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.
26 /* we know we are deprecated here, no need for warnings */
27 #define GLIB_DISABLE_DEPRECATION_WARNINGS
29 #include "gmessages.h"
33 #include "gthreadprivate.h"
34 #include "deprecated/gthread.h"
38 /* {{{1 Documentation */
41 * SECTION:threads-deprecated
42 * @title: Deprecated thread API
43 * @short_description: old thread APIs (for reference only)
46 * These APIs are deprecated. You should not use them in new code.
47 * This section remains only to assist with understanding code that was
48 * written to use these APIs at some point in the past.
53 * @G_THREAD_PRIORITY_LOW: a priority lower than normal
54 * @G_THREAD_PRIORITY_NORMAL: the default priority
55 * @G_THREAD_PRIORITY_HIGH: a priority higher than normal
56 * @G_THREAD_PRIORITY_URGENT: the highest priority
58 * Deprecated:2.32: Thread priorities no longer have any effect.
63 * @mutex_new: virtual function pointer for g_mutex_new()
64 * @mutex_lock: virtual function pointer for g_mutex_lock()
65 * @mutex_trylock: virtual function pointer for g_mutex_trylock()
66 * @mutex_unlock: virtual function pointer for g_mutex_unlock()
67 * @mutex_free: virtual function pointer for g_mutex_free()
68 * @cond_new: virtual function pointer for g_cond_new()
69 * @cond_signal: virtual function pointer for g_cond_signal()
70 * @cond_broadcast: virtual function pointer for g_cond_broadcast()
71 * @cond_wait: virtual function pointer for g_cond_wait()
72 * @cond_timed_wait: virtual function pointer for g_cond_timed_wait()
73 * @cond_free: virtual function pointer for g_cond_free()
74 * @private_new: virtual function pointer for g_private_new()
75 * @private_get: virtual function pointer for g_private_get()
76 * @private_set: virtual function pointer for g_private_set()
77 * @thread_create: virtual function pointer for g_thread_create()
78 * @thread_yield: virtual function pointer for g_thread_yield()
79 * @thread_join: virtual function pointer for g_thread_join()
80 * @thread_exit: virtual function pointer for g_thread_exit()
81 * @thread_set_priority: virtual function pointer for
82 * g_thread_set_priority()
83 * @thread_self: virtual function pointer for g_thread_self()
84 * @thread_equal: used internally by recursive mutex locks and by some
87 * This function table is no longer used by g_thread_init()
88 * to initialize the thread system.
92 * G_THREADS_IMPL_POSIX:
94 * This macro is defined if POSIX style threads are used.
96 * Deprecated:2.32:POSIX threads are in use on all non-Windows systems.
97 * Use G_OS_WIN32 to detect Windows.
101 * G_THREADS_IMPL_WIN32:
103 * This macro is defined if Windows style threads are used.
105 * Deprecated:2.32:Use G_OS_WIN32 to detect Windows.
109 /* {{{1 Exported Variables */
111 /* Set this FALSE to have previously-compiled GStaticMutex code use the
112 * slow path (ie: call into us) to avoid compatibility problems.
114 gboolean g_thread_use_default_impl = FALSE;
116 GThreadFunctions g_thread_functions_for_glib_use =
144 return g_get_monotonic_time () * 1000;
147 guint64 (*g_thread_gettime) (void) = gettime;
149 /* Initialisation {{{1 ---------------------------------------------------- */
150 gboolean g_threads_got_initialized = TRUE;
151 GSystemThread zero_thread; /* This is initialized to all zero */
156 * @vtable: a function table of type #GThreadFunctions, that provides
157 * the entry points to the thread system to be used. Since 2.32,
158 * this parameter is ignored and should always be %NULL
160 * If you use GLib from more than one thread, you must initialize the
161 * thread system by calling g_thread_init().
163 * Since version 2.24, calling g_thread_init() multiple times is allowed,
164 * but nothing happens except for the first call.
166 * Since version 2.32, GLib does not support custom thread implementations
167 * anymore and the @vtable parameter is ignored and you should pass %NULL.
169 * <note><para>g_thread_init() must not be called directly or indirectly
170 * in a callback from GLib. Also no mutexes may be currently locked while
171 * calling g_thread_init().</para></note>
173 * <note><para>To use g_thread_init() in your program, you have to link
174 * with the libraries that the command <command>pkg-config --libs
175 * gthread-2.0</command> outputs. This is not the case for all the
176 * other thread-related functions of GLib. Those can be used without
177 * having to link with the thread libraries.</para></note>
181 * g_thread_get_initialized:
183 * Indicates if g_thread_init() has been called.
185 * Returns: %TRUE if threads have been initialized.
190 g_thread_get_initialized (void)
192 return g_thread_supported ();
195 /* We need this for ABI compatibility */
196 void g_thread_init_glib (void) { }
198 /* Internal variables {{{1 */
200 static GRealThread *g_thread_all_threads = NULL;
201 static GSList *g_thread_free_indices = NULL;
203 /* Protects g_thread_all_threads and g_thread_free_indices */
204 G_LOCK_DEFINE_STATIC (g_thread);
206 /* Misc. GThread functions {{{1 */
209 * g_thread_set_priority:
210 * @thread: a #GThread.
