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 GSList *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 * @thread_func: function to call for all #GThread structures
226 * @user_data: second argument to @thread_func
228 * Call @thread_func on all #GThreads that have been
229 * created with g_thread_create().
231 * Note that threads may decide to exit while @thread_func is
232 * running, so without intimate knowledge about the lifetime of
233 * foreign threads, @thread_func shouldn't access the GThread*
234 * pointer passed in as first argument. However, @thread_func will
235 * not be called for threads which are known to have exited already.
237 * Due to thread lifetime checks, this function has an execution complexity
238 * which is quadratic in the number of existing threads.
242 * Deprecated:2.32: There aren't many things you can do with a #GThread,
243 * except comparing it with one that was returned from g_thread_create().
244 * There are better ways to find out if your thread is still alive.
247 g_thread_foreach (GFunc thread_func,
250 GSList *slist = NULL;
252 g_return_if_fail (thread_func != NULL);
253 /* snapshot the list of threads for iteration */
255 slist = g_slist_copy (g_thread_all_threads);
257 /* walk the list, skipping non-existent threads */
260 GSList *node = slist;
262 /* check whether the current thread still exists */
264 if (g_slist_find (g_thread_all_threads, node->data))
270 thread_func (thread, user_data);
271 g_slist_free_1 (node);
276 g_enumerable_thread_remove (gpointer data)
278 GRealThread *thread = data;
281 g_thread_all_threads = g_slist_remove (g_thread_all_threads, thread);
285 GPrivate enumerable_thread_private = G_PRIVATE_INIT (g_enumerable_thread_remove);
288 g_enumerable_thread_add (GRealThread *thread)
291 g_thread_all_threads = g_slist_prepend (g_thread_all_threads, thread);
294 g_private_set (&enumerable_thread_private, thread);
298 * @func: a function to execute in the new thread
299 * @data: an argument to supply to the new thread
300 * @joinable: should this thread be joinable?
301 * @error: return location for error, or %NULL
303 * This function creates a new thread.
305 * If @joinable is %TRUE, you can wait for this threads termination
306 * calling g_thread_join(). Otherwise the thread will just disappear
307 * when it terminates.
309 * The new thread executes the function @func with the argument @data.
310 * If the thread was created successfully, it is returned.
312 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
313 * The error is set, if and only if the function returns %NULL.
315 * Returns: the new #GThread on success
317 * Deprecated:2.32: Use g_thread_new() instead
320 g_thread_create (GThreadFunc func,
325 return g_thread_new_internal (NULL, func, data, joinable, 0, g_enumerable_thread_add, error);
329 * g_thread_create_full:
330 * @func: a function to execute in the new thread.
331 * @data: an argument to supply to the new thread.
332 * @stack_size: a stack size for the new thread.
333 * @joinable: should this thread be joinable?
336 * @error: return location for error.
337 * @Returns: the new #GThread on success.
339 * This function creates a new thread.
341 * Deprecated:2.32: The @bound and @priority arguments are now ignored.
342 * Use g_thread_new() or g_thread_new_full() instead.
345 g_thread_create_full (GThreadFunc func,
350 GThreadPriority priority,
353 return g_thread_new_internal (NULL, func, data, joinable, stack_size, g_enumerable_thread_add, error);
358 /* GOnce {{{1 ------------------------------------------------------------- */
360 g_once_init_enter_impl (volatile gsize *location)
362 return (g_once_init_enter) (location);
365 /* GStaticMutex {{{1 ------------------------------------------------------ */
370 * A #GStaticMutex works like a #GMutex.
372 * Prior to GLib 2.32, GStaticMutex had the significant advantage
373 * that it doesn't need to be created at run-time, but can be defined
374 * at compile-time. Since 2.32, #GMutex can be statically allocated
375 * as well, and GStaticMutex has been deprecated.
377 * Here is a version of our give_me_next_number() example using
382 * Using <structname>GStaticMutex</structname>
383 * to simplify thread-safe programming
387 * give_me_next_number (void)
389 * static int current_number = 0;
391 * static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
393 * g_static_mutex_lock (&mutex);
394 * ret_val = current_number = calc_next_number (current_number);
395 * g_static_mutex_unlock (&mutex);
402 * Sometimes you would like to dynamically create a mutex. If you don't
403 * want to require prior calling to g_thread_init(), because your code
404 * should also be usable in non-threaded programs, you are not able to
405 * use g_mutex_new() and thus #GMutex, as that requires a prior call to
406 * g_thread_init(). In theses cases you can also use a #GStaticMutex.
