1/* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
16 */
17
18/*
19 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
20 * file for a list of people on the GLib Team. See the ChangeLog
21 * files for a list of changes. These files are distributed with
22 * GLib at ftp://ftp.gtk.org/pub/gtk/.
23 */
24
25#ifndef __G_THREAD_H__
26#define __G_THREAD_H__
27
28#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
29#error "Only <glib.h> can be included directly."
30#endif
31
32#include <glib/gatomic.h>
33#include <glib/gerror.h>
34#include <glib/gutils.h>
35
36G_BEGIN_DECLS
37
38#define G_THREAD_ERROR g_thread_error_quark ()
39GLIB_AVAILABLE_IN_ALL
40GQuark g_thread_error_quark (void);
41
42typedef enum
43{
44 G_THREAD_ERROR_AGAIN /* Resource temporarily unavailable */
45} GThreadError;
46
47typedef gpointer (*GThreadFunc) (gpointer data);
48
49typedef struct _GThread GThread;
50
51typedef union _GMutex GMutex;
52typedef struct _GRecMutex GRecMutex;
53typedef struct _GRWLock GRWLock;
54typedef struct _GCond GCond;
55typedef struct _GPrivate GPrivate;
56typedef struct _GOnce GOnce;
57
58union _GMutex
59{
60 /*< private >*/
61 gpointer p;
62 guint i[2];
63};
64
65struct _GRWLock
66{
67 /*< private >*/
68 gpointer p;
69 guint i[2];
70};
71
72struct _GCond
73{
74 /*< private >*/
75 gpointer p;
76 guint i[2];
77};
78
79struct _GRecMutex
80{
81 /*< private >*/
82 gpointer p;
83 guint i[2];
84};
85
86#define G_PRIVATE_INIT(notify) { NULL, (notify), { NULL, NULL } }
87struct _GPrivate
88{
89 /*< private >*/
90 gpointer p;
91 GDestroyNotify notify;
92 gpointer future[2];
93};
94
95typedef enum
96{
97 G_ONCE_STATUS_NOTCALLED,
98 G_ONCE_STATUS_PROGRESS,
99 G_ONCE_STATUS_READY
100} GOnceStatus;
101
102#define G_ONCE_INIT { G_ONCE_STATUS_NOTCALLED, NULL }
103struct _GOnce
104{
105 volatile GOnceStatus status;
106 volatile gpointer retval;
107};
108
109#define G_LOCK_NAME(name) g__ ## name ## _lock
110#define G_LOCK_DEFINE_STATIC(name) static G_LOCK_DEFINE (name)
111#define G_LOCK_DEFINE(name) GMutex G_LOCK_NAME (name)
112#define G_LOCK_EXTERN(name) extern GMutex G_LOCK_NAME (name)
113
114#ifdef G_DEBUG_LOCKS
115# define G_LOCK(name) G_STMT_START{ \
116 g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
117 "file %s: line %d (%s): locking: %s ", \
118 __FILE__, __LINE__, G_STRFUNC, \
119 #name); \
120 g_mutex_lock (&G_LOCK_NAME (name)); \
121 }G_STMT_END
122# define G_UNLOCK(name) G_STMT_START{ \
123 g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
124 "file %s: line %d (%s): unlocking: %s ", \
125 __FILE__, __LINE__, G_STRFUNC, \
126 #name); \
127 g_mutex_unlock (&G_LOCK_NAME (name)); \
128 }G_STMT_END
129# define G_TRYLOCK(name) \
130 (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
131 "file %s: line %d (%s): try locking: %s ", \
132 __FILE__, __LINE__, G_STRFUNC, \
133 #name), g_mutex_trylock (&G_LOCK_NAME (name)))
134#else /* !G_DEBUG_LOCKS */
135# define G_LOCK(name) g_mutex_lock (&G_LOCK_NAME (name))
136# define G_UNLOCK(name) g_mutex_unlock (&G_LOCK_NAME (name))
137# define G_TRYLOCK(name) g_mutex_trylock (&G_LOCK_NAME (name))
138#endif /* !G_DEBUG_LOCKS */
139