213 * This function does nothing.
215 * Deprecated:2.32: Thread priorities no longer have any effect.
218 g_thread_set_priority (GThread *thread,
219 GThreadPriority priority)
225 * @func: a function to execute in the new thread
226 * @data: an argument to supply to the new thread
227 * @joinable: should this thread be joinable?
228 * @error: return location for error, or %NULL
230 * This function creates a new thread.
232 * If @joinable is %TRUE, you can wait for this threads termination
233 * calling g_thread_join(). Otherwise the thread will just disappear
234 * when it terminates.
236 * The new thread executes the function @func with the argument @data.
237 * If the thread was created successfully, it is returned.
239 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
240 * The error is set, if and only if the function returns %NULL.
242 * Returns: the new #GThread on success
244 * Deprecated:2.32: Use g_thread_new() instead
247 g_thread_create (GThreadFunc func,
252 return g_thread_new_internal (NULL, func, data, joinable, 0, TRUE, error);
256 * g_thread_create_full:
257 * @func: a function to execute in the new thread.
258 * @data: an argument to supply to the new thread.
259 * @stack_size: a stack size for the new thread.
260 * @joinable: should this thread be joinable?
263 * @error: return location for error.
264 * @Returns: the new #GThread on success.
266 * This function creates a new thread.
268 * Deprecated:2.32: The @bound and @priority arguments are now ignored.
269 * Use g_thread_new() or g_thread_new_full() instead.
272 g_thread_create_full (GThreadFunc func,
277 GThreadPriority priority,
280 return g_thread_new_internal (NULL, func, data, joinable, stack_size, TRUE, error);
285 * @thread_func: function to call for all #GThread structures
286 * @user_data: second argument to @thread_func
288 * Call @thread_func on all #GThreads that have been
289 * created with g_thread_create().
291 * Note that threads may decide to exit while @thread_func is
292 * running, so without intimate knowledge about the lifetime of
293 * foreign threads, @thread_func shouldn't access the GThread*
294 * pointer passed in as first argument. However, @thread_func will
295 * not be called for threads which are known to have exited already.
297 * Due to thread lifetime checks, this function has an execution complexity
298 * which is quadratic in the number of existing threads.
302 * Deprecated:2.32: There aren't many things you can do with a #GThread,
303 * except comparing it with one that was returned from g_thread_create().
304 * There are better ways to find out if your thread is still alive.
307 g_thread_foreach (GFunc thread_func,
310 GSList *slist = NULL;
312 g_return_if_fail (thread_func != NULL);
313 /* snapshot the list of threads for iteration */
315 for (thread = g_thread_all_threads; thread; thread = thread->next)
316 slist = g_slist_prepend (slist, thread);
318 /* walk the list, skipping non-existent threads */
321 GSList *node = slist;
323 /* check whether the current thread still exists */
325 for (thread = g_thread_all_threads; thread; thread = thread->next)
326 if (thread == node->data)
330 thread_func (thread, user_data);
331 g_slist_free_1 (node);
336 g_enumerable_thread_add (GRealThread *thread)
339 thread->next = g_thread_all_threads;
340 g_thread_all_threads = thread;
345 g_enumerable_thread_remove (GRealThread *thread)
350 for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
357 g_thread_all_threads = t->next;
364 /* GOnce {{{1 ------------------------------------------------------------- */
366 g_once_init_enter_impl (volatile gsize *location)
368 return (g_once_init_enter) (location);
371 /* GStaticMutex {{{1 ------------------------------------------------------ */
376 * A #GStaticMutex works like a #GMutex.
378 * Prior to GLib 2.32, GStaticMutex had the significant advantage
379 * that it doesn't need to be created at run-time, but can be defined
380 * at compile-time. Since 2.32, #GMutex can be statically allocated
381 * as well, and GStaticMutex has been deprecated.
383 * Here is a version of our give_me_next_number() example using
388 * Using <structname>GStaticMutex</structname>
389 * to simplify thread-safe programming
393 * give_me_next_number (void)
395 * static int current_number = 0;
397 * static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
399 * g_static_mutex_lock (&mutex);
400 * ret_val = current_number = calc_next_number (current_number);
401 * g_static_mutex_unlock (&mutex);
408 * Sometimes you would like to dynamically create a mutex. If you don't
409 * want to require prior calling to g_thread_init(), because your code
410 * should also be usable in non-threaded programs, you are not able to
411 * use g_mutex_new() and thus #GMutex, as that requires a prior call to
412 * g_thread_init(). In theses cases you can also use a #GStaticMutex.
413 * It must be initialized with g_static_mutex_init() before using it
414 * and freed with with g_static_mutex_free() when not needed anymore to
415 * free up any allocated resources.
