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;
154 * @vtable: a function table of type #GThreadFunctions, that provides
155 * the entry points to the thread system to be used. Since 2.32,
156 * this parameter is ignored and should always be %NULL
158 * If you use GLib from more than one thread, you must initialize the
159 * thread system by calling g_thread_init().
161 * Since version 2.24, calling g_thread_init() multiple times is allowed,
162 * but nothing happens except for the first call.
164 * Since version 2.32, GLib does not support custom thread implementations
165 * anymore and the @vtable parameter is ignored and you should pass %NULL.
167 * <note><para>g_thread_init() must not be called directly or indirectly
168 * in a callback from GLib. Also no mutexes may be currently locked while
169 * calling g_thread_init().</para></note>
171 * <note><para>To use g_thread_init() in your program, you have to link
172 * with the libraries that the command <command>pkg-config --libs
173 * gthread-2.0</command> outputs. This is not the case for all the
174 * other thread-related functions of GLib. Those can be used without
175 * having to link with the thread libraries.</para></note>
179 * g_thread_get_initialized:
181 * Indicates if g_thread_init() has been called.
183 * Returns: %TRUE if threads have been initialized.
188 g_thread_get_initialized (void)
190 return g_thread_supported ();
193 /* We need this for ABI compatibility */
194 void g_thread_init_glib (void) { }
196 /* Internal variables {{{1 */
198 static GSList *g_thread_all_threads = NULL;
199 static GSList *g_thread_free_indices = NULL;
201 /* Protects g_thread_all_threads and g_thread_free_indices */
202 G_LOCK_DEFINE_STATIC (g_thread);
204 /* Misc. GThread functions {{{1 */
207 * g_thread_set_priority:
208 * @thread: a #GThread.
211 * This function does nothing.
213 * Deprecated:2.32: Thread priorities no longer have any effect.
216 g_thread_set_priority (GThread *thread,
217 GThreadPriority priority)
223 * @thread_func: function to call for all #GThread structures
224 * @user_data: second argument to @thread_func
226 * Call @thread_func on all #GThreads that have been
227 * created with g_thread_create().
229 * Note that threads may decide to exit while @thread_func is
230 * running, so without intimate knowledge about the lifetime of
231 * foreign threads, @thread_func shouldn't access the GThread*
232 * pointer passed in as first argument. However, @thread_func will
233 * not be called for threads which are known to have exited already.
235 * Due to thread lifetime checks, this function has an execution complexity
236 * which is quadratic in the number of existing threads.
240 * Deprecated:2.32: There aren't many things you can do with a #GThread,
241 * except comparing it with one that was returned from g_thread_create().
242 * There are better ways to find out if your thread is still alive.
245 g_thread_foreach (GFunc thread_func,
248 GSList *slist = NULL;
250 g_return_if_fail (thread_func != NULL);
251 /* snapshot the list of threads for iteration */
253 slist = g_slist_copy (g_thread_all_threads);
255 /* walk the list, skipping non-existent threads */
258 GSList *node = slist;
260 /* check whether the current thread still exists */
262 if (g_slist_find (g_thread_all_threads, node->data))
268 thread_func (thread, user_data);
269 g_slist_free_1 (node);
274 g_enumerable_thread_remove (gpointer data)
276 GRealThread *thread = data;
279 g_thread_all_threads = g_slist_remove (g_thread_all_threads, thread);
283 GPrivate enumerable_thread_private = G_PRIVATE_INIT (g_enumerable_thread_remove);
286 g_enumerable_thread_add (GRealThread *thread)
289 g_thread_all_threads = g_slist_prepend (g_thread_all_threads, thread);
292 g_private_set (&enumerable_thread_private, thread);
296 g_deprecated_thread_proxy (gpointer data)
298 GRealThread *real = data;
300 g_enumerable_thread_add (real);
302 return g_thread_proxy (data);
307 * @func: a function to execute in the new thread
308 * @data: an argument to supply to the new thread
309 * @joinable: should this thread be joinable?
310 * @error: return location for error, or %NULL
312 * This function creates a new thread.
314 * If @joinable is %TRUE, you can wait for this threads termination
315 * calling g_thread_join(). Otherwise the thread will just disappear
316 * when it terminates.
318 * The new thread executes the function @func with the argument @data.
319 * If the thread was created successfully, it is returned.
321 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
322 * The error is set, if and only if the function returns %NULL.
324 * Returns: the new #GThread on success
326 * Deprecated:2.32: Use g_thread_new() instead
329 g_thread_create (GThreadFunc func,
334 return g_thread_new_internal (NULL, g_deprecated_thread_proxy, func, data, joinable, 0, error);
338 * g_thread_create_full:
339 * @func: a function to execute in the new thread.