140GLIB_AVAILABLE_IN_2_32
141GThread * g_thread_ref (GThread *thread);
142GLIB_AVAILABLE_IN_2_32
143void g_thread_unref (GThread *thread);
144GLIB_AVAILABLE_IN_2_32
145GThread * g_thread_new (const gchar *name,
146 GThreadFunc func,
147 gpointer data);
148GLIB_AVAILABLE_IN_2_32
149GThread * g_thread_try_new (const gchar *name,
150 GThreadFunc func,
151 gpointer data,
152 GError **error);
153GLIB_AVAILABLE_IN_ALL
154GThread * g_thread_self (void);
155GLIB_AVAILABLE_IN_ALL
156void g_thread_exit (gpointer retval);
157GLIB_AVAILABLE_IN_ALL
158gpointer g_thread_join (GThread *thread);
159GLIB_AVAILABLE_IN_ALL
160void g_thread_yield (void);
161
162
163GLIB_AVAILABLE_IN_2_32
164void g_mutex_init (GMutex *mutex);
165GLIB_AVAILABLE_IN_2_32
166void g_mutex_clear (GMutex *mutex);
167GLIB_AVAILABLE_IN_ALL
168void g_mutex_lock (GMutex *mutex);
169GLIB_AVAILABLE_IN_ALL
170gboolean g_mutex_trylock (GMutex *mutex);
171GLIB_AVAILABLE_IN_ALL
172void g_mutex_unlock (GMutex *mutex);
173
174GLIB_AVAILABLE_IN_2_32
175void g_rw_lock_init (GRWLock *rw_lock);
176GLIB_AVAILABLE_IN_2_32
177void g_rw_lock_clear (GRWLock *rw_lock);
178GLIB_AVAILABLE_IN_2_32
179void g_rw_lock_writer_lock (GRWLock *rw_lock);
180GLIB_AVAILABLE_IN_2_32
181gboolean g_rw_lock_writer_trylock (GRWLock *rw_lock);
182GLIB_AVAILABLE_IN_2_32
183void g_rw_lock_writer_unlock (GRWLock *rw_lock);
184GLIB_AVAILABLE_IN_2_32
185void g_rw_lock_reader_lock (GRWLock *rw_lock);
186GLIB_AVAILABLE_IN_2_32
187gboolean g_rw_lock_reader_trylock (GRWLock *rw_lock);
188GLIB_AVAILABLE_IN_2_32
189void g_rw_lock_reader_unlock (GRWLock *rw_lock);
190
191GLIB_AVAILABLE_IN_2_32
192void g_rec_mutex_init (GRecMutex *rec_mutex);
193GLIB_AVAILABLE_IN_2_32
194void g_rec_mutex_clear (GRecMutex *rec_mutex);
195GLIB_AVAILABLE_IN_2_32
196void g_rec_mutex_lock (GRecMutex *rec_mutex);
197GLIB_AVAILABLE_IN_2_32
198gboolean g_rec_mutex_trylock (GRecMutex *rec_mutex);
199GLIB_AVAILABLE_IN_2_32
200void g_rec_mutex_unlock (GRecMutex *rec_mutex);
201
202GLIB_AVAILABLE_IN_2_32
203void g_cond_init (GCond *cond);
204GLIB_AVAILABLE_IN_2_32
205void g_cond_clear (GCond *cond);
206GLIB_AVAILABLE_IN_ALL
207void g_cond_wait (GCond *cond,
208 GMutex *mutex);
209GLIB_AVAILABLE_IN_ALL
210void g_cond_signal (GCond *cond);
211GLIB_AVAILABLE_IN_ALL
212void g_cond_broadcast (GCond *cond);
213GLIB_AVAILABLE_IN_2_32
214gboolean g_cond_wait_until (GCond *cond,
215 GMutex *mutex,
216 gint64 end_time);
217
218GLIB_AVAILABLE_IN_ALL
219gpointer g_private_get (GPrivate *key);
220GLIB_AVAILABLE_IN_ALL
221void g_private_set (GPrivate *key,
222 gpointer value);
223GLIB_AVAILABLE_IN_2_32
224void g_private_replace (GPrivate *key,
225 gpointer value);
226
227GLIB_AVAILABLE_IN_ALL
228gpointer g_once_impl (GOnce *once,
229 GThreadFunc func,
230 gpointer arg);
231GLIB_AVAILABLE_IN_ALL
232gboolean g_once_init_enter (volatile void *location);
233GLIB_AVAILABLE_IN_ALL
234void g_once_init_leave (volatile void *location,
235 gsize result);
236
237/* Use C11-style atomic extensions to check the fast path for status=ready. If
238 * they are not available, fall back to using a mutex and condition variable in
239 * g_once_impl().
