1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * gthread.c: MT safety related functions
5 * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe
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.
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.
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.
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/.
44 #include "gthreadinit.h"
47 #if GLIB_SIZEOF_SYSTEM_THREAD == SIZEOF_VOID_P
48 # define g_system_thread_equal_simple(thread1, thread2) \
49 ((thread1).dummy_pointer == (thread2).dummy_pointer)
50 # define g_system_thread_assign(dest, src) \
51 ((dest).dummy_pointer = (src).dummy_pointer)
52 #else /* GLIB_SIZEOF_SYSTEM_THREAD != SIZEOF_VOID_P */
53 # define g_system_thread_equal_simple(thread1, thread2) \
54 (memcmp (&(thread1), &(thread2), GLIB_SIZEOF_SYSTEM_THREAD) == 0)
55 # define g_system_thread_assign(dest, src) \
56 (memcpy (&(dest), &(src), GLIB_SIZEOF_SYSTEM_THREAD))
57 #endif /* GLIB_SIZEOF_SYSTEM_THREAD == SIZEOF_VOID_P */
59 #define g_system_thread_equal(thread1, thread2) \
60 (g_thread_functions_for_glib_use.thread_equal ? \
61 g_thread_functions_for_glib_use.thread_equal (&(thread1), &(thread2)) :\
62 g_system_thread_equal_simple((thread1), (thread2)))
65 g_thread_error_quark (void)
69 quark = g_quark_from_static_string ("g_thread_error");
73 /* Keep this in sync with GRealThread in gmain.c! */
74 typedef struct _GRealThread GRealThread;
78 gpointer private_data;
80 GSystemThread system_thread;
83 typedef struct _GStaticPrivateNode GStaticPrivateNode;
84 struct _GStaticPrivateNode
87 GDestroyNotify destroy;
90 static void g_thread_cleanup (gpointer data);
91 static void g_thread_fail (void);
93 /* Global variables */
95 static GSystemThread zero_thread; /* This is initialized to all zero */
96 gboolean g_thread_use_default_impl = TRUE;
97 gboolean g_threads_got_initialized = FALSE;
99 GThreadFunctions g_thread_functions_for_glib_use = {
100 (GMutex*(*)())g_thread_fail, /* mutex_new */
101 NULL, /* mutex_lock */
102 NULL, /* mutex_trylock */
103 NULL, /* mutex_unlock */
104 NULL, /* mutex_free */
105 (GCond*(*)())g_thread_fail, /* cond_new */
106 NULL, /* cond_signal */
107 NULL, /* cond_broadcast */
108 NULL, /* cond_wait */
109 NULL, /* cond_timed_wait */
110 NULL, /* cond_free */
111 (GPrivate*(*)(GDestroyNotify))g_thread_fail, /* private_new */
112 NULL, /* private_get */
113 NULL, /* private_set */
114 (void(*)(GThreadFunc, gpointer, gulong,
115 gboolean, gboolean, GThreadPriority,
116 gpointer, GError**))g_thread_fail, /* thread_create */
117 NULL, /* thread_yield */
118 NULL, /* thread_join */
119 NULL, /* thread_exit */
120 NULL, /* thread_set_priority */
121 NULL /* thread_self */
126 static GMutex *g_once_mutex = NULL;
127 static GCond *g_once_cond = NULL;
128 static GPrivate *g_thread_specific_private = NULL;
129 static GSList *g_thread_all_threads = NULL;
130 static GSList *g_thread_free_indeces = NULL;
132 G_LOCK_DEFINE_STATIC (g_thread);
134 #ifdef G_THREADS_ENABLED
135 /* This must be called only once, before any threads are created.
136 * It will only be called from g_thread_init() in -lgthread.
