Fix strict aliasing warnings and viiolations to make GLib and
[platform/upstream/glib.git] / glib / gthread.c
1 /* GLIB - Library of useful routines for C programming
2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
3  *
4  * gthread.c: MT safety related functions
5  * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe
6  *                Owen Taylor
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with this library; if not, write to the
20  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21  * Boston, MA 02111-1307, USA.
22  */
23
24 /*
25  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
26  * file for a list of people on the GLib Team.  See the ChangeLog
27  * files for a list of changes.  These files are distributed with
28  * GLib at ftp://ftp.gtk.org/pub/gtk/.
29  */
30
31 /*
32  * MT safe
33  */
34
35 /* implement gthread.h's inline functions */
36 #define G_IMPLEMENT_INLINES 1
37 #define __G_THREAD_C__
38
39 #include "config.h"
40
41 #include "glib.h"
42 #include "gthreadprivate.h"
43
44 #ifdef HAVE_UNISTD_H
45 #include <unistd.h>
46 #endif
47
48 #ifndef G_OS_WIN32
49 #include <sys/time.h>
50 #include <time.h>
51 #else
52 #include <windows.h>
53 #endif /* G_OS_WIN32 */
54
55 #include <string.h>
56
57 #include "galias.h"
58
59 GQuark
60 g_thread_error_quark (void)
61 {
62   return g_quark_from_static_string ("g_thread_error");
63 }
64
65 /* Keep this in sync with GRealThread in gmain.c! */
66 typedef struct _GRealThread GRealThread;
67 struct  _GRealThread
68 {
69   GThread thread;
70   gpointer private_data;
71   GRealThread *next;
72   gpointer retval;
73   GSystemThread system_thread;
74 };
75
76 typedef struct _GStaticPrivateNode GStaticPrivateNode;
77 struct _GStaticPrivateNode
78 {
79   gpointer       data;
80   GDestroyNotify destroy;
81 };
82
83 static void    g_thread_cleanup (gpointer data);
84 static void    g_thread_fail (void);
85 static guint64 gettime (void);
86
87 guint64        (*g_thread_gettime) (void) = gettime;
88
89 /* Global variables */
90
91 static GSystemThread zero_thread; /* This is initialized to all zero */
92 gboolean g_thread_use_default_impl = TRUE;
93 gboolean g_threads_got_initialized = FALSE;
94
95 GThreadFunctions g_thread_functions_for_glib_use = {
96   (GMutex*(*)())g_thread_fail,                 /* mutex_new */
97   NULL,                                        /* mutex_lock */
98   NULL,                                        /* mutex_trylock */
99   NULL,                                        /* mutex_unlock */
100   NULL,                                        /* mutex_free */
101   (GCond*(*)())g_thread_fail,                  /* cond_new */
102   NULL,                                        /* cond_signal */
103   NULL,                                        /* cond_broadcast */
104   NULL,                                        /* cond_wait */
105   NULL,                                        /* cond_timed_wait  */
106   NULL,                                        /* cond_free */
107   (GPrivate*(*)(GDestroyNotify))g_thread_fail, /* private_new */
108   NULL,                                        /* private_get */
109   NULL,                                        /* private_set */
110   (void(*)(GThreadFunc, gpointer, gulong,
111            gboolean, gboolean, GThreadPriority,
112            gpointer, GError**))g_thread_fail,  /* thread_create */
113   NULL,                                        /* thread_yield */
114   NULL,                                        /* thread_join */
115   NULL,                                        /* thread_exit */
116   NULL,                                        /* thread_set_priority */
117   NULL,                                        /* thread_self */
118   NULL                                         /* thread_equal */
119 };
120
121 /* Local data */
122
123 static GMutex   *g_once_mutex = NULL;
124 static GCond    *g_once_cond = NULL;
125 static GPrivate *g_thread_specific_private = NULL;
126 static GRealThread *g_thread_all_threads = NULL;
127 static GSList   *g_thread_free_indeces = NULL;
128 static GSList*   g_once_init_list = NULL;
129
130 G_LOCK_DEFINE_STATIC (g_thread);
131
132 #ifdef G_THREADS_ENABLED
133 /* This must be called only once, before any threads are created.