240 *
241 * On the C11-style codepath, only the load of once->status needs to be atomic,
242 * as the writes to it and once->retval in g_once_impl() are related by a
243 * happens-before relation. Release-acquire semantics are defined such that any
244 * atomic/non-atomic write which happens-before a store/release is guaranteed to
245 * be seen by the load/acquire of the same atomic variable. */
246#if defined(G_ATOMIC_LOCK_FREE) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) && defined(__ATOMIC_SEQ_CST)
247# define g_once(once, func, arg) \
248 ((__atomic_load_n (&(once)->status, __ATOMIC_ACQUIRE) == G_ONCE_STATUS_READY) ? \
249 (once)->retval : \
250 g_once_impl ((once), (func), (arg)))
251#else
252# define g_once(once, func, arg) g_once_impl ((once), (func), (arg))
253#endif
254
255#ifdef __GNUC__
256# define g_once_init_enter(location) \
257 (G_GNUC_EXTENSION ({ \
258 G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer)); \
259 (void) (0 ? (gpointer) *(location) : NULL); \
260 (!g_atomic_pointer_get (location) && \
261 g_once_init_enter (location)); \
262 }))
263# define g_once_init_leave(location, result) \
264 (G_GNUC_EXTENSION ({ \
265 G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer)); \
266 0 ? (void) (*(location) = (result)) : (void) 0; \
267 g_once_init_leave ((location), (gsize) (result)); \
268 }))
269#else
270# define g_once_init_enter(location) \
271 (g_once_init_enter((location)))
272# define g_once_init_leave(location, result) \
273 (g_once_init_leave((location), (gsize) (result)))
274#endif
275
276GLIB_AVAILABLE_IN_2_36
277guint g_get_num_processors (void);
278
279/**
280 * GMutexLocker:
281 *
282 * Opaque type. See g_mutex_locker_new() for details.
283 * Since: 2.44
284 */
285typedef void GMutexLocker;
286
287/**
288 * g_mutex_locker_new:
289 * @mutex: a mutex to lock
290 *
291 * Lock @mutex and return a new #GMutexLocker. Unlock with
292 * g_mutex_locker_free(). Using g_mutex_unlock() on @mutex
293 * while a #GMutexLocker exists can lead to undefined behaviour.
294 *
295 * No allocation is performed, it is equivalent to a g_mutex_lock() call.
296 *
297 * This is intended to be used with g_autoptr(). Note that g_autoptr()
298 * is only available when using GCC or clang, so the following example
299 * will only work with those compilers:
300 * |[
301 * typedef struct
302 * {
303 * ...
304 * GMutex mutex;
305 * ...
306 * } MyObject;
307 *
308 * static void
309 * my_object_do_stuff (MyObject *self)
310 * {
311 * g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&self->mutex);
312 *
313 * // Code with mutex locked here
314 *
315 * if (cond)
316 * // No need to unlock
317 * return;
318 *
319 * // Optionally early unlock
320 * g_clear_pointer (&locker, g_mutex_locker_free);
321 *
322 * // Code with mutex unlocked here
323 * }
324 * ]|
325 *
326 * Returns: a #GMutexLocker
327 * Since: 2.44
328 */
329GLIB_AVAILABLE_STATIC_INLINE_IN_2_44
330static inline GMutexLocker *
331g_mutex_locker_new (GMutex *mutex)
332{
333 g_mutex_lock (mutex);
334 return (GMutexLocker *) mutex;
335}
336
337/**
338 * g_mutex_locker_free:
339 * @locker: a GMutexLocker
340 *
341 * Unlock @locker's mutex. See g_mutex_locker_new() for details.
342 *
343 * No memory is freed, it is equivalent to a g_mutex_unlock() call.
344 *
345 * Since: 2.44
346 */
347GLIB_AVAILABLE_STATIC_INLINE_IN_2_44
348static inline void
349g_mutex_locker_free (GMutexLocker *locker)
350{
351 g_mutex_unlock (mutex: (GMutex *) locker);
352}
353
354/**
355 * GRecMutexLocker:
356 *
357 * Opaque type. See g_rec_mutex_locker_new() for details.
