1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
3 *
4 * gmain.c: Main loop abstraction, timeouts, and idle functions
5 * Copyright 1998 Owen Taylor
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 */
20
21 /*
22 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
23 * file for a list of people on the GLib Team. See the ChangeLog
24 * files for a list of changes. These files are distributed with
25 * GLib at ftp://ftp.gtk.org/pub/gtk/.
26 */
27
28 /*
29 * MT safe
30 */
31
32 #include "config.h"
33 #include "glibconfig.h"
34
35 /* Uncomment the next line (and the corresponding line in gpoll.c) to
36 * enable debugging printouts if the environment variable
37 * G_MAIN_POLL_DEBUG is set to some value.
38 */
39 /* #define G_MAIN_POLL_DEBUG */
40
41 #ifdef _WIN32
42 /* Always enable debugging printout on Windows, as it is more often
43 * needed there...
44 */
45 #define G_MAIN_POLL_DEBUG
46 #endif
47
48 #ifdef G_OS_UNIX
49 #include "glib-unix.h"
50 #include <pthread.h>
51 #ifdef HAVE_EVENTFD
52 #include <sys/eventfd.h>
53 #endif
54 #endif
55
56 #include <signal.h>
57 #include <sys/types.h>
58 #include <time.h>
59 #include <stdlib.h>
60 #ifdef HAVE_SYS_TIME_H
61 #include <sys/time.h>
62 #endif /* HAVE_SYS_TIME_H */
63 #ifdef G_OS_UNIX
64 #include <unistd.h>
65 #endif /* G_OS_UNIX */
66 #include <errno.h>
67 #include <string.h>
68
69 #ifdef G_OS_WIN32
70 #define STRICT
71 #include <windows.h>
72 #endif /* G_OS_WIN32 */
73
74 #ifdef HAVE_MACH_MACH_TIME_H
75 #include <mach/mach_time.h>
76 #endif
77
78 #include "glib_trace.h"
79
80 #include "gmain.h"
81
82 #include "garray.h"
83 #include "giochannel.h"
84 #include "ghash.h"
85 #include "ghook.h"
86 #include "gqueue.h"
87 #include "gstrfuncs.h"
88 #include "gtestutils.h"
89
90 #ifdef G_OS_WIN32
91 #include "gwin32.h"
92 #endif
93
94 #ifdef G_MAIN_POLL_DEBUG
95 #include "gtimer.h"
96 #endif
97
98 #include "gwakeup.h"
99 #include "gmain-internal.h"
100 #include "glib-init.h"
101 #include "glib-private.h"
102
103 /**
104 * SECTION:main
105 * @title: The Main Event Loop
106 * @short_description: manages all available sources of events
107 *
108 * The main event loop manages all the available sources of events for
109 * GLib and GTK+ applications. These events can come from any number of
110 * different types of sources such as file descriptors (plain files,
111 * pipes or sockets) and timeouts. New types of event sources can also
112 * be added using g_source_attach().
113 *
114 * To allow multiple independent sets of sources to be handled in
115 * different threads, each source is associated with a #GMainContext.
116 * A GMainContext can only be running in a single thread, but
117 * sources can be added to it and removed from it from other threads.
118 *
119 * Each event source is assigned a priority. The default priority,
120 * #G_PRIORITY_DEFAULT, is 0. Values less than 0 denote higher priorities.
121 * Values greater than 0 denote lower priorities. Events from high priority
122 * sources are always processed before events from lower priority sources.
123 *
124 * Idle functions can also be added, and assigned a priority. These will
125 * be run whenever no events with a higher priority are ready to be processed.
126 *
127 * The #GMainLoop data type represents a main event loop. A GMainLoop is
128 * created with g_main_loop_new(). After adding the initial event sources,
129 * g_main_loop_run() is called. This continuously checks for new events from
130 * each of the event sources and dispatches them. Finally, the processing of
131 * an event from one of the sources leads to a call to g_main_loop_quit() to
132 * exit the main loop, and g_main_loop_run() returns.
133 *
134 * It is possible to create new instances of #GMainLoop recursively.
135 * This is often used in GTK+ applications when showing modal dialog
136 * boxes. Note that event sources are associated with a particular
137 * #GMainContext, and will be checked and dispatched for all main
138 * loops associated with that GMainContext.
139 *
140 * GTK+ contains wrappers of some of these functions, e.g. gtk_main(),
141 * gtk_main_quit() and gtk_events_pending().
142 *
143 * ## Creating new source types
144 *
145 * One of the unusual features of the #GMainLoop functionality
146 * is that new types of event source can be created and used in
147 * addition to the builtin type of event source. A new event source
148 * type is used for handling GDK events. A new source type is created
149 * by "deriving" from the #GSource structure. The derived type of
150 * source is represented by a structure that has the #GSource structure
151 * as a first element, and other elements specific to the new source
152 * type. To create an instance of the new source type, call
153 * g_source_new() passing in the size of the derived structure and
154 * a table of functions. These #GSourceFuncs determine the behavior of
155 * the new source type.
156 *
157 * New source types basically interact with the main context
158 * in two ways. Their prepare function in #GSourceFuncs can set a timeout
159 * to determine the maximum amount of time that the main loop will sleep
160 * before checking the source again. In addition, or as well, the source
161 * can add file descriptors to the set that the main context checks using
162 * g_source_add_poll().
163 *
164 * ## Customizing the main loop iteration
165 *
166 * Single iterations of a #GMainContext can be run with
167 * g_main_context_iteration(). In some cases, more detailed control
168 * of exactly how the details of the main loop work is desired, for
169 * instance, when integrating the #GMainLoop with an external main loop.
170 * In such cases, you can call the component functions of
171 * g_main_context_iteration() directly. These functions are
172 * g_main_context_prepare(), g_main_context_query(),
173 * g_main_context_check() and g_main_context_dispatch().
174 *
175 * ## State of a Main Context # {#mainloop-states}
176 *
177 * The operation of these functions can best be seen in terms
178 * of a state diagram, as shown in this image.
179 *
180 * 
181 *
182 * On UNIX, the GLib mainloop is incompatible with fork(). Any program
183 * using the mainloop must either exec() or exit() from the child
184 * without returning to the mainloop.
185 */
186
187 /* Types */
188
189 typedef struct _GTimeoutSource GTimeoutSource;
190 typedef struct _GChildWatchSource GChildWatchSource;
191 typedef struct _GUnixSignalWatchSource GUnixSignalWatchSource;
192 typedef struct _GPollRec GPollRec;
193 typedef struct _GSourceCallback GSourceCallback;
194
195 typedef enum
196 {
197 G_SOURCE_READY = 1 << G_HOOK_FLAG_USER_SHIFT,
198 G_SOURCE_CAN_RECURSE = 1 << (G_HOOK_FLAG_USER_SHIFT + 1),
199 G_SOURCE_BLOCKED = 1 << (G_HOOK_FLAG_USER_SHIFT + 2)
200 } GSourceFlags;
201
202 typedef struct _GSourceList GSourceList;
203
204 struct _GSourceList
205 {
206 GSource *head, *tail;
207 gint priority;
208 };
209
210 typedef struct _GMainWaiter GMainWaiter;
211
212 struct _GMainWaiter
213 {
214 GCond *cond;
215 GMutex *mutex;
216 };
217
218 typedef struct _GMainDispatch GMainDispatch;
219
220 struct _GMainDispatch
221 {
222 gint depth;
223 GSource *source;
224 };
225
226 #ifdef G_MAIN_POLL_DEBUG
227 gboolean _g_main_poll_debug = FALSE;
228 #endif
229
230 struct _GMainContext
231 {
232 /* The following lock is used for both the list of sources
233 * and the list of poll records
234 */
235 GMutex mutex;
236 GCond cond;
237 GThread *owner;
238 guint owner_count;
239 GSList *waiters;
240
241 gint ref_count;
242
243 GHashTable *sources; /* guint -> GSource */
244
245 GPtrArray *pending_dispatches;
246 gint timeout; /* Timeout for current iteration */
247
248 guint next_id;
249 GList *source_lists;
250 gint in_check_or_prepare;
251
252 GPollRec *poll_records, *poll_records_tail;
253 guint n_poll_records;
254 GPollFD *cached_poll_array;
255 guint cached_poll_array_size;
256
257 GWakeup *wakeup;
258
259 GPollFD wake_up_rec;
260
261 /* Flag indicating whether the set of fd's changed during a poll */
262 gboolean poll_changed;
263
264 GPollFunc poll_func;
265
266 gint64 time;
267 gboolean time_is_fresh;
268 };
269
270 struct _GSourceCallback
271 {
272 guint ref_count;
273 GSourceFunc func;
274 gpointer data;
275 GDestroyNotify notify;
276 };
277
278 struct _GMainLoop
279 {
280 GMainContext *context;
281 gboolean is_running;
282 gint ref_count;
283 };
284
285 struct _GTimeoutSource
286 {
287 GSource source;
288 guint interval;
289 gboolean seconds;
290 };
291
292 struct _GChildWatchSource
293 {
294 GSource source;
295 GPid pid;
296 gint child_status;
297 #ifdef G_OS_WIN32
298 GPollFD poll;
299 #else /* G_OS_WIN32 */
300 gboolean child_exited;
301 #endif /* G_OS_WIN32 */
302 };
303
304 struct _GUnixSignalWatchSource
305 {
306 GSource source;
307 int signum;
308 gboolean pending;
309 };
310
311 struct _GPollRec
312 {
313 GPollFD *fd;
314 GPollRec *prev;
315 GPollRec *next;
316 gint priority;
317 };
318
319 struct _GSourcePrivate
320 {
321 GSList *child_sources;
322 GSource *parent_source;
323
324 gint64 ready_time;
325
326 /* This is currently only used on UNIX, but we always declare it (and
327 * let it remain empty on Windows) to avoid #ifdef all over the place.
328 */
329 GSList *fds;
330 };
331
332 typedef struct _GSourceIter
333 {
334 GMainContext *context;
335 gboolean may_modify;
336 GList *current_list;
337 GSource *source;
338 } GSourceIter;
339
340 #define LOCK_CONTEXT(context) g_mutex_lock (&context->mutex)
341 #define UNLOCK_CONTEXT(context) g_mutex_unlock (&context->mutex)
342 #define G_THREAD_SELF g_thread_self ()
343
344 #define SOURCE_DESTROYED(source) (((source)->flags & G_HOOK_FLAG_ACTIVE) == 0)
345 #define SOURCE_BLOCKED(source) (((source)->flags & G_SOURCE_BLOCKED) != 0)
346
347 #define SOURCE_UNREF(source, context) \
348 G_STMT_START { \
349 if ((source)->ref_count > 1) \
350 (source)->ref_count--; \
351 else \
352 g_source_unref_internal ((source), (context), TRUE); \
353 } G_STMT_END
354
355
356 /* Forward declarations */
357
358 static void g_source_unref_internal (GSource *source,
359 GMainContext *context,
360 gboolean have_lock);
361 static void g_source_destroy_internal (GSource *source,
362 GMainContext *context,
363 gboolean have_lock);
364 static void g_source_set_priority_unlocked (GSource *source,
365 GMainContext *context,
366 gint priority);
367 static void g_child_source_remove_internal (GSource *child_source,
368 GMainContext *context);
369
370 static void g_main_context_poll (GMainContext *context,
371 gint timeout,
372 gint priority,
373 GPollFD *fds,
374 gint n_fds);
375 static void g_main_context_add_poll_unlocked (GMainContext *context,
376 gint priority,
377 GPollFD *fd);
378 static void g_main_context_remove_poll_unlocked (GMainContext *context,
379 GPollFD *fd);
380
381 static void g_source_iter_init (GSourceIter *iter,
382 GMainContext *context,
383 gboolean may_modify);
384 static gboolean g_source_iter_next (GSourceIter *iter,
385 GSource **source);
386 static void g_source_iter_clear (GSourceIter *iter);
387
388 static gboolean g_timeout_dispatch (GSource *source,
389 GSourceFunc callback,
390 gpointer user_data);
391 static gboolean g_child_watch_prepare (GSource *source,
392 gint *timeout);
393 static gboolean g_child_watch_check (GSource *source);
394 static gboolean g_child_watch_dispatch (GSource *source,
395 GSourceFunc callback,
396 gpointer user_data);
397 static void g_child_watch_finalize (GSource *source);
398 #ifdef G_OS_UNIX
399 static void g_unix_signal_handler (int signum);
400 static gboolean g_unix_signal_watch_prepare (GSource *source,
401 gint *timeout);
402 static gboolean g_unix_signal_watch_check (GSource *source);
403 static gboolean g_unix_signal_watch_dispatch (GSource *source,
404 GSourceFunc callback,
405 gpointer user_data);
406 static void g_unix_signal_watch_finalize (GSource *source);
407 #endif
408 static gboolean g_idle_prepare (GSource *source,
409 gint *timeout);
410 static gboolean g_idle_check (GSource *source);
411 static gboolean g_idle_dispatch (GSource *source,
412 GSourceFunc callback,
413 gpointer user_data);
414
415 static void block_source (GSource *source);
416
417 static GMainContext *glib_worker_context;
418
419 G_LOCK_DEFINE_STATIC (main_loop);
420 static GMainContext *default_main_context;
421
422 #ifndef G_OS_WIN32
423
424
425 /* UNIX signals work by marking one of these variables then waking the
426 * worker context to check on them and dispatch accordingly.
