http://gcc.gnu.org/ml/gcc-patches/2008-02/msg01094.html
[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;
50 typedef pthread_cond_t __gthread_cond_t;
52 /* POSIX like conditional variables are supported. Please look at comments
53 in gthr.h for details. */
54 #define __GTHREAD_HAS_COND 1
56 #define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER
57 #define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
58 #if defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER)
59 #define __GTHREAD_RECURSIVE_MUTEX_INIT PTHREAD_RECURSIVE_MUTEX_INITIALIZER
60 #elif defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP)
61 #define __GTHREAD_RECURSIVE_MUTEX_INIT PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
62 #else
63 #define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_recursive_mutex_init_function
64 #endif
65 #define __GTHREAD_COND_INIT PTHREAD_COND_INITIALIZER
67 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
68 # ifndef __gthrw_pragma
69 # define __gthrw_pragma(pragma)
70 # endif
71 # define __gthrw2(name,name2,type) \
72 static __typeof(type) name __attribute__ ((__weakref__(#name2))); \
73 __gthrw_pragma(weak type)
74 # define __gthrw_(name) __gthrw_ ## name
75 #else
76 # define __gthrw2(name,name2,type)
77 # define __gthrw_(name) name
78 #endif
80 /* Typically, __gthrw_foo is a weak reference to symbol foo. */
81 #define __gthrw(name) __gthrw2(__gthrw_ ## name,name,name)
83 /* On Tru64, /usr/include/pthread.h uses #pragma extern_prefix "__" to
84 map a subset of the POSIX pthread API to mangled versions of their
85 names. */
86 #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
87 #define __gthrw3(name) __gthrw2(__gthrw_ ## name, __ ## name, name)
88 __gthrw3(pthread_once)
89 __gthrw3(pthread_getspecific)
90 __gthrw3(pthread_setspecific)
91 __gthrw3(pthread_create)
92 __gthrw3(pthread_cancel)
93 __gthrw3(pthread_mutex_lock)
94 __gthrw3(pthread_mutex_trylock)
95 __gthrw3(pthread_mutex_unlock)
96 __gthrw3(pthread_mutex_init)
97 __gthrw3(pthread_cond_broadcast)
98 __gthrw3(pthread_cond_wait)
99 #else
100 __gthrw(pthread_once)
101 __gthrw(pthread_getspecific)
102 __gthrw(pthread_setspecific)
103 __gthrw(pthread_create)
104 __gthrw(pthread_cancel)
105 __gthrw(pthread_mutex_lock)
106 __gthrw(pthread_mutex_trylock)
107 __gthrw(pthread_mutex_unlock)
108 __gthrw(pthread_mutex_init)
109 __gthrw(pthread_cond_broadcast)
110 __gthrw(pthread_cond_wait)
111 #endif
113 __gthrw(pthread_key_create)
114 __gthrw(pthread_key_delete)
115 __gthrw(pthread_mutexattr_init)
116 __gthrw(pthread_mutexattr_settype)
117 __gthrw(pthread_mutexattr_destroy)
120 #if defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)
121 /* Objective-C. */
122 #if defined(__osf__) && defined(_PTHREAD_USE_MANGLED_NAMES_)
123 __gthrw3(pthread_cond_destroy)
124 __gthrw3(pthread_cond_init)
125 __gthrw3(pthread_cond_signal)
126 __gthrw3(pthread_exit)
127 __gthrw3(pthread_mutex_destroy)
128 __gthrw3(pthread_self)
129 #else
130 __gthrw(pthread_cond_destroy)
131 __gthrw(pthread_cond_init)
132 __gthrw(pthread_cond_signal)
133 __gthrw(pthread_exit)
134 __gthrw(pthread_mutex_destroy)
135 __gthrw(pthread_self)
136 #endif /* __osf__ && _PTHREAD_USE_MANGLED_NAMES_ */
137 #ifdef _POSIX_PRIORITY_SCHEDULING
138 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
139 __gthrw(sched_get_priority_max)
140 __gthrw(sched_get_priority_min)
141 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
142 #endif /* _POSIX_PRIORITY_SCHEDULING */
143 __gthrw(sched_yield)
144 __gthrw(pthread_attr_destroy)
145 __gthrw(pthread_attr_init)
146 __gthrw(pthread_attr_setdetachstate)
147 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
148 __gthrw(pthread_getschedparam)
149 __gthrw(pthread_setschedparam)