358 * Since: 2.60
359 */
360typedef void GRecMutexLocker;
361
362/**
363 * g_rec_mutex_locker_new:
364 * @rec_mutex: a recursive mutex to lock
365 *
366 * Lock @rec_mutex and return a new #GRecMutexLocker. Unlock with
367 * g_rec_mutex_locker_free(). Using g_rec_mutex_unlock() on @rec_mutex
368 * while a #GRecMutexLocker exists can lead to undefined behaviour.
369 *
370 * No allocation is performed, it is equivalent to a g_rec_mutex_lock() call.
371 *
372 * This is intended to be used with g_autoptr(). Note that g_autoptr()
373 * is only available when using GCC or clang, so the following example
374 * will only work with those compilers:
375 * |[
376 * typedef struct
377 * {
378 * ...
379 * GRecMutex rec_mutex;
380 * ...
381 * } MyObject;
382 *
383 * static void
384 * my_object_do_stuff (MyObject *self)
385 * {
386 * g_autoptr(GRecMutexLocker) locker = g_rec_mutex_locker_new (&self->rec_mutex);
387 *
388 * // Code with rec_mutex locked here
389 *
390 * if (cond)
391 * // No need to unlock
392 * return;
393 *
394 * // Optionally early unlock
395 * g_clear_pointer (&locker, g_rec_mutex_locker_free);
396 *
397 * // Code with rec_mutex unlocked here
398 * }
399 * ]|
400 *
401 * Returns: a #GRecMutexLocker
402 * Since: 2.60
403 */
404G_GNUC_BEGIN_IGNORE_DEPRECATIONS
405GLIB_AVAILABLE_STATIC_INLINE_IN_2_60
406static inline GRecMutexLocker *
407g_rec_mutex_locker_new (GRecMutex *rec_mutex)
408{
409 g_rec_mutex_lock (rec_mutex);
410 return (GRecMutexLocker *) rec_mutex;
411}
412G_GNUC_END_IGNORE_DEPRECATIONS
413
414/**
415 * g_rec_mutex_locker_free:
416 * @locker: a GRecMutexLocker
417 *
418 * Unlock @locker's recursive mutex. See g_rec_mutex_locker_new() for details.
419 *
420 * No memory is freed, it is equivalent to a g_rec_mutex_unlock() call.
421 *
422 * Since: 2.60
423 */
424G_GNUC_BEGIN_IGNORE_DEPRECATIONS
425GLIB_AVAILABLE_STATIC_INLINE_IN_2_60
426static inline void
427g_rec_mutex_locker_free (GRecMutexLocker *locker)
428{
429 g_rec_mutex_unlock (rec_mutex: (GRecMutex *) locker);
430}
431G_GNUC_END_IGNORE_DEPRECATIONS
432
433/**
434 * GRWLockWriterLocker:
435 *
436 * Opaque type. See g_rw_lock_writer_locker_new() for details.
437 * Since: 2.62
438 */
439typedef void GRWLockWriterLocker;
440
441/**
442 * g_rw_lock_writer_locker_new:
443 * @rw_lock: a #GRWLock
444 *
445 * Obtain a write lock on @rw_lock and return a new #GRWLockWriterLocker.
446 * Unlock with g_rw_lock_writer_locker_free(). Using g_rw_lock_writer_unlock()
447 * on @rw_lock while a #GRWLockWriterLocker exists can lead to undefined
448 * behaviour.
449 *
450 * No allocation is performed, it is equivalent to a g_rw_lock_writer_lock() call.
451 *
452 * This is intended to be used with g_autoptr(). Note that g_autoptr()
453 * is only available when using GCC or clang, so the following example
454 * will only work with those compilers:
455 * |[
456 * typedef struct
457 * {
458 * ...
459 * GRWLock rw_lock;
460 * GPtrArray *array;
461 * ...