340 * @data: an argument to supply to the new thread.
341 * @stack_size: a stack size for the new thread.
342 * @joinable: should this thread be joinable?
345 * @error: return location for error.
346 * @Returns: the new #GThread on success.
348 * This function creates a new thread.
350 * Deprecated:2.32: The @bound and @priority arguments are now ignored.
351 * Use g_thread_new() or g_thread_new_full() instead.
354 g_thread_create_full (GThreadFunc func,
359 GThreadPriority priority,
362 return g_thread_new_internal (NULL, g_deprecated_thread_proxy, func, data, joinable, stack_size, error);
367 /* GOnce {{{1 ------------------------------------------------------------- */
369 g_once_init_enter_impl (volatile gsize *location)
371 return (g_once_init_enter) (location);
374 /* GStaticMutex {{{1 ------------------------------------------------------ */
379 * A #GStaticMutex works like a #GMutex.
381 * Prior to GLib 2.32, GStaticMutex had the significant advantage
382 * that it doesn't need to be created at run-time, but can be defined
383 * at compile-time. Since 2.32, #GMutex can be statically allocated
384 * as well, and GStaticMutex has been deprecated.
386 * Here is a version of our give_me_next_number() example using
391 * Using <structname>GStaticMutex</structname>
392 * to simplify thread-safe programming
396 * give_me_next_number (void)
398 * static int current_number = 0;
400 * static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
402 * g_static_mutex_lock (&mutex);
403 * ret_val = current_number = calc_next_number (current_number);
404 * g_static_mutex_unlock (&mutex);
411 * Sometimes you would like to dynamically create a mutex. If you don't
412 * want to require prior calling to g_thread_init(), because your code
413 * should also be usable in non-threaded programs, you are not able to
414 * use g_mutex_new() and thus #GMutex, as that requires a prior call to
415 * g_thread_init(). In theses cases you can also use a #GStaticMutex.
416 * It must be initialized with g_static_mutex_init() before using it
417 * and freed with with g_static_mutex_free() when not needed anymore to
418 * free up any allocated resources.
420 * Even though #GStaticMutex is not opaque, it should only be used with
421 * the following functions, as it is defined differently on different
424 * All of the <function>g_static_mutex_*</function> functions apart
425 * from <function>g_static_mutex_get_mutex</function> can also be used
426 * even if g_thread_init() has not yet been called. Then they do
427 * nothing, apart from <function>g_static_mutex_trylock</function>,
428 * which does nothing but returning %TRUE.
430 * <note><para>All of the <function>g_static_mutex_*</function>
431 * functions are actually macros. Apart from taking their addresses, you
432 * can however use them as if they were functions.</para></note>
436 * G_STATIC_MUTEX_INIT:
438 * A #GStaticMutex must be initialized with this macro, before it can
439 * be used. This macro can used be to initialize a variable, but it
440 * cannot be assigned to a variable. In that case you have to use
441 * g_static_mutex_init().
444 * GStaticMutex my_mutex = G_STATIC_MUTEX_INIT;
449 * g_static_mutex_init:
450 * @mutex: a #GStaticMutex to be initialized.
452 * Initializes @mutex.
453 * Alternatively you can initialize it with #G_STATIC_MUTEX_INIT.
455 * Deprecated: 2.32: Use g_mutex_init()
458 g_static_mutex_init (GStaticMutex *mutex)
460 static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
462 g_return_if_fail (mutex);
467 /* IMPLEMENTATION NOTE:
469 * On some platforms a GStaticMutex is actually a normal GMutex stored
470 * inside of a structure instead of being allocated dynamically. We can
471 * only do this for platforms on which we know, in advance, how to
472 * allocate (size) and initialise (value) that memory.
474 * On other platforms, a GStaticMutex is nothing more than a pointer to
475 * a GMutex. In that case, the first access we make to the static mutex
476 * must first allocate the normal GMutex and store it into the pointer.
478 * configure.ac writes macros into glibconfig.h to determine if
479 * g_static_mutex_get_mutex() accesses the structure in memory directly
480 * (on platforms where we are able to do that) or if it ends up here,
481 * where we may have to allocate the GMutex before returning it.
485 * g_static_mutex_get_mutex:
486 * @mutex: a #GStaticMutex.
487 * @Returns: the #GMutex corresponding to @mutex.
489 * For some operations (like g_cond_wait()) you must have a #GMutex
490 * instead of a #GStaticMutex. This function will return the
491 * corresponding #GMutex for @mutex.