417 * Even though #GStaticMutex is not opaque, it should only be used with
418 * the following functions, as it is defined differently on different
421 * All of the <function>g_static_mutex_*</function> functions apart
422 * from <function>g_static_mutex_get_mutex</function> can also be used
423 * even if g_thread_init() has not yet been called. Then they do
424 * nothing, apart from <function>g_static_mutex_trylock</function>,
425 * which does nothing but returning %TRUE.
427 * <note><para>All of the <function>g_static_mutex_*</function>
428 * functions are actually macros. Apart from taking their addresses, you
429 * can however use them as if they were functions.</para></note>
433 * G_STATIC_MUTEX_INIT:
435 * A #GStaticMutex must be initialized with this macro, before it can
436 * be used. This macro can used be to initialize a variable, but it
437 * cannot be assigned to a variable. In that case you have to use
438 * g_static_mutex_init().
441 * GStaticMutex my_mutex = G_STATIC_MUTEX_INIT;
446 * g_static_mutex_init:
447 * @mutex: a #GStaticMutex to be initialized.
449 * Initializes @mutex.
450 * Alternatively you can initialize it with #G_STATIC_MUTEX_INIT.
452 * Deprecated: 2.32: Use g_mutex_init()
455 g_static_mutex_init (GStaticMutex *mutex)
457 static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
459 g_return_if_fail (mutex);
464 /* IMPLEMENTATION NOTE:
466 * On some platforms a GStaticMutex is actually a normal GMutex stored
467 * inside of a structure instead of being allocated dynamically. We can
468 * only do this for platforms on which we know, in advance, how to
469 * allocate (size) and initialise (value) that memory.
471 * On other platforms, a GStaticMutex is nothing more than a pointer to
472 * a GMutex. In that case, the first access we make to the static mutex
473 * must first allocate the normal GMutex and store it into the pointer.
475 * configure.ac writes macros into glibconfig.h to determine if
476 * g_static_mutex_get_mutex() accesses the structure in memory directly
477 * (on platforms where we are able to do that) or if it ends up here,
478 * where we may have to allocate the GMutex before returning it.
482 * g_static_mutex_get_mutex:
483 * @mutex: a #GStaticMutex.
484 * @Returns: the #GMutex corresponding to @mutex.
486 * For some operations (like g_cond_wait()) you must have a #GMutex
487 * instead of a #GStaticMutex. This function will return the
488 * corresponding #GMutex for @mutex.
490 * Deprecated: 2.32: Just use a #GMutex
493 g_static_mutex_get_mutex_impl (GStaticMutex* mutex)
497 if (!g_thread_supported ())
500 result = g_atomic_pointer_get (&mutex->mutex);
504 g_mutex_lock (&g_once_mutex);
506 result = mutex->mutex;
509 result = g_mutex_new ();
510 g_atomic_pointer_set (&mutex->mutex, result);
513 g_mutex_unlock (&g_once_mutex);
519 /* IMPLEMENTATION NOTE:
521 * g_static_mutex_lock(), g_static_mutex_trylock() and
522 * g_static_mutex_unlock() are all preprocessor macros that wrap the
523 * corresponding g_mutex_*() function around a call to
524 * g_static_mutex_get_mutex().
528 * g_static_mutex_lock:
529 * @mutex: a #GStaticMutex.
531 * Works like g_mutex_lock(), but for a #GStaticMutex.
533 * Deprecated: 2.32: Use g_mutex_lock()
537 * g_static_mutex_trylock:
538 * @mutex: a #GStaticMutex.
539 * @Returns: %TRUE, if the #GStaticMutex could be locked.
541 * Works like g_mutex_trylock(), but for a #GStaticMutex.
543 * Deprecated: 2.32: Use g_mutex_trylock()
547 * g_static_mutex_unlock:
548 * @mutex: a #GStaticMutex.
550 * Works like g_mutex_unlock(), but for a #GStaticMutex.
552 * Deprecated: 2.32: Use g_mutex_unlock()
556 * g_static_mutex_free:
557 * @mutex: a #GStaticMutex to be freed.
559 * Releases all resources allocated to @mutex.
561 * You don't have to call this functions for a #GStaticMutex with an
562 * unbounded lifetime, i.e. objects declared 'static', but if you have
563 * a #GStaticMutex as a member of a structure and the structure is
564 * freed, you should also free the #GStaticMutex.
566 * <note><para>Calling g_static_mutex_free() on a locked mutex may
567 * result in undefined behaviour.</para></note>
569 * Deprecated: 2.32: Use g_mutex_free()
572 g_static_mutex_free (GStaticMutex* mutex)
574 GMutex **runtime_mutex;
576 g_return_if_fail (mutex);
578 /* The runtime_mutex is the first (or only) member of GStaticMutex,
579 * see both versions (of glibconfig.h) in configure.ac. Note, that
580 * this variable is NULL, if g_thread_init() hasn't been called or
581 * if we're using the default thread implementation and it provides
583 runtime_mutex = ((GMutex**)mutex);
586 g_mutex_free (*runtime_mutex);
588 *runtime_mutex = NULL;
591 /* {{{1 GStaticRecMutex */
596 * A #GStaticRecMutex works like a #GStaticMutex, but it can be locked
597 * multiple times by one thread. If you enter it n times, you have to
598 * unlock it n times again to let other threads lock it. An exception
599 * is the function g_static_rec_mutex_unlock_full(): that allows you to
600 * unlock a #GStaticRecMutex completely returning the depth, (i.e. the
601 * number of times this mutex was locked). The depth can later be used
602 * to restore the state of the #GStaticRecMutex by calling
603 * g_static_rec_mutex_lock_full(). In GLib 2.32, #GStaticRecMutex has
604 * been deprecated in favor of #GRecMutex.