427 */
428 #ifdef HAVE_SIG_ATOMIC_T
429 static volatile sig_atomic_t unix_signal_pending[NSIG];
430 static volatile sig_atomic_t any_unix_signal_pending;
431 #else
432 static volatile int unix_signal_pending[NSIG];
433 static volatile int any_unix_signal_pending;
434 #endif
435 static volatile guint unix_signal_refcount[NSIG];
436
437 /* Guards all the data below */
438 G_LOCK_DEFINE_STATIC (unix_signal_lock);
439 static GSList *unix_signal_watches;
440 static GSList *unix_child_watches;
441
442 GSourceFuncs g_unix_signal_funcs =
443 {
444 g_unix_signal_watch_prepare,
445 g_unix_signal_watch_check,
446 g_unix_signal_watch_dispatch,
447 g_unix_signal_watch_finalize
448 };
449 #endif /* !G_OS_WIN32 */
450 G_LOCK_DEFINE_STATIC (main_context_list);
451 static GSList *main_context_list = NULL;
452
453 GSourceFuncs g_timeout_funcs =
454 {
455 NULL, /* prepare */
456 NULL, /* check */
457 g_timeout_dispatch,
458 NULL
459 };
460
461 GSourceFuncs g_child_watch_funcs =
462 {
463 g_child_watch_prepare,
464 g_child_watch_check,
465 g_child_watch_dispatch,
466 g_child_watch_finalize
467 };
468
469 GSourceFuncs g_idle_funcs =
470 {
471 g_idle_prepare,
472 g_idle_check,
473 g_idle_dispatch,
474 NULL
475 };
476
477 /**
478 * g_main_context_ref:
479 * @context: a #GMainContext
480 *
481 * Increases the reference count on a #GMainContext object by one.
482 *
483 * Returns: the @context that was passed in (since 2.6)
484 **/
485 GMainContext *
486 g_main_context_ref (GMainContext *context)
487 {
488 g_return_val_if_fail (context != NULL, NULL);
489 g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL);
490
491 g_atomic_int_inc (&context->ref_count);
492
493 return context;
494 }
495
496 static inline void
497 poll_rec_list_free (GMainContext *context,
498 GPollRec *list)
499 {
500 g_slice_free_chain (GPollRec, list, next);
501 }
502
503 /**
504 * g_main_context_unref:
505 * @context: a #GMainContext
506 *
507 * Decreases the reference count on a #GMainContext object by one. If
508 * the result is zero, free the context and free all associated memory.
509 **/
510 void
511 g_main_context_unref (GMainContext *context)
512 {
513 GSourceIter iter;
514 GSource *source;
515 GList *sl_iter;
516 GSourceList *list;
517 gint i;
518
519 g_return_if_fail (context != NULL);
520 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
521
522 if (!g_atomic_int_dec_and_test (&context->ref_count))
523 return;
524
525 G_LOCK (main_context_list);
526 main_context_list = g_slist_remove (main_context_list, context);
527 G_UNLOCK (main_context_list);
528
529 /* Free pending dispatches */
530 for (i = 0; i < context->pending_dispatches->len; i++)
531 g_source_unref_internal (context->pending_dispatches->pdata[i], context, FALSE);
532
533 /* g_source_iter_next() assumes the context is locked. */
534 LOCK_CONTEXT (context);
535 g_source_iter_init (&iter, context, TRUE);
536 while (g_source_iter_next (&iter, &source))
537 {
538 source->context = NULL;
539 g_source_destroy_internal (source, context, TRUE);
540 }
541 UNLOCK_CONTEXT (context);
542
543 for (sl_iter = context->source_lists; sl_iter; sl_iter = sl_iter->next)
544 {
545 list = sl_iter->data;
546 g_slice_free (GSourceList, list);
547 }
548 g_list_free (context->source_lists);
549
550 g_hash_table_destroy (context->sources);
551
552 g_mutex_clear (&context->mutex);
553
554 g_ptr_array_free (context->pending_dispatches, TRUE);
555 g_free (context->cached_poll_array);
556
557 poll_rec_list_free (context, context->poll_records);
558
559 g_wakeup_free (context->wakeup);
560 g_cond_clear (&context->cond);
561
562 g_free (context);
563 }
564
565 /* Helper function used by mainloop/overflow test.
566 */
567 GMainContext *
568 g_main_context_new_with_next_id (guint next_id)
569 {
570 GMainContext *ret = g_main_context_new ();
571
572 ret->next_id = next_id;
573
574 return ret;
575 }
576
577 /**
578 * g_main_context_new:
579 *
580 * Creates a new #GMainContext structure.
581 *
582 * Returns: the new #GMainContext
583 **/
584 GMainContext *
585 g_main_context_new (void)
586 {
587 static gsize initialised;
588 GMainContext *context;
589
590 if (g_once_init_enter (&initialised))
591 {
592 #ifdef G_MAIN_POLL_DEBUG
593 if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
594 _g_main_poll_debug = TRUE;
595 #endif
596
597 g_once_init_leave (&initialised, TRUE);
598 }
599
600 context = g_new0 (GMainContext, 1);
601
602 g_mutex_init (&context->mutex);
603 g_cond_init (&context->cond);
604
605 context->sources = g_hash_table_new (NULL, NULL);
606 context->owner = NULL;
607 context->waiters = NULL;
608
609 context->ref_count = 1;
610
611 context->next_id = 1;
612
613 context->source_lists = NULL;
614
615 context->poll_func = g_poll;
616
617 context->cached_poll_array = NULL;
618 context->cached_poll_array_size = 0;
619
620 context->pending_dispatches = g_ptr_array_new ();
621
622 context->time_is_fresh = FALSE;
623
624 context->wakeup = g_wakeup_new ();
625 g_wakeup_get_pollfd (context->wakeup, &context->wake_up_rec);
626 g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec);
627
628 G_LOCK (main_context_list);
629 main_context_list = g_slist_append (main_context_list, context);
630
631 #ifdef G_MAIN_POLL_DEBUG
632 if (_g_main_poll_debug)
633 g_print ("created context=%p\n", context);
634 #endif
635
636 G_UNLOCK (main_context_list);
637
638 return context;
639 }
640
641 /**
642 * g_main_context_default:
643 *
644 * Returns the global default main context. This is the main context
645 * used for main loop functions when a main loop is not explicitly
646 * specified, and corresponds to the "main" main loop. See also
647 * g_main_context_get_thread_default().
648 *
649 * Returns: (transfer none): the global default main context.
650 **/
651 GMainContext *
652 g_main_context_default (void)
653 {
654 /* Slow, but safe */
655
656 G_LOCK (main_loop);
657
658 if (!default_main_context)
659 {
660 default_main_context = g_main_context_new ();
661 #ifdef G_MAIN_POLL_DEBUG
662 if (_g_main_poll_debug)
663 g_print ("default context=%p\n", default_main_context);
664 #endif
665 }
666
667 G_UNLOCK (main_loop);
668
669 return default_main_context;
670 }
671
672 static void
673 free_context (gpointer data)
674 {
675 GMainContext *context = data;
676
677 g_main_context_release (context);
678 if (context)
679 g_main_context_unref (context);
680 }
681
682 static void
683 free_context_stack (gpointer data)
684 {
685 g_queue_free_full((GQueue *) data, (GDestroyNotify) free_context);
686 }
687
688 static GPrivate thread_context_stack = G_PRIVATE_INIT (free_context_stack);
689
690 /**
691 * g_main_context_push_thread_default:
692 * @context: (allow-none): a #GMainContext, or %NULL for the global default context
693 *
694 * Acquires @context and sets it as the thread-default context for the
695 * current thread. This will cause certain asynchronous operations
696 * (such as most [gio][gio]-based I/O) which are
697 * started in this thread to run under @context and deliver their
698 * results to its main loop, rather than running under the global
699 * default context in the main thread. Note that calling this function
700 * changes the context returned by g_main_context_get_thread_default(),
701 * not the one returned by g_main_context_default(), so it does not affect
702 * the context used by functions like g_idle_add().
703 *
704 * Normally you would call this function shortly after creating a new
705 * thread, passing it a #GMainContext which will be run by a
706 * #GMainLoop in that thread, to set a new default context for all
707 * async operations in that thread. (In this case, you don't need to
708 * ever call g_main_context_pop_thread_default().) In some cases
709 * however, you may want to schedule a single operation in a
710 * non-default context, or temporarily use a non-default context in
711 * the main thread. In that case, you can wrap the call to the
712 * asynchronous operation inside a
713 * g_main_context_push_thread_default() /
714 * g_main_context_pop_thread_default() pair, but it is up to you to
715 * ensure that no other asynchronous operations accidentally get
716 * started while the non-default context is active.
717 *
718 * Beware that libraries that predate this function may not correctly
719 * handle being used from a thread with a thread-default context. Eg,
720 * see g_file_supports_thread_contexts().
721 *
722 * Since: 2.22
723 **/
724 void
725 g_main_context_push_thread_default (GMainContext *context)
726 {
727 GQueue *stack;
728 gboolean acquired_context;
729
730 acquired_context = g_main_context_acquire (context);
731 g_return_if_fail (acquired_context);
732
733 if (context == g_main_context_default ())
734 context = NULL;
735 else if (context)
736 g_main_context_ref (context);
737
738 stack = g_private_get (&thread_context_stack);
739 if (!stack)
740 {
741 stack = g_queue_new ();
742 g_private_set (&thread_context_stack, stack);
743 }
744
745 g_queue_push_head (stack, context);
746 }
747
748 /**
749 * g_main_context_pop_thread_default:
750 * @context: (allow-none): a #GMainContext object, or %NULL
751 *
752 * Pops @context off the thread-default context stack (verifying that
753 * it was on the top of the stack).
754 *
755 * Since: 2.22
756 **/
757 void
758 g_main_context_pop_thread_default (GMainContext *context)
759 {
760 GQueue *stack;
761
762 if (context == g_main_context_default ())
763 context = NULL;
764
765 stack = g_private_get (&thread_context_stack);
766
767 g_return_if_fail (stack != NULL);
768 g_return_if_fail (g_queue_peek_head (stack) == context);
769
770 g_queue_pop_head (stack);
771
772 g_main_context_release (context);
773 if (context)
774 g_main_context_unref (context);
775 }
776
777 /**
778 * g_main_context_get_thread_default:
779 *
780 * Gets the thread-default #GMainContext for this thread. Asynchronous
781 * operations that want to be able to be run in contexts other than
782 * the default one should call this method or
783 * g_main_context_ref_thread_default() to get a #GMainContext to add
784 * their #GSources to. (Note that even in single-threaded
785 * programs applications may sometimes want to temporarily push a
786 * non-default context, so it is not safe to assume that this will
787 * always return %NULL if you are running in the default thread.)
788 *
789 * If you need to hold a reference on the context, use
790 * g_main_context_ref_thread_default() instead.
791 *
792 * Returns: (transfer none): the thread-default #GMainContext, or
793 * %NULL if the thread-default context is the global default context.
794 *
795 * Since: 2.22
796 **/
797 GMainContext *
798 g_main_context_get_thread_default (void)
799 {
800 GQueue *stack;
801
802 stack = g_private_get (&thread_context_stack);
803 if (stack)
804 return g_queue_peek_head (stack);
805 else
806 return NULL;
807 }
808
809 /**
810 * g_main_context_ref_thread_default:
811 *
812 * Gets the thread-default #GMainContext for this thread, as with
813 * g_main_context_get_thread_default(), but also adds a reference to
814 * it with g_main_context_ref(). In addition, unlike
815 * g_main_context_get_thread_default(), if the thread-default context
816 * is the global default context, this will return that #GMainContext
817 * (with a ref added to it) rather than returning %NULL.
818 *
819 * Returns: (transfer full): the thread-default #GMainContext. Unref
820 * with g_main_context_unref() when you are done with it.
821 *
822 * Since: 2.32
823 */
824 GMainContext *
825 g_main_context_ref_thread_default (void)
826 {
827 GMainContext *context;
828
829 context = g_main_context_get_thread_default ();
830 if (!context)
831 context = g_main_context_default ();
832 return g_main_context_ref (context);
833 }
834
835 /* Hooks for adding to the main loop */
836
837 /**
838 * g_source_new:
839 * @source_funcs: structure containing functions that implement
840 * the sources behavior.
841 * @struct_size: size of the #GSource structure to create.
842 *
843 * Creates a new #GSource structure. The size is specified to
844 * allow creating structures derived from #GSource that contain
845 * additional data. The size passed in must be at least
846 * `sizeof (GSource)`.
847 *
848 * The source will not initially be associated with any #GMainContext
849 * and must be added to one with g_source_attach() before it will be
850 * executed.
851 *
852 * Returns: the newly-created #GSource.
853 **/
854 GSource *
855 g_source_new (GSourceFuncs *source_funcs,
856 guint struct_size)
857 {
858 GSource *source;
859
860 g_return_val_if_fail (source_funcs != NULL, NULL);
861 g_return_val_if_fail (struct_size >= sizeof (GSource), NULL);
862
863 source = (GSource*) g_malloc0 (struct_size);
864 #ifdef GSTREAMER_LITE
865 if (source == NULL)
866 return NULL;
867 #endif // GSTREAMER_LITE
868 source->priv = g_slice_new0 (GSourcePrivate);
869 #ifdef GSTREAMER_LITE
870 if (source->priv == NULL)
871 {
872 g_free(source);
873 return NULL;
874 }
875 #endif // GSTREAMER_LITE
876 source->source_funcs = source_funcs;
877 source->ref_count = 1;
878
879 source->priority = G_PRIORITY_DEFAULT;
880
881 source->flags = G_HOOK_FLAG_ACTIVE;
882
883 source->priv->ready_time = -1;
884
885 /* NULL/0 initialization for all other fields */
886
887 return source;
888 }
889
890 /* Holds context's lock */
891 static void
892 g_source_iter_init (GSourceIter *iter,
893 GMainContext *context,
894 gboolean may_modify)
895 {
896 iter->context = context;
897 iter->current_list = NULL;
898 iter->source = NULL;
899 iter->may_modify = may_modify;
900 }
901
902 /* Holds context's lock */
903 static gboolean
904 g_source_iter_next (GSourceIter *iter, GSource **source)
905 {
906 GSource *next_source;
907
908 if (iter->source)
909 next_source = iter->source->next;
910 else
911 next_source = NULL;
912
913 if (!next_source)
914 {
915 if (iter->current_list)
916 iter->current_list = iter->current_list->next;
917 else
918 iter->current_list = iter->context->source_lists;
919
920 if (iter->current_list)
921 {
922 GSourceList *source_list = iter->current_list->data;
923
924 next_source = source_list->head;
925 }
926 }
927
928 /* Note: unreffing iter->source could potentially cause its
929 * GSourceList to be removed from source_lists (if iter->source is
930 * the only source in its list, and it is destroyed), so we have to
931 * keep it reffed until after we advance iter->current_list, above.