493 * Deprecated: 2.32: Just use a #GMutex
496 g_static_mutex_get_mutex_impl (GStaticMutex* mutex)
500 if (!g_thread_supported ())
503 result = g_atomic_pointer_get (&mutex->mutex);
507 g_mutex_lock (&g_once_mutex);
509 result = mutex->mutex;
512 result = g_mutex_new ();
513 g_atomic_pointer_set (&mutex->mutex, result);
516 g_mutex_unlock (&g_once_mutex);
522 /* IMPLEMENTATION NOTE:
524 * g_static_mutex_lock(), g_static_mutex_trylock() and
525 * g_static_mutex_unlock() are all preprocessor macros that wrap the
526 * corresponding g_mutex_*() function around a call to
527 * g_static_mutex_get_mutex().
531 * g_static_mutex_lock:
532 * @mutex: a #GStaticMutex.
534 * Works like g_mutex_lock(), but for a #GStaticMutex.
536 * Deprecated: 2.32: Use g_mutex_lock()
540 * g_static_mutex_trylock:
541 * @mutex: a #GStaticMutex.
542 * @Returns: %TRUE, if the #GStaticMutex could be locked.
544 * Works like g_mutex_trylock(), but for a #GStaticMutex.
546 * Deprecated: 2.32: Use g_mutex_trylock()
550 * g_static_mutex_unlock:
551 * @mutex: a #GStaticMutex.
553 * Works like g_mutex_unlock(), but for a #GStaticMutex.
555 * Deprecated: 2.32: Use g_mutex_unlock()
559 * g_static_mutex_free:
560 * @mutex: a #GStaticMutex to be freed.
562 * Releases all resources allocated to @mutex.
564 * You don't have to call this functions for a #GStaticMutex with an
565 * unbounded lifetime, i.e. objects declared 'static', but if you have
566 * a #GStaticMutex as a member of a structure and the structure is
567 * freed, you should also free the #GStaticMutex.
569 * <note><para>Calling g_static_mutex_free() on a locked mutex may
570 * result in undefined behaviour.</para></note>
572 * Deprecated: 2.32: Use g_mutex_free()
575 g_static_mutex_free (GStaticMutex* mutex)
577 GMutex **runtime_mutex;
579 g_return_if_fail (mutex);
581 /* The runtime_mutex is the first (or only) member of GStaticMutex,
582 * see both versions (of glibconfig.h) in configure.ac. Note, that
583 * this variable is NULL, if g_thread_init() hasn't been called or
584 * if we're using the default thread implementation and it provides
586 runtime_mutex = ((GMutex**)mutex);
589 g_mutex_free (*runtime_mutex);
591 *runtime_mutex = NULL;
594 /* {{{1 GStaticRecMutex */
599 * A #GStaticRecMutex works like a #GStaticMutex, but it can be locked
600 * multiple times by one thread. If you enter it n times, you have to
601 * unlock it n times again to let other threads lock it. An exception
602 * is the function g_static_rec_mutex_unlock_full(): that allows you to
603 * unlock a #GStaticRecMutex completely returning the depth, (i.e. the
604 * number of times this mutex was locked). The depth can later be used
605 * to restore the state of the #GStaticRecMutex by calling
606 * g_static_rec_mutex_lock_full(). In GLib 2.32, #GStaticRecMutex has
607 * been deprecated in favor of #GRecMutex.
609 * Even though #GStaticRecMutex is not opaque, it should only be used
610 * with the following functions.
612 * All of the <function>g_static_rec_mutex_*</function> functions can
613 * be used even if g_thread_init() has not been called. Then they do
614 * nothing, apart from <function>g_static_rec_mutex_trylock</function>,
615 * which does nothing but returning %TRUE.
619 * G_STATIC_REC_MUTEX_INIT:
621 * A #GStaticRecMutex must be initialized with this macro before it can
622 * be used. This macro can used be to initialize a variable, but it
623 * cannot be assigned to a variable. In that case you have to use
624 * g_static_rec_mutex_init().
627 * GStaticRecMutex my_mutex = G_STATIC_REC_MUTEX_INIT;
632 * g_static_rec_mutex_init:
633 * @mutex: a #GStaticRecMutex to be initialized.
635 * A #GStaticRecMutex must be initialized with this function before it
636 * can be used. Alternatively you can initialize it with
637 * #G_STATIC_REC_MUTEX_INIT.