606 * Even though #GStaticRecMutex is not opaque, it should only be used
607 * with the following functions.
609 * All of the <function>g_static_rec_mutex_*</function> functions can
610 * be used even if g_thread_init() has not been called. Then they do
611 * nothing, apart from <function>g_static_rec_mutex_trylock</function>,
612 * which does nothing but returning %TRUE.
616 * G_STATIC_REC_MUTEX_INIT:
618 * A #GStaticRecMutex must be initialized with this macro before it can
619 * be used. This macro can used be to initialize a variable, but it
620 * cannot be assigned to a variable. In that case you have to use
621 * g_static_rec_mutex_init().
624 * GStaticRecMutex my_mutex = G_STATIC_REC_MUTEX_INIT;
629 * g_static_rec_mutex_init:
630 * @mutex: a #GStaticRecMutex to be initialized.
632 * A #GStaticRecMutex must be initialized with this function before it
633 * can be used. Alternatively you can initialize it with
634 * #G_STATIC_REC_MUTEX_INIT.
636 * Deprecated: 2.32: Use g_rec_mutex_init()
639 g_static_rec_mutex_init (GStaticRecMutex *mutex)
641 static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
643 g_return_if_fail (mutex);
649 * g_static_rec_mutex_lock:
650 * @mutex: a #GStaticRecMutex to lock.
652 * Locks @mutex. If @mutex is already locked by another thread, the
653 * current thread will block until @mutex is unlocked by the other
654 * thread. If @mutex is already locked by the calling thread, this
655 * functions increases the depth of @mutex and returns immediately.
657 * Deprecated: 2.32: Use g_rec_mutex_lock()
660 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
664 g_return_if_fail (mutex);
666 if (!g_thread_supported ())
669 g_system_thread_self (&self);
671 if (g_system_thread_equal (&self, &mutex->owner))
676 g_static_mutex_lock (&mutex->mutex);
677 g_system_thread_assign (mutex->owner, self);
682 * g_static_rec_mutex_trylock:
683 * @mutex: a #GStaticRecMutex to lock.
684 * @Returns: %TRUE, if @mutex could be locked.
686 * Tries to lock @mutex. If @mutex is already locked by another thread,
687 * it immediately returns %FALSE. Otherwise it locks @mutex and returns
688 * %TRUE. If @mutex is already locked by the calling thread, this
689 * functions increases the depth of @mutex and immediately returns
692 * Deprecated: 2.32: Use g_rec_mutex_trylock()
695 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
699 g_return_val_if_fail (mutex, FALSE);
701 if (!g_thread_supported ())
704 g_system_thread_self (&self);
706 if (g_system_thread_equal (&self, &mutex->owner))
712 if (!g_static_mutex_trylock (&mutex->mutex))
715 g_system_thread_assign (mutex->owner, self);
721 * g_static_rec_mutex_unlock:
722 * @mutex: a #GStaticRecMutex to unlock.
724 * Unlocks @mutex. Another thread will be allowed to lock @mutex only
725 * when it has been unlocked as many times as it had been locked
726 * before. If @mutex is completely unlocked and another thread is
727 * blocked in a g_static_rec_mutex_lock() call for @mutex, it will be
728 * woken and can lock @mutex itself.
730 * Deprecated: 2.32: Use g_rec_mutex_unlock()
733 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
735 g_return_if_fail (mutex);
737 if (!g_thread_supported ())
740 if (mutex->depth > 1)
745 g_system_thread_assign (mutex->owner, zero_thread);
746 g_static_mutex_unlock (&mutex->mutex);
750 * g_static_rec_mutex_lock_full:
751 * @mutex: a #GStaticRecMutex to lock.
752 * @depth: number of times this mutex has to be unlocked to be
753 * completely unlocked.
755 * Works like calling g_static_rec_mutex_lock() for @mutex @depth times.
757 * Deprecated: 2.32: Use g_rec_mutex_lock()
760 g_static_rec_mutex_lock_full (GStaticRecMutex *mutex,
764 g_return_if_fail (mutex);
766 if (!g_thread_supported ())
772 g_system_thread_self (&self);
774 if (g_system_thread_equal (&self, &mutex->owner))
776 mutex->depth += depth;
779 g_static_mutex_lock (&mutex->mutex);
780 g_system_thread_assign (mutex->owner, self);
781 mutex->depth = depth;
785 * g_static_rec_mutex_unlock_full:
786 * @mutex: a #GStaticRecMutex to completely unlock.
