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.
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 2, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING.  If not, write to the Free
20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2102110-1301, USA.  */
22
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.  */
29
30#ifndef _GLIBCXX_GCC_GTHR_POSIX_H
31#define _GLIBCXX_GCC_GTHR_POSIX_H
32
33/* POSIX threads specific definitions.
34   Easy, since the interface is just one-to-one mapping.  */
35
36#define __GTHREADS 1
37
38/* Some implementations of <pthread.h> require this to be defined.  */
39#if !defined(_REENTRANT) && defined(__osf__)
40#define _REENTRANT 1
41#endif
42
43#include <pthread.h>
44#include <unistd.h>
45
46typedef pthread_key_t __gthread_key_t;
47typedef pthread_once_t __gthread_once_t;
48typedef pthread_mutex_t __gthread_mutex_t;
49typedef pthread_mutex_t __gthread_recursive_mutex_t;
50
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
60
61#if __GXX_WEAK__ && _GLIBCXX_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
73
74/* Typically, __gthrw_foo is a weak reference to symbol foo.  */
75#define __gthrw(name) __gthrw2(__gthrw_ ## name,name,name)
76
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
102
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)
108
109
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 */
146
147#if __GXX_WEAK__ && _GLIBCXX_GTHREAD_USE_WEAK
148
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.  */
156
157#if defined(__sun) && defined(__svr4__)
158
159static volatile int __gthread_active = -1;
160
161static void
162__gthread_trigger (void)
163{
164  __gthread_active = 1;
165}
166
167static inline int
168__gthread_active_p (void)
169{
170  static pthread_mutex_t __gthread_active_mutex = PTHREAD_MUTEX_INITIALIZER;
171  static pthread_once_t __gthread_active_once = PTHREAD_ONCE_INIT;
172
173  /* Avoid reading __gthread_active twice on the main code path.  */
174  int __gthread_active_latest_value = __gthread_active;
175
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))
180    {
181      if (__gthrw_(pthread_once))
182	{
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);
188	}
189
190      /* Make sure we'll never enter this block again.  */
191      if (__gthread_active < 0)
192	__gthread_active = 0;
193
194      __gthread_active_latest_value = __gthread_active;
195    }
196
197  return __gthread_active_latest_value != 0;
198}
199
200#else /* not Solaris */
201
202static inline int
203__gthread_active_p (void)
204{
205  static void *const __gthread_active_ptr
206    = __extension__ (void *) &__gthrw_(pthread_cancel);
207  return __gthread_active_ptr != 0;
208}
209
210#endif /* Solaris */
211
212#else /* not __GXX_WEAK__ */
213
214static inline int
215__gthread_active_p (void)
216{
217  return 1;
218}
219
220#endif /* __GXX_WEAK__ */
221
222#ifdef _LIBOBJC
223
224/* This is the config.h file in libobjc/ */
225#include <config.h>
226
227#ifdef HAVE_SCHED_H
228# include <sched.h>
229#endif
230
231/* Key structure for maintaining thread specific storage */
232static pthread_key_t _objc_thread_storage;
233static pthread_attr_t _objc_thread_attribs;
234
235/* Thread local storage for a single thread */
236static void *thread_local_storage = NULL;
237
238/* Backend initialization functions */
239
240/* Initialize the threads subsystem.  */
241static inline int
242__gthread_objc_init_thread_system (void)
243{
244  if (__gthread_active_p ())
245    {
246      /* Initialize the thread storage key.  */
247      if (__gthrw_(pthread_key_create) (&_objc_thread_storage, NULL) == 0)
248	{
249	  /* The normal default detach state for threads is