139 g_thread_init_glib (void)
141 /* We let the main thread (the one that calls g_thread_init) inherit
142 * the static_private data set before calling g_thread_init
144 GRealThread* main_thread = (GRealThread*) g_thread_self ();
146 g_once_mutex = g_mutex_new ();
147 g_once_cond = g_cond_new ();
149 _g_convert_thread_init ();
150 _g_rand_thread_init ();
151 _g_main_thread_init ();
152 _g_mem_thread_init ();
153 _g_messages_thread_init ();
154 _g_atomic_thread_init ();
155 _g_utils_thread_init ();
157 _g_win32_thread_init ();
160 g_threads_got_initialized = TRUE;
162 g_thread_specific_private = g_private_new (g_thread_cleanup);
163 g_private_set (g_thread_specific_private, main_thread);
164 G_THREAD_UF (thread_self, (&main_thread->system_thread));
166 _g_mem_thread_private_init ();
167 _g_messages_thread_private_init ();
170 #endif /* G_THREADS_ENABLED */
173 g_once_impl (GOnce *once,
177 g_mutex_lock (g_once_mutex);
179 while (once->status == G_ONCE_STATUS_PROGRESS)
180 g_cond_wait (g_once_cond, g_once_mutex);
182 if (once->status != G_ONCE_STATUS_READY)
184 once->status = G_ONCE_STATUS_PROGRESS;
185 g_mutex_unlock (g_once_mutex);
187 once->retval = func (arg);
189 g_mutex_lock (g_once_mutex);
190 once->status = G_ONCE_STATUS_READY;
191 g_cond_broadcast (g_once_cond);
194 g_mutex_unlock (g_once_mutex);
200 g_static_mutex_init (GStaticMutex *mutex)
202 static GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
204 g_return_if_fail (mutex);
210 g_static_mutex_get_mutex_impl (GMutex** mutex)
212 if (!g_thread_supported ())
215 g_assert (g_once_mutex);
217 g_mutex_lock (g_once_mutex);
221 GMutex *new_mutex = g_mutex_new ();
223 /* The following is a memory barrier to avoid the write
224 * to *new_mutex being reordered to after writing *mutex */
225 g_mutex_lock (new_mutex);
226 g_mutex_unlock (new_mutex);
231 g_mutex_unlock (g_once_mutex);
237 g_static_mutex_free (GStaticMutex* mutex)
239 GMutex **runtime_mutex;
241 g_return_if_fail (mutex);
243 /* The runtime_mutex is the first (or only) member of GStaticMutex,
244 * see both versions (of glibconfig.h) in configure.in */
245 runtime_mutex = ((GMutex**)mutex);
248 g_mutex_free (*runtime_mutex);
250 *runtime_mutex = NULL;
254 g_static_rec_mutex_init (GStaticRecMutex *mutex)
256 static GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
258 g_return_if_fail (mutex);
264 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
268 g_return_if_fail (mutex);
270 if (!g_thread_supported ())
273 G_THREAD_UF (thread_self, (&self));
275 if (g_system_thread_equal (self, mutex->owner))
280 g_static_mutex_lock (&mutex->mutex);
281 g_system_thread_assign (mutex->owner, self);
286 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
290 g_return_val_if_fail (mutex, FALSE);
292 if (!g_thread_supported ())
295 G_THREAD_UF (thread_self, (&self));
297 if (g_system_thread_equal (self, mutex->owner))
303 if (!g_static_mutex_trylock (&mutex->mutex))
306 g_system_thread_assign (mutex->owner, self);
312 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
314 g_return_if_fail (mutex);
316 if (!g_thread_supported ())
319 if (mutex->depth > 1)
324 g_system_thread_assign (mutex->owner, zero_thread);
325 g_static_mutex_unlock (&mutex->mutex);
329 g_static_rec_mutex_lock_full (GStaticRecMutex *mutex,
333 g_return_if_fail (mutex);
335 if (!g_thread_supported ())
341 G_THREAD_UF (thread_self, (&self));
343 if (g_system_thread_equal (self, mutex->owner))
345 mutex->depth += depth;
348 g_static_mutex_lock (&mutex->mutex);
349 g_system_thread_assign (mutex->owner, self);
350 mutex->depth = depth;
354 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
358 g_return_val_if_fail (mutex, 0);
360 if (!g_thread_supported ())
363 depth = mutex->depth;
365 g_system_thread_assign (mutex->owner, zero_thread);
367 g_static_mutex_unlock (&mutex->mutex);
373 g_static_rec_mutex_free (GStaticRecMutex *mutex)
375 g_return_if_fail (mutex);
377 g_static_mutex_free (&mutex->mutex);
381 g_static_private_init (GStaticPrivate *private_key)
383 private_key->index = 0;
387 g_static_private_get (GStaticPrivate *private_key)
389 GRealThread *self = (GRealThread*) g_thread_self ();
392 array = self->private_data;
396 if (!private_key->index)