787 * @Returns: number of times @mutex has been locked by the current
790 * Completely unlocks @mutex. If another thread is blocked in a
791 * g_static_rec_mutex_lock() call for @mutex, it will be woken and can
792 * lock @mutex itself. This function returns the number of times that
793 * @mutex has been locked by the current thread. To restore the state
794 * before the call to g_static_rec_mutex_unlock_full() you can call
795 * g_static_rec_mutex_lock_full() with the depth returned by this
798 * Deprecated: 2.32: Use g_rec_mutex_unlock()
801 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
805 g_return_val_if_fail (mutex, 0);
807 if (!g_thread_supported ())
810 depth = mutex->depth;
812 g_system_thread_assign (mutex->owner, zero_thread);
814 g_static_mutex_unlock (&mutex->mutex);
820 * g_static_rec_mutex_free:
821 * @mutex: a #GStaticRecMutex to be freed.
823 * Releases all resources allocated to a #GStaticRecMutex.
825 * You don't have to call this functions for a #GStaticRecMutex with an
826 * unbounded lifetime, i.e. objects declared 'static', but if you have
827 * a #GStaticRecMutex as a member of a structure and the structure is
828 * freed, you should also free the #GStaticRecMutex.
830 * Deprecated: 2.32: Use g_rec_mutex_clear()
833 g_static_rec_mutex_free (GStaticRecMutex *mutex)
835 g_return_if_fail (mutex);
837 g_static_mutex_free (&mutex->mutex);
840 /* GStaticRWLock {{{1 ----------------------------------------------------- */
845 * The #GStaticRWLock struct represents a read-write lock. A read-write
846 * lock can be used for protecting data that some portions of code only
847 * read from, while others also write. In such situations it is
848 * desirable that several readers can read at once, whereas of course
849 * only one writer may write at a time. Take a look at the following
853 * <title>An array with access functions</title>
855 * GStaticRWLock rwlock = G_STATIC_RW_LOCK_INIT;
859 * my_array_get (guint index)
861 * gpointer retval = NULL;
866 * g_static_rw_lock_reader_lock (&rwlock);
867 * if (index < array->len)
868 * retval = g_ptr_array_index (array, index);
869 * g_static_rw_lock_reader_unlock (&rwlock);
875 * my_array_set (guint index, gpointer data)
877 * g_static_rw_lock_writer_lock (&rwlock);
880 * array = g_ptr_array_new (<!-- -->);
882 * if (index >= array->len)
883 * g_ptr_array_set_size (array, index+1);
884 * g_ptr_array_index (array, index) = data;
886 * g_static_rw_lock_writer_unlock (&rwlock);
891 * This example shows an array which can be accessed by many readers
892 * (the <function>my_array_get()</function> function) simultaneously,
893 * whereas the writers (the <function>my_array_set()</function>
894 * function) will only be allowed once at a time and only if no readers
895 * currently access the array. This is because of the potentially
896 * dangerous resizing of the array. Using these functions is fully
897 * multi-thread safe now.
899 * Most of the time, writers should have precedence over readers. That
900 * means, for this implementation, that as soon as a writer wants to
901 * lock the data, no other reader is allowed to lock the data, whereas,
902 * of course, the readers that already have locked the data are allowed
903 * to finish their operation. As soon as the last reader unlocks the
904 * data, the writer will lock it.
906 * Even though #GStaticRWLock is not opaque, it should only be used
907 * with the following functions.
909 * All of the <function>g_static_rw_lock_*</function> functions can be
910 * used even if g_thread_init() has not been called. Then they do
911 * nothing, apart from <function>g_static_rw_lock_*_trylock</function>,
912 * which does nothing but returning %TRUE.
914 * <note><para>A read-write lock has a higher overhead than a mutex. For
915 * example, both g_static_rw_lock_reader_lock() and
916 * g_static_rw_lock_reader_unlock() have to lock and unlock a
917 * #GStaticMutex, so it takes at least twice the time to lock and unlock
918 * a #GStaticRWLock that it does to lock and unlock a #GStaticMutex. So
919 * only data structures that are accessed by multiple readers, and which
920 * keep the lock for a considerable time justify a #GStaticRWLock. The
921 * above example most probably would fare better with a
922 * #GStaticMutex.</para></note>
924 * Deprecated: 2.32: Use a #GRWLock instead
928 * G_STATIC_RW_LOCK_INIT:
930 * A #GStaticRWLock must be initialized with this macro before it can
931 * be used. This macro can used be to initialize a variable, but it
932 * cannot be assigned to a variable. In that case you have to use
933 * g_static_rw_lock_init().
936 * GStaticRWLock my_lock = G_STATIC_RW_LOCK_INIT;
941 * g_static_rw_lock_init:
942 * @lock: a #GStaticRWLock to be initialized.
944 * A #GStaticRWLock must be initialized with this function before it
945 * can be used. Alternatively you can initialize it with
946 * #G_STATIC_RW_LOCK_INIT.