639 * Deprecated: 2.32: Use g_rec_mutex_init()
642 g_static_rec_mutex_init (GStaticRecMutex *mutex)
644 static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
646 g_return_if_fail (mutex);
652 g_static_rec_mutex_get_rec_mutex_impl (GStaticRecMutex* mutex)
656 if (!g_thread_supported ())
659 result = g_atomic_pointer_get (&mutex->mutex.mutex);
663 g_mutex_lock (&g_once_mutex);
665 result = (GRecMutex *) mutex->mutex.mutex;
668 result = g_slice_new (GRecMutex);
669 g_rec_mutex_init (result);
670 g_atomic_pointer_set (&mutex->mutex.mutex, result);
673 g_mutex_unlock (&g_once_mutex);
680 * g_static_rec_mutex_lock:
681 * @mutex: a #GStaticRecMutex to lock.
683 * Locks @mutex. If @mutex is already locked by another thread, the
684 * current thread will block until @mutex is unlocked by the other
685 * thread. If @mutex is already locked by the calling thread, this
686 * functions increases the depth of @mutex and returns immediately.
688 * Deprecated: 2.32: Use g_rec_mutex_lock()
691 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
694 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
695 g_rec_mutex_lock (rm);
700 * g_static_rec_mutex_trylock:
701 * @mutex: a #GStaticRecMutex to lock.
702 * @Returns: %TRUE, if @mutex could be locked.
704 * Tries to lock @mutex. If @mutex is already locked by another thread,
705 * it immediately returns %FALSE. Otherwise it locks @mutex and returns
706 * %TRUE. If @mutex is already locked by the calling thread, this
707 * functions increases the depth of @mutex and immediately returns
710 * Deprecated: 2.32: Use g_rec_mutex_trylock()
713 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
716 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
718 if (g_rec_mutex_trylock (rm))
728 * g_static_rec_mutex_unlock:
729 * @mutex: a #GStaticRecMutex to unlock.
731 * Unlocks @mutex. Another thread will be allowed to lock @mutex only
732 * when it has been unlocked as many times as it had been locked
733 * before. If @mutex is completely unlocked and another thread is
734 * blocked in a g_static_rec_mutex_lock() call for @mutex, it will be
735 * woken and can lock @mutex itself.
737 * Deprecated: 2.32: Use g_rec_mutex_unlock()
740 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
743 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
745 g_rec_mutex_unlock (rm);
749 * g_static_rec_mutex_lock_full:
750 * @mutex: a #GStaticRecMutex to lock.
751 * @depth: number of times this mutex has to be unlocked to be
752 * completely unlocked.
754 * Works like calling g_static_rec_mutex_lock() for @mutex @depth times.
756 * Deprecated: 2.32: Use g_rec_mutex_lock()
759 g_static_rec_mutex_lock_full (GStaticRecMutex *mutex,
764 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
767 g_rec_mutex_lock (rm);
773 * g_static_rec_mutex_unlock_full:
774 * @mutex: a #GStaticRecMutex to completely unlock.
775 * @Returns: number of times @mutex has been locked by the current
778 * Completely unlocks @mutex. If another thread is blocked in a
779 * g_static_rec_mutex_lock() call for @mutex, it will be woken and can
780 * lock @mutex itself. This function returns the number of times that
781 * @mutex has been locked by the current thread. To restore the state
782 * before the call to g_static_rec_mutex_unlock_full() you can call
783 * g_static_rec_mutex_lock_full() with the depth returned by this
786 * Deprecated: 2.32: Use g_rec_mutex_unlock()
789 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
794 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
795 depth = mutex->depth;
796 while (mutex->depth--)
797 g_rec_mutex_unlock (rm);
803 * g_static_rec_mutex_free:
804 * @mutex: a #GStaticRecMutex to be freed.
806 * Releases all resources allocated to a #GStaticRecMutex.
808 * You don't have to call this functions for a #GStaticRecMutex with an
809 * unbounded lifetime, i.e. objects declared 'static', but if you have
810 * a #GStaticRecMutex as a member of a structure and the structure is
811 * freed, you should also free the #GStaticRecMutex.