932 */
933
934 if (iter->source && iter->may_modify)
935 SOURCE_UNREF (iter->source, iter->context);
936 iter->source = next_source;
937 if (iter->source && iter->may_modify)
938 iter->source->ref_count++;
939
940 *source = iter->source;
941 return *source != NULL;
942 }
943
944 /* Holds context's lock. Only necessary to call if you broke out of
945 * the g_source_iter_next() loop early.
946 */
947 static void
948 g_source_iter_clear (GSourceIter *iter)
949 {
950 if (iter->source && iter->may_modify)
951 {
952 SOURCE_UNREF (iter->source, iter->context);
953 iter->source = NULL;
954 }
955 }
956
957 /* Holds context's lock
958 */
959 static GSourceList *
960 find_source_list_for_priority (GMainContext *context,
961 gint priority,
962 gboolean create)
963 {
964 GList *iter, *last;
965 GSourceList *source_list;
966
967 last = NULL;
968 for (iter = context->source_lists; iter != NULL; last = iter, iter = iter->next)
969 {
970 source_list = iter->data;
971
972 if (source_list->priority == priority)
973 return source_list;
974
975 if (source_list->priority > priority)
976 {
977 if (!create)
978 return NULL;
979
980 source_list = g_slice_new0 (GSourceList);
981 source_list->priority = priority;
982 context->source_lists = g_list_insert_before (context->source_lists,
983 iter,
984 source_list);
985 return source_list;
986 }
987 }
988
989 if (!create)
990 return NULL;
991
992 source_list = g_slice_new0 (GSourceList);
993 source_list->priority = priority;
994
995 if (!last)
996 context->source_lists = g_list_append (NULL, source_list);
997 else
998 {
999 /* This just appends source_list to the end of
1000 * context->source_lists without having to walk the list again.
1001 */
1002 last = g_list_append (last, source_list);
1003 }
1004 return source_list;
1005 }
1006
1007 /* Holds context's lock
1008 */
1009 static void
1010 source_add_to_context (GSource *source,
1011 GMainContext *context)
1012 {
1013 GSourceList *source_list;
1014 GSource *prev, *next;
1015
1016 source_list = find_source_list_for_priority (context, source->priority, TRUE);
1017
1018 if (source->priv->parent_source)
1019 {
1020 g_assert (source_list->head != NULL);
1021
1022 /* Put the source immediately before its parent */
1023 prev = source->priv->parent_source->prev;
1024 next = source->priv->parent_source;
1025 }
1026 else
1027 {
1028 prev = source_list->tail;
1029 next = NULL;
1030 }
1031
1032 source->next = next;
1033 if (next)
1034 next->prev = source;
1035 else
1036 source_list->tail = source;
1037
1038 source->prev = prev;
1039 if (prev)
1040 prev->next = source;
1041 else
1042 source_list->head = source;
1043 }
1044
1045 /* Holds context's lock
1046 */
1047 static void
1048 source_remove_from_context (GSource *source,
1049 GMainContext *context)
1050 {
1051 GSourceList *source_list;
1052
1053 source_list = find_source_list_for_priority (context, source->priority, FALSE);
1054 g_return_if_fail (source_list != NULL);
1055 #ifdef GSTREAMER_LITE
1056 if (source_list == NULL)
1057 return;
1058 #endif // GSTREAMER_LITE
1059
1060 if (source->prev)
1061 source->prev->next = source->next;
1062 else
1063 source_list->head = source->next;
1064
1065 if (source->next)
1066 source->next->prev = source->prev;
1067 else
1068 source_list->tail = source->prev;
1069
1070 source->prev = NULL;
1071 source->next = NULL;
1072
1073 if (source_list->head == NULL)
1074 {
1075 context->source_lists = g_list_remove (context->source_lists, source_list);
1076 g_slice_free (GSourceList, source_list);
1077 }
1078 }
1079
1080 static guint
1081 g_source_attach_unlocked (GSource *source,
1082 GMainContext *context,
1083 gboolean do_wakeup)
1084 {
1085 GSList *tmp_list;
1086 guint id;
1087
1088 /* The counter may have wrapped, so we must ensure that we do not
1089 * reuse the source id of an existing source.
1090 */
1091 do
1092 id = context->next_id++;
1093 while (id == 0 || g_hash_table_contains (context->sources, GUINT_TO_POINTER (id)));
1094
1095 source->context = context;
1096 source->source_id = id;
1097 source->ref_count++;
1098
1099 g_hash_table_insert (context->sources, GUINT_TO_POINTER (id), source);
1100
1101 source_add_to_context (source, context);
1102
1103 if (!SOURCE_BLOCKED (source))
1104 {
1105 tmp_list = source->poll_fds;
1106 while (tmp_list)
1107 {
1108 g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
1109 tmp_list = tmp_list->next;
1110 }
1111
1112 for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
1113 g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
1114 }
1115
1116 tmp_list = source->priv->child_sources;
1117 while (tmp_list)
1118 {
1119 g_source_attach_unlocked (tmp_list->data, context, FALSE);
1120 tmp_list = tmp_list->next;
1121 }
1122
1123 /* If another thread has acquired the context, wake it up since it
1124 * might be in poll() right now.
1125 */
1126 if (do_wakeup && context->owner && context->owner != G_THREAD_SELF)
1127 g_wakeup_signal (context->wakeup);
1128
1129 return source->source_id;
1130 }
1131
1132 /**
1133 * g_source_attach:
1134 * @source: a #GSource
1135 * @context: (allow-none): a #GMainContext (if %NULL, the default context will be used)
1136 *
1137 * Adds a #GSource to a @context so that it will be executed within
1138 * that context. Remove it by calling g_source_destroy().
1139 *
1140 * Returns: the ID (greater than 0) for the source within the
1141 * #GMainContext.
1142 **/
1143 guint
1144 g_source_attach (GSource *source,
1145 GMainContext *context)
1146 {
1147 guint result = 0;
1148
1149 #ifdef GSTREAMER_LITE
1150 if (source == NULL) {
1151 return 0;
1152 }
1153 #endif // GSTREAMER_LITE
1154
1155 g_return_val_if_fail (source->context == NULL, 0);
1156 g_return_val_if_fail (!SOURCE_DESTROYED (source), 0);
1157
1158 TRACE (GLIB_MAIN_SOURCE_ATTACH (g_source_get_name (source)));
1159
1160 if (!context)
1161 context = g_main_context_default ();
1162
1163 LOCK_CONTEXT (context);
1164
1165 result = g_source_attach_unlocked (source, context, TRUE);
1166
1167 UNLOCK_CONTEXT (context);
1168
1169 return result;
1170 }
1171
1172 static void
1173 g_source_destroy_internal (GSource *source,
1174 GMainContext *context,
1175 gboolean have_lock)
1176 {
1177 TRACE (GLIB_MAIN_SOURCE_DESTROY (g_source_get_name (source)));
1178
1179 if (!have_lock)
1180 LOCK_CONTEXT (context);
1181
1182 if (!SOURCE_DESTROYED (source))
1183 {
1184 GSList *tmp_list;
1185 gpointer old_cb_data;
1186 GSourceCallbackFuncs *old_cb_funcs;
1187
1188 source->flags &= ~G_HOOK_FLAG_ACTIVE;
1189
1190 old_cb_data = source->callback_data;
1191 old_cb_funcs = source->callback_funcs;
1192
1193 source->callback_data = NULL;
1194 source->callback_funcs = NULL;
1195
1196 if (old_cb_funcs)
1197 {
1198 UNLOCK_CONTEXT (context);
1199 old_cb_funcs->unref (old_cb_data);
1200 LOCK_CONTEXT (context);
1201 }
1202
1203 if (!SOURCE_BLOCKED (source))
1204 {
1205 tmp_list = source->poll_fds;
1206 while (tmp_list)
1207 {
1208 g_main_context_remove_poll_unlocked (context, tmp_list->data);
1209 tmp_list = tmp_list->next;
1210 }
1211
1212 for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
1213 g_main_context_remove_poll_unlocked (context, tmp_list->data);
1214 }
1215
1216 while (source->priv->child_sources)
1217 g_child_source_remove_internal (source->priv->child_sources->data, context);
1218
1219 if (source->priv->parent_source)
1220 g_child_source_remove_internal (source, context);
1221
1222 g_source_unref_internal (source, context, TRUE);
1223 }
1224
1225 if (!have_lock)
1226 UNLOCK_CONTEXT (context);
1227 }
1228
1229 /**
1230 * g_source_destroy:
1231 * @source: a #GSource
1232 *
1233 * Removes a source from its #GMainContext, if any, and mark it as
1234 * destroyed. The source cannot be subsequently added to another
1235 * context. It is safe to call this on sources which have already been
1236 * removed from their context.
1237 **/
1238 void
1239 g_source_destroy (GSource *source)
1240 {
1241 GMainContext *context;
1242
1243 g_return_if_fail (source != NULL);
1244
1245 context = source->context;
1246
1247 if (context)
1248 g_source_destroy_internal (source, context, FALSE);
1249 else
1250 source->flags &= ~G_HOOK_FLAG_ACTIVE;
1251 }
1252
1253 /**
1254 * g_source_get_id:
1255 * @source: a #GSource
1256 *
1257 * Returns the numeric ID for a particular source. The ID of a source
1258 * is a positive integer which is unique within a particular main loop
1259 * context. The reverse
1260 * mapping from ID to source is done by g_main_context_find_source_by_id().
1261 *
1262 * Returns: the ID (greater than 0) for the source
1263 **/
1264 guint
1265 g_source_get_id (GSource *source)
1266 {
1267 guint result;
1268
1269 g_return_val_if_fail (source != NULL, 0);
1270 g_return_val_if_fail (source->context != NULL, 0);
1271
1272 LOCK_CONTEXT (source->context);
1273 result = source->source_id;
1274 UNLOCK_CONTEXT (source->context);
1275
1276 return result;
1277 }
1278
1279 /**
1280 * g_source_get_context:
1281 * @source: a #GSource
1282 *
1283 * Gets the #GMainContext with which the source is associated.
1284 *
1285 * You can call this on a source that has been destroyed, provided
1286 * that the #GMainContext it was attached to still exists (in which
1287 * case it will return that #GMainContext). In particular, you can
1288 * always call this function on the source returned from
1289 * g_main_current_source(). But calling this function on a source
1290 * whose #GMainContext has been destroyed is an error.
1291 *
1292 * Returns: (transfer none) (allow-none): the #GMainContext with which the
1293 * source is associated, or %NULL if the context has not
1294 * yet been added to a source.
1295 **/
1296 GMainContext *
1297 g_source_get_context (GSource *source)
1298 {
1299 g_return_val_if_fail (source->context != NULL || !SOURCE_DESTROYED (source), NULL);
1300
1301 return source->context;
1302 }
1303
1304 /**
1305 * g_source_add_poll:
1306 * @source:a #GSource
1307 * @fd: a #GPollFD structure holding information about a file
1308 * descriptor to watch.
1309 *
1310 * Adds a file descriptor to the set of file descriptors polled for
1311 * this source. This is usually combined with g_source_new() to add an
1312 * event source. The event source's check function will typically test
1313 * the @revents field in the #GPollFD struct and return %TRUE if events need
1314 * to be processed.
1315 *
1316 * This API is only intended to be used by implementations of #GSource.
1317 * Do not call this API on a #GSource that you did not create.
1318 *
1319 * Using this API forces the linear scanning of event sources on each
1320 * main loop iteration. Newly-written event sources should try to use
1321 * g_source_add_unix_fd() instead of this API.
1322 **/
1323 void
1324 g_source_add_poll (GSource *source,
1325 GPollFD *fd)
1326 {
1327 GMainContext *context;
1328
1329 g_return_if_fail (source != NULL);
1330 g_return_if_fail (fd != NULL);
1331 g_return_if_fail (!SOURCE_DESTROYED (source));
1332
1333 #ifdef GSTREAMER_LITE
1334 if (source == NULL)
1335 return;
1336 #endif // GSTREAMER_LITE
1337
1338 context = source->context;
1339
1340 if (context)
1341 LOCK_CONTEXT (context);
1342
1343 source->poll_fds = g_slist_prepend (source->poll_fds, fd);
1344
1345 if (context)
1346 {
1347 if (!SOURCE_BLOCKED (source))
1348 g_main_context_add_poll_unlocked (context, source->priority, fd);
1349 UNLOCK_CONTEXT (context);
1350 }
1351 }
1352
1353 /**
1354 * g_source_remove_poll:
1355 * @source:a #GSource
1356 * @fd: a #GPollFD structure previously passed to g_source_add_poll().