948 * Deprecated: 2.32: Use g_rw_lock_init() instead
951 g_static_rw_lock_init (GStaticRWLock* lock)
953 static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
955 g_return_if_fail (lock);
961 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
964 *cond = g_cond_new ();
965 g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
969 g_static_rw_lock_signal (GStaticRWLock* lock)
971 if (lock->want_to_write && lock->write_cond)
972 g_cond_signal (lock->write_cond);
973 else if (lock->want_to_read && lock->read_cond)
974 g_cond_broadcast (lock->read_cond);
978 * g_static_rw_lock_reader_lock:
979 * @lock: a #GStaticRWLock to lock for reading.
981 * Locks @lock for reading. There may be unlimited concurrent locks for
982 * reading of a #GStaticRWLock at the same time. If @lock is already
983 * locked for writing by another thread or if another thread is already
984 * waiting to lock @lock for writing, this function will block until
985 * @lock is unlocked by the other writing thread and no other writing
986 * threads want to lock @lock. This lock has to be unlocked by
987 * g_static_rw_lock_reader_unlock().
989 * #GStaticRWLock is not recursive. It might seem to be possible to
990 * recursively lock for reading, but that can result in a deadlock, due
991 * to writer preference.
993 * Deprecated: 2.32: Use g_rw_lock_reader_lock() instead
996 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
998 g_return_if_fail (lock);
1000 if (!g_threads_got_initialized)
1003 g_static_mutex_lock (&lock->mutex);
1004 lock->want_to_read++;
1005 while (lock->have_writer || lock->want_to_write)
1006 g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
1007 lock->want_to_read--;
1008 lock->read_counter++;
1009 g_static_mutex_unlock (&lock->mutex);
1013 * g_static_rw_lock_reader_trylock:
1014 * @lock: a #GStaticRWLock to lock for reading.
1015 * @Returns: %TRUE, if @lock could be locked for reading.
1017 * Tries to lock @lock for reading. If @lock is already locked for
1018 * writing by another thread or if another thread is already waiting to
1019 * lock @lock for writing, immediately returns %FALSE. Otherwise locks
1020 * @lock for reading and returns %TRUE. This lock has to be unlocked by
1021 * g_static_rw_lock_reader_unlock().
1023 * Deprectated: 2.32: Use g_rw_lock_reader_trylock() instead
1026 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
1028 gboolean ret_val = FALSE;
1030 g_return_val_if_fail (lock, FALSE);
1032 if (!g_threads_got_initialized)
1035 g_static_mutex_lock (&lock->mutex);
1036 if (!lock->have_writer && !lock->want_to_write)
1038 lock->read_counter++;
1041 g_static_mutex_unlock (&lock->mutex);
1046 * g_static_rw_lock_reader_unlock:
1047 * @lock: a #GStaticRWLock to unlock after reading.
1049 * Unlocks @lock. If a thread waits to lock @lock for writing and all
1050 * locks for reading have been unlocked, the waiting thread is woken up
1051 * and can lock @lock for writing.
1053 * Deprectated: 2.32: Use g_rw_lock_reader_unlock() instead
1056 g_static_rw_lock_reader_unlock (GStaticRWLock* lock)
1058 g_return_if_fail (lock);
1060 if (!g_threads_got_initialized)
1063 g_static_mutex_lock (&lock->mutex);
1064 lock->read_counter--;
1065 if (lock->read_counter == 0)
1066 g_static_rw_lock_signal (lock);
1067 g_static_mutex_unlock (&lock->mutex);
1071 * g_static_rw_lock_writer_lock:
1072 * @lock: a #GStaticRWLock to lock for writing.
1074 * Locks @lock for writing. If @lock is already locked for writing or
1075 * reading by other threads, this function will block until @lock is
1076 * completely unlocked and then lock @lock for writing. While this
1077 * functions waits to lock @lock, no other thread can lock @lock for
1078 * reading. When @lock is locked for writing, no other thread can lock
1079 * @lock (neither for reading nor writing). This lock has to be
1080 * unlocked by g_static_rw_lock_writer_unlock().
1082 * Deprectated: 2.32: Use g_rw_lock_writer_lock() instead
1085 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
1087 g_return_if_fail (lock);
1089 if (!g_threads_got_initialized)
1092 g_static_mutex_lock (&lock->mutex);
1093 lock->want_to_write++;
1094 while (lock->have_writer || lock->read_counter)
1095 g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
1096 lock->want_to_write--;
1097 lock->have_writer = TRUE;
1098 g_static_mutex_unlock (&lock->mutex);
1102 * g_static_rw_lock_writer_trylock:
1103 * @lock: a #GStaticRWLock to lock for writing.
1104 * @Returns: %TRUE, if @lock could be locked for writing.
1106 * Tries to lock @lock for writing. If @lock is already locked (for
1107 * either reading or writing) by another thread, it immediately returns
1108 * %FALSE. Otherwise it locks @lock for writing and returns %TRUE. This
1109 * lock has to be unlocked by g_static_rw_lock_writer_unlock().