134  * It will only be called from g_thread_init() in -lgthread.
135  */
136 void
137 g_thread_init_glib (void)
138 {
139   /* We let the main thread (the one that calls g_thread_init) inherit
140    * the static_private data set before calling g_thread_init
141    */
142   GRealThread* main_thread = (GRealThread*) g_thread_self ();
143
144   /* mutex and cond creation works without g_threads_got_initialized */
145   g_once_mutex = g_mutex_new ();
146   g_once_cond = g_cond_new ();
147
148   /* we may only create mutex and cond in here */
149   _g_mem_thread_init_noprivate_nomessage ();
150
151   /* setup the basic threading system */
152   g_threads_got_initialized = TRUE;
153   g_thread_specific_private = g_private_new (g_thread_cleanup);
154   g_private_set (g_thread_specific_private, main_thread);
155   G_THREAD_UF (thread_self, (&main_thread->system_thread));
156
157   /* complete memory system initialization, g_private_*() works now */
158   _g_slice_thread_init_nomessage ();
159
160   /* accomplish log system initialization to enable messaging */
161   _g_messages_thread_init_nomessage ();
162
163   /* we may run full-fledged initializers from here */
164   _g_atomic_thread_init ();
165   _g_convert_thread_init ();
166   _g_rand_thread_init ();
167   _g_main_thread_init ();
168   _g_utils_thread_init ();
169 #ifdef G_OS_WIN32
170   _g_win32_thread_init ();
171 #endif
172 }
173 #endif /* G_THREADS_ENABLED */
174
175 gpointer
176 g_once_impl (GOnce       *once,
177              GThreadFunc  func,
178              gpointer     arg)
179 {
180   g_mutex_lock (g_once_mutex);
181
182   while (once->status == G_ONCE_STATUS_PROGRESS)
183     g_cond_wait (g_once_cond, g_once_mutex);
184
185   if (once->status != G_ONCE_STATUS_READY)
186     {
187       once->status = G_ONCE_STATUS_PROGRESS;
188       g_mutex_unlock (g_once_mutex);
189
190       once->retval = func (arg);
191
192       g_mutex_lock (g_once_mutex);
193       once->status = G_ONCE_STATUS_READY;
194       g_cond_broadcast (g_once_cond);
195     }
196
197   g_mutex_unlock (g_once_mutex);
198
199   return once->retval;
200 }
201
202 gboolean
203 g_once_init_enter_impl (volatile gsize *value_location)
204 {
205   gboolean need_init = FALSE;
206   g_mutex_lock (g_once_mutex);
207   if (g_atomic_pointer_get (value_location) == NULL)
208     {
209       if (!g_slist_find (g_once_init_list, (void*) value_location))
210         {
211           need_init = TRUE;
212           g_once_init_list = g_slist_prepend (g_once_init_list, (void*) value_location);
213         }
214       else
215         do
216           g_cond_wait (g_once_cond, g_once_mutex);
217         while (g_slist_find (g_once_init_list, (void*) value_location));
218     }
219   g_mutex_unlock (g_once_mutex);
220   return need_init;
221 }
222
223 void
224 g_once_init_leave (volatile gsize *value_location,
225                    gsize           initialization_value)
226 {
227   g_return_if_fail (g_atomic_pointer_get (value_location) == NULL);
228   g_return_if_fail (initialization_value != 0);
229   g_return_if_fail (g_once_init_list != NULL);
230
231   g_atomic_pointer_set (value_location, (void*) initialization_value);
232   g_mutex_lock (g_once_mutex);
233   g_once_init_list = g_slist_remove (g_once_init_list, (void*) value_location);
234   g_cond_broadcast (g_once_cond);
235   g_mutex_unlock (g_once_mutex);
236 }
237
238 void
239 g_static_mutex_init (GStaticMutex *mutex)
240 {
241   static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
242
243   g_return_if_fail (mutex);
244
245   *mutex = init_mutex;
246 }
247
248 GMutex *
249 g_static_mutex_get_mutex_impl (GMutex** mutex)
250 {
251   if (!g_thread_supported ())
252     return NULL;
253
254   g_assert (g_once_mutex);
255
256   g_mutex_lock (g_once_mutex);
257
258   if (!(*mutex))
259     g_atomic_pointer_set (mutex, g_mutex_new());
260
261   g_mutex_unlock (g_once_mutex);
262
263   return *mutex;
264 }
265