398 else if (private_key->index <= array->len)
399 return g_array_index (array, GStaticPrivateNode,
400 private_key->index - 1).data;
406 g_static_private_set (GStaticPrivate *private_key,
408 GDestroyNotify notify)
410 GRealThread *self = (GRealThread*) g_thread_self ();
412 static guint next_index = 0;
413 GStaticPrivateNode *node;
415 array = self->private_data;
418 array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
419 self->private_data = array;
422 if (!private_key->index)
426 if (!private_key->index)
428 if (g_thread_free_indeces)
431 GPOINTER_TO_UINT (g_thread_free_indeces->data);
432 g_thread_free_indeces =
433 g_slist_delete_link (g_thread_free_indeces,
434 g_thread_free_indeces);
437 private_key->index = ++next_index;
443 if (private_key->index > array->len)
444 g_array_set_size (array, private_key->index);
446 node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
449 gpointer ddata = node->data;
450 GDestroyNotify ddestroy = node->destroy;
453 node->destroy = notify;
460 node->destroy = notify;
465 g_static_private_free (GStaticPrivate *private_key)
467 guint index = private_key->index;
473 private_key->index = 0;
476 list = g_thread_all_threads;
479 GRealThread *thread = list->data;
480 GArray *array = thread->private_data;
483 if (array && index <= array->len)
485 GStaticPrivateNode *node = &g_array_index (array,
488 gpointer ddata = node->data;
489 GDestroyNotify ddestroy = node->destroy;
492 node->destroy = NULL;
502 g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
503 GUINT_TO_POINTER (index));
508 g_thread_cleanup (gpointer data)
512 GRealThread* thread = data;
513 if (thread->private_data)
515 GArray* array = thread->private_data;
518 for (i = 0; i < array->len; i++ )
520 GStaticPrivateNode *node =
521 &g_array_index (array, GStaticPrivateNode, i);
523 node->destroy (node->data);
525 g_array_free (array, TRUE);
528 /* We only free the thread structure, if it isn't joinable. If
529 it is, the structure is freed in g_thread_join */
530 if (!thread->thread.joinable)
533 g_thread_all_threads = g_slist_remove (g_thread_all_threads, data);
536 /* Just to make sure, this isn't used any more */
537 g_system_thread_assign (thread->system_thread, zero_thread);
546 g_error ("The thread system is not yet initialized.");
550 g_thread_create_proxy (gpointer data)
552 GRealThread* thread = data;
556 /* This has to happen before G_LOCK, as that might call g_thread_self */
557 g_private_set (g_thread_specific_private, data);
559 /* the lock makes sure, that thread->system_thread is written,
560 before thread->thread.func is called. See g_thread_create. */
564 thread->retval = thread->thread.func (thread->thread.data);
570 g_thread_create_full (GThreadFunc func,
575 GThreadPriority priority,
579 GError *local_error = NULL;
580 g_return_val_if_fail (func, NULL);
581 g_return_val_if_fail (priority >= G_THREAD_PRIORITY_LOW, NULL);
582 g_return_val_if_fail (priority <= G_THREAD_PRIORITY_URGENT, NULL);
584 result = g_new (GRealThread, 1);
586 result->thread.joinable = joinable;
587 result->thread.priority = priority;
588 result->thread.func = func;
589 result->thread.data = data;
590 result->private_data = NULL;
592 G_THREAD_UF (thread_create, (g_thread_create_proxy, result,
593 stack_size, joinable, bound, priority,
594 &result->system_thread, &local_error));
595 g_thread_all_threads = g_slist_prepend (g_thread_all_threads, result);
600 g_propagate_error (error, local_error);
605 return (GThread*) result;
609 g_thread_exit (gpointer retval)
611 GRealThread* real = (GRealThread*) g_thread_self ();
612 real->retval = retval;
613 G_THREAD_CF (thread_exit, (void)0, ());
617 g_thread_join (GThread* thread)
619 GRealThread* real = (GRealThread*) thread;
622 g_return_val_if_fail (thread, NULL);
623 g_return_val_if_fail (thread->joinable, NULL);
624 g_return_val_if_fail (!g_system_thread_equal (real->system_thread,
627 G_THREAD_UF (thread_join, (&real->system_thread));
629 retval = real->retval;
632 g_thread_all_threads = g_slist_remove (g_thread_all_threads, thread);
635 /* Just to make sure, this isn't used any more */
636 thread->joinable = 0;
637 g_system_thread_assign (real->system_thread, zero_thread);