1111 * Deprectated: 2.32: Use g_rw_lock_writer_trylock() instead
1114 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
1116 gboolean ret_val = FALSE;
1118 g_return_val_if_fail (lock, FALSE);
1120 if (!g_threads_got_initialized)
1123 g_static_mutex_lock (&lock->mutex);
1124 if (!lock->have_writer && !lock->read_counter)
1126 lock->have_writer = TRUE;
1129 g_static_mutex_unlock (&lock->mutex);
1134 * g_static_rw_lock_writer_unlock:
1135 * @lock: a #GStaticRWLock to unlock after writing.
1137 * Unlocks @lock. If a thread is waiting to lock @lock for writing and
1138 * all locks for reading have been unlocked, the waiting thread is
1139 * woken up and can lock @lock for writing. If no thread is waiting to
1140 * lock @lock for writing, and some thread or threads are waiting to
1141 * lock @lock for reading, the waiting threads are woken up and can
1142 * lock @lock for reading.
1144 * Deprectated: 2.32: Use g_rw_lock_writer_unlock() instead
1147 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
1149 g_return_if_fail (lock);
1151 if (!g_threads_got_initialized)
1154 g_static_mutex_lock (&lock->mutex);
1155 lock->have_writer = FALSE;
1156 g_static_rw_lock_signal (lock);
1157 g_static_mutex_unlock (&lock->mutex);
1161 * g_static_rw_lock_free:
1162 * @lock: a #GStaticRWLock to be freed.
1164 * Releases all resources allocated to @lock.
1166 * You don't have to call this functions for a #GStaticRWLock with an
1167 * unbounded lifetime, i.e. objects declared 'static', but if you have
1168 * a #GStaticRWLock as a member of a structure, and the structure is
1169 * freed, you should also free the #GStaticRWLock.
1171 * Deprecated: 2.32: Use a #GRWLock instead
1174 g_static_rw_lock_free (GStaticRWLock* lock)
1176 g_return_if_fail (lock);
1178 if (lock->read_cond)
1180 g_cond_free (lock->read_cond);
1181 lock->read_cond = NULL;
1183 if (lock->write_cond)
1185 g_cond_free (lock->write_cond);
1186 lock->write_cond = NULL;
1188 g_static_mutex_free (&lock->mutex);
1191 /* GPrivate {{{1 ------------------------------------------------------ */
1195 * @notify: a #GDestroyNotify
1197 * Deprecated:2.32: dynamic allocation of #GPrivate is a bad idea. Use
1198 * static storage and G_PRIVATE_INIT() instead.
1200 * Returns: a newly allocated #GPrivate (which can never be destroyed)
1203 g_private_new (GDestroyNotify notify)
1205 GPrivate tmp = G_PRIVATE_INIT (notify);
1208 key = g_slice_new (GPrivate);
1214 /* {{{1 GStaticPrivate */
1216 typedef struct _GStaticPrivateNode GStaticPrivateNode;
1217 struct _GStaticPrivateNode
1220 GDestroyNotify destroy;
1221 GStaticPrivate *owner;
1225 g_static_private_cleanup (gpointer data)
1227 GArray *array = data;
1230 for (i = 0; i < array->len; i++ )
1232 GStaticPrivateNode *node = &g_array_index (array, GStaticPrivateNode, i);
1234 node->destroy (node->data);
1237 g_array_free (array, TRUE);
1240 GPrivate static_private_private = G_PRIVATE_INIT (g_static_private_cleanup);
1245 * A #GStaticPrivate works almost like a #GPrivate, but it has one
1246 * significant advantage. It doesn't need to be created at run-time
1247 * like a #GPrivate, but can be defined at compile-time. This is
1248 * similar to the difference between #GMutex and #GStaticMutex. Now
1249 * look at our <function>give_me_next_number()</function> example with
1253 * <title>Using GStaticPrivate for per-thread data</title>
1256 * give_me_next_number (<!-- -->)
1258 * static GStaticPrivate current_number_key = G_STATIC_PRIVATE_INIT;
1259 * int *current_number = g_static_private_get (&current_number_key);
1261 * if (!current_number)
1263 * current_number = g_new (int,1);
1264 * *current_number = 0;
1265 * g_static_private_set (&current_number_key, current_number, g_free);
1268 * *current_number = calc_next_number (*current_number);
1270 * return *current_number;
1277 * G_STATIC_PRIVATE_INIT:
1279 * Every #GStaticPrivate must be initialized with this macro, before it
1283 * GStaticPrivate my_private = G_STATIC_PRIVATE_INIT;
1288 * g_static_private_init:
1289 * @private_key: a #GStaticPrivate to be initialized
1291 * Initializes @private_key. Alternatively you can initialize it with
1292 * #G_STATIC_PRIVATE_INIT.
1295 g_static_private_init (GStaticPrivate *private_key)
1297 private_key->index = 0;
1301 * g_static_private_get:
1302 * @private_key: a #GStaticPrivate
1304 * Works like g_private_get() only for a #GStaticPrivate.