250	   * PTHREAD_CREATE_JOINABLE which causes threads to not die
251	   * when you think they should.  */
252	  if (__gthrw_(pthread_attr_init) (&_objc_thread_attribs) == 0
253	      && __gthrw_(pthread_attr_setdetachstate) (&_objc_thread_attribs,
254					      PTHREAD_CREATE_DETACHED) == 0)
255	    return 0;
256	}
257    }
258
259  return -1;
260}
261
262/* Close the threads subsystem.  */
263static inline int
264__gthread_objc_close_thread_system (void)
265{
266  if (__gthread_active_p ()
267      && __gthrw_(pthread_key_delete) (_objc_thread_storage) == 0
268      && __gthrw_(pthread_attr_destroy) (&_objc_thread_attribs) == 0)
269    return 0;
270
271  return -1;
272}
273
274/* Backend thread functions */
275
276/* Create a new thread of execution.  */
277static inline objc_thread_t
278__gthread_objc_thread_detach (void (*func)(void *), void *arg)
279{
280  objc_thread_t thread_id;
281  pthread_t new_thread_handle;
282
283  if (!__gthread_active_p ())
284    return NULL;
285
286  if (!(__gthrw_(pthread_create) (&new_thread_handle, NULL, (void *) func, arg)))
287    thread_id = (objc_thread_t) new_thread_handle;
288  else
289    thread_id = NULL;
290
291  return thread_id;
292}
293
294/* Set the current thread's priority.  */
295static inline int
296__gthread_objc_thread_set_priority (int priority)
297{
298  if (!__gthread_active_p ())
299    return -1;
300  else
301    {
302#ifdef _POSIX_PRIORITY_SCHEDULING
303#ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
304      pthread_t thread_id = __gthrw_(pthread_self) ();
305      int policy;
306      struct sched_param params;
307      int priority_min, priority_max;
308
309      if (__gthrw_(pthread_getschedparam) (thread_id, &policy, &params) == 0)
310	{
311	  if ((priority_max = __gthrw_(sched_get_priority_max) (policy)) == -1)
312	    return -1;
313
314	  if ((priority_min = __gthrw_(sched_get_priority_min) (policy)) == -1)
315	    return -1;
316
317	  if (priority > priority_max)
318	    priority = priority_max;
319	  else if (priority < priority_min)
320	    priority = priority_min;
321	  params.sched_priority = priority;
322
323	  /*
324	   * The solaris 7 and several other man pages incorrectly state that
325	   * this should be a pointer to policy but pthread.h is universally
326	   * at odds with this.
327	   */
328	  if (__gthrw_(pthread_setschedparam) (thread_id, policy, &params) == 0)
329	    return 0;
330	}
331#endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
332#endif /* _POSIX_PRIORITY_SCHEDULING */
333      return -1;
334    }
335}
336
337/* Return the current thread's priority.  */
338static inline int
339__gthread_objc_thread_get_priority (void)
340{
341#ifdef _POSIX_PRIORITY_SCHEDULING
342#ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
343  if (__gthread_active_p ())
344    {
345      int policy;
346      struct sched_param params;
347
348      if (__gthrw_(pthread_getschedparam) (__gthrw_(pthread_self) (), &policy, &params) == 0)
349	return params.sched_priority;
350      else
351	return -1;
352    }
353  else
354#endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
355#endif /* _POSIX_PRIORITY_SCHEDULING */
356    return OBJC_THREAD_INTERACTIVE_PRIORITY;
357}
358
359/* Yield our process time to another thread.  */
360static inline void
361__gthread_objc_thread_yield (void)
362{
363  if (__gthread_active_p ())
364    __gthrw_(sched_yield) ();
365}
366
367/* Terminate the current thread.  */
368static inline int
369__gthread_objc_thread_exit (void)
370{
371  if (__gthread_active_p ())
372    /* exit the thread */
373    __gthrw_(pthread_exit) (&__objc_thread_exit_status);
374