1357 *
1358 * Removes a file descriptor from the set of file descriptors polled for
1359 * this source.
1360 *
1361 * This API is only intended to be used by implementations of #GSource.
1362 * Do not call this API on a #GSource that you did not create.
1363 **/
1364 void
1365 g_source_remove_poll (GSource *source,
1366 GPollFD *fd)
1367 {
1368 GMainContext *context;
1369
1370 g_return_if_fail (source != NULL);
1371 g_return_if_fail (fd != NULL);
1372 g_return_if_fail (!SOURCE_DESTROYED (source));
1373
1374 context = source->context;
1375
1376 if (context)
1377 LOCK_CONTEXT (context);
1378
1379 source->poll_fds = g_slist_remove (source->poll_fds, fd);
1380
1381 if (context)
1382 {
1383 if (!SOURCE_BLOCKED (source))
1384 g_main_context_remove_poll_unlocked (context, fd);
1385 UNLOCK_CONTEXT (context);
1386 }
1387 }
1388
1389 /**
1390 * g_source_add_child_source:
1391 * @source:a #GSource
1392 * @child_source: a second #GSource that @source should "poll"
1393 *
1394 * Adds @child_source to @source as a "polled" source; when @source is
1395 * added to a #GMainContext, @child_source will be automatically added
1396 * with the same priority, when @child_source is triggered, it will
1397 * cause @source to dispatch (in addition to calling its own
1398 * callback), and when @source is destroyed, it will destroy
1399 * @child_source as well. (@source will also still be dispatched if
1400 * its own prepare/check functions indicate that it is ready.)
1401 *
1402 * If you don't need @child_source to do anything on its own when it
1403 * triggers, you can call g_source_set_dummy_callback() on it to set a
1404 * callback that does nothing (except return %TRUE if appropriate).
1405 *
1406 * @source will hold a reference on @child_source while @child_source
1407 * is attached to it.
1408 *
1409 * This API is only intended to be used by implementations of #GSource.
1410 * Do not call this API on a #GSource that you did not create.
1411 *
1412 * Since: 2.28
1413 **/
1414 void
1415 g_source_add_child_source (GSource *source,
1416 GSource *child_source)
1417 {
1418 GMainContext *context;
1419
1420 g_return_if_fail (source != NULL);
1421 g_return_if_fail (child_source != NULL);
1422 g_return_if_fail (!SOURCE_DESTROYED (source));
1423 g_return_if_fail (!SOURCE_DESTROYED (child_source));
1424 g_return_if_fail (child_source->context == NULL);
1425 g_return_if_fail (child_source->priv->parent_source == NULL);
1426
1427 context = source->context;
1428
1429 if (context)
1430 LOCK_CONTEXT (context);
1431
1432 source->priv->child_sources = g_slist_prepend (source->priv->child_sources,
1433 g_source_ref (child_source));
1434 child_source->priv->parent_source = source;
1435 g_source_set_priority_unlocked (child_source, NULL, source->priority);
1436 if (SOURCE_BLOCKED (source))
1437 block_source (child_source);
1438
1439 if (context)
1440 {
1441 g_source_attach_unlocked (child_source, context, TRUE);
1442 UNLOCK_CONTEXT (context);
1443 }
1444 }
1445
1446 static void
1447 g_child_source_remove_internal (GSource *child_source,
1448 GMainContext *context)
1449 {
1450 GSource *parent_source = child_source->priv->parent_source;
1451
1452 parent_source->priv->child_sources =
1453 g_slist_remove (parent_source->priv->child_sources, child_source);
1454 child_source->priv->parent_source = NULL;
1455
1456 g_source_destroy_internal (child_source, context, TRUE);
1457 g_source_unref_internal (child_source, context, TRUE);
1458 }
1459
1460 /**
1461 * g_source_remove_child_source:
1462 * @source:a #GSource
1463 * @child_source: a #GSource previously passed to
1464 * g_source_add_child_source().
1465 *
1466 * Detaches @child_source from @source and destroys it.
1467 *
1468 * This API is only intended to be used by implementations of #GSource.
1469 * Do not call this API on a #GSource that you did not create.
1470 *
1471 * Since: 2.28
1472 **/
1473 void
1474 g_source_remove_child_source (GSource *source,
1475 GSource *child_source)
1476 {
1477 GMainContext *context;
1478
1479 g_return_if_fail (source != NULL);
1480 g_return_if_fail (child_source != NULL);
1481 g_return_if_fail (child_source->priv->parent_source == source);
1482 g_return_if_fail (!SOURCE_DESTROYED (source));
1483 g_return_if_fail (!SOURCE_DESTROYED (child_source));
1484
1485 context = source->context;
1486
1487 if (context)
1488 LOCK_CONTEXT (context);
1489
1490 g_child_source_remove_internal (child_source, context);
1491
1492 if (context)
1493 UNLOCK_CONTEXT (context);
1494 }
1495
1496 /**
1497 * g_source_set_callback_indirect:
1498 * @source: the source
1499 * @callback_data: pointer to callback data "object"
1500 * @callback_funcs: functions for reference counting @callback_data
1501 * and getting the callback and data
1502 *
1503 * Sets the callback function storing the data as a refcounted callback
1504 * "object". This is used internally. Note that calling
1505 * g_source_set_callback_indirect() assumes
1506 * an initial reference count on @callback_data, and thus
1507 * @callback_funcs->unref will eventually be called once more
1508 * than @callback_funcs->ref.
1509 **/
1510 void
1511 g_source_set_callback_indirect (GSource *source,
1512 gpointer callback_data,
1513 GSourceCallbackFuncs *callback_funcs)
1514 {
1515 GMainContext *context;
1516 gpointer old_cb_data;
1517 GSourceCallbackFuncs *old_cb_funcs;
1518
1519 g_return_if_fail (source != NULL);
1520 g_return_if_fail (callback_funcs != NULL || callback_data == NULL);
1521
1522 context = source->context;
1523
1524 if (context)
1525 LOCK_CONTEXT (context);
1526
1527 old_cb_data = source->callback_data;
1528 old_cb_funcs = source->callback_funcs;
1529
1530 source->callback_data = callback_data;
1531 source->callback_funcs = callback_funcs;
1532
1533 if (context)
1534 UNLOCK_CONTEXT (context);
1535
1536 if (old_cb_funcs)
1537 old_cb_funcs->unref (old_cb_data);
1538 }
1539
1540 static void
1541 g_source_callback_ref (gpointer cb_data)
1542 {
1543 GSourceCallback *callback = cb_data;
1544
1545 callback->ref_count++;
1546 }
1547
1548
1549 static void
1550 g_source_callback_unref (gpointer cb_data)
1551 {
1552 GSourceCallback *callback = cb_data;
1553
1554 callback->ref_count--;
1555 if (callback->ref_count == 0)
1556 {
1557 if (callback->notify)
1558 callback->notify (callback->data);
1559 g_free (callback);
1560 }
1561 }
1562
1563 static void
1564 g_source_callback_get (gpointer cb_data,
1565 GSource *source,
1566 GSourceFunc *func,
1567 gpointer *data)
1568 {
1569 GSourceCallback *callback = cb_data;
1570
1571 *func = callback->func;
1572 *data = callback->data;
1573 }
1574
1575 static GSourceCallbackFuncs g_source_callback_funcs = {
1576 g_source_callback_ref,
1577 g_source_callback_unref,
1578 g_source_callback_get,
1579 };
1580
1581 /**
1582 * g_source_set_callback:
1583 * @source: the source
1584 * @func: a callback function
1585 * @data: the data to pass to callback function
1586 * @notify: (allow-none): a function to call when @data is no longer in use, or %NULL.
1587 *
1588 * Sets the callback function for a source. The callback for a source is
1589 * called from the source's dispatch function.
1590 *
1591 * The exact type of @func depends on the type of source; ie. you
1592 * should not count on @func being called with @data as its first
1593 * parameter.
1594 *
1595 * Typically, you won't use this function. Instead use functions specific
1596 * to the type of source you are using.
1597 **/
1598 void
1599 g_source_set_callback (GSource *source,
1600 GSourceFunc func,
1601 gpointer data,
1602 GDestroyNotify notify)
1603 {
1604 GSourceCallback *new_callback;
1605
1606 g_return_if_fail (source != NULL);
1607 #ifdef GSTREAMER_LITE
1608 if (source == NULL)
1609 return;
1610 #endif // GSTREAMER_LITE
1611
1612 new_callback = g_new (GSourceCallback, 1);
1613
1614 new_callback->ref_count = 1;
1615 new_callback->func = func;
1616 new_callback->data = data;
1617 new_callback->notify = notify;
1618
1619 g_source_set_callback_indirect (source, new_callback, &g_source_callback_funcs);
1620 }
1621
1622
1623 /**
1624 * g_source_set_funcs:
1625 * @source: a #GSource
1626 * @funcs: the new #GSourceFuncs
1627 *
1628 * Sets the source functions (can be used to override
1629 * default implementations) of an unattached source.
1630 *
1631 * Since: 2.12
1632 */
1633 void
1634 g_source_set_funcs (GSource *source,
1635 GSourceFuncs *funcs)
1636 {
1637 g_return_if_fail (source != NULL);
1638 g_return_if_fail (source->context == NULL);
1639 g_return_if_fail (source->ref_count > 0);
1640 g_return_if_fail (funcs != NULL);
1641
1642 source->source_funcs = funcs;
1643 }
1644
1645 static void
1646 g_source_set_priority_unlocked (GSource *source,
1647 GMainContext *context,
1648 gint priority)
1649 {
1650 GSList *tmp_list;
1651
1652 #ifdef GSTREAMER_LITE
1653 if (source == NULL || source->priv == NULL || source->priv->parent_source == NULL)
1654 return;
1655
1656 if (context == NULL)
1657 return;
1658 #endif // GSTREAMER_LITE
1659
1660 g_return_if_fail (source->priv->parent_source == NULL ||
1661 source->priv->parent_source->priority == priority);
1662
1663 if (context)
1664 {
1665 /* Remove the source from the context's source and then
1666 * add it back after so it is sorted in the correct place
1667 */
1668 source_remove_from_context (source, source->context);
1669 }
1670
1671 source->priority = priority;
1672
1673 if (context)
1674 {
1675 source_add_to_context (source, source->context);
1676
1677 if (!SOURCE_BLOCKED (source))
1678 {
1679 tmp_list = source->poll_fds;
1680 while (tmp_list)
1681 {
1682 g_main_context_remove_poll_unlocked (context, tmp_list->data);
1683 g_main_context_add_poll_unlocked (context, priority, tmp_list->data);
1684
1685 tmp_list = tmp_list->next;
1686 }
1687
1688 for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
1689 {
1690 g_main_context_remove_poll_unlocked (context, tmp_list->data);
1691 g_main_context_add_poll_unlocked (context, priority, tmp_list->data);
1692 }
1693 }
1694 }
1695
1696 if (source->priv->child_sources)
1697 {
1698 tmp_list = source->priv->child_sources;
1699 while (tmp_list)
1700 {
1701 g_source_set_priority_unlocked (tmp_list->data, context, priority);
1702 tmp_list = tmp_list->next;
1703 }
1704 }
1705 }
1706
1707 /**
1708 * g_source_set_priority:
1709 * @source: a #GSource
1710 * @priority: the new priority.
1711 *
1712 * Sets the priority of a source. While the main loop is being run, a
1713 * source will be dispatched if it is ready to be dispatched and no
1714 * sources at a higher (numerically smaller) priority are ready to be
1715 * dispatched.
1716 *
1717 * A child source always has the same priority as its parent. It is not
1718 * permitted to change the priority of a source once it has been added
1719 * as a child of another source.
1720 **/
1721 void
1722 g_source_set_priority (GSource *source,
1723 gint priority)
1724 {
1725 GMainContext *context;
1726
1727 #ifdef GSTREAMER_LITE
1728 if (source == NULL || source->priv == NULL || source->priv->parent_source == NULL)
1729 return;
1730 #endif // GSTREAMER_LITE
1731
1732 g_return_if_fail (source != NULL);
1733 g_return_if_fail (source->priv->parent_source == NULL);
1734
1735 context = source->context;
1736
1737 if (context)
1738 LOCK_CONTEXT (context);
1739 g_source_set_priority_unlocked (source, context, priority);
1740 if (context)
1741 UNLOCK_CONTEXT (source->context);
1742 }
1743
1744 /**
1745 * g_source_get_priority:
1746 * @source: a #GSource
1747 *
1748 * Gets the priority of a source.
1749 *
1750 * Returns: the priority of the source
1751 **/
1752 gint
1753 g_source_get_priority (GSource *source)
1754 {
1755 g_return_val_if_fail (source != NULL, 0);
1756
1757 return source->priority;
1758 }
1759
1760 /**
1761 * g_source_set_ready_time:
1762 * @source: a #GSource
1763 * @ready_time: the monotonic time at which the source will be ready,
1764 * 0 for "immediately", -1 for "never"
1765 *
1766 * Sets a #GSource to be dispatched when the given monotonic time is
1767 * reached (or passed). If the monotonic time is in the past (as it
1768 * always will be if @ready_time is 0) then the source will be
1769 * dispatched immediately.
1770 *
1771 * If @ready_time is -1 then the source is never woken up on the basis
1772 * of the passage of time.
1773 *
1774 * Dispatching the source does not reset the ready time. You should do
1775 * so yourself, from the source dispatch function.
1776 *
1777 * Note that if you have a pair of sources where the ready time of one
1778 * suggests that it will be delivered first but the priority for the
1779 * other suggests that it would be delivered first, and the ready time
1780 * for both sources is reached during the same main context iteration
1781 * then the order of dispatch is undefined.