266 void
267 g_static_mutex_free (GStaticMutex* mutex)
268 {
269   GMutex **runtime_mutex;
270
271   g_return_if_fail (mutex);
272
273   /* The runtime_mutex is the first (or only) member of GStaticMutex,
274    * see both versions (of glibconfig.h) in configure.in. Note, that
275    * this variable is NULL, if g_thread_init() hasn't been called or
276    * if we're using the default thread implementation and it provides
277    * static mutexes. */
278   runtime_mutex = ((GMutex**)mutex);
279
280   if (*runtime_mutex)
281     g_mutex_free (*runtime_mutex);
282
283   *runtime_mutex = NULL;
284 }
285
286 void
287 g_static_rec_mutex_init (GStaticRecMutex *mutex)
288 {
289   static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
290
291   g_return_if_fail (mutex);
292
293   *mutex = init_mutex;
294 }
295
296 void
297 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
298 {
299   GSystemThread self;
300
301   g_return_if_fail (mutex);
302
303   if (!g_thread_supported ())
304     return;
305
306   G_THREAD_UF (thread_self, (&self));
307
308   if (g_system_thread_equal (self, mutex->owner))
309     {
310       mutex->depth++;
311       return;
312     }
313   g_static_mutex_lock (&mutex->mutex);
314   g_system_thread_assign (mutex->owner, self);
315   mutex->depth = 1;
316 }
317
318 gboolean
319 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
320 {
321   GSystemThread self;
322
323   g_return_val_if_fail (mutex, FALSE);
324
325   if (!g_thread_supported ())
326     return TRUE;
327
328   G_THREAD_UF (thread_self, (&self));
329
330   if (g_system_thread_equal (self, mutex->owner))
331     {
332       mutex->depth++;
333       return TRUE;
334     }
335
336   if (!g_static_mutex_trylock (&mutex->mutex))
337     return FALSE;
338
339   g_system_thread_assign (mutex->owner, self);
340   mutex->depth = 1;
341   return TRUE;
342 }
343
344 void
345 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
346 {
347   g_return_if_fail (mutex);
348
349   if (!g_thread_supported ())
350     return;
351
352   if (mutex->depth > 1)
353     {
354       mutex->depth--;
355       return;
356     }
357   g_system_thread_assign (mutex->owner, zero_thread);
358   g_static_mutex_unlock (&mutex->mutex);
359 }
360
361 void
362 g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
363                                 guint            depth)
364 {
365   GSystemThread self;
366   g_return_if_fail (mutex);
367
368   if (!g_thread_supported ())
369     return;
370
371   if (depth == 0)
372     return;
373
374   G_THREAD_UF (thread_self, (&self));
375
376   if (g_system_thread_equal (self, mutex->owner))
377     {
378       mutex->depth += depth;
379       return;
380     }
381   g_static_mutex_lock (&mutex->mutex);
382   g_system_thread_assign (mutex->owner, self);
383   mutex->depth = depth;
384 }
385
386 guint
387 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
388 {
389   guint depth;
390
391   g_return_val_if_fail (mutex, 0);
392
393   if (!g_thread_supported ())
394     return 1;
395
396   depth = mutex->depth;
397
398   g_system_thread_assign (mutex->owner, zero_thread);
399   mutex->depth = 0;
400   g_static_mutex_unlock (&mutex->mutex);
401
402   return depth;
403 }
404
405 void
406 g_static_rec_mutex_free (GStaticRecMutex *mutex)
407 {
408   g_return_if_fail (mutex);
409
410   g_static_mutex_free (&mutex->mutex);
411 }
412
413 void
414 g_static_private_init (GStaticPrivate *private_key)
415 {
416   private_key->index = 0;
417 }
418
419 gpointer
420 g_static_private_get (GStaticPrivate *private_key)
421 {
422   GRealThread *self = (GRealThread*) g_thread_self ();
423   GArray *array;
424
425   array = self->private_data;
426   if (!array)
427     return NULL;
428
429   if (!private_key->index)
430     return NULL;
431   else if (private_key->index <= array->len)
432     return g_array_index (array, GStaticPrivateNode,
433                           private_key->index - 1).data;
434   else