813 * Deprecated: 2.32: Use g_rec_mutex_clear()
816 g_static_rec_mutex_free (GStaticRecMutex *mutex)
818 g_return_if_fail (mutex);
820 if (mutex->mutex.mutex)
822 GRecMutex *rm = (GRecMutex *) mutex->mutex.mutex;
824 g_rec_mutex_clear (rm);
825 g_slice_free (GRecMutex, rm);
829 /* GStaticRWLock {{{1 ----------------------------------------------------- */
834 * The #GStaticRWLock struct represents a read-write lock. A read-write
835 * lock can be used for protecting data that some portions of code only
836 * read from, while others also write. In such situations it is
837 * desirable that several readers can read at once, whereas of course
838 * only one writer may write at a time. Take a look at the following
842 * <title>An array with access functions</title>
844 * GStaticRWLock rwlock = G_STATIC_RW_LOCK_INIT;
848 * my_array_get (guint index)
850 * gpointer retval = NULL;
855 * g_static_rw_lock_reader_lock (&rwlock);
856 * if (index < array->len)
857 * retval = g_ptr_array_index (array, index);
858 * g_static_rw_lock_reader_unlock (&rwlock);
864 * my_array_set (guint index, gpointer data)
866 * g_static_rw_lock_writer_lock (&rwlock);
869 * array = g_ptr_array_new (<!-- -->);
871 * if (index >= array->len)
872 * g_ptr_array_set_size (array, index+1);
873 * g_ptr_array_index (array, index) = data;
875 * g_static_rw_lock_writer_unlock (&rwlock);
880 * This example shows an array which can be accessed by many readers
881 * (the <function>my_array_get()</function> function) simultaneously,
882 * whereas the writers (the <function>my_array_set()</function>
883 * function) will only be allowed once at a time and only if no readers
884 * currently access the array. This is because of the potentially
885 * dangerous resizing of the array. Using these functions is fully
886 * multi-thread safe now.
888 * Most of the time, writers should have precedence over readers. That
889 * means, for this implementation, that as soon as a writer wants to
890 * lock the data, no other reader is allowed to lock the data, whereas,
891 * of course, the readers that already have locked the data are allowed
892 * to finish their operation. As soon as the last reader unlocks the
893 * data, the writer will lock it.
895 * Even though #GStaticRWLock is not opaque, it should only be used
896 * with the following functions.
898 * All of the <function>g_static_rw_lock_*</function> functions can be
899 * used even if g_thread_init() has not been called. Then they do
900 * nothing, apart from <function>g_static_rw_lock_*_trylock</function>,
901 * which does nothing but returning %TRUE.
903 * <note><para>A read-write lock has a higher overhead than a mutex. For
904 * example, both g_static_rw_lock_reader_lock() and
905 * g_static_rw_lock_reader_unlock() have to lock and unlock a
906 * #GStaticMutex, so it takes at least twice the time to lock and unlock
907 * a #GStaticRWLock that it does to lock and unlock a #GStaticMutex. So
908 * only data structures that are accessed by multiple readers, and which
909 * keep the lock for a considerable time justify a #GStaticRWLock. The
910 * above example most probably would fare better with a
911 * #GStaticMutex.</para></note>
913 * Deprecated: 2.32: Use a #GRWLock instead
917 * G_STATIC_RW_LOCK_INIT:
919 * A #GStaticRWLock must be initialized with this macro before it can
920 * be used. This macro can used be to initialize a variable, but it
921 * cannot be assigned to a variable. In that case you have to use
922 * g_static_rw_lock_init().
925 * GStaticRWLock my_lock = G_STATIC_RW_LOCK_INIT;
930 * g_static_rw_lock_init:
931 * @lock: a #GStaticRWLock to be initialized.
933 * A #GStaticRWLock must be initialized with this function before it
934 * can be used. Alternatively you can initialize it with
935 * #G_STATIC_RW_LOCK_INIT.
937 * Deprecated: 2.32: Use g_rw_lock_init() instead
940 g_static_rw_lock_init (GStaticRWLock* lock)
942 static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
944 g_return_if_fail (lock);
950 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
953 *cond = g_cond_new ();
954 g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
958 g_static_rw_lock_signal (GStaticRWLock* lock)
960 if (lock->want_to_write && lock->write_cond)
961 g_cond_signal (lock->write_cond);
962 else if (lock->want_to_read && lock->read_cond)
963 g_cond_broadcast (lock->read_cond);
967 * g_static_rw_lock_reader_lock:
968 * @lock: a #GStaticRWLock to lock for reading.
970 * Locks @lock for reading. There may be unlimited concurrent locks for
971 * reading of a #GStaticRWLock at the same time. If @lock is already
972 * locked for writing by another thread or if another thread is already
973 * waiting to lock @lock for writing, this function will block until
974 * @lock is unlocked by the other writing thread and no other writing
975 * threads want to lock @lock. This lock has to be unlocked by
976 * g_static_rw_lock_reader_unlock().
978 * #GStaticRWLock is not recursive. It might seem to be possible to
979 * recursively lock for reading, but that can result in a deadlock, due
980 * to writer preference.