150 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
151 #endif /* _LIBOBJC || _LIBOBJC_WEAK */
153 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
155 /* On Solaris 2.6 up to 9, the libc exposes a POSIX threads interface even if
156 -pthreads is not specified. The functions are dummies and most return an
157 error value. However pthread_once returns 0 without invoking the routine
158 it is passed so we cannot pretend that the interface is active if -pthreads
159 is not specified. On Solaris 2.5.1, the interface is not exposed at all so
160 we need to play the usual game with weak symbols. On Solaris 10 and up, a
161 working interface is always exposed. */
163 #if defined(__sun) && defined(__svr4__)
165 static volatile int __gthread_active = -1;
167 static void
168 __gthread_trigger (void)
170 __gthread_active = 1;
173 static inline int
174 __gthread_active_p (void)
176 static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
177 static pthread_once_t __gthread_active_once = PTHREAD_ONCE_INIT;
179 /* Avoid reading __gthread_active twice on the main code path. */
180 int __gthread_active_latest_value = __gthread_active;
182 /* This test is not protected to avoid taking a lock on the main code
183 path so every update of __gthread_active in a threaded program must
184 be atomic with regard to the result of the test. */
185 if (__builtin_expect (__gthread_active_latest_value < 0, 0))
187 if (__gthrw_(pthread_once))
189 /* If this really is a threaded program, then we must ensure that
190 __gthread_active has been set to 1 before exiting this block. */
191 __gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
192 __gthrw_(pthread_once) (&__gthread_active_once, __gthread_trigger);
193 __gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
196 /* Make sure we'll never enter this block again. */
197 if (__gthread_active < 0)
198 __gthread_active = 0;
200 __gthread_active_latest_value = __gthread_active;
203 return __gthread_active_latest_value != 0;
206 #else /* not Solaris */
208 static inline int
209 __gthread_active_p (void)
211 static void *const __gthread_active_ptr
212 = __extension__ (void *) &__gthrw_(pthread_cancel);
213 return __gthread_active_ptr != 0;
216 #endif /* Solaris */
218 #else /* not SUPPORTS_WEAK */
220 /* Similar to Solaris, HP-UX 11 for PA-RISC provides stubs for pthread
221 calls in shared flavors of the HP-UX C library. Most of the stubs
222 have no functionality. The details are described in the "libc cumulative
223 patch" for each subversion of HP-UX 11. There are two special interfaces
224 provided for checking whether an application is linked to a pthread
225 library or not. However, these interfaces aren't available in early
226 libc versions. We also can't use pthread_once as some libc versions
227 call the init function. So, we use pthread_create to check whether it
228 is possible to create a thread or not. The stub implementation returns
229 the error number ENOSYS. */
231 #if defined(__hppa__) && defined(__hpux__)
233 #include <errno.h>
235 static volatile int __gthread_active = -1;
237 static void *
238 __gthread_start (void *arg __attribute__((unused)))
240 return NULL;
243 static void __gthread_active_init (void) __attribute__((noinline));
244 static void
245 __gthread_active_init (void)
247 static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
248 pthread_t t;
249 pthread_attr_t a;
250 int result;
252 __gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
253 if (__gthread_active < 0)
255 __gthrw_(pthread_attr_init) (&a);
256 __gthrw_(pthread_attr_setdetachstate) (&a, PTHREAD_CREATE_DETACHED);
257 result = __gthrw_(pthread_create) (&t, &a, __gthread_start, NULL);
258 if (result != ENOSYS)