435     return NULL;
436 }
437
438 void
439 g_static_private_set (GStaticPrivate *private_key,
440                       gpointer        data,
441                       GDestroyNotify  notify)
442 {
443   GRealThread *self = (GRealThread*) g_thread_self ();
444   GArray *array;
445   static guint next_index = 0;
446   GStaticPrivateNode *node;
447
448   array = self->private_data;
449   if (!array)
450     {
451       array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
452       self->private_data = array;
453     }
454
455   if (!private_key->index)
456     {
457       G_LOCK (g_thread);
458
459       if (!private_key->index)
460         {
461           if (g_thread_free_indeces)
462             {
463               private_key->index =
464                 GPOINTER_TO_UINT (g_thread_free_indeces->data);
465               g_thread_free_indeces =
466                 g_slist_delete_link (g_thread_free_indeces,
467                                      g_thread_free_indeces);
468             }
469           else
470             private_key->index = ++next_index;
471         }
472
473       G_UNLOCK (g_thread);
474     }
475
476   if (private_key->index > array->len)
477     g_array_set_size (array, private_key->index);
478
479   node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
480   if (node->destroy)
481     {
482       gpointer ddata = node->data;
483       GDestroyNotify ddestroy = node->destroy;
484
485       node->data = data;
486       node->destroy = notify;
487
488       ddestroy (ddata);
489     }
490   else
491     {
492       node->data = data;
493       node->destroy = notify;
494     }
495 }
496
497 void
498 g_static_private_free (GStaticPrivate *private_key)
499 {
500   guint idx = private_key->index;
501   GRealThread *thread;
502
503   if (!idx)
504     return;
505
506   private_key->index = 0;
507
508   G_LOCK (g_thread);
509
510   thread = g_thread_all_threads;
511   while (thread)
512     {
513       GArray *array = thread->private_data;
514       thread = thread->next;
515
516       if (array && idx <= array->len)
517         {
518           GStaticPrivateNode *node = &g_array_index (array,
519                                                      GStaticPrivateNode,
520                                                      idx - 1);
521           gpointer ddata = node->data;
522           GDestroyNotify ddestroy = node->destroy;
523
524           node->data = NULL;
525           node->destroy = NULL;
526
527           if (ddestroy)
528             {
529               G_UNLOCK (g_thread);
530               ddestroy (ddata);
531               G_LOCK (g_thread);
532             }
533         }
534     }
535   g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
536                                            GUINT_TO_POINTER (idx));
537   G_UNLOCK (g_thread);
538 }
539
540 static void
541 g_thread_cleanup (gpointer data)
542 {
543   if (data)
544     {
545       GRealThread* thread = data;
546       if (thread->private_data)
547         {
548           GArray* array = thread->private_data;
549           guint i;
550
551           for (i = 0; i < array->len; i++ )
552             {
553               GStaticPrivateNode *node =
554                 &g_array_index (array, GStaticPrivateNode, i);
555               if (node->destroy)
556                 node->destroy (node->data);
557             }
558           g_array_free (array, TRUE);
559         }
560
561       /* We only free the thread structure, if it isn't joinable. If
562          it is, the structure is freed in g_thread_join */
563       if (!thread->thread.joinable)
564         {
565           GRealThread *t, *p;
566
567           G_LOCK (g_thread);
568           for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
569             {
570               if (t == thread)
571                 {
572                   if (p)
573                     p->next = t->next;
574                   else