375  /* Failed if we reached here */
376  return -1;
377}
378
379/* Returns an integer value which uniquely describes a thread.  */
380static inline objc_thread_t
381__gthread_objc_thread_id (void)
382{
383  if (__gthread_active_p ())
384    return (objc_thread_t) __gthrw_(pthread_self) ();
385  else
386    return (objc_thread_t) 1;
387}
388
389/* Sets the thread's local storage pointer.  */
390static inline int
391__gthread_objc_thread_set_data (void *value)
392{
393  if (__gthread_active_p ())
394    return __gthrw_(pthread_setspecific) (_objc_thread_storage, value);
395  else
396    {
397      thread_local_storage = value;
398      return 0;
399    }
400}
401
402/* Returns the thread's local storage pointer.  */
403static inline void *
404__gthread_objc_thread_get_data (void)
405{
406  if (__gthread_active_p ())
407    return __gthrw_(pthread_getspecific) (_objc_thread_storage);
408  else
409    return thread_local_storage;
410}
411
412/* Backend mutex functions */
413
414/* Allocate a mutex.  */
415static inline int
416__gthread_objc_mutex_allocate (objc_mutex_t mutex)
417{
418  if (__gthread_active_p ())
419    {
420      mutex->backend = objc_malloc (sizeof (pthread_mutex_t));
421
422      if (__gthrw_(pthread_mutex_init) ((pthread_mutex_t *) mutex->backend, NULL))
423	{
424	  objc_free (mutex->backend);
425	  mutex->backend = NULL;
426	  return -1;
427	}
428    }
429
430  return 0;
431}
432
433/* Deallocate a mutex.  */
434static inline int
435__gthread_objc_mutex_deallocate (objc_mutex_t mutex)
436{
437  if (__gthread_active_p ())
438    {
439      int count;
440
441      /*
442       * Posix Threads specifically require that the thread be unlocked
443       * for __gthrw_(pthread_mutex_destroy) to work.
444       */
445
446      do
447	{
448	  count = __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend);
449	  if (count < 0)
450	    return -1;
451	}
452      while (count);
453
454      if (__gthrw_(pthread_mutex_destroy) ((pthread_mutex_t *) mutex->backend))
455	return -1;
456
457      objc_free (mutex->backend);
458      mutex->backend = NULL;
459    }
460  return 0;
461}
462
463/* Grab a lock on a mutex.  */
464static inline int
465__gthread_objc_mutex_lock (objc_mutex_t mutex)
466{
467  if (__gthread_active_p ()
468      && __gthrw_(pthread_mutex_lock) ((pthread_mutex_t *) mutex->backend) != 0)
469    {
470      return -1;
471    }
472
473  return 0;
474}
475
476/* Try to grab a lock on a mutex.  */
477static inline int
478__gthread_objc_mutex_trylock (objc_mutex_t mutex)
479{
480  if (__gthread_active_p ()
481      && __gthrw_(pthread_mutex_trylock) ((pthread_mutex_t *) mutex->backend) != 0)
482    {
483      return -1;
484    }
485
486  return 0;
487}
488
489/* Unlock the mutex */
490static inline int
491__gthread_objc_mutex_unlock (objc_mutex_t mutex)
492{
493  if (__gthread_active_p ()
494      && __gthrw_(pthread_mutex_unlock) ((pthread_mutex_t *) mutex->backend) != 0)
495    {
496      return -1;
497    }
498
499  return 0;
500}
501
502/* Backend condition mutex functions */
503
504/* Allocate a condition.  */
505static inline int
506__gthread_objc_condition_allocate (objc_condition_t condition)
507{
508  if (__gthread_active_p ())
509    {
510      condition->backend = objc_malloc (sizeof (pthread_cond_t));
511
512      if (__gthrw_(pthread_cond_init) ((pthread_cond_t *) condition->backend, NULL))
513	{
514	  objc_free (condition->backend);
515	  condition->backend = NULL;
516	  return -1;
517	}
518    }
519
520  return 0;
521}
522
523/* Deallocate a condition.  */
524static inline int
525__gthread_objc_condition_deallocate (objc_condition_t condition)
526{
527  if (__gthread_active_p ())