407 * It must be initialized with g_static_mutex_init() before using it
408 * and freed with with g_static_mutex_free() when not needed anymore to
409 * free up any allocated resources.
411 * Even though #GStaticMutex is not opaque, it should only be used with
412 * the following functions, as it is defined differently on different
415 * All of the <function>g_static_mutex_*</function> functions apart
416 * from <function>g_static_mutex_get_mutex</function> can also be used
417 * even if g_thread_init() has not yet been called. Then they do
418 * nothing, apart from <function>g_static_mutex_trylock</function>,
419 * which does nothing but returning %TRUE.
421 * <note><para>All of the <function>g_static_mutex_*</function>
422 * functions are actually macros. Apart from taking their addresses, you
423 * can however use them as if they were functions.</para></note>
427 * G_STATIC_MUTEX_INIT:
429 * A #GStaticMutex must be initialized with this macro, before it can
430 * be used. This macro can used be to initialize a variable, but it
431 * cannot be assigned to a variable. In that case you have to use
432 * g_static_mutex_init().
435 * GStaticMutex my_mutex = G_STATIC_MUTEX_INIT;
440 * g_static_mutex_init:
441 * @mutex: a #GStaticMutex to be initialized.
443 * Initializes @mutex.
444 * Alternatively you can initialize it with #G_STATIC_MUTEX_INIT.
446 * Deprecated: 2.32: Use g_mutex_init()
449 g_static_mutex_init (GStaticMutex *mutex)
451 static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
453 g_return_if_fail (mutex);
458 /* IMPLEMENTATION NOTE:
460 * On some platforms a GStaticMutex is actually a normal GMutex stored
461 * inside of a structure instead of being allocated dynamically. We can
462 * only do this for platforms on which we know, in advance, how to
463 * allocate (size) and initialise (value) that memory.
465 * On other platforms, a GStaticMutex is nothing more than a pointer to
466 * a GMutex. In that case, the first access we make to the static mutex
467 * must first allocate the normal GMutex and store it into the pointer.
469 * configure.ac writes macros into glibconfig.h to determine if
470 * g_static_mutex_get_mutex() accesses the structure in memory directly
471 * (on platforms where we are able to do that) or if it ends up here,
472 * where we may have to allocate the GMutex before returning it.
476 * g_static_mutex_get_mutex:
477 * @mutex: a #GStaticMutex.
478 * @Returns: the #GMutex corresponding to @mutex.
480 * For some operations (like g_cond_wait()) you must have a #GMutex
481 * instead of a #GStaticMutex. This function will return the
482 * corresponding #GMutex for @mutex.
484 * Deprecated: 2.32: Just use a #GMutex
487 g_static_mutex_get_mutex_impl (GStaticMutex* mutex)
491 if (!g_thread_supported ())
494 result = g_atomic_pointer_get (&mutex->mutex);
498 g_mutex_lock (&g_once_mutex);
500 result = mutex->mutex;
503 result = g_mutex_new ();
504 g_atomic_pointer_set (&mutex->mutex, result);
507 g_mutex_unlock (&g_once_mutex);
513 /* IMPLEMENTATION NOTE:
515 * g_static_mutex_lock(), g_static_mutex_trylock() and
516 * g_static_mutex_unlock() are all preprocessor macros that wrap the
517 * corresponding g_mutex_*() function around a call to
518 * g_static_mutex_get_mutex().
522 * g_static_mutex_lock:
523 * @mutex: a #GStaticMutex.
525 * Works like g_mutex_lock(), but for a #GStaticMutex.
527 * Deprecated: 2.32: Use g_mutex_lock()
531 * g_static_mutex_trylock:
532 * @mutex: a #GStaticMutex.
533 * @Returns: %TRUE, if the #GStaticMutex could be locked.
535 * Works like g_mutex_trylock(), but for a #GStaticMutex.
537 * Deprecated: 2.32: Use g_mutex_trylock()
541 * g_static_mutex_unlock:
542 * @mutex: a #GStaticMutex.
544 * Works like g_mutex_unlock(), but for a #GStaticMutex.