575                     g_thread_all_threads = t->next;
576                   break;
577                 }
578             }
579           G_UNLOCK (g_thread);
580
581           /* Just to make sure, this isn't used any more */
582           g_system_thread_assign (thread->system_thread, zero_thread);
583           g_free (thread);
584         }
585     }
586 }
587
588 static void
589 g_thread_fail (void)
590 {
591   g_error ("The thread system is not yet initialized.");
592 }
593
594 #define G_NSEC_PER_SEC 1000000000
595
596 static guint64
597 gettime (void)
598 {
599 #ifdef G_OS_WIN32
600   guint64 v;
601
602   /* Returns 100s of nanoseconds since start of 1601 */
603   GetSystemTimeAsFileTime ((FILETIME *)&v);
604
605   /* Offset to Unix epoch */
606   v -= G_GINT64_CONSTANT (116444736000000000);
607   /* Convert to nanoseconds */
608   v *= 100;
609
610   return v;
611 #else
612   struct timeval tv;
613
614   gettimeofday (&tv, NULL);
615
616   return (guint64) tv.tv_sec * G_NSEC_PER_SEC + tv.tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC); 
617 #endif
618 }
619
620 static gpointer
621 g_thread_create_proxy (gpointer data)
622 {
623   GRealThread* thread = data;
624
625   g_assert (data);
626
627   /* This has to happen before G_LOCK, as that might call g_thread_self */
628   g_private_set (g_thread_specific_private, data);
629
630   /* the lock makes sure, that thread->system_thread is written,
631      before thread->thread.func is called. See g_thread_create. */
632   G_LOCK (g_thread);
633   G_UNLOCK (g_thread);
634
635   thread->retval = thread->thread.func (thread->thread.data);
636
637   return NULL;
638 }
639
640 GThread*
641 g_thread_create_full (GThreadFunc       func,
642                       gpointer          data,
643                       gulong            stack_size,
644                       gboolean          joinable,
645                       gboolean          bound,
646                       GThreadPriority   priority,
647                       GError          **error)
648 {
649   GRealThread* result;
650   GError *local_error = NULL;
651   g_return_val_if_fail (func, NULL);
652   g_return_val_if_fail (priority >= G_THREAD_PRIORITY_LOW, NULL);
653   g_return_val_if_fail (priority <= G_THREAD_PRIORITY_URGENT, NULL);
654
655   result = g_new0 (GRealThread, 1);
656
657   result->thread.joinable = joinable;
658   result->thread.priority = priority;
659   result->thread.func = func;
660   result->thread.data = data;
661   result->private_data = NULL;
662   G_LOCK (g_thread);
663   G_THREAD_UF (thread_create, (g_thread_create_proxy, result,
664                                stack_size, joinable, bound, priority,
665                                &result->system_thread, &local_error));
666   if (!local_error)
667     {
668       result->next = g_thread_all_threads;
669       g_thread_all_threads = result;
670     }
671   G_UNLOCK (g_thread);
672
673   if (local_error)
674     {
675       g_propagate_error (error, local_error);
676       g_free (result);
677       return NULL;
678     }
679
680   return (GThread*) result;
681 }
682
683 void
684 g_thread_exit (gpointer retval)
685 {
686   GRealThread* real = (GRealThread*) g_thread_self ();
687   real->retval = retval;
688   G_THREAD_CF (thread_exit, (void)0, ());
689 }
690
691 gpointer
692 g_thread_join (GThread* thread)
693 {
694   GRealThread* real = (GRealThread*) thread;
695   GRealThread *p, *t;
696   gpointer retval;
697
698   g_return_val_if_fail (thread, NULL);
699   g_return_val_if_fail (thread->joinable, NULL);
700   g_return_val_if_fail (!g_system_thread_equal (real->system_thread,
701                                                 zero_thread), NULL);
702
703   G_THREAD_UF (thread_join, (&real->system_thread));
704
705   retval = real->retval;
706
707   G_LOCK (g_thread);
708   for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
709     {
710       if (t == (GRealThread*) thread)
711         {
