PR tree-optimization/43833
[official-gcc/alias-decl.git] / gcc / gthr-posix95.h
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1 /* Threads compatibility routines for libgcc2 and libobjc. */
2 /* Compile this one with gcc. */
3 /* Copyright (C) 2004, 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 Under Section 7 of GPL version 3, you are granted additional
18 permissions described in the GCC Runtime Library Exception, version
19 3.1, as published by the Free Software Foundation.
21 You should have received a copy of the GNU General Public License and
22 a copy of the GCC Runtime Library Exception along with this program;
23 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 <http://www.gnu.org/licenses/>. */
26 #ifndef GCC_GTHR_POSIX_H
27 #define GCC_GTHR_POSIX_H
29 /* POSIX threads specific definitions.
30 Easy, since the interface is just one-to-one mapping. */
32 #define __GTHREADS 1
34 /* Some implementations of <pthread.h> require this to be defined. */
35 #ifndef _REENTRANT
36 #define _REENTRANT 1
37 #endif
39 #include <pthread.h>
40 #include <unistd.h>
42 typedef pthread_key_t __gthread_key_t;
43 typedef pthread_once_t __gthread_once_t;
44 typedef pthread_mutex_t __gthread_mutex_t;
45 typedef pthread_cond_t __gthread_cond_t;
47 /* POSIX like conditional variables are supported. Please look at comments
48 in gthr.h for details. */
49 #define __GTHREAD_HAS_COND 1
51 typedef struct {
52 long depth;
53 pthread_t owner;
54 pthread_mutex_t actual;
55 } __gthread_recursive_mutex_t;
57 #define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER
58 #define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
59 #define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_recursive_mutex_init_function
60 #define __GTHREAD_COND_INIT PTHREAD_COND_INITIALIZER
62 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
63 # define __gthrw(name) \
64 static __typeof(name) __gthrw_ ## name __attribute__ ((__weakref__(#name)));
65 # define __gthrw_(name) __gthrw_ ## name
66 #else
67 # define __gthrw(name)
68 # define __gthrw_(name) name
69 #endif
71 __gthrw(pthread_once)
72 __gthrw(pthread_key_create)
73 __gthrw(pthread_key_delete)
74 __gthrw(pthread_getspecific)
75 __gthrw(pthread_setspecific)
76 __gthrw(pthread_create)
77 __gthrw(pthread_cancel)
78 __gthrw(pthread_self)
80 __gthrw(pthread_mutex_init)
81 __gthrw(pthread_mutex_destroy)
82 __gthrw(pthread_mutex_lock)
83 __gthrw(pthread_mutex_trylock)
84 __gthrw(pthread_mutex_unlock)
85 __gthrw(pthread_mutexattr_init)
86 __gthrw(pthread_mutexattr_destroy)
88 __gthrw(pthread_cond_broadcast)
89 __gthrw(pthread_cond_wait)
91 #if defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)
92 /* Objective-C. */
93 __gthrw(pthread_cond_destroy)
94 __gthrw(pthread_cond_init)
95 __gthrw(pthread_cond_signal)
96 __gthrw(pthread_exit)
97 #ifdef _POSIX_PRIORITY_SCHEDULING
98 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
99 __gthrw(sched_get_priority_max)
100 __gthrw(sched_get_priority_min)
101 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
102 #endif /* _POSIX_PRIORITY_SCHEDULING */
103 __gthrw(sched_yield)
104 __gthrw(pthread_attr_destroy)
105 __gthrw(pthread_attr_init)
106 __gthrw(pthread_attr_setdetachstate)
107 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
108 __gthrw(pthread_getschedparam)
109 __gthrw(pthread_setschedparam)
110 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
111 #endif /* _LIBOBJC || _LIBOBJC_WEAK */
113 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
115 /* On Solaris 2.6 up to 9, the libc exposes a POSIX threads interface even if
116 -pthreads is not specified. The functions are dummies and most return an