546 * Deprecated: 2.32: Use g_mutex_unlock()
550 * g_static_mutex_free:
551 * @mutex: a #GStaticMutex to be freed.
553 * Releases all resources allocated to @mutex.
555 * You don't have to call this functions for a #GStaticMutex with an
556 * unbounded lifetime, i.e. objects declared 'static', but if you have
557 * a #GStaticMutex as a member of a structure and the structure is
558 * freed, you should also free the #GStaticMutex.
560 * <note><para>Calling g_static_mutex_free() on a locked mutex may
561 * result in undefined behaviour.</para></note>
563 * Deprecated: 2.32: Use g_mutex_free()
566 g_static_mutex_free (GStaticMutex* mutex)
568 GMutex **runtime_mutex;
570 g_return_if_fail (mutex);
572 /* The runtime_mutex is the first (or only) member of GStaticMutex,
573 * see both versions (of glibconfig.h) in configure.ac. Note, that
574 * this variable is NULL, if g_thread_init() hasn't been called or
575 * if we're using the default thread implementation and it provides
577 runtime_mutex = ((GMutex**)mutex);
580 g_mutex_free (*runtime_mutex);
582 *runtime_mutex = NULL;
585 /* {{{1 GStaticRecMutex */
590 * A #GStaticRecMutex works like a #GStaticMutex, but it can be locked
591 * multiple times by one thread. If you enter it n times, you have to
592 * unlock it n times again to let other threads lock it. An exception
593 * is the function g_static_rec_mutex_unlock_full(): that allows you to
594 * unlock a #GStaticRecMutex completely returning the depth, (i.e. the
595 * number of times this mutex was locked). The depth can later be used
596 * to restore the state of the #GStaticRecMutex by calling
597 * g_static_rec_mutex_lock_full(). In GLib 2.32, #GStaticRecMutex has
598 * been deprecated in favor of #GRecMutex.
600 * Even though #GStaticRecMutex is not opaque, it should only be used
601 * with the following functions.
603 * All of the <function>g_static_rec_mutex_*</function> functions can
604 * be used even if g_thread_init() has not been called. Then they do
605 * nothing, apart from <function>g_static_rec_mutex_trylock</function>,
606 * which does nothing but returning %TRUE.
610 * G_STATIC_REC_MUTEX_INIT:
612 * A #GStaticRecMutex must be initialized with this macro before it can
613 * be used. This macro can used be to initialize a variable, but it
614 * cannot be assigned to a variable. In that case you have to use
615 * g_static_rec_mutex_init().
618 * GStaticRecMutex my_mutex = G_STATIC_REC_MUTEX_INIT;
623 * g_static_rec_mutex_init:
624 * @mutex: a #GStaticRecMutex to be initialized.
626 * A #GStaticRecMutex must be initialized with this function before it
627 * can be used. Alternatively you can initialize it with
628 * #G_STATIC_REC_MUTEX_INIT.
630 * Deprecated: 2.32: Use g_rec_mutex_init()
633 g_static_rec_mutex_init (GStaticRecMutex *mutex)
635 static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
637 g_return_if_fail (mutex);
643 g_static_rec_mutex_get_rec_mutex_impl (GStaticRecMutex* mutex)
647 if (!g_thread_supported ())
650 result = g_atomic_pointer_get (&mutex->mutex.mutex);
654 g_mutex_lock (&g_once_mutex);
656 result = (GRecMutex *) mutex->mutex.mutex;
659 result = g_slice_new (GRecMutex);
660 g_rec_mutex_init (result);
661 g_atomic_pointer_set (&mutex->mutex.mutex, result);
664 g_mutex_unlock (&g_once_mutex);
671 * g_static_rec_mutex_lock:
672 * @mutex: a #GStaticRecMutex to lock.
674 * Locks @mutex. If @mutex is already locked by another thread, the
675 * current thread will block until @mutex is unlocked by the other
676 * thread. If @mutex is already locked by the calling thread, this
677 * functions increases the depth of @mutex and returns immediately.
679 * Deprecated: 2.32: Use g_rec_mutex_lock()
682 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
685 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
686 g_rec_mutex_lock (rm);
691 * g_static_rec_mutex_trylock:
692 * @mutex: a #GStaticRecMutex to lock.
693 * @Returns: %TRUE, if @mutex could be locked.