982 * Deprecated: 2.32: Use g_rw_lock_reader_lock() instead
985 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
987 g_return_if_fail (lock);
989 if (!g_threads_got_initialized)
992 g_static_mutex_lock (&lock->mutex);
993 lock->want_to_read++;
994 while (lock->have_writer || lock->want_to_write)
995 g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
996 lock->want_to_read--;
997 lock->read_counter++;
998 g_static_mutex_unlock (&lock->mutex);
1002 * g_static_rw_lock_reader_trylock:
1003 * @lock: a #GStaticRWLock to lock for reading.
1004 * @Returns: %TRUE, if @lock could be locked for reading.
1006 * Tries to lock @lock for reading. If @lock is already locked for
1007 * writing by another thread or if another thread is already waiting to
1008 * lock @lock for writing, immediately returns %FALSE. Otherwise locks
1009 * @lock for reading and returns %TRUE. This lock has to be unlocked by
1010 * g_static_rw_lock_reader_unlock().
1012 * Deprectated: 2.32: Use g_rw_lock_reader_trylock() instead
1015 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
1017 gboolean ret_val = FALSE;
1019 g_return_val_if_fail (lock, FALSE);
1021 if (!g_threads_got_initialized)
1024 g_static_mutex_lock (&lock->mutex);
1025 if (!lock->have_writer && !lock->want_to_write)
1027 lock->read_counter++;
1030 g_static_mutex_unlock (&lock->mutex);
1035 * g_static_rw_lock_reader_unlock:
1036 * @lock: a #GStaticRWLock to unlock after reading.
1038 * Unlocks @lock. If a thread waits to lock @lock for writing and all
1039 * locks for reading have been unlocked, the waiting thread is woken up
1040 * and can lock @lock for writing.
1042 * Deprectated: 2.32: Use g_rw_lock_reader_unlock() instead
1045 g_static_rw_lock_reader_unlock (GStaticRWLock* lock)
1047 g_return_if_fail (lock);
1049 if (!g_threads_got_initialized)
1052 g_static_mutex_lock (&lock->mutex);
1053 lock->read_counter--;
1054 if (lock->read_counter == 0)
1055 g_static_rw_lock_signal (lock);
1056 g_static_mutex_unlock (&lock->mutex);
1060 * g_static_rw_lock_writer_lock:
1061 * @lock: a #GStaticRWLock to lock for writing.
1063 * Locks @lock for writing. If @lock is already locked for writing or
1064 * reading by other threads, this function will block until @lock is
1065 * completely unlocked and then lock @lock for writing. While this
1066 * functions waits to lock @lock, no other thread can lock @lock for
1067 * reading. When @lock is locked for writing, no other thread can lock
1068 * @lock (neither for reading nor writing). This lock has to be
1069 * unlocked by g_static_rw_lock_writer_unlock().
1071 * Deprectated: 2.32: Use g_rw_lock_writer_lock() instead
1074 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
1076 g_return_if_fail (lock);
1078 if (!g_threads_got_initialized)
1081 g_static_mutex_lock (&lock->mutex);
1082 lock->want_to_write++;
1083 while (lock->have_writer || lock->read_counter)
1084 g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
1085 lock->want_to_write--;
1086 lock->have_writer = TRUE;
1087 g_static_mutex_unlock (&lock->mutex);
1091 * g_static_rw_lock_writer_trylock:
1092 * @lock: a #GStaticRWLock to lock for writing.
1093 * @Returns: %TRUE, if @lock could be locked for writing.
1095 * Tries to lock @lock for writing. If @lock is already locked (for
1096 * either reading or writing) by another thread, it immediately returns
1097 * %FALSE. Otherwise it locks @lock for writing and returns %TRUE. This
1098 * lock has to be unlocked by g_static_rw_lock_writer_unlock().
1100 * Deprectated: 2.32: Use g_rw_lock_writer_trylock() instead
1103 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
1105 gboolean ret_val = FALSE;
1107 g_return_val_if_fail (lock, FALSE);
1109 if (!g_threads_got_initialized)
1112 g_static_mutex_lock (&lock->mutex);
1113 if (!lock->have_writer && !lock->read_counter)
1115 lock->have_writer = TRUE;
1118 g_static_mutex_unlock (&lock->mutex);
1123 * g_static_rw_lock_writer_unlock:
1124 * @lock: a #GStaticRWLock to unlock after writing.
1126 * Unlocks @lock. If a thread is waiting to lock @lock for writing and
1127 * all locks for reading have been unlocked, the waiting thread is
1128 * woken up and can lock @lock for writing. If no thread is waiting to
1129 * lock @lock for writing, and some thread or threads are waiting to
1130 * lock @lock for reading, the waiting threads are woken up and can
1131 * lock @lock for reading.