117 error value. However pthread_once returns 0 without invoking the routine
118 it is passed so we cannot pretend that the interface is active if -pthreads
119 is not specified. On Solaris 2.5.1, the interface is not exposed at all so
120 we need to play the usual game with weak symbols. On Solaris 10 and up, a
121 working interface is always exposed. On FreeBSD 6 and later, libc also
122 exposes a dummy POSIX threads interface, similar to what Solaris 2.6 up
123 to 9 does. FreeBSD >= 700014 even provides a pthread_cancel stub in libc,
124 which means the alternate __gthread_active_p below cannot be used there. */
126 #if defined(__FreeBSD__) || (defined(__sun) && defined(__svr4__))
128 static volatile int __gthread_active = -1;
130 static void
131 __gthread_trigger (void)
133 __gthread_active = 1;
136 static inline int
137 __gthread_active_p (void)
139 static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
140 static pthread_once_t __gthread_active_once = PTHREAD_ONCE_INIT;
142 /* Avoid reading __gthread_active twice on the main code path. */
143 int __gthread_active_latest_value = __gthread_active;
145 /* This test is not protected to avoid taking a lock on the main code
146 path so every update of __gthread_active in a threaded program must
147 be atomic with regard to the result of the test. */
148 if (__builtin_expect (__gthread_active_latest_value < 0, 0))
150 if (__gthrw_(pthread_once))
152 /* If this really is a threaded program, then we must ensure that
153 __gthread_active has been set to 1 before exiting this block. */
154 __gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
155 __gthrw_(pthread_once) (&__gthread_active_once, __gthread_trigger);
156 __gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
159 /* Make sure we'll never enter this block again. */
160 if (__gthread_active < 0)
161 __gthread_active = 0;
163 __gthread_active_latest_value = __gthread_active;
166 return __gthread_active_latest_value != 0;
169 #else /* neither FreeBSD nor Solaris */
171 static inline int
172 __gthread_active_p (void)
174 static void *const __gthread_active_ptr
175 = __extension__ (void *) &__gthrw_(pthread_cancel);
176 return __gthread_active_ptr != 0;
179 #endif /* FreeBSD or Solaris */
181 #else /* not SUPPORTS_WEAK */
183 /* Similar to Solaris, HP-UX 11 for PA-RISC provides stubs for pthread
184 calls in shared flavors of the HP-UX C library. Most of the stubs
185 have no functionality. The details are described in the "libc cumulative
186 patch" for each subversion of HP-UX 11. There are two special interfaces
187 provided for checking whether an application is linked to a pthread
188 library or not. However, these interfaces aren't available in early
189 libc versions. We also can't use pthread_once as some libc versions
190 call the init function. So, we use pthread_create to check whether it
191 is possible to create a thread or not. The stub implementation returns
192 the error number ENOSYS. */
194 #if defined(__hppa__) && defined(__hpux__)
196 #include <errno.h>
198 static volatile int __gthread_active = -1;
200 static void *
201 __gthread_start (void *arg __attribute__((unused)))
203 return NULL;
206 static void __gthread_active_init (void) __attribute__((noinline));
207 static void
208 __gthread_active_init (void)
210 static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
211 pthread_t t;
212 pthread_attr_t a;
213 int result;
215 __gthrw_(pthread_mutex_lock) (&__gthread_active_mutex);
216 if (__gthread_active < 0)
218 __gthrw_(pthread_attr_init) (&a);
219 __gthrw_(pthread_attr_setdetachstate) (&a, PTHREAD_CREATE_DETACHED);
220 result = __gthrw_(pthread_create) (&t, &a, __gthread_start, NULL);
221 if (result != ENOSYS)
222 __gthread_active = 1;