695 * Tries to lock @mutex. If @mutex is already locked by another thread,
696 * it immediately returns %FALSE. Otherwise it locks @mutex and returns
697 * %TRUE. If @mutex is already locked by the calling thread, this
698 * functions increases the depth of @mutex and immediately returns
701 * Deprecated: 2.32: Use g_rec_mutex_trylock()
704 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
707 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
709 if (g_rec_mutex_trylock (rm))
719 * g_static_rec_mutex_unlock:
720 * @mutex: a #GStaticRecMutex to unlock.
722 * Unlocks @mutex. Another thread will be allowed to lock @mutex only
723 * when it has been unlocked as many times as it had been locked
724 * before. If @mutex is completely unlocked and another thread is
725 * blocked in a g_static_rec_mutex_lock() call for @mutex, it will be
726 * woken and can lock @mutex itself.
728 * Deprecated: 2.32: Use g_rec_mutex_unlock()
731 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
734 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
736 g_rec_mutex_unlock (rm);
740 * g_static_rec_mutex_lock_full:
741 * @mutex: a #GStaticRecMutex to lock.
742 * @depth: number of times this mutex has to be unlocked to be
743 * completely unlocked.
745 * Works like calling g_static_rec_mutex_lock() for @mutex @depth times.
747 * Deprecated: 2.32: Use g_rec_mutex_lock()
750 g_static_rec_mutex_lock_full (GStaticRecMutex *mutex,
755 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
758 g_rec_mutex_lock (rm);
764 * g_static_rec_mutex_unlock_full:
765 * @mutex: a #GStaticRecMutex to completely unlock.
766 * @Returns: number of times @mutex has been locked by the current
769 * Completely unlocks @mutex. If another thread is blocked in a
770 * g_static_rec_mutex_lock() call for @mutex, it will be woken and can
771 * lock @mutex itself. This function returns the number of times that
772 * @mutex has been locked by the current thread. To restore the state
773 * before the call to g_static_rec_mutex_unlock_full() you can call
774 * g_static_rec_mutex_lock_full() with the depth returned by this
777 * Deprecated: 2.32: Use g_rec_mutex_unlock()
780 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
785 rm = g_static_rec_mutex_get_rec_mutex_impl (mutex);
786 depth = mutex->depth;
787 while (mutex->depth--)
788 g_rec_mutex_unlock (rm);
794 * g_static_rec_mutex_free:
795 * @mutex: a #GStaticRecMutex to be freed.
797 * Releases all resources allocated to a #GStaticRecMutex.
799 * You don't have to call this functions for a #GStaticRecMutex with an
800 * unbounded lifetime, i.e. objects declared 'static', but if you have
801 * a #GStaticRecMutex as a member of a structure and the structure is
802 * freed, you should also free the #GStaticRecMutex.
804 * Deprecated: 2.32: Use g_rec_mutex_clear()
807 g_static_rec_mutex_free (GStaticRecMutex *mutex)
809 g_return_if_fail (mutex);
811 if (mutex->mutex.mutex)
813 GRecMutex *rm = (GRecMutex *) mutex->mutex.mutex;
815 g_rec_mutex_clear (rm);
816 g_slice_free (GRecMutex, rm);
820 /* GStaticRWLock {{{1 ----------------------------------------------------- */
825 * The #GStaticRWLock struct represents a read-write lock. A read-write
826 * lock can be used for protecting data that some portions of code only
827 * read from, while others also write. In such situations it is
828 * desirable that several readers can read at once, whereas of course
829 * only one writer may write at a time. Take a look at the following
833 * <title>An array with access functions</title>
835 * GStaticRWLock rwlock = G_STATIC_RW_LOCK_INIT;
839 * my_array_get (guint index)
841 * gpointer retval = NULL;
846 * g_static_rw_lock_reader_lock (&rwlock);
847 * if (index < array->len)
848 * retval = g_ptr_array_index (array, index);
849 * g_static_rw_lock_reader_unlock (&rwlock);
855 * my_array_set (guint index, gpointer data)
857 * g_static_rw_lock_writer_lock (&rwlock);
860 * array = g_ptr_array_new (<!-- -->);
862 * if (index >= array->len)
863 * g_ptr_array_set_size (array, index+1);
864 * g_ptr_array_index (array, index) = data;
866 * g_static_rw_lock_writer_unlock (&rwlock);
871 * This example shows an array which can be accessed by many readers
872 * (the <function>my_array_get()</function> function) simultaneously,
873 * whereas the writers (the <function>my_array_set()</function>
874 * function) will only be allowed once at a time and only if no readers
875 * currently access the array. This is because of the potentially
876 * dangerous resizing of the array. Using these functions is fully
877 * multi-thread safe now.