259 __gthread_active = 1;
260 else
261 __gthread_active = 0;
262 __gthrw_(pthread_attr_destroy) (&a);
264 __gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
267 static inline int
268 __gthread_active_p (void)
270 /* Avoid reading __gthread_active twice on the main code path. */
271 int __gthread_active_latest_value = __gthread_active;
273 /* This test is not protected to avoid taking a lock on the main code
274 path so every update of __gthread_active in a threaded program must
275 be atomic with regard to the result of the test. */
276 if (__builtin_expect (__gthread_active_latest_value < 0, 0))
278 __gthread_active_init ();
279 __gthread_active_latest_value = __gthread_active;
282 return __gthread_active_latest_value != 0;
285 #else /* not hppa-hpux */
287 static inline int
288 __gthread_active_p (void)
290 return 1;
293 #endif /* hppa-hpux */
295 #endif /* SUPPORTS_WEAK */
297 #ifdef _LIBOBJC
299 /* This is the config.h file in libobjc/ */
300 #include <config.h>
302 #ifdef HAVE_SCHED_H
303 # include <sched.h>
304 #endif
306 /* Key structure for maintaining thread specific storage */
307 static pthread_key_t _objc_thread_storage;
308 static pthread_attr_t _objc_thread_attribs;
310 /* Thread local storage for a single thread */
311 static void *thread_local_storage = NULL;
313 /* Backend initialization functions */
315 /* Initialize the threads subsystem. */
316 static inline int
317 __gthread_objc_init_thread_system (void)
319 if (__gthread_active_p ())
321 /* Initialize the thread storage key. */
322 if (__gthrw_(pthread_key_create) (&_objc_thread_storage, NULL) == 0)
324 /* The normal default detach state for threads is
325 * PTHREAD_CREATE_JOINABLE which causes threads to not die
326 * when you think they should. */
327 if (__gthrw_(pthread_attr_init) (&_objc_thread_attribs) == 0
328 && __gthrw_(pthread_attr_setdetachstate) (&_objc_thread_attribs,
329 PTHREAD_CREATE_DETACHED) == 0)
330 return 0;
334 return -1;
337 /* Close the threads subsystem. */
338 static inline int
339 __gthread_objc_close_thread_system (void)
341 if (__gthread_active_p ()
342 && __gthrw_(pthread_key_delete) (_objc_thread_storage) == 0
343 && __gthrw_(pthread_attr_destroy) (&_objc_thread_attribs) == 0)
344 return 0;
346 return -1;
349 /* Backend thread functions */
351 /* Create a new thread of execution. */
352 static inline objc_thread_t
353 __gthread_objc_thread_detach (void (*func)(void *), void *arg)
355 objc_thread_t thread_id;
356 pthread_t new_thread_handle;
358 if (!__gthread_active_p ())
359 return NULL;
361 if (!(__gthrw_(pthread_create) (&new_thread_handle, NULL, (void *) func, arg)))
362 thread_id = (objc_thread_t) new_thread_handle;
363 else
364 thread_id = NULL;
366 return thread_id;
369 /* Set the current thread's priority. */
370 static inline int
371 __gthread_objc_thread_set_priority (int priority)
373 if (!__gthread_active_p ())
374 return -1;
375 else
377 #ifdef _POSIX_PRIORITY_SCHEDULING
378 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
379 pthread_t thread_id = __gthrw_(pthread_self) ();
380 int policy;
381 struct sched_param params;
382 int priority_min, priority_max;
384 if (__gthrw_(pthread_getschedparam) (thread_id, &policy, &params) == 0)
386 if ((priority_max = __gthrw_(sched_get_priority_max) (policy)) == -1)
387 return -1;
389 if ((priority_min = __gthrw_(sched_get_priority_min) (policy)) == -1)
390 return -1;
392 if (priority > priority_max)
393 priority = priority_max;
394 else if (priority < priority_min)
395 priority = priority_min;
396 params.sched_priority = priority;
399 * The solaris 7 and several other man pages incorrectly state that
400 * this should be a pointer to policy but pthread.h is universally
401 * at odds with this.