1782 *
1783 * This API is only intended to be used by implementations of #GSource.
1784 * Do not call this API on a #GSource that you did not create.
1785 *
1786 * Since: 2.36
1787 **/
1788 void
1789 g_source_set_ready_time (GSource *source,
1790 gint64 ready_time)
1791 {
1792 GMainContext *context;
1793
1794 g_return_if_fail (source != NULL);
1795 g_return_if_fail (source->ref_count > 0);
1796
1797 #ifdef GSTREAMER_LITE
1798 if (source == NULL)
1799 return;
1800 #endif // GSTREAMER_LITE
1801
1802 if (source->priv->ready_time == ready_time)
1803 return;
1804
1805 context = source->context;
1806
1807 if (context)
1808 LOCK_CONTEXT (context);
1809
1810 source->priv->ready_time = ready_time;
1811
1812 if (context)
1813 {
1814 /* Quite likely that we need to change the timeout on the poll */
1815 if (!SOURCE_BLOCKED (source))
1816 g_wakeup_signal (context->wakeup);
1817 UNLOCK_CONTEXT (context);
1818 }
1819 }
1820
1821 /**
1822 * g_source_get_ready_time:
1823 * @source: a #GSource
1824 *
1825 * Gets the "ready time" of @source, as set by
1826 * g_source_set_ready_time().
1827 *
1828 * Any time before the current monotonic time (including 0) is an
1829 * indication that the source will fire immediately.
1830 *
1831 * Returns: the monotonic ready time, -1 for "never"
1832 **/
1833 gint64
1834 g_source_get_ready_time (GSource *source)
1835 {
1836 g_return_val_if_fail (source != NULL, -1);
1837
1838 return source->priv->ready_time;
1839 }
1840
1841 /**
1842 * g_source_set_can_recurse:
1843 * @source: a #GSource
1844 * @can_recurse: whether recursion is allowed for this source
1845 *
1846 * Sets whether a source can be called recursively. If @can_recurse is
1847 * %TRUE, then while the source is being dispatched then this source
1848 * will be processed normally. Otherwise, all processing of this
1849 * source is blocked until the dispatch function returns.
1850 **/
1851 void
1852 g_source_set_can_recurse (GSource *source,
1853 gboolean can_recurse)
1854 {
1855 GMainContext *context;
1856
1857 g_return_if_fail (source != NULL);
1858
1859 context = source->context;
1860
1861 if (context)
1862 LOCK_CONTEXT (context);
1863
1864 if (can_recurse)
1865 source->flags |= G_SOURCE_CAN_RECURSE;
1866 else
1867 source->flags &= ~G_SOURCE_CAN_RECURSE;
1868
1869 if (context)
1870 UNLOCK_CONTEXT (context);
1871 }
1872
1873 /**
1874 * g_source_get_can_recurse:
1875 * @source: a #GSource
1876 *
1877 * Checks whether a source is allowed to be called recursively.
1878 * see g_source_set_can_recurse().
1879 *
1880 * Returns: whether recursion is allowed.
1881 **/
1882 gboolean
1883 g_source_get_can_recurse (GSource *source)
1884 {
1885 g_return_val_if_fail (source != NULL, FALSE);
1886
1887 return (source->flags & G_SOURCE_CAN_RECURSE) != 0;
1888 }
1889
1890
1891 /**
1892 * g_source_set_name:
1893 * @source: a #GSource
1894 * @name: debug name for the source
1895 *
1896 * Sets a name for the source, used in debugging and profiling.
1897 * The name defaults to #NULL.
1898 *
1899 * The source name should describe in a human-readable way
1900 * what the source does. For example, "X11 event queue"
1901 * or "GTK+ repaint idle handler" or whatever it is.
1902 *
1903 * It is permitted to call this function multiple times, but is not
1904 * recommended due to the potential performance impact. For example,
1905 * one could change the name in the "check" function of a #GSourceFuncs
1906 * to include details like the event type in the source name.
1907 *
1908 * Use caution if changing the name while another thread may be
1909 * accessing it with g_source_get_name(); that function does not copy
1910 * the value, and changing the value will free it while the other thread
1911 * may be attempting to use it.
1912 *
1913 * Since: 2.26
1914 **/
1915 void
1916 g_source_set_name (GSource *source,
1917 const char *name)
1918 {
1919 GMainContext *context;
1920
1921 g_return_if_fail (source != NULL);
1922
1923 context = source->context;
1924
1925 if (context)
1926 LOCK_CONTEXT (context);
1927
1928 /* setting back to NULL is allowed, just because it's
1929 * weird if get_name can return NULL but you can't
1930 * set that.
1931 */
1932
1933 g_free (source->name);
1934 source->name = g_strdup (name);
1935
1936 if (context)
1937 UNLOCK_CONTEXT (context);
1938 }
1939
1940 /**
1941 * g_source_get_name:
1942 * @source: a #GSource
1943 *
1944 * Gets a name for the source, used in debugging and profiling. The
1945 * name may be #NULL if it has never been set with g_source_set_name().
1946 *
1947 * Returns: the name of the source
1948 *
1949 * Since: 2.26
1950 **/
1951 const char *
1952 g_source_get_name (GSource *source)
1953 {
1954 g_return_val_if_fail (source != NULL, NULL);
1955
1956 return source->name;
1957 }
1958
1959 /**
1960 * g_source_set_name_by_id:
1961 * @tag: a #GSource ID
1962 * @name: debug name for the source
1963 *
1964 * Sets the name of a source using its ID.
1965 *
1966 * This is a convenience utility to set source names from the return
1967 * value of g_idle_add(), g_timeout_add(), etc.
1968 *
1969 * It is a programmer error to attempt to set the name of a non-existent
1970 * source.
1971 *
1972 * More specifically: source IDs can be reissued after a source has been
1973 * destroyed and therefore it is never valid to use this function with a
1974 * source ID which may have already been removed. An example is when
1975 * scheduling an idle to run in another thread with g_idle_add(): the
1976 * idle may already have run and been removed by the time this function
1977 * is called on its (now invalid) source ID. This source ID may have
1978 * been reissued, leading to the operation being performed against the
1979 * wrong source.
1980 *
1981 * Since: 2.26
1982 **/
1983 void
1984 g_source_set_name_by_id (guint tag,
1985 const char *name)
1986 {
1987 GSource *source;
1988
1989 g_return_if_fail (tag > 0);
1990
1991 source = g_main_context_find_source_by_id (NULL, tag);
1992 if (source == NULL)
1993 return;
1994
1995 g_source_set_name (source, name);
1996 }
1997
1998
1999 /**
2000 * g_source_ref:
2001 * @source: a #GSource
2002 *
2003 * Increases the reference count on a source by one.
2004 *
2005 * Returns: @source
2006 **/
2007 GSource *
2008 g_source_ref (GSource *source)
2009 {
2010 GMainContext *context;
2011
2012 g_return_val_if_fail (source != NULL, NULL);
2013
2014 context = source->context;
2015
2016 if (context)
2017 LOCK_CONTEXT (context);
2018
2019 source->ref_count++;
2020
2021 if (context)
2022 UNLOCK_CONTEXT (context);
2023
2024 return source;
2025 }
2026
2027 /* g_source_unref() but possible to call within context lock
2028 */
2029 static void
2030 g_source_unref_internal (GSource *source,
2031 GMainContext *context,
2032 gboolean have_lock)
2033 {
2034 gpointer old_cb_data = NULL;
2035 GSourceCallbackFuncs *old_cb_funcs = NULL;
2036
2037 g_return_if_fail (source != NULL);
2038
2039 if (!have_lock && context)
2040 LOCK_CONTEXT (context);
2041
2042 source->ref_count--;
2043 if (source->ref_count == 0)
2044 {
2045 old_cb_data = source->callback_data;
2046 old_cb_funcs = source->callback_funcs;
2047
2048 source->callback_data = NULL;
2049 source->callback_funcs = NULL;
2050
2051 if (context)
2052 {
2053 if (!SOURCE_DESTROYED (source))
2054 g_warning (G_STRLOC ": ref_count == 0, but source was still attached to a context!");
2055 source_remove_from_context (source, context);
2056
2057 g_hash_table_remove (context->sources, GUINT_TO_POINTER (source->source_id));
2058 }
2059
2060 if (source->source_funcs->finalize)
2061 {
2062 if (context)
2063 UNLOCK_CONTEXT (context);
2064 source->source_funcs->finalize (source);
2065 if (context)
2066 LOCK_CONTEXT (context);
2067 }
2068
2069 g_free (source->name);
2070 source->name = NULL;
2071
2072 g_slist_free (source->poll_fds);
2073 source->poll_fds = NULL;
2074
2075 g_slist_free_full (source->priv->fds, g_free);
2076
2077 g_slice_free (GSourcePrivate, source->priv);
2078 source->priv = NULL;
2079
2080 g_free (source);
2081 }
2082
2083 if (!have_lock && context)
2084 UNLOCK_CONTEXT (context);
2085
2086 if (old_cb_funcs)
2087 {
2088 if (have_lock)
2089 UNLOCK_CONTEXT (context);
2090
2091 old_cb_funcs->unref (old_cb_data);
2092
2093 if (have_lock)
2094 LOCK_CONTEXT (context);
2095 }
2096 }
2097
2098 /**
2099 * g_source_unref:
2100 * @source: a #GSource
2101 *
2102 * Decreases the reference count of a source by one. If the
2103 * resulting reference count is zero the source and associated
2104 * memory will be destroyed.
2105 **/
2106 void
2107 g_source_unref (GSource *source)
2108 {
2109 g_return_if_fail (source != NULL);
2110 #ifdef GSTREAMER_LITE
2111 if (source == NULL)
2112 return;
2113 #endif // GSTREAMER_LITE
2114
2115 g_source_unref_internal (source, source->context, FALSE);
2116 }
2117
2118 /**
2119 * g_main_context_find_source_by_id:
2120 * @context: (allow-none): a #GMainContext (if %NULL, the default context will be used)
2121 * @source_id: the source ID, as returned by g_source_get_id().
2122 *
2123 * Finds a #GSource given a pair of context and ID.
2124 *
2125 * It is a programmer error to attempt to lookup a non-existent source.
2126 *
2127 * More specifically: source IDs can be reissued after a source has been
2128 * destroyed and therefore it is never valid to use this function with a
2129 * source ID which may have already been removed. An example is when
2130 * scheduling an idle to run in another thread with g_idle_add(): the
2131 * idle may already have run and been removed by the time this function
2132 * is called on its (now invalid) source ID. This source ID may have
2133 * been reissued, leading to the operation being performed against the
2134 * wrong source.
2135 *
2136 * Returns: (transfer none): the #GSource
2137 **/
2138 GSource *
2139 g_main_context_find_source_by_id (GMainContext *context,
2140 guint source_id)
2141 {
2142 GSource *source;
2143
2144 g_return_val_if_fail (source_id > 0, NULL);
2145
2146 if (context == NULL)
2147 context = g_main_context_default ();
2148
2149 LOCK_CONTEXT (context);
2150 source = g_hash_table_lookup (context->sources, GUINT_TO_POINTER (source_id));
2151 UNLOCK_CONTEXT (context);
2152
2153 if (source && SOURCE_DESTROYED (source))
2154 source = NULL;
2155
2156 return source;
2157 }
2158
2159 /**
2160 * g_main_context_find_source_by_funcs_user_data:
2161 * @context: (allow-none): a #GMainContext (if %NULL, the default context will be used).
2162 * @funcs: the @source_funcs passed to g_source_new().
2163 * @user_data: the user data from the callback.
2164 *
2165 * Finds a source with the given source functions and user data. If
2166 * multiple sources exist with the same source function and user data,
2167 * the first one found will be returned.
2168 *
2169 * Returns: (transfer none): the source, if one was found, otherwise %NULL
2170 **/
2171 GSource *
2172 g_main_context_find_source_by_funcs_user_data (GMainContext *context,
2173 GSourceFuncs *funcs,
2174 gpointer user_data)
2175 {
2176 GSourceIter iter;
2177 GSource *source;
2178
2179 g_return_val_if_fail (funcs != NULL, NULL);
2180
2181 if (context == NULL)
2182 context = g_main_context_default ();
2183
2184 LOCK_CONTEXT (context);
2185
2186 g_source_iter_init (&iter, context, FALSE);
2187 while (g_source_iter_next (&iter, &source))
2188 {
2189 if (!SOURCE_DESTROYED (source) &&
2190 source->source_funcs == funcs &&
2191 source->callback_funcs)
2192 {
2193 GSourceFunc callback;
2194 gpointer callback_data;
2195
2196 source->callback_funcs->get (source->callback_data, source, &callback, &callback_data);
2197
2198 if (callback_data == user_data)
2199 break;
2200 }
2201 }
2202 g_source_iter_clear (&iter);
2203
2204 UNLOCK_CONTEXT (context);
2205
2206 return source;
2207 }
2208
2209 /**
2210 * g_main_context_find_source_by_user_data:
2211 * @context: a #GMainContext
2212 * @user_data: the user_data for the callback.
2213 *
2214 * Finds a source with the given user data for the callback. If
2215 * multiple sources exist with the same user data, the first
2216 * one found will be returned.