879 * Most of the time, writers should have precedence over readers. That
880 * means, for this implementation, that as soon as a writer wants to
881 * lock the data, no other reader is allowed to lock the data, whereas,
882 * of course, the readers that already have locked the data are allowed
883 * to finish their operation. As soon as the last reader unlocks the
884 * data, the writer will lock it.
886 * Even though #GStaticRWLock is not opaque, it should only be used
887 * with the following functions.
889 * All of the <function>g_static_rw_lock_*</function> functions can be
890 * used even if g_thread_init() has not been called. Then they do
891 * nothing, apart from <function>g_static_rw_lock_*_trylock</function>,
892 * which does nothing but returning %TRUE.
894 * <note><para>A read-write lock has a higher overhead than a mutex. For
895 * example, both g_static_rw_lock_reader_lock() and
896 * g_static_rw_lock_reader_unlock() have to lock and unlock a
897 * #GStaticMutex, so it takes at least twice the time to lock and unlock
898 * a #GStaticRWLock that it does to lock and unlock a #GStaticMutex. So
899 * only data structures that are accessed by multiple readers, and which
900 * keep the lock for a considerable time justify a #GStaticRWLock. The
901 * above example most probably would fare better with a
902 * #GStaticMutex.</para></note>
904 * Deprecated: 2.32: Use a #GRWLock instead
908 * G_STATIC_RW_LOCK_INIT:
910 * A #GStaticRWLock must be initialized with this macro before it can
911 * be used. This macro can used be to initialize a variable, but it
912 * cannot be assigned to a variable. In that case you have to use
913 * g_static_rw_lock_init().
916 * GStaticRWLock my_lock = G_STATIC_RW_LOCK_INIT;
921 * g_static_rw_lock_init:
922 * @lock: a #GStaticRWLock to be initialized.
924 * A #GStaticRWLock must be initialized with this function before it
925 * can be used. Alternatively you can initialize it with
926 * #G_STATIC_RW_LOCK_INIT.
928 * Deprecated: 2.32: Use g_rw_lock_init() instead
931 g_static_rw_lock_init (GStaticRWLock* lock)
933 static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
935 g_return_if_fail (lock);
941 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
944 *cond = g_cond_new ();
945 g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
949 g_static_rw_lock_signal (GStaticRWLock* lock)
951 if (lock->want_to_write && lock->write_cond)
952 g_cond_signal (lock->write_cond);
953 else if (lock->want_to_read && lock->read_cond)
954 g_cond_broadcast (lock->read_cond);
958 * g_static_rw_lock_reader_lock:
959 * @lock: a #GStaticRWLock to lock for reading.
961 * Locks @lock for reading. There may be unlimited concurrent locks for
962 * reading of a #GStaticRWLock at the same time. If @lock is already
963 * locked for writing by another thread or if another thread is already
964 * waiting to lock @lock for writing, this function will block until
965 * @lock is unlocked by the other writing thread and no other writing
966 * threads want to lock @lock. This lock has to be unlocked by
967 * g_static_rw_lock_reader_unlock().
969 * #GStaticRWLock is not recursive. It might seem to be possible to
970 * recursively lock for reading, but that can result in a deadlock, due
971 * to writer preference.
973 * Deprecated: 2.32: Use g_rw_lock_reader_lock() instead
976 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
978 g_return_if_fail (lock);
980 if (!g_threads_got_initialized)
983 g_static_mutex_lock (&lock->mutex);
984 lock->want_to_read++;
985 while (lock->have_writer || lock->want_to_write)
986 g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
987 lock->want_to_read--;
988 lock->read_counter++;
989 g_static_mutex_unlock (&lock->mutex);
993 * g_static_rw_lock_reader_trylock:
994 * @lock: a #GStaticRWLock to lock for reading.
995 * @Returns: %TRUE, if @lock could be locked for reading.