223 else
224 __gthread_active = 0;
225 __gthrw_(pthread_attr_destroy) (&a);
227 __gthrw_(pthread_mutex_unlock) (&__gthread_active_mutex);
230 static inline int
231 __gthread_active_p (void)
233 /* Avoid reading __gthread_active twice on the main code path. */
234 int __gthread_active_latest_value = __gthread_active;
236 /* This test is not protected to avoid taking a lock on the main code
237 path so every update of __gthread_active in a threaded program must
238 be atomic with regard to the result of the test. */
239 if (__builtin_expect (__gthread_active_latest_value < 0, 0))
241 __gthread_active_init ();
242 __gthread_active_latest_value = __gthread_active;
245 return __gthread_active_latest_value != 0;
248 #else /* not hppa-hpux */
250 static inline int
251 __gthread_active_p (void)
253 return 1;
256 #endif /* hppa-hpux */
258 #endif /* SUPPORTS_WEAK */
260 #ifdef _LIBOBJC
262 /* This is the config.h file in libobjc/ */
263 #include <config.h>
265 #ifdef HAVE_SCHED_H
266 # include <sched.h>
267 #endif
269 /* Key structure for maintaining thread specific storage */
270 static pthread_key_t _objc_thread_storage;
271 static pthread_attr_t _objc_thread_attribs;
273 /* Thread local storage for a single thread */
274 static void *thread_local_storage = NULL;
276 /* Backend initialization functions */
278 /* Initialize the threads subsystem. */
279 static inline int
280 __gthread_objc_init_thread_system (void)
282 if (__gthread_active_p ())
284 /* Initialize the thread storage key. */
285 if (__gthrw_(pthread_key_create) (&_objc_thread_storage, NULL) == 0)
287 /* The normal default detach state for threads is
288 * PTHREAD_CREATE_JOINABLE which causes threads to not die
289 * when you think they should. */
290 if (__gthrw_(pthread_attr_init) (&_objc_thread_attribs) == 0
291 && __gthrw_(pthread_attr_setdetachstate) (&_objc_thread_attribs,
292 PTHREAD_CREATE_DETACHED) == 0)
293 return 0;
297 return -1;
300 /* Close the threads subsystem. */
301 static inline int
302 __gthread_objc_close_thread_system (void)
304 if (__gthread_active_p ()
305 && __gthrw_(pthread_key_delete) (_objc_thread_storage) == 0
306 && __gthrw_(pthread_attr_destroy) (&_objc_thread_attribs) == 0)
307 return 0;
309 return -1;
312 /* Backend thread functions */
314 /* Create a new thread of execution. */
315 static inline objc_thread_t
316 __gthread_objc_thread_detach (void (*func)(void *), void *arg)
318 objc_thread_t thread_id;
319 pthread_t new_thread_handle;
321 if (!__gthread_active_p ())
322 return NULL;
324 if (!(__gthrw_(pthread_create) (&new_thread_handle, NULL, (void *) func, arg)))
325 thread_id = (objc_thread_t) new_thread_handle;
326 else
327 thread_id = NULL;
329 return thread_id;
332 /* Set the current thread's priority. */
333 static inline int
334 __gthread_objc_thread_set_priority (int priority)
336 if (!__gthread_active_p ())
337 return -1;
338 else
340 #ifdef _POSIX_PRIORITY_SCHEDULING
341 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
342 pthread_t thread_id = __gthrw_(pthread_self) ();
343 int policy;
344 struct sched_param params;
345 int priority_min, priority_max;
347 if (__gthrw_(pthread_getschedparam) (thread_id, &policy, &params) == 0)
349 if ((priority_max = __gthrw_(sched_get_priority_max) (policy)) == -1)
350 return -1;
352 if ((priority_min = __gthrw_(sched_get_priority_min) (policy)) == -1)
353 return -1;
355 if (priority > priority_max)
356 priority = priority_max;
357 else if (priority < priority_min)
358 priority = priority_min;
359 params.sched_priority = priority;
362 * The solaris 7 and several other man pages incorrectly state that
363 * this should be a pointer to policy but pthread.h is universally
364 * at odds with this.