403 if (__gthrw_(pthread_setschedparam) (thread_id, policy, &params) == 0)
404 return 0;
406 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
407 #endif /* _POSIX_PRIORITY_SCHEDULING */
408 return -1;
412 /* Return the current thread's priority. */
413 static inline int
414 __gthread_objc_thread_get_priority (void)
416 #ifdef _POSIX_PRIORITY_SCHEDULING
417 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
418 if (__gthread_active_p ())
420 int policy;
421 struct sched_param params;
423 if (__gthrw_(pthread_getschedparam) (__gthrw_(pthread_self) (), &policy, &params) == 0)
424 return params.sched_priority;
425 else
426 return -1;
428 else
429 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
430 #endif /* _POSIX_PRIORITY_SCHEDULING */
431 return OBJC_THREAD_INTERACTIVE_PRIORITY;
434 /* Yield our process time to another thread. */
435 static inline void
436 __gthread_objc_thread_yield (void)
438 if (__gthread_active_p ())
439 __gthrw_(sched_yield) ();
442 /* Terminate the current thread. */
443 static inline int
444 __gthread_objc_thread_exit (void)
446 if (__gthread_active_p ())
447 /* exit the thread */
448 __gthrw_(pthread_exit) (&__objc_thread_exit_status);
450 /* Failed if we reached here */
451 return -1;
454 /* Returns an integer value which uniquely describes a thread. */
455 static inline objc_thread_t
456 __gthread_objc_thread_id (void)
458 if (__gthread_active_p ())
459 return (objc_thread_t) __gthrw_(pthread_self) ();
460 else
461 return (objc_thread_t) 1;
464 /* Sets the thread's local storage pointer. */
465 static inline int
466 __gthread_objc_thread_set_data (void *value)
468 if (__gthread_active_p ())
469 return __gthrw_(pthread_setspecific) (_objc_thread_storage, value);
470 else
472 thread_local_storage = value;
473 return 0;
477 /* Returns the thread's local storage pointer. */
478 static inline void *
479 __gthread_objc_thread_get_data (void)
481 if (__gthread_active_p ())
482 return __gthrw_(pthread_getspecific) (_objc_thread_storage);
483 else
484 return thread_local_storage;
487 /* Backend mutex functions */
489 /* Allocate a mutex. */
490 static inline int
491 __gthread_objc_mutex_allocate (objc_mutex_t mutex)
493 if (__gthread_active_p ())
495 mutex->backend = objc_malloc (sizeof (pthread_mutex_t));
497 if (__gthrw_(pthread_mutex_init) ((pthread_mutex_t *) mutex->backend, NULL))
499 objc_free (mutex->backend);
500 mutex->backend = NULL;
501 return -1;
505 return 0;
508 /* Deallocate a mutex. */
509 static inline int
510 __gthread_objc_mutex_deallocate (objc_mutex_t mutex)
512 if (__gthread_active_p ())
514 int count;
517 * Posix Threads specifically require that the thread be unlocked
518 * for __gthrw_(pthread_mutex_destroy) to work.
523 count = __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend);
524 if (count < 0)
525 return -1;
527 while (count);
529 if (__gthrw_(pthread_mutex_destroy) ((pthread_mutex_t *) mutex->backend))
530 return -1;
532 objc_free (mutex->backend);
533 mutex->backend = NULL;
535 return 0;
538 /* Grab a lock on a mutex. */
539 static inline int
540 __gthread_objc_mutex_lock (objc_mutex_t mutex)
542 if (__gthread_active_p ()
543 && __gthrw_(pthread_mutex_lock) ((pthread_mutex_t *) mutex->backend) != 0)
545 return -1;
548 return 0;
551 /* Try to grab a lock on a mutex. */
552 static inline int
553 __gthread_objc_mutex_trylock (objc_mutex_t mutex)
555 if (__gthread_active_p ()
556 && __gthrw_(pthread_mutex_trylock) ((pthread_mutex_t *) mutex->backend) != 0)
558 return -1;
561 return 0;
564 /* Unlock the mutex */
565 static inline int
566 __gthread_objc_mutex_unlock (objc_mutex_t mutex)
568 if (__gthread_active_p ()
569 && __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend) != 0)
571 return -1;
574 return 0;
577 /* Backend condition mutex functions */
579 /* Allocate a condition. */
580 static inline int
581 __gthread_objc_condition_allocate (objc_condition_t condition)
583 if (__gthread_active_p ())
585 condition->backend = objc_malloc (sizeof (pthread_cond_t));