997 * Tries to lock @lock for reading. If @lock is already locked for
998 * writing by another thread or if another thread is already waiting to
999 * lock @lock for writing, immediately returns %FALSE. Otherwise locks
1000 * @lock for reading and returns %TRUE. This lock has to be unlocked by
1001 * g_static_rw_lock_reader_unlock().
1003 * Deprectated: 2.32: Use g_rw_lock_reader_trylock() instead
1006 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
1008 gboolean ret_val = FALSE;
1010 g_return_val_if_fail (lock, FALSE);
1012 if (!g_threads_got_initialized)
1015 g_static_mutex_lock (&lock->mutex);
1016 if (!lock->have_writer && !lock->want_to_write)
1018 lock->read_counter++;
1021 g_static_mutex_unlock (&lock->mutex);
1026 * g_static_rw_lock_reader_unlock:
1027 * @lock: a #GStaticRWLock to unlock after reading.
1029 * Unlocks @lock. If a thread waits to lock @lock for writing and all
1030 * locks for reading have been unlocked, the waiting thread is woken up
1031 * and can lock @lock for writing.
1033 * Deprectated: 2.32: Use g_rw_lock_reader_unlock() instead
1036 g_static_rw_lock_reader_unlock (GStaticRWLock* lock)
1038 g_return_if_fail (lock);
1040 if (!g_threads_got_initialized)
1043 g_static_mutex_lock (&lock->mutex);
1044 lock->read_counter--;
1045 if (lock->read_counter == 0)
1046 g_static_rw_lock_signal (lock);
1047 g_static_mutex_unlock (&lock->mutex);
1051 * g_static_rw_lock_writer_lock:
1052 * @lock: a #GStaticRWLock to lock for writing.
1054 * Locks @lock for writing. If @lock is already locked for writing or
1055 * reading by other threads, this function will block until @lock is
1056 * completely unlocked and then lock @lock for writing. While this
1057 * functions waits to lock @lock, no other thread can lock @lock for
1058 * reading. When @lock is locked for writing, no other thread can lock
1059 * @lock (neither for reading nor writing). This lock has to be
1060 * unlocked by g_static_rw_lock_writer_unlock().
1062 * Deprectated: 2.32: Use g_rw_lock_writer_lock() instead
1065 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
1067 g_return_if_fail (lock);
1069 if (!g_threads_got_initialized)
1072 g_static_mutex_lock (&lock->mutex);
1073 lock->want_to_write++;
1074 while (lock->have_writer || lock->read_counter)
1075 g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
1076 lock->want_to_write--;
1077 lock->have_writer = TRUE;
1078 g_static_mutex_unlock (&lock->mutex);
1082 * g_static_rw_lock_writer_trylock:
1083 * @lock: a #GStaticRWLock to lock for writing.
1084 * @Returns: %TRUE, if @lock could be locked for writing.
1086 * Tries to lock @lock for writing. If @lock is already locked (for
1087 * either reading or writing) by another thread, it immediately returns
1088 * %FALSE. Otherwise it locks @lock for writing and returns %TRUE. This
1089 * lock has to be unlocked by g_static_rw_lock_writer_unlock().
1091 * Deprectated: 2.32: Use g_rw_lock_writer_trylock() instead
1094 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
1096 gboolean ret_val = FALSE;
1098 g_return_val_if_fail (lock, FALSE);
1100 if (!g_threads_got_initialized)
1103 g_static_mutex_lock (&lock->mutex);
1104 if (!lock->have_writer && !lock->read_counter)
1106 lock->have_writer = TRUE;
1109 g_static_mutex_unlock (&lock->mutex);
1114 * g_static_rw_lock_writer_unlock:
1115 * @lock: a #GStaticRWLock to unlock after writing.
1117 * Unlocks @lock. If a thread is waiting to lock @lock for writing and
1118 * all locks for reading have been unlocked, the waiting thread is
1119 * woken up and can lock @lock for writing. If no thread is waiting to
1120 * lock @lock for writing, and some thread or threads are waiting to
1121 * lock @lock for reading, the waiting threads are woken up and can
1122 * lock @lock for reading.
1124 * Deprectated: 2.32: Use g_rw_lock_writer_unlock() instead
1127 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
1129 g_return_if_fail (lock);
1131 if (!g_threads_got_initialized)
1134 g_static_mutex_lock (&lock->mutex);
1135 lock->have_writer = FALSE;
1136 g_static_rw_lock_signal (lock);
1137 g_static_mutex_unlock (&lock->mutex);
1141 * g_static_rw_lock_free:
1142 * @lock: a #GStaticRWLock to be freed.