366 if (__gthrw_(pthread_setschedparam) (thread_id, policy, &params) == 0)
367 return 0;
369 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
370 #endif /* _POSIX_PRIORITY_SCHEDULING */
371 return -1;
375 /* Return the current thread's priority. */
376 static inline int
377 __gthread_objc_thread_get_priority (void)
379 #ifdef _POSIX_PRIORITY_SCHEDULING
380 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
381 if (__gthread_active_p ())
383 int policy;
384 struct sched_param params;
386 if (__gthrw_(pthread_getschedparam) (__gthrw_(pthread_self) (), &policy, &params) == 0)
387 return params.sched_priority;
388 else
389 return -1;
391 else
392 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
393 #endif /* _POSIX_PRIORITY_SCHEDULING */
394 return OBJC_THREAD_INTERACTIVE_PRIORITY;
397 /* Yield our process time to another thread. */
398 static inline void
399 __gthread_objc_thread_yield (void)
401 if (__gthread_active_p ())
402 __gthrw_(sched_yield) ();
405 /* Terminate the current thread. */
406 static inline int
407 __gthread_objc_thread_exit (void)
409 if (__gthread_active_p ())
410 /* exit the thread */
411 __gthrw_(pthread_exit) (&__objc_thread_exit_status);
413 /* Failed if we reached here */
414 return -1;
417 /* Returns an integer value which uniquely describes a thread. */
418 static inline objc_thread_t
419 __gthread_objc_thread_id (void)
421 if (__gthread_active_p ())
422 return (objc_thread_t) __gthrw_(pthread_self) ();
423 else
424 return (objc_thread_t) 1;
427 /* Sets the thread's local storage pointer. */
428 static inline int
429 __gthread_objc_thread_set_data (void *value)
431 if (__gthread_active_p ())
432 return __gthrw_(pthread_setspecific) (_objc_thread_storage, value);
433 else
435 thread_local_storage = value;
436 return 0;
440 /* Returns the thread's local storage pointer. */
441 static inline void *
442 __gthread_objc_thread_get_data (void)
444 if (__gthread_active_p ())
445 return __gthrw_(pthread_getspecific) (_objc_thread_storage);
446 else
447 return thread_local_storage;
450 /* Backend mutex functions */
452 /* Allocate a mutex. */
453 static inline int
454 __gthread_objc_mutex_allocate (objc_mutex_t mutex)
456 if (__gthread_active_p ())
458 mutex->backend = objc_malloc (sizeof (pthread_mutex_t));
460 if (__gthrw_(pthread_mutex_init) ((pthread_mutex_t *) mutex->backend, NULL))
462 objc_free (mutex->backend);
463 mutex->backend = NULL;
464 return -1;
468 return 0;
471 /* Deallocate a mutex. */
472 static inline int
473 __gthread_objc_mutex_deallocate (objc_mutex_t mutex)
475 if (__gthread_active_p ())
477 int count;
480 * Posix Threads specifically require that the thread be unlocked
481 * for __gthrw_(pthread_mutex_destroy) to work.
486 count = __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend);
487 if (count < 0)
488 return -1;
490 while (count);
492 if (__gthrw_(pthread_mutex_destroy) ((pthread_mutex_t *) mutex->backend))
493 return -1;
495 objc_free (mutex->backend);
496 mutex->backend = NULL;
498 return 0;
501 /* Grab a lock on a mutex. */
502 static inline int
503 __gthread_objc_mutex_lock (objc_mutex_t mutex)
505 if (__gthread_active_p ()
506 && __gthrw_(pthread_mutex_lock) ((pthread_mutex_t *) mutex->backend) != 0)
508 return -1;
511 return 0;
514 /* Try to grab a lock on a mutex. */
515 static inline int
516 __gthread_objc_mutex_trylock (objc_mutex_t mutex)
518 if (__gthread_active_p ()
519 && __gthrw_(pthread_mutex_trylock) ((pthread_mutex_t *) mutex->backend) != 0)
521 return -1;
524 return 0;
527 /* Unlock the mutex */
528 static inline int
529 __gthread_objc_mutex_unlock (objc_mutex_t mutex)
531 if (__gthread_active_p ()
532 && __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend) != 0)
534 return -1;
537 return 0;
540 /* Backend condition mutex functions */
542 /* Allocate a condition. */
543 static inline int
544 __gthread_objc_condition_allocate (objc_condition_t condition)
546 if (__gthread_active_p ())
548 condition->backend = objc_malloc (sizeof (pthread_cond_t));
550 if (__gthrw_(pthread_cond_init) ((pthread_cond_t *) condition->backend, NULL))
552 objc_free (condition->backend);
553 condition->backend = NULL;
554 return -1;
558 return 0;
561 /* Deallocate a condition. */
562 static inline int
563 __gthread_objc_condition_deallocate (objc_condition_t condition)