1306 * This function works even if g_thread_init() has not yet been called.
1308 * Returns: the corresponding pointer
1311 g_static_private_get (GStaticPrivate *private_key)
1314 gpointer ret = NULL;
1316 array = g_private_get (&static_private_private);
1318 if (array && private_key->index != 0 && private_key->index <= array->len)
1320 GStaticPrivateNode *node;
1322 node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
1324 /* Deal with the possibility that the GStaticPrivate which used
1325 * to have this index got freed and the index got allocated to
1326 * a new one. In this case, the data in the node is stale, so
1327 * free it and return NULL.
1329 if (G_UNLIKELY (node->owner != private_key))
1332 node->destroy (node->data);
1333 node->destroy = NULL;
1344 * g_static_private_set:
1345 * @private_key: a #GStaticPrivate
1346 * @data: the new pointer
1347 * @notify: a function to be called with the pointer whenever the
1348 * current thread ends or sets this pointer again
1350 * Sets the pointer keyed to @private_key for the current thread and
1351 * the function @notify to be called with that pointer (%NULL or
1352 * non-%NULL), whenever the pointer is set again or whenever the
1353 * current thread ends.
1355 * This function works even if g_thread_init() has not yet been called.
1356 * If g_thread_init() is called later, the @data keyed to @private_key
1357 * will be inherited only by the main thread, i.e. the one that called
1360 * <note><para>@notify is used quite differently from @destructor in
1361 * g_private_new().</para></note>
1364 g_static_private_set (GStaticPrivate *private_key,
1366 GDestroyNotify notify)
1369 static guint next_index = 0;
1370 GStaticPrivateNode *node;
1372 if (!private_key->index)
1376 if (!private_key->index)
1378 if (g_thread_free_indices)
1380 private_key->index = GPOINTER_TO_UINT (g_thread_free_indices->data);
1381 g_thread_free_indices = g_slist_delete_link (g_thread_free_indices,
1382 g_thread_free_indices);
1385 private_key->index = ++next_index;
1388 G_UNLOCK (g_thread);
1391 array = g_private_get (&static_private_private);
1394 array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
1395 g_private_set (&static_private_private, array);
1397 if (private_key->index > array->len)
1398 g_array_set_size (array, private_key->index);
1400 node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
1403 node->destroy (node->data);
1406 node->destroy = notify;
1407 node->owner = private_key;
1411 * g_static_private_free:
1412 * @private_key: a #GStaticPrivate to be freed
1414 * Releases all resources allocated to @private_key.
1416 * You don't have to call this functions for a #GStaticPrivate with an
1417 * unbounded lifetime, i.e. objects declared 'static', but if you have
1418 * a #GStaticPrivate as a member of a structure and the structure is
1419 * freed, you should also free the #GStaticPrivate.
1422 g_static_private_free (GStaticPrivate *private_key)
1424 guint idx = private_key->index;
1429 private_key->index = 0;
1431 /* Freeing the per-thread data is deferred to either the
1432 * thread end or the next g_static_private_get() call for
1436 g_thread_free_indices = g_slist_prepend (g_thread_free_indices,
1437 GUINT_TO_POINTER (idx));
1438 G_UNLOCK (g_thread);
1441 /* GMutex {{{1 ------------------------------------------------------ */
1446 * Allocates and initializes a new #GMutex.
1448 * Returns: a newly allocated #GMutex. Use g_mutex_free() to free
1450 * Deprecated:3.32:GMutex can now be statically allocated, or embedded
1451 * in structures and initialised with g_mutex_init().
1458 mutex = g_slice_new (GMutex);
1459 g_mutex_init (mutex);
1468 * Destroys a @mutex that has been created with g_mutex_new().
1470 * Calling g_mutex_free() on a locked mutex may result
1471 * in undefined behaviour.
1473 * Deprecated:3.32:GMutex can now be statically allocated, or embedded
1474 * in structures and initialised with g_mutex_init().
1477 g_mutex_free (GMutex *mutex)
1479 g_mutex_clear (mutex);
1480 g_slice_free (GMutex, mutex);
1483 /* GCond {{{1 ------------------------------------------------------ */
1488 * Allocates and initializes a new #GCond.
1490 * Returns: a newly allocated #GCond. Free with g_cond_free()
1492 * Deprecated:3.32:GCond can now be statically allocated, or embedded
1493 * in structures and initialised with g_cond_init().
1500 cond = g_slice_new (GCond);
1510 * Destroys a #GCond that has been created with g_cond_new().
1512 * Calling g_cond_free() for a #GCond on which threads are
1513 * blocking leads to undefined behaviour.
1515 * Deprecated:3.32:GCond can now be statically allocated, or embedded
1516 * in structures and initialised with g_cond_init().
1519 g_cond_free (GCond *cond)
1521 g_cond_clear (cond);
1522 g_slice_free (GCond, cond);
1526 /* vim: set foldmethod=marker: */