2217 *
2218 * Returns: (transfer none): the source, if one was found, otherwise %NULL
2219 **/
2220 GSource *
2221 g_main_context_find_source_by_user_data (GMainContext *context,
2222 gpointer user_data)
2223 {
2224 GSourceIter iter;
2225 GSource *source;
2226
2227 if (context == NULL)
2228 context = g_main_context_default ();
2229
2230 LOCK_CONTEXT (context);
2231
2232 g_source_iter_init (&iter, context, FALSE);
2233 while (g_source_iter_next (&iter, &source))
2234 {
2235 if (!SOURCE_DESTROYED (source) &&
2236 source->callback_funcs)
2237 {
2238 GSourceFunc callback;
2239 gpointer callback_data = NULL;
2240
2241 source->callback_funcs->get (source->callback_data, source, &callback, &callback_data);
2242
2243 if (callback_data == user_data)
2244 break;
2245 }
2246 }
2247 g_source_iter_clear (&iter);
2248
2249 UNLOCK_CONTEXT (context);
2250
2251 return source;
2252 }
2253
2254 /**
2255 * g_source_remove:
2256 * @tag: the ID of the source to remove.
2257 *
2258 * Removes the source with the given id from the default main context.
2259 *
2260 * The id of a #GSource is given by g_source_get_id(), or will be
2261 * returned by the functions g_source_attach(), g_idle_add(),
2262 * g_idle_add_full(), g_timeout_add(), g_timeout_add_full(),
2263 * g_child_watch_add(), g_child_watch_add_full(), g_io_add_watch(), and
2264 * g_io_add_watch_full().
2265 *
2266 * See also g_source_destroy(). You must use g_source_destroy() for sources
2267 * added to a non-default main context.
2268 *
2269 * It is a programmer error to attempt to remove a non-existent source.
2270 *
2271 * More specifically: source IDs can be reissued after a source has been
2272 * destroyed and therefore it is never valid to use this function with a
2273 * source ID which may have already been removed. An example is when
2274 * scheduling an idle to run in another thread with g_idle_add(): the
2275 * idle may already have run and been removed by the time this function
2276 * is called on its (now invalid) source ID. This source ID may have
2277 * been reissued, leading to the operation being performed against the
2278 * wrong source.
2279 *
2280 * Returns: For historical reasons, this function always returns %TRUE
2281 **/
2282 gboolean
2283 g_source_remove (guint tag)
2284 {
2285 GSource *source;
2286
2287 g_return_val_if_fail (tag > 0, FALSE);
2288
2289 source = g_main_context_find_source_by_id (NULL, tag);
2290 if (source)
2291 g_source_destroy (source);
2292 else
2293 g_critical ("Source ID %u was not found when attempting to remove it", tag);
2294
2295 return source != NULL;
2296 }
2297
2298 /**
2299 * g_source_remove_by_user_data:
2300 * @user_data: the user_data for the callback.
2301 *
2302 * Removes a source from the default main loop context given the user
2303 * data for the callback. If multiple sources exist with the same user
2304 * data, only one will be destroyed.
2305 *
2306 * Returns: %TRUE if a source was found and removed.
2307 **/
2308 gboolean
2309 g_source_remove_by_user_data (gpointer user_data)
2310 {
2311 GSource *source;
2312
2313 source = g_main_context_find_source_by_user_data (NULL, user_data);
2314 if (source)
2315 {
2316 g_source_destroy (source);
2317 return TRUE;
2318 }
2319 else
2320 return FALSE;
2321 }
2322
2323 /**
2324 * g_source_remove_by_funcs_user_data:
2325 * @funcs: The @source_funcs passed to g_source_new()
2326 * @user_data: the user data for the callback
2327 *
2328 * Removes a source from the default main loop context given the
2329 * source functions and user data. If multiple sources exist with the
2330 * same source functions and user data, only one will be destroyed.
2331 *
2332 * Returns: %TRUE if a source was found and removed.
2333 **/
2334 gboolean
2335 g_source_remove_by_funcs_user_data (GSourceFuncs *funcs,
2336 gpointer user_data)
2337 {
2338 GSource *source;
2339
2340 g_return_val_if_fail (funcs != NULL, FALSE);
2341
2342 source = g_main_context_find_source_by_funcs_user_data (NULL, funcs, user_data);
2343 if (source)
2344 {
2345 g_source_destroy (source);
2346 return TRUE;
2347 }
2348 else
2349 return FALSE;
2350 }
2351
2352 #ifdef G_OS_UNIX
2353 /**
2354 * g_source_add_unix_fd:
2355 * @source: a #GSource
2356 * @fd: the fd to monitor
2357 * @events: an event mask
2358 *
2359 * Monitors @fd for the IO events in @events.
2360 *
2361 * The tag returned by this function can be used to remove or modify the
2362 * monitoring of the fd using g_source_remove_unix_fd() or
2363 * g_source_modify_unix_fd().
2364 *
2365 * It is not necessary to remove the fd before destroying the source; it
2366 * will be cleaned up automatically.
2367 *
2368 * This API is only intended to be used by implementations of #GSource.
2369 * Do not call this API on a #GSource that you did not create.
2370 *
2371 * As the name suggests, this function is not available on Windows.
2372 *
2373 * Returns: an opaque tag
2374 *
2375 * Since: 2.36
2376 **/
2377 gpointer
2378 g_source_add_unix_fd (GSource *source,
2379 gint fd,
2380 GIOCondition events)
2381 {
2382 GMainContext *context;
2383 GPollFD *poll_fd;
2384
2385 g_return_val_if_fail (source != NULL, NULL);
2386 g_return_val_if_fail (!SOURCE_DESTROYED (source), NULL);
2387
2388 poll_fd = g_new (GPollFD, 1);
2389 poll_fd->fd = fd;
2390 poll_fd->events = events;
2391 poll_fd->revents = 0;
2392
2393 context = source->context;
2394
2395 if (context)
2396 LOCK_CONTEXT (context);
2397
2398 source->priv->fds = g_slist_prepend (source->priv->fds, poll_fd);
2399
2400 if (context)
2401 {
2402 if (!SOURCE_BLOCKED (source))
2403 g_main_context_add_poll_unlocked (context, source->priority, poll_fd);
2404 UNLOCK_CONTEXT (context);
2405 }
2406
2407 return poll_fd;
2408 }
2409
2410 /**
2411 * g_source_modify_unix_fd:
2412 * @source: a #GSource
2413 * @tag: the tag from g_source_add_unix_fd()
2414 * @new_events: the new event mask to watch
2415 *
2416 * Updates the event mask to watch for the fd identified by @tag.
2417 *
2418 * @tag is the tag returned from g_source_add_unix_fd().
2419 *
2420 * If you want to remove a fd, don't set its event mask to zero.
2421 * Instead, call g_source_remove_unix_fd().
2422 *
2423 * This API is only intended to be used by implementations of #GSource.
2424 * Do not call this API on a #GSource that you did not create.
2425 *
2426 * As the name suggests, this function is not available on Windows.
2427 *
2428 * Since: 2.36
2429 **/
2430 void
2431 g_source_modify_unix_fd (GSource *source,
2432 gpointer tag,
2433 GIOCondition new_events)
2434 {
2435 GMainContext *context;
2436 GPollFD *poll_fd;
2437
2438 g_return_if_fail (source != NULL);
2439 g_return_if_fail (g_slist_find (source->priv->fds, tag));
2440
2441 context = source->context;
2442 poll_fd = tag;
2443
2444 poll_fd->events = new_events;
2445
2446 if (context)
2447 g_main_context_wakeup (context);
2448 }
2449
2450 /**
2451 * g_source_remove_unix_fd:
2452 * @source: a #GSource
2453 * @tag: the tag from g_source_add_unix_fd()
2454 *
2455 * Reverses the effect of a previous call to g_source_add_unix_fd().
2456 *
2457 * You only need to call this if you want to remove an fd from being
2458 * watched while keeping the same source around. In the normal case you
2459 * will just want to destroy the source.
2460 *
2461 * This API is only intended to be used by implementations of #GSource.
2462 * Do not call this API on a #GSource that you did not create.
2463 *
2464 * As the name suggests, this function is not available on Windows.
2465 *
2466 * Since: 2.36
2467 **/
2468 void
2469 g_source_remove_unix_fd (GSource *source,
2470 gpointer tag)
2471 {
2472 GMainContext *context;
2473 GPollFD *poll_fd;
2474
2475 g_return_if_fail (source != NULL);
2476 g_return_if_fail (g_slist_find (source->priv->fds, tag));
2477
2478 context = source->context;
2479 poll_fd = tag;
2480
2481 if (context)
2482 LOCK_CONTEXT (context);
2483
2484 source->priv->fds = g_slist_remove (source->priv->fds, poll_fd);
2485
2486 if (context)
2487 {
2488 if (!SOURCE_BLOCKED (source))
2489 g_main_context_remove_poll_unlocked (context, poll_fd);
2490
2491 UNLOCK_CONTEXT (context);
2492 }
2493
2494 g_free (poll_fd);
2495 }
2496
2497 /**
2498 * g_source_query_unix_fd:
2499 * @source: a #GSource
2500 * @tag: the tag from g_source_add_unix_fd()
2501 *
2502 * Queries the events reported for the fd corresponding to @tag on
2503 * @source during the last poll.
2504 *
2505 * The return value of this function is only defined when the function
2506 * is called from the check or dispatch functions for @source.
2507 *
2508 * This API is only intended to be used by implementations of #GSource.
2509 * Do not call this API on a #GSource that you did not create.
2510 *
2511 * As the name suggests, this function is not available on Windows.
2512 *
2513 * Returns: the conditions reported on the fd
2514 *
2515 * Since: 2.36
2516 **/
2517 GIOCondition
2518 g_source_query_unix_fd (GSource *source,
2519 gpointer tag)
2520 {
2521 GPollFD *poll_fd;
2522
2523 g_return_val_if_fail (source != NULL, 0);
2524 g_return_val_if_fail (g_slist_find (source->priv->fds, tag), 0);
2525
2526 poll_fd = tag;
2527
2528 return poll_fd->revents;
2529 }
2530 #endif /* G_OS_UNIX */
2531
2532 /**
2533 * g_get_current_time:
2534 * @result: #GTimeVal structure in which to store current time.
2535 *
2536 * Equivalent to the UNIX gettimeofday() function, but portable.
2537 *
2538 * You may find g_get_real_time() to be more convenient.
2539 **/
2540 void
2541 g_get_current_time (GTimeVal *result)
2542 {
2543 #ifndef G_OS_WIN32
2544 struct timeval r;
2545
2546 g_return_if_fail (result != NULL);
2547
2548 /*this is required on alpha, there the timeval structs are int's
2549 not longs and a cast only would fail horribly*/
2550 gettimeofday (&r, NULL);
2551 result->tv_sec = r.tv_sec;
2552 result->tv_usec = r.tv_usec;
2553 #else
2554 FILETIME ft;
2555 guint64 time64;
2556
2557 g_return_if_fail (result != NULL);
2558
2559 GetSystemTimeAsFileTime (&ft);
2560 memmove (&time64, &ft, sizeof (FILETIME));
2561
2562 /* Convert from 100s of nanoseconds since 1601-01-01
2563 * to Unix epoch. Yes, this is Y2038 unsafe.
2564 */
2565 time64 -= G_GINT64_CONSTANT (116444736000000000);
2566 time64 /= 10;
2567
2568 result->tv_sec = time64 / 1000000;
2569 result->tv_usec = time64 % 1000000;
2570 #endif
2571 }
2572
2573 /**
2574 * g_get_real_time:
2575 *
2576 * Queries the system wall-clock time.
2577 *
2578 * This call is functionally equivalent to g_get_current_time() except
2579 * that the return value is often more convenient than dealing with a
2580 * #GTimeVal.
2581 *
2582 * You should only use this call if you are actually interested in the real
2583 * wall-clock time. g_get_monotonic_time() is probably more useful for
2584 * measuring intervals.
2585 *
2586 * Returns: the number of microseconds since January 1, 1970 UTC.
2587 *
2588 * Since: 2.28
2589 **/
2590 gint64
2591 g_get_real_time (void)
2592 {
2593 GTimeVal tv;
2594
2595 g_get_current_time (&tv);
2596
2597 return (((gint64) tv.tv_sec) * 1000000) + tv.tv_usec;
2598 }
2599
2600 /**
2601 * g_get_monotonic_time:
2602 *
2603 * Queries the system monotonic time.
2604 *
2605 * The monotonic clock will always increase and doesn't suffer
2606 * discontinuities when the user (or NTP) changes the system time. It
2607 * may or may not continue to tick during times where the machine is
2608 * suspended.
2609 *
2610 * We try to use the clock that corresponds as closely as possible to
2611 * the passage of time as measured by system calls such as poll() but it
2612 * may not always be possible to do this.
2613 *
2614 * Returns: the monotonic time, in microseconds
2615 *
2616 * Since: 2.28
2617 **/
2618 #if defined (G_OS_WIN32)
2619 static ULONGLONG (*g_GetTickCount64) (void) = NULL;
2620 static guint32 g_win32_tick_epoch = 0;
2621
2622 void
2623 g_clock_win32_init (void)
2624 {
2625 HMODULE kernel32;
2626
2627 g_GetTickCount64 = NULL;
2628 kernel32 = GetModuleHandle ("KERNEL32.DLL");
2629 if (kernel32 != NULL)
2630 g_GetTickCount64 = (void *) GetProcAddress (kernel32, "GetTickCount64");
2631 g_win32_tick_epoch = ((guint32)GetTickCount()) >> 31;
2632 }
2633
2634 gint64
2635 g_get_monotonic_time (void)
2636 {
2637 guint64 ticks;
2638 guint32 ticks32;
2639
2640 /* There are four sources for the monotonic time on Windows:
2641 *
2642 * Three are based on a (1 msec accuracy, but only read periodically) clock chip:
2643 * - GetTickCount (GTC)
2644 * 32bit msec counter, updated each ~15msec, wraps in ~50 days
2645 * - GetTickCount64 (GTC64)
2646 * Same as GetTickCount, but extended to 64bit, so no wrap
2647 * Only available in Vista or later
2648 * - timeGetTime (TGT)
2649 * similar to GetTickCount by default: 15msec, 50 day wrap.