565 if (__gthread_active_p ())
567 if (__gthrw_(pthread_cond_destroy) ((pthread_cond_t *) condition->backend))
568 return -1;
570 objc_free (condition->backend);
571 condition->backend = NULL;
573 return 0;
576 /* Wait on the condition */
577 static inline int
578 __gthread_objc_condition_wait (objc_condition_t condition, objc_mutex_t mutex)
580 if (__gthread_active_p ())
581 return __gthrw_(pthread_cond_wait) ((pthread_cond_t *) condition->backend,
582 (pthread_mutex_t *) mutex->backend);
583 else
584 return 0;
587 /* Wake up all threads waiting on this condition. */
588 static inline int
589 __gthread_objc_condition_broadcast (objc_condition_t condition)
591 if (__gthread_active_p ())
592 return __gthrw_(pthread_cond_broadcast) ((pthread_cond_t *) condition->backend);
593 else
594 return 0;
597 /* Wake up one thread waiting on this condition. */
598 static inline int
599 __gthread_objc_condition_signal (objc_condition_t condition)
601 if (__gthread_active_p ())
602 return __gthrw_(pthread_cond_signal) ((pthread_cond_t *) condition->backend);
603 else
604 return 0;
607 #else /* _LIBOBJC */
609 static inline int
610 __gthread_once (__gthread_once_t *__once, void (*__func) (void))
612 if (__gthread_active_p ())
613 return __gthrw_(pthread_once) (__once, __func);
614 else
615 return -1;
618 static inline int
619 __gthread_key_create (__gthread_key_t *__key, void (*__dtor) (void *))
621 return __gthrw_(pthread_key_create) (__key, __dtor);
624 static inline int
625 __gthread_key_delete (__gthread_key_t __key)
627 return __gthrw_(pthread_key_delete) (__key);
630 static inline void *
631 __gthread_getspecific (__gthread_key_t __key)
633 return __gthrw_(pthread_getspecific) (__key);
636 static inline int
637 __gthread_setspecific (__gthread_key_t __key, const void *__ptr)
639 return __gthrw_(pthread_setspecific) (__key, __ptr);
642 static inline int
643 __gthread_mutex_destroy (__gthread_mutex_t *__mutex)
645 if (__gthread_active_p ())
646 return __gthrw_(pthread_mutex_destroy) (__mutex);
647 else
648 return 0;
651 static inline int
652 __gthread_mutex_lock (__gthread_mutex_t *__mutex)
654 if (__gthread_active_p ())
655 return __gthrw_(pthread_mutex_lock) (__mutex);
656 else
657 return 0;
660 static inline int
661 __gthread_mutex_trylock (__gthread_mutex_t *__mutex)
663 if (__gthread_active_p ())
664 return __gthrw_(pthread_mutex_trylock) (__mutex);
665 else
666 return 0;
669 static inline int
670 __gthread_mutex_unlock (__gthread_mutex_t *__mutex)
672 if (__gthread_active_p ())
673 return __gthrw_(pthread_mutex_unlock) (__mutex);
674 else
675 return 0;
678 static inline int
679 __gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *__mutex)
681 __mutex->depth = 0;
682 __mutex->owner = (pthread_t) 0;
683 return __gthrw_(pthread_mutex_init) (&__mutex->actual, NULL);
686 static inline int
687 __gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *__mutex)
689 if (__gthread_active_p ())
691 pthread_t __me = __gthrw_(pthread_self) ();
693 if (__mutex->owner != __me)
695 __gthrw_(pthread_mutex_lock) (&__mutex->actual);
696 __mutex->owner = __me;
699 __mutex->depth++;
701 return 0;
704 static inline int
705 __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *__mutex)
707 if (__gthread_active_p ())
709 pthread_t __me = __gthrw_(pthread_self) ();
711 if (__mutex->owner != __me)
713 if (__gthrw_(pthread_mutex_trylock) (&__mutex->actual))
714 return 1;
715 __mutex->owner = __me;
718 __mutex->depth++;
720 return 0;
723 static inline int
724 __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *__mutex)
726 if (__gthread_active_p ())
728 if (--__mutex->depth == 0)
730 __mutex->owner = (pthread_t) 0;
731 __gthrw_(pthread_mutex_unlock) (&__mutex->actual);
734 return 0;
737 static inline int
738 __gthread_cond_broadcast (__gthread_cond_t *__cond)
740 return __gthrw_(pthread_cond_broadcast) (__cond);
743 static inline int
744 __gthread_cond_wait (__gthread_cond_t *__cond, __gthread_mutex_t *__mutex)
746 return __gthrw_(pthread_cond_wait) (__cond, __mutex);
749 static inline int
750 __gthread_cond_wait_recursive (__gthread_cond_t *__cond,
751 __gthread_recursive_mutex_t *__mutex)
753 return __gthrw_(pthread_cond_wait) (__cond, &__mutex->actual);
756 #endif /* _LIBOBJC */
758 #endif /* ! GCC_GTHR_POSIX_H */