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
59GQuark
60g_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! */
66typedef struct _GRealThread GRealThread;
67struct  _GRealThread
68{
69  GThread thread;
70  gpointer private_data;
71  GRealThread *next;
72  gpointer retval;
73  GSystemThread system_thread;
74};
75
76typedef struct _GStaticPrivateNode GStaticPrivateNode;
77struct _GStaticPrivateNode
78{
79  gpointer       data;
80  GDestroyNotify destroy;
81};
82
83static void    g_thread_cleanup (gpointer data);
84static void    g_thread_fail (void);
85static guint64 gettime (void);
86
87guint64        (*g_thread_gettime) (void) = gettime;
88
89/* Global variables */
90
91static GSystemThread zero_thread; /* This is initialized to all zero */
92gboolean g_thread_use_default_impl = TRUE;
93gboolean g_threads_got_initialized = FALSE;
94
95GThreadFunctions 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
123static GMutex   *g_once_mutex = NULL;
124static GCond    *g_once_cond = NULL;
125static GPrivate *g_thread_specific_private = NULL;
126static GRealThread *g_thread_all_threads = NULL;
127static GSList   *g_thread_free_indeces = NULL;
128static GSList*   g_once_init_list = NULL;
129
130G_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 */
136void
137g_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
175gpointer
176g_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
202gboolean
203g_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
223void
224g_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 ((void**)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
238void
239g_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
248GMutex *
249g_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
266void
267g_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
286void
287g_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
296void
297g_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
318gboolean
319g_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
344void
345g_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
361void
362g_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
386guint
387g_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
405void
406g_static_rec_mutex_free (GStaticRecMutex *mutex)
407{
408  g_return_if_fail (mutex);
409
410  g_static_mutex_free (&mutex->mutex);
411}
412
413void
414g_static_private_init (GStaticPrivate *private_key)
415{
416  private_key->index = 0;
417}
418
419gpointer
420g_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
438void
439g_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
497void
498g_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
540static void
541g_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
588static void
589g_thread_fail (void)
590{
591  g_error ("The thread system is not yet initialized.");
592}
593
594#define G_NSEC_PER_SEC 1000000000
595
596static guint64
597gettime (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
620static gpointer
621g_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
640GThread*
641g_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
683void
684g_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
691gpointer
692g_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
734void
735g_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
751GThread*
752g_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
783void
784g_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
793inline static void
794g_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
801inline static void
802g_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
810void
811g_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
827gboolean
828g_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
847void
848g_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
862void
863g_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
879gboolean
880g_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
899void
900g_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
913void
914g_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 */
948void
949g_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 * Returns: %TRUE if threads have been initialized.
983 *
984 * Since: 2.20
985 */
986gboolean
987g_thread_get_initialized ()
988{
989  return g_thread_supported ();
990}
991
992#define __G_THREAD_C__
993#include "galiasdef.c"
994