2650 * available in winmm.dll (thus known as the multimedia timers)
2651 * However apps can raise the system timer clock frequency using timeBeginPeriod()
2652 * increasing the accuracy up to 1 msec, at a cost in general system performance
2653 * and battery use.
2654 *
2655 * One is based on high precision clocks:
2656 * - QueryPrecisionCounter (QPC)
2657 * This has much higher accuracy, but is not guaranteed monotonic, and
2658 * has lots of complications like clock jumps and different times on different
2659 * CPUs. It also has lower long term accuracy (i.e. it will drift compared to
2660 * the low precision clocks.
2661 *
2662 * Additionally, the precision available in the timer-based wakeup such as
2663 * MsgWaitForMultipleObjectsEx (which is what the mainloop is based on) is based
2664 * on the TGT resolution, so by default it is ~15msec, but can be increased by apps.
2665 *
2666 * The QPC timer has too many issues to be used as is. The only way it could be used
2667 * is to use it to interpolate the lower precision clocks. Firefox does something like
2668 * this:
2669 * https://bugzilla.mozilla.org/show_bug.cgi?id=363258
2670 *
2671 * However this seems quite complicated, so we're not doing this right now.
2672 *
2673 * The approach we take instead is to use the TGT timer, extending it to 64bit
2674 * either by using the GTC64 value, or if that is not available, a process local
2675 * time epoch that we increment when we detect a timer wrap (assumes that we read
2676 * the time at least once every 50 days).
2677 *
2678 * This means that:
2679 * - We have a globally consistent monotonic clock on Vista and later
2680 * - We have a locally monotonic clock on XP
2681 * - Apps that need higher precision in timeouts and clock reads can call
2682 * timeBeginPeriod() to increase it as much as they want
2683 */
2684
2685 if (g_GetTickCount64 != NULL)
2686 {
2687 guint32 ticks_as_32bit;
2688
2689 ticks = g_GetTickCount64 ();
2690 ticks32 = timeGetTime();
2691
2692 /* GTC64 and TGT are sampled at different times, however they
2693 * have the same base and source (msecs since system boot).
2694 * They can differ by as much as -16 to +16 msecs.
2695 * We can't just inject the low bits into the 64bit counter
2696 * as one of the counters can have wrapped in 32bit space and
2697 * the other not. Instead we calculate the signed difference
2698 * in 32bit space and apply that difference to the 64bit counter.
2699 */
2700 ticks_as_32bit = (guint32)ticks;
2701
2702 /* We could do some 2's complement hack, but we play it safe */
2703 if (ticks32 - ticks_as_32bit <= G_MAXINT32)
2704 ticks += ticks32 - ticks_as_32bit;
2705 else
2706 ticks -= ticks_as_32bit - ticks32;
2707 }
2708 else
2709 {
2710 guint32 epoch;
2711
2712 epoch = g_atomic_int_get (&g_win32_tick_epoch);
2713
2714 /* Must read ticks after the epoch. Then we're guaranteed
2715 * that the ticks value we read is higher or equal to any
2716 * previous ones that lead to the writing of the epoch.
2717 */
2718 ticks32 = timeGetTime();
2719
2720 /* We store the MSB of the current time as the LSB
2721 * of the epoch. Comparing these bits lets us detect when
2722 * the 32bit counter has wrapped so we can increase the
2723 * epoch.
2724 *
2725 * This will work as long as this function is called at
2726 * least once every ~24 days, which is half the wrap time
2727 * of a 32bit msec counter. I think this is pretty likely.
2728 *
2729 * Note that g_win32_tick_epoch is a process local state,
2730 * so the monotonic clock will not be the same between
2731 * processes.
2732 */
2733 if ((ticks32 >> 31) != (epoch & 1))
2734 {
2735 epoch++;
2736 g_atomic_int_set (&g_win32_tick_epoch, epoch);
2737 }
2738
2739
2740 ticks = (guint64)ticks32 | ((guint64)epoch) << 31;
2741 }
2742
2743 return ticks * 1000;
2744 }
2745 #elif defined(HAVE_MACH_MACH_TIME_H) /* Mac OS */
2746 gint64
2747 g_get_monotonic_time (void)
2748 {
2749 static mach_timebase_info_data_t timebase_info;
2750
2751 if (timebase_info.denom == 0)
2752 {
2753 /* This is a fraction that we must use to scale
2754 * mach_absolute_time() by in order to reach nanoseconds.
2755 *
2756 * We've only ever observed this to be 1/1, but maybe it could be
2757 * 1000/1 if mach time is microseconds already, or 1/1000 if
2758 * picoseconds. Try to deal nicely with that.
2759 */
2760 mach_timebase_info (&timebase_info);
2761
2762 /* We actually want microseconds... */
2763 if (timebase_info.numer % 1000 == 0)
2764 timebase_info.numer /= 1000;
2765 else
2766 timebase_info.denom *= 1000;
2767
2768 /* We want to make the numer 1 to avoid having to multiply... */
2769 if (timebase_info.denom % timebase_info.numer == 0)
2770 {
2771 timebase_info.denom /= timebase_info.numer;
2772 timebase_info.numer = 1;
2773 }
2774 else
2775 {
2776 /* We could just multiply by timebase_info.numer below, but why
2777 * bother for a case that may never actually exist...
2778 *
2779 * Plus -- performing the multiplication would risk integer
2780 * overflow. If we ever actually end up in this situation, we
2781 * should more carefully evaluate the correct course of action.
2782 */
2783 mach_timebase_info (&timebase_info); /* Get a fresh copy for a better message */
2784 g_error ("Got weird mach timebase info of %d/%d. Please file a bug against GLib.",
2785 timebase_info.numer, timebase_info.denom);
2786 }
2787 }
2788
2789 return mach_absolute_time () / timebase_info.denom;
2790 }
2791 #else
2792 gint64
2793 g_get_monotonic_time (void)
2794 {
2795 struct timespec ts;
2796 gint result;
2797
2798 result = clock_gettime (CLOCK_MONOTONIC, &ts);
2799
2800 if G_UNLIKELY (result != 0)
2801 g_error ("GLib requires working CLOCK_MONOTONIC");
2802
2803 return (((gint64) ts.tv_sec) * 1000000) + (ts.tv_nsec / 1000);
2804 }
2805 #endif
2806
2807 static void
2808 g_main_dispatch_free (gpointer dispatch)
2809 {
2810 g_slice_free (GMainDispatch, dispatch);
2811 }
2812
2813 /* Running the main loop */
2814
2815 static GMainDispatch *
2816 get_dispatch (void)
2817 {
2818 static GPrivate depth_private = G_PRIVATE_INIT (g_main_dispatch_free);
2819 GMainDispatch *dispatch;
2820
2821 dispatch = g_private_get (&depth_private);
2822
2823 if (!dispatch)
2824 {
2825 dispatch = g_slice_new0 (GMainDispatch);
2826 g_private_set (&depth_private, dispatch);
2827 }
2828
2829 return dispatch;
2830 }
2831
2832 /**
2833 * g_main_depth:
2834 *
2835 * Returns the depth of the stack of calls to
2836 * g_main_context_dispatch() on any #GMainContext in the current thread.
2837 * That is, when called from the toplevel, it gives 0. When
2838 * called from within a callback from g_main_context_iteration()
2839 * (or g_main_loop_run(), etc.) it returns 1. When called from within
2840 * a callback to a recursive call to g_main_context_iteration(),
2841 * it returns 2. And so forth.
2842 *
2843 * This function is useful in a situation like the following:
2844 * Imagine an extremely simple "garbage collected" system.
2845 *
2846 * |[<!-- language="C" -->
2847 * static GList *free_list;
2848 *
2849 * gpointer
2850 * allocate_memory (gsize size)
2851 * {
2852 * gpointer result = g_malloc (size);
2853 * free_list = g_list_prepend (free_list, result);
2854 * return result;
2855 * }
2856 *
2857 * void
2858 * free_allocated_memory (void)
2859 * {
2860 * GList *l;
2861 * for (l = free_list; l; l = l->next);
2862 * g_free (l->data);
2863 * g_list_free (free_list);
2864 * free_list = NULL;
2865 * }
2866 *
2867 * [...]
2868 *
2869 * while (TRUE);
2870 * {
2871 * g_main_context_iteration (NULL, TRUE);
2872 * free_allocated_memory();
2873 * }
2874 * ]|
2875 *
2876 * This works from an application, however, if you want to do the same
2877 * thing from a library, it gets more difficult, since you no longer
2878 * control the main loop. You might think you can simply use an idle
2879 * function to make the call to free_allocated_memory(), but that
2880 * doesn't work, since the idle function could be called from a
2881 * recursive callback. This can be fixed by using g_main_depth()
2882 *
2883 * |[<!-- language="C" -->
2884 * gpointer
2885 * allocate_memory (gsize size)
2886 * {
2887 * FreeListBlock *block = g_new (FreeListBlock, 1);
2888 * block->mem = g_malloc (size);
2889 * block->depth = g_main_depth ();
2890 * free_list = g_list_prepend (free_list, block);
2891 * return block->mem;
2892 * }
2893 *
2894 * void
2895 * free_allocated_memory (void)
2896 * {
2897 * GList *l;
2898 *
2899 * int depth = g_main_depth ();
2900 * for (l = free_list; l; );
2901 * {
2902 * GList *next = l->next;
2903 * FreeListBlock *block = l->data;
2904 * if (block->depth > depth)
2905 * {
2906 * g_free (block->mem);
2907 * g_free (block);
2908 * free_list = g_list_delete_link (free_list, l);
2909 * }
2910 *
2911 * l = next;
2912 * }
2913 * }
2914 * ]|
2915 *
2916 * There is a temptation to use g_main_depth() to solve
2917 * problems with reentrancy. For instance, while waiting for data
2918 * to be received from the network in response to a menu item,
2919 * the menu item might be selected again. It might seem that
2920 * one could make the menu item's callback return immediately
2921 * and do nothing if g_main_depth() returns a value greater than 1.
2922 * However, this should be avoided since the user then sees selecting
2923 * the menu item do nothing. Furthermore, you'll find yourself adding
2924 * these checks all over your code, since there are doubtless many,
2925 * many things that the user could do. Instead, you can use the
2926 * following techniques:
2927 *
2928 * 1. Use gtk_widget_set_sensitive() or modal dialogs to prevent
2929 * the user from interacting with elements while the main
2930 * loop is recursing.
2931 *
2932 * 2. Avoid main loop recursion in situations where you can't handle
2933 * arbitrary callbacks. Instead, structure your code so that you
2934 * simply return to the main loop and then get called again when
2935 * there is more work to do.
2936 *
2937 * Returns: The main loop recursion level in the current thread
2938 */
2939 int
2940 g_main_depth (void)
2941 {
2942 GMainDispatch *dispatch = get_dispatch ();
2943 return dispatch->depth;
2944 }
2945
2946 /**
2947 * g_main_current_source:
2948 *
2949 * Returns the currently firing source for this thread.
2950 *
2951 * Returns: (transfer none): The currently firing source or %NULL.
2952 *
2953 * Since: 2.12
2954 */
2955 GSource *
2956 g_main_current_source (void)
2957 {
2958 GMainDispatch *dispatch = get_dispatch ();
2959 return dispatch->source;
2960 }
2961
2962 /**
2963 * g_source_is_destroyed:
2964 * @source: a #GSource
2965 *
2966 * Returns whether @source has been destroyed.
2967 *
2968 * This is important when you operate upon your objects
2969 * from within idle handlers, but may have freed the object
2970 * before the dispatch of your idle handler.
2971 *
2972 * |[<!-- language="C" -->
2973 * static gboolean
2974 * idle_callback (gpointer data)
2975 * {
2976 * SomeWidget *self = data;
2977 *
2978 * GDK_THREADS_ENTER ();
2979 * // do stuff with self
2980 * self->idle_id = 0;
2981 * GDK_THREADS_LEAVE ();
2982 *
2983 * return G_SOURCE_REMOVE;
2984 * }
2985 *
2986 * static void
2987 * some_widget_do_stuff_later (SomeWidget *self)
2988 * {
2989 * self->idle_id = g_idle_add (idle_callback, self);
2990 * }
2991 *
2992 * static void
2993 * some_widget_finalize (GObject *object)
2994 * {
2995 * SomeWidget *self = SOME_WIDGET (object);
2996 *
2997 * if (self->idle_id)
2998 * g_source_remove (self->idle_id);
2999 *
3000 * G_OBJECT_CLASS (parent_class)->finalize (object);
3001 * }
3002 * ]|
3003 *
3004 * This will fail in a multi-threaded application if the
3005 * widget is destroyed before the idle handler fires due
3006 * to the use after free in the callback. A solution, to
3007 * this particular problem, is to check to if the source
3008 * has already been destroy within the callback.