1144 * Releases all resources allocated to @lock.
1146 * You don't have to call this functions for a #GStaticRWLock with an
1147 * unbounded lifetime, i.e. objects declared 'static', but if you have
1148 * a #GStaticRWLock as a member of a structure, and the structure is
1149 * freed, you should also free the #GStaticRWLock.
1151 * Deprecated: 2.32: Use a #GRWLock instead
1154 g_static_rw_lock_free (GStaticRWLock* lock)
1156 g_return_if_fail (lock);
1158 if (lock->read_cond)
1160 g_cond_free (lock->read_cond);
1161 lock->read_cond = NULL;
1163 if (lock->write_cond)
1165 g_cond_free (lock->write_cond);
1166 lock->write_cond = NULL;
1168 g_static_mutex_free (&lock->mutex);
1171 /* GPrivate {{{1 ------------------------------------------------------ */
1175 * @notify: a #GDestroyNotify
1177 * Deprecated:2.32: dynamic allocation of #GPrivate is a bad idea. Use
1178 * static storage and G_PRIVATE_INIT() instead.
1180 * Returns: a newly allocated #GPrivate (which can never be destroyed)
1183 g_private_new (GDestroyNotify notify)
1185 GPrivate tmp = G_PRIVATE_INIT (notify);
1188 key = g_slice_new (GPrivate);
1194 /* {{{1 GStaticPrivate */
1196 typedef struct _GStaticPrivateNode GStaticPrivateNode;
1197 struct _GStaticPrivateNode
1200 GDestroyNotify destroy;
1201 GStaticPrivate *owner;
1205 g_static_private_cleanup (gpointer data)
1207 GArray *array = data;
1210 for (i = 0; i < array->len; i++ )
1212 GStaticPrivateNode *node = &g_array_index (array, GStaticPrivateNode, i);
1214 node->destroy (node->data);
1217 g_array_free (array, TRUE);
1220 GPrivate static_private_private = G_PRIVATE_INIT (g_static_private_cleanup);
1225 * A #GStaticPrivate works almost like a #GPrivate, but it has one
1226 * significant advantage. It doesn't need to be created at run-time
1227 * like a #GPrivate, but can be defined at compile-time. This is
1228 * similar to the difference between #GMutex and #GStaticMutex. Now
1229 * look at our <function>give_me_next_number()</function> example with
1233 * <title>Using GStaticPrivate for per-thread data</title>
1236 * give_me_next_number (<!-- -->)
1238 * static GStaticPrivate current_number_key = G_STATIC_PRIVATE_INIT;
1239 * int *current_number = g_static_private_get (&current_number_key);
1241 * if (!current_number)
1243 * current_number = g_new (int,1);
1244 * *current_number = 0;
1245 * g_static_private_set (&current_number_key, current_number, g_free);
1248 * *current_number = calc_next_number (*current_number);
1250 * return *current_number;
1257 * G_STATIC_PRIVATE_INIT:
1259 * Every #GStaticPrivate must be initialized with this macro, before it
1263 * GStaticPrivate my_private = G_STATIC_PRIVATE_INIT;
1268 * g_static_private_init:
1269 * @private_key: a #GStaticPrivate to be initialized
1271 * Initializes @private_key. Alternatively you can initialize it with
1272 * #G_STATIC_PRIVATE_INIT.
1275 g_static_private_init (GStaticPrivate *private_key)
1277 private_key->index = 0;
1281 * g_static_private_get:
1282 * @private_key: a #GStaticPrivate
1284 * Works like g_private_get() only for a #GStaticPrivate.
1286 * This function works even if g_thread_init() has not yet been called.
1288 * Returns: the corresponding pointer
1291 g_static_private_get (GStaticPrivate *private_key)
1294 gpointer ret = NULL;
1296 array = g_private_get (&static_private_private);
1298 if (array && private_key->index != 0 && private_key->index <= array->len)
1300 GStaticPrivateNode *node;
1302 node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
1304 /* Deal with the possibility that the GStaticPrivate which used
1305 * to have this index got freed and the index got allocated to
1306 * a new one. In this case, the data in the node is stale, so
1307 * free it and return NULL.
