getspecific) (_objc_thread_storage);
477 else
478 return thread_local_storage;
481 /* Backend mutex functions */
483 /* Allocate a mutex. */
484 static inline int
485 __gthread_objc_mutex_allocate (objc_mutex_t mutex)
487 if (__gthread_active_p ())
489 mutex->backend = objc_malloc (sizeof (pthread_mutex_t));
491 if (__gthrw_(pthread_mutex_init) ((pthread_mutex_t *) mutex->backend, NULL))
493 objc_free (mutex->backend);
494 mutex->backend = NULL;
495 return -1;
499 return 0;
502 /* Deallocate a mutex. */
503 static inline int
504 __gthread_objc_mutex_deallocate (objc_mutex_t mutex)
506 if (__gthread_active_p ())
508 int count;
511 * Posix Threads specifically require that the thread be unlocked
512 * for __gthrw_(pthread_mutex_destroy) to work.
517 count = __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend);
518 if (count < 0)
519 return -1;
521 while (count);
523 if (__gthrw_(pthread_mutex_destroy) ((pthread_mutex_t *) mutex->backend))
524 return -1;
526 objc_free (mutex->backend);
527 mutex->backend = NULL;
529 return 0;
532 /* Grab a lock on a mutex. */
533 static inline int
534 __gthread_objc_mutex_lock (objc_mutex_t mutex)
536 if (__gthread_active_p ()
537 && __gthrw_(pthread_mutex_lock) ((pthread_mutex_t *) mutex->backend) != 0)
539 return -1;
542 return 0;
545 /* Try to grab a lock on a mutex. */
546 static inline int
547 __gthread_objc_mutex_trylock (objc_mutex_t mutex)
549 if (__gthread_active_p ()
550 && __gthrw_(pthread_mutex_trylock) ((pthread_mutex_t *) mutex->backend) != 0)
552 return -1;
555 return 0;
558 /* Unlock the mutex */
559 static inline int
560 __gthread_objc_mutex_unlock (objc_mutex_t mutex)
562 if (__gthread_active_p ()
563 && __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend) != 0)
565 return -1;
568 return 0;
571 /* Backend condition mutex functions */
573 /* Allocate a condition. */
574 static inline int
575 __gthread_objc_condition_allocate (objc_condition_t condition)
577 if (__gthread_active_p ())
579 condition->backend = objc_malloc (sizeof (pthread_cond_t));
581 if (__gthrw_(pthread_cond_init) ((pthread_cond_t *) condition->backend, NULL))
583 objc_free (condition->backend);
584 condition->backend = NULL;
585 return -1;
589 return 0;
592 /* Deallocate a condition. */
593 static inline int
594 __gthread_objc_condition_deallocate (objc_condition_t condition)
596 if (__gthread_active_p ())
598 if (__gthrw_(pthread_cond_destroy) ((pthread_cond_t *) condition->backend))
599 return -1;
601 objc_free (condition->backend);
602 condition->backend = NULL;
604 return 0;
607 /* Wait on the condition */
608 static inline int
609 __gthread_objc_condition_wait (objc_condition_t condition, objc_mutex_t mutex)
611 if (__gthread_active_p ())
612 return __gthrw_(pthread_cond_wait) ((pthread_cond_t *) condition->backend,
613 (pthread_mutex_t *) mutex->backend);
614 else
615 return 0;
618 /* Wake up all threads waiting on this condition. */
619 static inline int
620 __gthread_objc_condition_broadcast (objc_condition_t condition)
622 if (__gthread_active_p ())
623 return __gthrw_(pthread_cond_broadcast) ((pthread_cond_t *) condition->backend);
624 else
625 return 0;
628 /* Wake up one thread waiting on this condition. */
629 static inline int
630 __gthread_objc_condition_signal (objc_condition_t condition)
632 if (__gthread_active_p ())
633 return __gthrw_(pthread_cond_signal) ((pthread_cond_t *) condition->backend);
634 else
635 return 0;
638 #else /* _LIBOBJC */
640 static inline int
641 __gthread_once (__gthread_once_t *once, void (*func) (void))
643 if (__gthread_active_p ())
644 return __gthrw_(pthread_once) (once, func);
645 else
646 return -1;
649 static inline int
650 __gthread_key_create (__gthread_key_t *key, void (*dtor) (void *))
652 return __gthrw_(pthread_key_create) (key, dtor);
655 static inline int
656 __gthread_key_delete (__gthread_key_t key)
658 return __gthrw_(pthread_key_delete) (key);
661 static inline void *
662 __gthread_getspecific (__gthread_key_t key)
664 return __gthrw_(pthread_getspecific) (key);
667 static inline int
668 __gthread_setspecific (__gthread_key_t key, const void *ptr)
670 return __gthrw_(pthread_setspecific) (key, ptr);
673 static inline int
674 __gthread_mutex_lock (__gthread_mutex_t *mutex)
676 if (__gthread_active_p ())
677 return __gthrw_(pthread_mutex_lock) (mutex);
678 else
679 return 0;
682 static inline int
683 __gthread_mutex_trylock (__gthread_mutex_t *mutex)
685 if (__gthread_active_p ())
686 return __gthrw_(pthread_mutex_trylock) (mutex);
687 else
688 return 0;
691 static inline int
692 __gthread_mutex_unlock (__gthread_mutex_t *mutex)
694 if (__gthread_active_p ())
695 return __gthrw_(pthread_mutex_unlock) (mutex);
696 else
697 return 0;
700 #ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
701 static inline int
702 __gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex)
704 if (__gthread_active_p ())
706 pthread_mutexattr_t attr;
707 int r;
709 r = __gthrw_(pthread_mutexattr_init) (&attr);
710 if (!r)
711 r = __gthrw_(pthread_mutexattr_settype) (&attr, PTHREAD_MUTEX_RECURSIVE);
712 if (!r)
713 r = __gthrw_(pthread_mutex_init) (mutex, &attr);
714 if (!r)
715 r = __gthrw_(pthread_mutexattr_destroy) (&attr);
716 return r;
718 return 0;
720 #endif
722 static inline int
723 __gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex)
725 return __gthread_mutex_lock (mutex);
728 static inline int
729 __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
731 return __gthread_mutex_trylock (mutex);
734 static inline int
735 __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
737 return __gthread_mutex_unlock (mutex);
740 #endif /* _LIBOBJC */
742 #endif /* ! GCC_GTHR_POSIX_H */