1133 * Deprectated: 2.32: Use g_rw_lock_writer_unlock() instead
1136 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
1138 g_return_if_fail (lock);
1140 if (!g_threads_got_initialized)
1143 g_static_mutex_lock (&lock->mutex);
1144 lock->have_writer = FALSE;
1145 g_static_rw_lock_signal (lock);
1146 g_static_mutex_unlock (&lock->mutex);
1150 * g_static_rw_lock_free:
1151 * @lock: a #GStaticRWLock to be freed.
1153 * Releases all resources allocated to @lock.
1155 * You don't have to call this functions for a #GStaticRWLock with an
1156 * unbounded lifetime, i.e. objects declared 'static', but if you have
1157 * a #GStaticRWLock as a member of a structure, and the structure is
1158 * freed, you should also free the #GStaticRWLock.
1160 * Deprecated: 2.32: Use a #GRWLock instead
1163 g_static_rw_lock_free (GStaticRWLock* lock)
1165 g_return_if_fail (lock);
1167 if (lock->read_cond)
1169 g_cond_free (lock->read_cond);
1170 lock->read_cond = NULL;
1172 if (lock->write_cond)
1174 g_cond_free (lock->write_cond);
1175 lock->write_cond = NULL;
1177 g_static_mutex_free (&lock->mutex);
1180 /* GPrivate {{{1 ------------------------------------------------------ */
1184 * @notify: a #GDestroyNotify
1186 * Deprecated:2.32: dynamic allocation of #GPrivate is a bad idea. Use
1187 * static storage and G_PRIVATE_INIT() instead.
1189 * Returns: a newly allocated #GPrivate (which can never be destroyed)
1192 g_private_new (GDestroyNotify notify)
1194 GPrivate tmp = G_PRIVATE_INIT (notify);
1197 key = g_slice_new (GPrivate);
1203 /* {{{1 GStaticPrivate */
1205 typedef struct _GStaticPrivateNode GStaticPrivateNode;
1206 struct _GStaticPrivateNode
1209 GDestroyNotify destroy;
1210 GStaticPrivate *owner;
1214 g_static_private_cleanup (gpointer data)
1216 GArray *array = data;
1219 for (i = 0; i < array->len; i++ )
1221 GStaticPrivateNode *node = &g_array_index (array, GStaticPrivateNode, i);
1223 node->destroy (node->data);
1226 g_array_free (array, TRUE);
1229 GPrivate static_private_private = G_PRIVATE_INIT (g_static_private_cleanup);
1234 * A #GStaticPrivate works almost like a #GPrivate, but it has one
1235 * significant advantage. It doesn't need to be created at run-time
1236 * like a #GPrivate, but can be defined at compile-time. This is
1237 * similar to the difference between #GMutex and #GStaticMutex. Now
1238 * look at our <function>give_me_next_number()</function> example with
1242 * <title>Using GStaticPrivate for per-thread data</title>
1245 * give_me_next_number (<!-- -->)
1247 * static GStaticPrivate current_number_key = G_STATIC_PRIVATE_INIT;
1248 * int *current_number = g_static_private_get (&current_number_key);
1250 * if (!current_number)
1252 * current_number = g_new (int,1);
1253 * *current_number = 0;
1254 * g_static_private_set (&current_number_key, current_number, g_free);
1257 * *current_number = calc_next_number (*current_number);
1259 * return *current_number;
1266 * G_STATIC_PRIVATE_INIT:
1268 * Every #GStaticPrivate must be initialized with this macro, before it
1272 * GStaticPrivate my_private = G_STATIC_PRIVATE_INIT;
1277 * g_static_private_init:
1278 * @private_key: a #GStaticPrivate to be initialized
1280 * Initializes @private_key. Alternatively you can initialize it with
1281 * #G_STATIC_PRIVATE_INIT.
1284 g_static_private_init (GStaticPrivate *private_key)
1286 private_key->index = 0;
1290 * g_static_private_get:
1291 * @private_key: a #GStaticPrivate
1293 * Works like g_private_get() only for a #GStaticPrivate.
1295 * This function works even if g_thread_init() has not yet been called.
1297 * Returns: the corresponding pointer
1300 g_static_private_get (GStaticPrivate *private_key)
1303 gpointer ret = NULL;
1305 array = g_private_get (&static_private_private);
1307 if (array && private_key->index != 0 && private_key->index <= array->len)
1309 GStaticPrivateNode *node;
1311 node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
1313 /* Deal with the possibility that the GStaticPrivate which used
1314 * to have this index got freed and the index got allocated to
1315 * a new one. In this case, the data in the node is stale, so
1316 * free it and return NULL.