712           if (p)
713             p->next = t->next;
714           else
715             g_thread_all_threads = t->next;
716           break;
717         }
718     }
719   G_UNLOCK (g_thread);
720
721   /* Just to make sure, this isn't used any more */
722   thread->joinable = 0;
723   g_system_thread_assign (real->system_thread, zero_thread);
724
725   /* the thread structure for non-joinable threads is freed upon
726      thread end. We free the memory here. This will leave a loose end,
727      if a joinable thread is not joined. */
728
729   g_free (thread);
730
731   return retval;
732 }
733
734 void
735 g_thread_set_priority (GThread* thread,
736                        GThreadPriority priority)
737 {
738   GRealThread* real = (GRealThread*) thread;
739
740   g_return_if_fail (thread);
741   g_return_if_fail (!g_system_thread_equal (real->system_thread, zero_thread));
742   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
743   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
744
745   thread->priority = priority;
746
747   G_THREAD_CF (thread_set_priority, (void)0,
748                (&real->system_thread, priority));
749 }
750
751 GThread*
752 g_thread_self (void)
753 {
754   GRealThread* thread = g_private_get (g_thread_specific_private);
755
756   if (!thread)
757     {
758       /* If no thread data is available, provide and set one.  This
759          can happen for the main thread and for threads, that are not
760          created by GLib. */
761       thread = g_new0 (GRealThread, 1);
762       thread->thread.joinable = FALSE; /* This is a save guess */
763       thread->thread.priority = G_THREAD_PRIORITY_NORMAL; /* This is
764                                                              just a guess */
765       thread->thread.func = NULL;
766       thread->thread.data = NULL;
767       thread->private_data = NULL;
768
769       if (g_thread_supported ())
770         G_THREAD_UF (thread_self, (&thread->system_thread));
771
772       g_private_set (g_thread_specific_private, thread);
773
774       G_LOCK (g_thread);
775       thread->next = g_thread_all_threads;
776       g_thread_all_threads = thread;
777       G_UNLOCK (g_thread);
778     }
779
780   return (GThread*)thread;
781 }
782
783 void
784 g_static_rw_lock_init (GStaticRWLock* lock)
785 {
786   static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
787
788   g_return_if_fail (lock);
789
790   *lock = init_lock;
791 }
792
793 inline static void
794 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
795 {
796   if (!*cond)
797       *cond = g_cond_new ();
798   g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
799 }
800
801 inline static void
802 g_static_rw_lock_signal (GStaticRWLock* lock)
803 {
804   if (lock->want_to_write && lock->write_cond)
805     g_cond_signal (lock->write_cond);
806   else if (lock->want_to_read && lock->read_cond)
807     g_cond_broadcast (lock->read_cond);
808 }
809
810 void
811 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
812 {
813   g_return_if_fail (lock);
814
815   if (!g_threads_got_initialized)
816     return;
817
818   g_static_mutex_lock (&lock->mutex);
819   lock->want_to_read++;
820   while (lock->have_writer || lock->want_to_write)
821     g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
822   lock->want_to_read--;
823   lock->read_counter++;
824   g_static_mutex_unlock (&lock->mutex);
825 }
826
827 gboolean
828 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
829 {
830   gboolean ret_val = FALSE;
831
832   g_return_val_if_fail (lock, FALSE);
833
834   if (!g_threads_got_initialized)
835     return TRUE;
836
837   g_static_mutex_lock (&lock->mutex);
838   if (!lock->have_writer && !lock->want_to_write)
839     {
840       lock->read_counter++;
841       ret_val = TRUE;
842     }
843   g_static_mutex_unlock (&lock->mutex);
844   return ret_val;
845 }
846
847 void
848 g_static_rw_lock_reader_unlock  (GStaticRWLock* lock)
849 {