528    {
529      if (__gthrw_(pthread_cond_destroy) ((pthread_cond_t *) condition->backend))
530	return -1;
531
532      objc_free (condition->backend);
533      condition->backend = NULL;
534    }
535  return 0;
536}
537
538/* Wait on the condition */
539static inline int
540__gthread_objc_condition_wait (objc_condition_t condition, objc_mutex_t mutex)
541{
542  if (__gthread_active_p ())
543    return __gthrw_(pthread_cond_wait) ((pthread_cond_t *) condition->backend,
544			      (pthread_mutex_t *) mutex->backend);
545  else
546    return 0;
547}
548
549/* Wake up all threads waiting on this condition.  */
550static inline int
551__gthread_objc_condition_broadcast (objc_condition_t condition)
552{
553  if (__gthread_active_p ())
554    return __gthrw_(pthread_cond_broadcast) ((pthread_cond_t *) condition->backend);
555  else
556    return 0;
557}
558
559/* Wake up one thread waiting on this condition.  */
560static inline int
561__gthread_objc_condition_signal (objc_condition_t condition)
562{
563  if (__gthread_active_p ())
564    return __gthrw_(pthread_cond_signal) ((pthread_cond_t *) condition->backend);
565  else
566    return 0;
567}
568
569#else /* _LIBOBJC */
570
571static inline int
572__gthread_once (__gthread_once_t *once, void (*func) (void))
573{
574  if (__gthread_active_p ())
575    return __gthrw_(pthread_once) (once, func);
576  else
577    return -1;
578}
579
580static inline int
581__gthread_key_create (__gthread_key_t *key, void (*dtor) (void *))
582{
583  return __gthrw_(pthread_key_create) (key, dtor);
584}
585
586static inline int
587__gthread_key_delete (__gthread_key_t key)
588{
589  return __gthrw_(pthread_key_delete) (key);
590}
591
592static inline void *
593__gthread_getspecific (__gthread_key_t key)
594{
595  return __gthrw_(pthread_getspecific) (key);
596}
597
598static inline int
599__gthread_setspecific (__gthread_key_t key, const void *ptr)
600{
601  return __gthrw_(pthread_setspecific) (key, ptr);
602}
603
604static inline int
605__gthread_mutex_lock (__gthread_mutex_t *mutex)
606{
607  if (__gthread_active_p ())
608    return __gthrw_(pthread_mutex_lock) (mutex);
609  else
610    return 0;
611}
612
613static inline int
614__gthread_mutex_trylock (__gthread_mutex_t *mutex)
615{
616  if (__gthread_active_p ())
617    return __gthrw_(pthread_mutex_trylock) (mutex);
618  else
619    return 0;
620}
621
622static inline int
623__gthread_mutex_unlock (__gthread_mutex_t *mutex)
624{
625  if (__gthread_active_p ())
626    return __gthrw_(pthread_mutex_unlock) (mutex);
627  else
628    return 0;
629}
630
631#ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
632static inline int
633__gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex)
634{
635  if (__gthread_active_p ())
636    {
637      pthread_mutexattr_t attr;
638      int r;
639
640      r = __gthrw_(pthread_mutexattr_init) (&attr);
641      if (!r)
642	r = __gthrw_(pthread_mutexattr_settype) (&attr, PTHREAD_MUTEX_RECURSIVE);
643      if (!r)
644	r = __gthrw_(pthread_mutex_init) (mutex, &attr);
645      if (!r)
646	r = __gthrw_(pthread_mutexattr_destroy) (&attr);
647      return r;
648    }
649  return 0;
650}
651#endif
652
653static inline int
654__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex)
655{
656  return __gthread_mutex_lock (mutex);
657}
658
659static inline int
660__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
661{
662  return __gthread_mutex_trylock (mutex);
663}
664
665static inline int
666__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
667{
668  return __gthread_mutex_unlock (mutex);
669}
670
671#endif /* _LIBOBJC */
672
673#endif /* ! _GLIBCXX_GCC_GTHR_POSIX_H */
674