587 if (__gthrw_(pthread_cond_init) ((pthread_cond_t *) condition->backend, NULL))
589 objc_free (condition->backend);
590 condition->backend = NULL;
591 return -1;
595 return 0;
598 /* Deallocate a condition. */
599 static inline int
600 __gthread_objc_condition_deallocate (objc_condition_t condition)
602 if (__gthread_active_p ())
604 if (__gthrw_(pthread_cond_destroy) ((pthread_cond_t *) condition->backend))
605 return -1;
607 objc_free (condition->backend);
608 condition->backend = NULL;
610 return 0;
613 /* Wait on the condition */
614 static inline int
615 __gthread_objc_condition_wait (objc_condition_t condition, objc_mutex_t mutex)
617 if (__gthread_active_p ())
618 return __gthrw_(pthread_cond_wait) ((pthread_cond_t *) condition->backend,
619 (pthread_mutex_t *) mutex->backend);
620 else
621 return 0;
624 /* Wake up all threads waiting on this condition. */
625 static inline int
626 __gthread_objc_condition_broadcast (objc_condition_t condition)
628 if (__gthread_active_p ())
629 return __gthrw_(pthread_cond_broadcast) ((pthread_cond_t *) condition->backend);
630 else
631 return 0;
634 /* Wake up one thread waiting on this condition. */
635 static inline int
636 __gthread_objc_condition_signal (objc_condition_t condition)
638 if (__gthread_active_p ())
639 return __gthrw_(pthread_cond_signal) ((pthread_cond_t *) condition->backend);
640 else
641 return 0;
644 #else /* _LIBOBJC */
646 static inline int
647 __gthread_once (__gthread_once_t *once, void (*func) (void))
649 if (__gthread_active_p ())
650 return __gthrw_(pthread_once) (once, func);
651 else
652 return -1;
655 static inline int
656 __gthread_key_create (__gthread_key_t *key, void (*dtor) (void *))
658 return __gthrw_(pthread_key_create) (key, dtor);
661 static inline int
662 __gthread_key_delete (__gthread_key_t key)
664 return __gthrw_(pthread_key_delete) (key);
667 static inline void *
668 __gthread_getspecific (__gthread_key_t key)
670 return __gthrw_(pthread_getspecific) (key);
673 static inline int
674 __gthread_setspecific (__gthread_key_t key, const void *ptr)
676 return __gthrw_(pthread_setspecific) (key, ptr);
679 static inline int
680 __gthread_mutex_lock (__gthread_mutex_t *mutex)
682 if (__gthread_active_p ())
683 return __gthrw_(pthread_mutex_lock) (mutex);
684 else
685 return 0;
688 static inline int
689 __gthread_mutex_trylock (__gthread_mutex_t *mutex)
691 if (__gthread_active_p ())
692 return __gthrw_(pthread_mutex_trylock) (mutex);
693 else
694 return 0;
697 static inline int
698 __gthread_mutex_unlock (__gthread_mutex_t *mutex)
700 if (__gthread_active_p ())
701 return __gthrw_(pthread_mutex_unlock) (mutex);
702 else
703 return 0;
706 #ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
707 static inline int
708 __gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex)
710 if (__gthread_active_p ())
712 pthread_mutexattr_t attr;
713 int r;
715 r = __gthrw_(pthread_mutexattr_init) (&attr);
716 if (!r)
717 r = __gthrw_(pthread_mutexattr_settype) (&attr, PTHREAD_MUTEX_RECURSIVE);
718 if (!r)
719 r = __gthrw_(pthread_mutex_init) (mutex, &attr);
720 if (!r)
721 r = __gthrw_(pthread_mutexattr_destroy) (&attr);
722 return r;
724 return 0;
726 #endif
728 static inline int
729 __gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex)
731 return __gthread_mutex_lock (mutex);
734 static inline int
735 __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
737 return __gthread_mutex_trylock (mutex);
740 static inline int
741 __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
743 return __gthread_mutex_unlock (mutex);
746 static inline int
747 __gthread_cond_broadcast (__gthread_cond_t *cond)
749 return __gthrw_(pthread_cond_broadcast) (cond);
752 static inline int
753 __gthread_cond_wait (__gthread_cond_t *cond, __gthread_mutex_t *mutex)
755 return __gthrw_(pthread_cond_wait) (cond, mutex);
758 static inline int
759 __gthread_cond_wait_recursive (__gthread_cond_t *cond,
760 __gthread_recursive_mutex_t *mutex)
762 return __gthread_cond_wait (cond, mutex);
765 #endif /* _LIBOBJC */
767 #endif /* ! GCC_GTHR_POSIX_H */