1318 if (G_UNLIKELY (node->owner != private_key))
1321 node->destroy (node->data);
1322 node->destroy = NULL;
1333 * g_static_private_set:
1334 * @private_key: a #GStaticPrivate
1335 * @data: the new pointer
1336 * @notify: a function to be called with the pointer whenever the
1337 * current thread ends or sets this pointer again
1339 * Sets the pointer keyed to @private_key for the current thread and
1340 * the function @notify to be called with that pointer (%NULL or
1341 * non-%NULL), whenever the pointer is set again or whenever the
1342 * current thread ends.
1344 * This function works even if g_thread_init() has not yet been called.
1345 * If g_thread_init() is called later, the @data keyed to @private_key
1346 * will be inherited only by the main thread, i.e. the one that called
1349 * <note><para>@notify is used quite differently from @destructor in
1350 * g_private_new().</para></note>
1353 g_static_private_set (GStaticPrivate *private_key,
1355 GDestroyNotify notify)
1358 static guint next_index = 0;
1359 GStaticPrivateNode *node;
1361 if (!private_key->index)
1365 if (!private_key->index)
1367 if (g_thread_free_indices)
1369 private_key->index = GPOINTER_TO_UINT (g_thread_free_indices->data);
1370 g_thread_free_indices = g_slist_delete_link (g_thread_free_indices,
1371 g_thread_free_indices);
1374 private_key->index = ++next_index;
1377 G_UNLOCK (g_thread);
1380 array = g_private_get (&static_private_private);
1383 array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
1384 g_private_set (&static_private_private, array);
1386 if (private_key->index > array->len)
1387 g_array_set_size (array, private_key->index);
1389 node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
1392 node->destroy (node->data);
1395 node->destroy = notify;
1396 node->owner = private_key;
1400 * g_static_private_free:
1401 * @private_key: a #GStaticPrivate to be freed
1403 * Releases all resources allocated to @private_key.
1405 * You don't have to call this functions for a #GStaticPrivate with an
1406 * unbounded lifetime, i.e. objects declared 'static', but if you have
1407 * a #GStaticPrivate as a member of a structure and the structure is
1408 * freed, you should also free the #GStaticPrivate.
1411 g_static_private_free (GStaticPrivate *private_key)
1413 guint idx = private_key->index;
1418 private_key->index = 0;
1420 /* Freeing the per-thread data is deferred to either the
1421 * thread end or the next g_static_private_get() call for
1425 g_thread_free_indices = g_slist_prepend (g_thread_free_indices,
1426 GUINT_TO_POINTER (idx));
1427 G_UNLOCK (g_thread);
1430 /* GMutex {{{1 ------------------------------------------------------ */
1435 * Allocates and initializes a new #GMutex.
1437 * Returns: a newly allocated #GMutex. Use g_mutex_free() to free
1439 * Deprecated:3.32:GMutex can now be statically allocated, or embedded
1440 * in structures and initialised with g_mutex_init().
1447 mutex = g_slice_new (GMutex);
1448 g_mutex_init (mutex);
1457 * Destroys a @mutex that has been created with g_mutex_new().
1459 * Calling g_mutex_free() on a locked mutex may result
1460 * in undefined behaviour.
1462 * Deprecated:3.32:GMutex can now be statically allocated, or embedded
1463 * in structures and initialised with g_mutex_init().
1466 g_mutex_free (GMutex *mutex)
1468 g_mutex_clear (mutex);
1469 g_slice_free (GMutex, mutex);
1472 /* GCond {{{1 ------------------------------------------------------ */
1477 * Allocates and initializes a new #GCond.
1479 * Returns: a newly allocated #GCond. Free with g_cond_free()
1481 * Deprecated:3.32:GCond can now be statically allocated, or embedded
1482 * in structures and initialised with g_cond_init().
1489 cond = g_slice_new (GCond);
1499 * Destroys a #GCond that has been created with g_cond_new().
1501 * Calling g_cond_free() for a #GCond on which threads are
1502 * blocking leads to undefined behaviour.
1504 * Deprecated:3.32:GCond can now be statically allocated, or embedded
1505 * in structures and initialised with g_cond_init().
1508 g_cond_free (GCond *cond)
1510 g_cond_clear (cond);
1511 g_slice_free (GCond, cond);
1515 /* vim: set foldmethod=marker: */