462 * } MyObject;
463 *
464 * static gchar *
465 * my_object_get_data (MyObject *self, guint index)
466 * {
467 * g_autoptr(GRWLockReaderLocker) locker = g_rw_lock_reader_locker_new (&self->rw_lock);
468 *
469 * // Code with a read lock obtained on rw_lock here
470 *
471 * if (self->array == NULL)
472 * // No need to unlock
473 * return NULL;
474 *
475 * if (index < self->array->len)
476 * // No need to unlock
477 * return g_ptr_array_index (self->array, index);
478 *
479 * // Optionally early unlock
480 * g_clear_pointer (&locker, g_rw_lock_reader_locker_free);
481 *
482 * // Code with rw_lock unlocked here
483 * return NULL;
484 * }
485 *
486 * static void
487 * my_object_set_data (MyObject *self, guint index, gpointer data)
488 * {
489 * g_autoptr(GRWLockWriterLocker) locker = g_rw_lock_writer_locker_new (&self->rw_lock);
490 *
491 * // Code with a write lock obtained on rw_lock here
492 *
493 * if (self->array == NULL)
494 * self->array = g_ptr_array_new ();
495 *
496 * if (cond)
497 * // No need to unlock
498 * return;
499 *
500 * if (index >= self->array->len)
501 * g_ptr_array_set_size (self->array, index+1);
502 * g_ptr_array_index (self->array, index) = data;
503 *
504 * // Optionally early unlock
505 * g_clear_pointer (&locker, g_rw_lock_writer_locker_free);
506 *
507 * // Code with rw_lock unlocked here
508 * }
509 * ]|
510 *
511 * Returns: a #GRWLockWriterLocker
512 * Since: 2.62
513 */
514G_GNUC_BEGIN_IGNORE_DEPRECATIONS
515GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
516static inline GRWLockWriterLocker *
517g_rw_lock_writer_locker_new (GRWLock *rw_lock)
518{
519 g_rw_lock_writer_lock (rw_lock);
520 return (GRWLockWriterLocker *) rw_lock;
521}
522G_GNUC_END_IGNORE_DEPRECATIONS
523
524/**
525 * g_rw_lock_writer_locker_free:
526 * @locker: a GRWLockWriterLocker
527 *
528 * Release a write lock on @locker's read-write lock. See
529 * g_rw_lock_writer_locker_new() for details.
530 *
531 * No memory is freed, it is equivalent to a g_rw_lock_writer_unlock() call.
532 *
533 * Since: 2.62
534 */
535G_GNUC_BEGIN_IGNORE_DEPRECATIONS
536GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
537static inline void
538g_rw_lock_writer_locker_free (GRWLockWriterLocker *locker)
539{
540 g_rw_lock_writer_unlock (rw_lock: (GRWLock *) locker);
541}
542G_GNUC_END_IGNORE_DEPRECATIONS
543
544/**
545 * GRWLockReaderLocker:
546 *
547 * Opaque type. See g_rw_lock_reader_locker_new() for details.
548 * Since: 2.62
549 */
550typedef void GRWLockReaderLocker;
551
552/**
553 * g_rw_lock_reader_locker_new:
554 * @rw_lock: a #GRWLock
555 *
556 * Obtain a read lock on @rw_lock and return a new #GRWLockReaderLocker.
557 * Unlock with g_rw_lock_reader_locker_free(). Using g_rw_lock_reader_unlock()
558 * on @rw_lock while a #GRWLockReaderLocker exists can lead to undefined
559 * behaviour.
560 *
561 * No allocation is performed, it is equivalent to a g_rw_lock_reader_lock() call.
562 *
563 * This is intended to be used with g_autoptr(). For a code sample, see
564 * g_rw_lock_writer_locker_new().
565 *
566 * Returns: a #GRWLockReaderLocker
567 * Since: 2.62
568 */
569G_GNUC_BEGIN_IGNORE_DEPRECATIONS
570GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
571static inline GRWLockReaderLocker *
572g_rw_lock_reader_locker_new (GRWLock *rw_lock)
573{
574 g_rw_lock_reader_lock (rw_lock);
575 return (GRWLockReaderLocker *) rw_lock;
576}
577G_GNUC_END_IGNORE_DEPRECATIONS
578
579/**
580 * g_rw_lock_reader_locker_free:
581 * @locker: a GRWLockReaderLocker
582 *
583 * Release a read lock on @locker's read-write lock. See
584 * g_rw_lock_reader_locker_new() for details.
585 *
586 * No memory is freed, it is equivalent to a g_rw_lock_reader_unlock() call.
587 *
588 * Since: 2.62
589 */
590G_GNUC_BEGIN_IGNORE_DEPRECATIONS
591GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
592static inline void
593g_rw_lock_reader_locker_free (GRWLockReaderLocker *locker)
594{
595 g_rw_lock_reader_unlock (rw_lock: (GRWLock *) locker);
596}
597G_GNUC_END_IGNORE_DEPRECATIONS
598
599G_END_DECLS
600
601#endif /* __G_THREAD_H__ */
602

source code of include/glib-2.0/glib/gthread.h