850   g_return_if_fail (lock);
851
852   if (!g_threads_got_initialized)
853     return;
854
855   g_static_mutex_lock (&lock->mutex);
856   lock->read_counter--;
857   if (lock->read_counter == 0)
858     g_static_rw_lock_signal (lock);
859   g_static_mutex_unlock (&lock->mutex);
860 }
861
862 void
863 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
864 {
865   g_return_if_fail (lock);
866
867   if (!g_threads_got_initialized)
868     return;
869
870   g_static_mutex_lock (&lock->mutex);
871   lock->want_to_write++;
872   while (lock->have_writer || lock->read_counter)
873     g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
874   lock->want_to_write--;
875   lock->have_writer = TRUE;
876   g_static_mutex_unlock (&lock->mutex);
877 }
878
879 gboolean
880 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
881 {
882   gboolean ret_val = FALSE;
883
884   g_return_val_if_fail (lock, FALSE);
885
886   if (!g_threads_got_initialized)
887     return TRUE;
888
889   g_static_mutex_lock (&lock->mutex);
890   if (!lock->have_writer && !lock->read_counter)
891     {
892       lock->have_writer = TRUE;
893       ret_val = TRUE;
894     }
895   g_static_mutex_unlock (&lock->mutex);
896   return ret_val;
897 }
898
899 void
900 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
901 {
902   g_return_if_fail (lock);
903
904   if (!g_threads_got_initialized)
905     return;
906
907   g_static_mutex_lock (&lock->mutex);
908   lock->have_writer = FALSE;
909   g_static_rw_lock_signal (lock);
910   g_static_mutex_unlock (&lock->mutex);
911 }
912
913 void
914 g_static_rw_lock_free (GStaticRWLock* lock)
915 {
916   g_return_if_fail (lock);
917
918   if (lock->read_cond)
919     {
920       g_cond_free (lock->read_cond);
921       lock->read_cond = NULL;
922     }
923   if (lock->write_cond)
924     {
925       g_cond_free (lock->write_cond);
926       lock->write_cond = NULL;
927     }
928   g_static_mutex_free (&lock->mutex);
929 }
930
931 /**
932  * g_thread_foreach
933  * @thread_func: function to call for all GThread structures
934  * @user_data:   second argument to @thread_func
935  *
936  * Call @thread_func on all existing #GThread structures. Note that
937  * threads may decide to exit while @thread_func is running, so
938  * without intimate knowledge about the lifetime of foreign threads,
939  * @thread_func shouldn't access the GThread* pointer passed in as
940  * first argument. However, @thread_func will not be called for threads
941  * which are known to have exited already.
942  *
943  * Due to thread lifetime checks, this function has an execution complexity
944  * which is quadratic in the number of existing threads.
945  *
946  * Since: 2.10
947  */
948 void
949 g_thread_foreach (GFunc    thread_func,
950                   gpointer user_data)
951 {
952   GSList *slist = NULL;
953   GRealThread *thread;
954   g_return_if_fail (thread_func != NULL);
955   /* snapshot the list of threads for iteration */
956   G_LOCK (g_thread);
957   for (thread = g_thread_all_threads; thread; thread = thread->next)
958     slist = g_slist_prepend (slist, thread);
959   G_UNLOCK (g_thread);
960   /* walk the list, skipping non-existant threads */
961   while (slist)
962     {
963       GSList *node = slist;
964       slist = node->next;
965       /* check whether the current thread still exists */
966       G_LOCK (g_thread);
967       for (thread = g_thread_all_threads; thread; thread = thread->next)
968         if (thread == node->data)
969           break;
970       G_UNLOCK (g_thread);
971       if (thread)
972         thread_func (thread, user_data);
973       g_slist_free_1 (node);
974     }
975 }
976
977 /**
978  * g_thread_get_initialized
979  *
980  * Indicates if g_thread_init() has been called.
981  *
982  * Since: 2.20
983  */
984 gboolean
985 g_thread_get_initialized ()
986 {
987   return g_thread_supported ();
988 }
989
990 #define __G_THREAD_C__
991 #include "galiasdef.c"