639 /* the thread structure for non-joinable threads is freed upon
640 thread end. We free the memory here. This will leave a loose end,
641 if a joinable thread is not joined. */
649 g_thread_set_priority (GThread* thread,
650 GThreadPriority priority)
652 GRealThread* real = (GRealThread*) thread;
654 g_return_if_fail (thread);
655 g_return_if_fail (!g_system_thread_equal (real->system_thread, zero_thread));
656 g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
657 g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
659 thread->priority = priority;
661 G_THREAD_CF (thread_set_priority, (void)0,
662 (&real->system_thread, priority));
668 GRealThread* thread = g_private_get (g_thread_specific_private);
672 /* If no thread data is available, provide and set one. This
673 can happen for the main thread and for threads, that are not
675 thread = g_new (GRealThread, 1);
676 thread->thread.joinable = FALSE; /* This is a save guess */
677 thread->thread.priority = G_THREAD_PRIORITY_NORMAL; /* This is
679 thread->thread.func = NULL;
680 thread->thread.data = NULL;
681 thread->private_data = NULL;
683 if (g_thread_supported ())
684 G_THREAD_UF (thread_self, (&thread->system_thread));
686 g_private_set (g_thread_specific_private, thread);
689 g_thread_all_threads = g_slist_prepend (g_thread_all_threads, thread);
693 return (GThread*)thread;
697 g_static_rw_lock_init (GStaticRWLock* lock)
699 static GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
701 g_return_if_fail (lock);
707 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
710 *cond = g_cond_new ();
711 g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
715 g_static_rw_lock_signal (GStaticRWLock* lock)
717 if (lock->want_to_write && lock->write_cond)
718 g_cond_signal (lock->write_cond);
719 else if (lock->want_to_read && lock->read_cond)
720 g_cond_broadcast (lock->read_cond);
724 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
726 g_return_if_fail (lock);
728 if (!g_threads_got_initialized)
731 g_static_mutex_lock (&lock->mutex);
732 lock->want_to_read++;
733 while (lock->have_writer || lock->want_to_write)
734 g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
735 lock->want_to_read--;
736 lock->read_counter++;
737 g_static_mutex_unlock (&lock->mutex);
741 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
743 gboolean ret_val = FALSE;
745 g_return_val_if_fail (lock, FALSE);
747 if (!g_threads_got_initialized)
750 g_static_mutex_lock (&lock->mutex);
751 if (!lock->have_writer && !lock->want_to_write)
753 lock->read_counter++;
756 g_static_mutex_unlock (&lock->mutex);
761 g_static_rw_lock_reader_unlock (GStaticRWLock* lock)
763 g_return_if_fail (lock);
765 if (!g_threads_got_initialized)
768 g_static_mutex_lock (&lock->mutex);
769 lock->read_counter--;
770 if (lock->read_counter == 0)
771 g_static_rw_lock_signal (lock);
772 g_static_mutex_unlock (&lock->mutex);
776 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
778 g_return_if_fail (lock);
780 if (!g_threads_got_initialized)
783 g_static_mutex_lock (&lock->mutex);
784 lock->want_to_write++;
785 while (lock->have_writer || lock->read_counter)
786 g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
787 lock->want_to_write--;
788 lock->have_writer = TRUE;
789 g_static_mutex_unlock (&lock->mutex);
793 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
795 gboolean ret_val = FALSE;
797 g_return_val_if_fail (lock, FALSE);
799 if (!g_threads_got_initialized)
802 g_static_mutex_lock (&lock->mutex);
803 if (!lock->have_writer && !lock->read_counter)
805 lock->have_writer = TRUE;
808 g_static_mutex_unlock (&lock->mutex);
813 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
815 g_return_if_fail (lock);
817 if (!g_threads_got_initialized)
820 g_static_mutex_lock (&lock->mutex);
821 lock->have_writer = FALSE;
822 g_static_rw_lock_signal (lock);
823 g_static_mutex_unlock (&lock->mutex);
827 g_static_rw_lock_free (GStaticRWLock* lock)
829 g_return_if_fail (lock);
833 g_cond_free (lock->read_cond);
834 lock->read_cond = NULL;
836 if (lock->write_cond)
838 g_cond_free (lock->write_cond);
839 lock->write_cond = NULL;
841 g_static_mutex_free (&lock->mutex);
844 #define __G_THREAD_C__
845 #include "galiasdef.c"