1309 if (G_UNLIKELY (node->owner != private_key))
1312 node->destroy (node->data);
1313 node->destroy = NULL;
1324 * g_static_private_set:
1325 * @private_key: a #GStaticPrivate
1326 * @data: the new pointer
1327 * @notify: a function to be called with the pointer whenever the
1328 * current thread ends or sets this pointer again
1330 * Sets the pointer keyed to @private_key for the current thread and
1331 * the function @notify to be called with that pointer (%NULL or
1332 * non-%NULL), whenever the pointer is set again or whenever the
1333 * current thread ends.
1335 * This function works even if g_thread_init() has not yet been called.
1336 * If g_thread_init() is called later, the @data keyed to @private_key
1337 * will be inherited only by the main thread, i.e. the one that called
1340 * <note><para>@notify is used quite differently from @destructor in
1341 * g_private_new().</para></note>
1344 g_static_private_set (GStaticPrivate *private_key,
1346 GDestroyNotify notify)
1349 static guint next_index = 0;
1350 GStaticPrivateNode *node;
1352 if (!private_key->index)
1356 if (!private_key->index)
1358 if (g_thread_free_indices)
1360 private_key->index = GPOINTER_TO_UINT (g_thread_free_indices->data);
1361 g_thread_free_indices = g_slist_delete_link (g_thread_free_indices,
1362 g_thread_free_indices);
1365 private_key->index = ++next_index;
1368 G_UNLOCK (g_thread);
1371 array = g_private_get (&static_private_private);
1374 array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
1375 g_private_set (&static_private_private, array);
1377 if (private_key->index > array->len)
1378 g_array_set_size (array, private_key->index);
1380 node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
1383 node->destroy (node->data);
1386 node->destroy = notify;
1387 node->owner = private_key;
1391 * g_static_private_free:
1392 * @private_key: a #GStaticPrivate to be freed
1394 * Releases all resources allocated to @private_key.
1396 * You don't have to call this functions for a #GStaticPrivate with an
1397 * unbounded lifetime, i.e. objects declared 'static', but if you have
1398 * a #GStaticPrivate as a member of a structure and the structure is
1399 * freed, you should also free the #GStaticPrivate.
1402 g_static_private_free (GStaticPrivate *private_key)
1404 guint idx = private_key->index;
1409 private_key->index = 0;
1411 /* Freeing the per-thread data is deferred to either the
1412 * thread end or the next g_static_private_get() call for
1416 g_thread_free_indices = g_slist_prepend (g_thread_free_indices,
1417 GUINT_TO_POINTER (idx));
1418 G_UNLOCK (g_thread);
1421 /* GMutex {{{1 ------------------------------------------------------ */
1426 * Allocates and initializes a new #GMutex.
1428 * Returns: a newly allocated #GMutex. Use g_mutex_free() to free
1430 * Deprecated:3.32:GMutex can now be statically allocated, or embedded
1431 * in structures and initialised with g_mutex_init().
1438 mutex = g_slice_new (GMutex);
1439 g_mutex_init (mutex);
1448 * Destroys a @mutex that has been created with g_mutex_new().
1450 * Calling g_mutex_free() on a locked mutex may result
1451 * in undefined behaviour.
1453 * Deprecated:3.32:GMutex can now be statically allocated, or embedded
1454 * in structures and initialised with g_mutex_init().
1457 g_mutex_free (GMutex *mutex)
1459 g_mutex_clear (mutex);
1460 g_slice_free (GMutex, mutex);
1463 /* GCond {{{1 ------------------------------------------------------ */
1468 * Allocates and initializes a new #GCond.
1470 * Returns: a newly allocated #GCond. Free with g_cond_free()
1472 * Deprecated:3.32:GCond can now be statically allocated, or embedded
1473 * in structures and initialised with g_cond_init().
1480 cond = g_slice_new (GCond);
1490 * Destroys a #GCond that has been created with g_cond_new().
1492 * Calling g_cond_free() for a #GCond on which threads are
1493 * blocking leads to undefined behaviour.
1495 * Deprecated:3.32:GCond can now be statically allocated, or embedded
1496 * in structures and initialised with g_cond_init().
1499 g_cond_free (GCond *cond)
1501 g_cond_clear (cond);
1502 g_slice_free (GCond, cond);
1506 /* vim: set foldmethod=marker: */