3009 *
3010 * |[<!-- language="C" -->
3011 * static gboolean
3012 * idle_callback (gpointer data)
3013 * {
3014 * SomeWidget *self = data;
3015 *
3016 * GDK_THREADS_ENTER ();
3017 * if (!g_source_is_destroyed (g_main_current_source ()))
3018 * {
3019 * // do stuff with self
3020 * }
3021 * GDK_THREADS_LEAVE ();
3022 *
3023 * return FALSE;
3024 * }
3025 * ]|
3026 *
3027 * Returns: %TRUE if the source has been destroyed
3028 *
3029 * Since: 2.12
3030 */
3031 gboolean
3032 g_source_is_destroyed (GSource *source)
3033 {
3034 return SOURCE_DESTROYED (source);
3035 }
3036
3037 /* Temporarily remove all this source's file descriptors from the
3038 * poll(), so that if data comes available for one of the file descriptors
3039 * we don't continually spin in the poll()
3040 */
3041 /* HOLDS: source->context's lock */
3042 static void
3043 block_source (GSource *source)
3044 {
3045 GSList *tmp_list;
3046
3047 g_return_if_fail (!SOURCE_BLOCKED (source));
3048
3049 source->flags |= G_SOURCE_BLOCKED;
3050
3051 if (source->context)
3052 {
3053 tmp_list = source->poll_fds;
3054 while (tmp_list)
3055 {
3056 g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
3057 tmp_list = tmp_list->next;
3058 }
3059
3060 for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
3061 g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
3062 }
3063
3064 if (source->priv && source->priv->child_sources)
3065 {
3066 tmp_list = source->priv->child_sources;
3067 while (tmp_list)
3068 {
3069 block_source (tmp_list->data);
3070 tmp_list = tmp_list->next;
3071 }
3072 }
3073 }
3074
3075 /* HOLDS: source->context's lock */
3076 static void
3077 unblock_source (GSource *source)
3078 {
3079 GSList *tmp_list;
3080
3081 g_return_if_fail (SOURCE_BLOCKED (source)); /* Source already unblocked */
3082 g_return_if_fail (!SOURCE_DESTROYED (source));
3083
3084 source->flags &= ~G_SOURCE_BLOCKED;
3085
3086 tmp_list = source->poll_fds;
3087 while (tmp_list)
3088 {
3089 g_main_context_add_poll_unlocked (source->context, source->priority, tmp_list->data);
3090 tmp_list = tmp_list->next;
3091 }
3092
3093 for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
3094 g_main_context_add_poll_unlocked (source->context, source->priority, tmp_list->data);
3095
3096 if (source->priv && source->priv->child_sources)
3097 {
3098 tmp_list = source->priv->child_sources;
3099 while (tmp_list)
3100 {
3101 unblock_source (tmp_list->data);
3102 tmp_list = tmp_list->next;
3103 }
3104 }
3105 }
3106
3107 /* HOLDS: context's lock */
3108 static void
3109 g_main_dispatch (GMainContext *context)
3110 {
3111 GMainDispatch *current = get_dispatch ();
3112 guint i;
3113
3114 for (i = 0; i < context->pending_dispatches->len; i++)
3115 {
3116 GSource *source = context->pending_dispatches->pdata[i];
3117
3118 context->pending_dispatches->pdata[i] = NULL;
3119 g_assert (source);
3120
3121 source->flags &= ~G_SOURCE_READY;
3122
3123 if (!SOURCE_DESTROYED (source))
3124 {
3125 gboolean was_in_call;
3126 gpointer user_data = NULL;
3127 GSourceFunc callback = NULL;
3128 GSourceCallbackFuncs *cb_funcs;
3129 gpointer cb_data;
3130 gboolean need_destroy;
3131
3132 gboolean (*dispatch) (GSource *,
3133 GSourceFunc,
3134 gpointer);
3135 GSource *prev_source;
3136
3137 dispatch = source->source_funcs->dispatch;
3138 cb_funcs = source->callback_funcs;
3139 cb_data = source->callback_data;
3140
3141 if (cb_funcs)
3142 cb_funcs->ref (cb_data);
3143
3144 if ((source->flags & G_SOURCE_CAN_RECURSE) == 0)
3145 block_source (source);
3146
3147 was_in_call = source->flags & G_HOOK_FLAG_IN_CALL;
3148 source->flags |= G_HOOK_FLAG_IN_CALL;
3149
3150 if (cb_funcs)
3151 cb_funcs->get (cb_data, source, &callback, &user_data);
3152
3153 UNLOCK_CONTEXT (context);
3154
3155 /* These operations are safe because 'current' is thread-local
3156 * and not modified from anywhere but this function.
3157 */
3158 prev_source = current->source;
3159 current->source = source;
3160 current->depth++;
3161
3162 TRACE( GLIB_MAIN_BEFORE_DISPATCH (g_source_get_name (source)));
3163 need_destroy = !(* dispatch) (source, callback, user_data);
3164 TRACE( GLIB_MAIN_AFTER_DISPATCH (g_source_get_name (source)));
3165
3166 current->source = prev_source;
3167 current->depth--;
3168
3169 if (cb_funcs)
3170 cb_funcs->unref (cb_data);
3171
3172 LOCK_CONTEXT (context);
3173
3174 if (!was_in_call)
3175 source->flags &= ~G_HOOK_FLAG_IN_CALL;
3176
3177 if (SOURCE_BLOCKED (source) && !SOURCE_DESTROYED (source))
3178 unblock_source (source);
3179
3180 /* Note: this depends on the fact that we can't switch
3181 * sources from one main context to another
3182 */
3183 if (need_destroy && !SOURCE_DESTROYED (source))
3184 {
3185 g_assert (source->context == context);
3186 g_source_destroy_internal (source, context, TRUE);
3187 }
3188 }
3189
3190 SOURCE_UNREF (source, context);
3191 }
3192
3193 g_ptr_array_set_size (context->pending_dispatches, 0);
3194 }
3195
3196 /**
3197 * g_main_context_acquire:
3198 * @context: a #GMainContext
3199 *
3200 * Tries to become the owner of the specified context.
3201 * If some other thread is the owner of the context,
3202 * returns %FALSE immediately. Ownership is properly
3203 * recursive: the owner can require ownership again
3204 * and will release ownership when g_main_context_release()
3205 * is called as many times as g_main_context_acquire().
3206 *
3207 * You must be the owner of a context before you
3208 * can call g_main_context_prepare(), g_main_context_query(),
3209 * g_main_context_check(), g_main_context_dispatch().
3210 *
3211 * Returns: %TRUE if the operation succeeded, and
3212 * this thread is now the owner of @context.
3213 **/
3214 gboolean
3215 g_main_context_acquire (GMainContext *context)
3216 {
3217 gboolean result = FALSE;
3218 GThread *self = G_THREAD_SELF;
3219
3220 if (context == NULL)
3221 context = g_main_context_default ();
3222
3223 LOCK_CONTEXT (context);
3224
3225 if (!context->owner)
3226 {
3227 context->owner = self;
3228 g_assert (context->owner_count == 0);
3229 }
3230
3231 if (context->owner == self)
3232 {
3233 context->owner_count++;
3234 result = TRUE;
3235 }
3236
3237 UNLOCK_CONTEXT (context);
3238
3239 return result;
3240 }
3241
3242 /**
3243 * g_main_context_release:
3244 * @context: a #GMainContext
3245 *
3246 * Releases ownership of a context previously acquired by this thread
3247 * with g_main_context_acquire(). If the context was acquired multiple
3248 * times, the ownership will be released only when g_main_context_release()
3249 * is called as many times as it was acquired.
3250 **/
3251 void
3252 g_main_context_release (GMainContext *context)
3253 {
3254 if (context == NULL)
3255 context = g_main_context_default ();
3256
3257 LOCK_CONTEXT (context);
3258
3259 context->owner_count--;
3260 if (context->owner_count == 0)
3261 {
3262 context->owner = NULL;
3263
3264 if (context->waiters)
3265 {
3266 GMainWaiter *waiter = context->waiters->data;
3267 gboolean loop_internal_waiter = (waiter->mutex == &context->mutex);
3268 context->waiters = g_slist_delete_link (context->waiters,
3269 context->waiters);
3270 if (!loop_internal_waiter)
3271 g_mutex_lock (waiter->mutex);
3272
3273 g_cond_signal (waiter->cond);
3274
3275 if (!loop_internal_waiter)
3276 g_mutex_unlock (waiter->mutex);
3277 }
3278 }
3279
3280 UNLOCK_CONTEXT (context);
3281 }
3282
3283 /**
3284 * g_main_context_wait:
3285 * @context: a #GMainContext
3286 * @cond: a condition variable
3287 * @mutex: a mutex, currently held
3288 *
3289 * Tries to become the owner of the specified context,
3290 * as with g_main_context_acquire(). But if another thread
3291 * is the owner, atomically drop @mutex and wait on @cond until
3292 * that owner releases ownership or until @cond is signaled, then
3293 * try again (once) to become the owner.
3294 *
3295 * Returns: %TRUE if the operation succeeded, and
3296 * this thread is now the owner of @context.
3297 **/
3298 gboolean
3299 g_main_context_wait (GMainContext *context,
3300 GCond *cond,
3301 GMutex *mutex)
3302 {
3303 gboolean result = FALSE;
3304 GThread *self = G_THREAD_SELF;
3305 gboolean loop_internal_waiter;
3306
3307 if (context == NULL)
3308 context = g_main_context_default ();
3309
3310 if G_UNLIKELY (cond != &context->cond || mutex != &context->mutex)
3311 {
3312 static gboolean warned;
3313
3314 if (!warned)
3315 {
3316 g_critical ("WARNING!! g_main_context_wait() will be removed in a future release. "
3317 "If you see this message, please file a bug immediately.");
3318 warned = TRUE;
3319 }
3320 }
3321
3322 loop_internal_waiter = (mutex == &context->mutex);
3323
3324 if (!loop_internal_waiter)
3325 LOCK_CONTEXT (context);
3326
3327 if (context->owner && context->owner != self)
3328 {
3329 GMainWaiter waiter;
3330
3331 waiter.cond = cond;
3332 waiter.mutex = mutex;
3333
3334 context->waiters = g_slist_append (context->waiters, &waiter);
3335
3336 if (!loop_internal_waiter)
3337 UNLOCK_CONTEXT (context);
3338 g_cond_wait (cond, mutex);
3339 if (!loop_internal_waiter)
3340 LOCK_CONTEXT (context);
3341
3342 context->waiters = g_slist_remove (context->waiters, &waiter);
3343 }
3344
3345 if (!context->owner)
3346 {
3347 context->owner = self;
3348 g_assert (context->owner_count == 0);
3349 }
3350
3351 if (context->owner == self)
3352 {
3353 context->owner_count++;
3354 result = TRUE;
3355 }
3356
3357 if (!loop_internal_waiter)
3358 UNLOCK_CONTEXT (context);
3359
3360 return result;
3361 }
3362
3363 /**
3364 * g_main_context_prepare:
3365 * @context: a #GMainContext
3366 * @priority: location to store priority of highest priority
3367 * source already ready.
3368 *
3369 * Prepares to poll sources within a main loop. The resulting information
3370 * for polling is determined by calling g_main_context_query ().
3371 *
3372 * You must have successfully acquired the context with
3373 * g_main_context_acquire() before you may call this function.
3374 *
3375 * Returns: %TRUE if some source is ready to be dispatched
3376 * prior to polling.
3377 **/
3378 gboolean
3379 g_main_context_prepare (GMainContext *context,
3380 gint *priority)
3381 {
3382 gint i;
3383 gint n_ready = 0;
3384 gint current_priority = G_MAXINT;
3385 GSource *source;
3386 GSourceIter iter;
3387
3388 if (context == NULL)
3389 context = g_main_context_default ();
3390
3391 LOCK_CONTEXT (context);
3392
3393 context->time_is_fresh = FALSE;
3394
3395 if (context->in_check_or_prepare)
3396 {
3397 g_warning ("g_main_context_prepare() called recursively from within a source's check() or "
3398 "prepare() member.");
3399 UNLOCK_CONTEXT (context);
3400 return FALSE;
3401 }
3402
3403 #if 0
3404 /* If recursing, finish up current dispatch, before starting over */
3405 if (context->pending_dispatches)
3406 {
3407 if (dispatch)
3408 g_main_dispatch (context, ¤t_time);
3409
3410 UNLOCK_CONTEXT (context);
3411 return TRUE;
3412 }
3413 #endif
3414
3415 /* If recursing, clear list of pending dispatches */
3416
3417 for (i = 0; i < context->pending_dispatches->len; i++)
3418 {
3419 if (context->pending_dispatches->pdata[i])
3420 SOURCE_UNREF ((GSource *)context->pending_dispatches->pdata[i], context);
3421 }
3422 g_ptr_array_set_size (context->pending_dispatches, 0);
3423
3424 /* Prepare all sources */
3425
3426 context->timeout = -1;
3427
3428 g_source_iter_init (&iter, context, TRUE);
3429 while (g_source_iter_next (&iter, &source))
3430 {
3431 gint source_timeout = -1;
3432
3433 if (SOURCE_DESTROYED (source) || SOURCE_BLOCKED (source))
3434 continue;
3435 if ((n_ready > 0) && (source->priority > current_priority))
3436 break;
3437
3438 if (!(source->flags & G_SOURCE_READY))
3439 {
3440 gboolean result;
3441 gboolean (* prepare) (GSource *source,
3442 gint *timeout);
3443
3444 prepare = source->source_funcs->prepare;
3445
3446 if (prepare)
3447 {
3448 context->in_check_or_prepare++;
3449 UNLOCK_CONTEXT (context);
3450
3451 result = (* prepare) (source, &source_timeout);
3452
3453 LOCK_CONTEXT (context);
3454 context->in_check_or_prepare--;
3455 }
3456 else
3457 {
3458 source_timeout = -1;
3459 result = FALSE;
3460 }
3461
3462 if (result == FALSE && source->priv->ready_time != -1)
3463 {
3464 if (!context->time_is_fresh)
3465 {
3466 context->time = g_get_monotonic_time ();
3467 context->time_is_fresh = TRUE;
3468 }
3469
3470 if (source->priv->ready_time <= context->time)
3471 {
3472 source_timeout = 0;
3473 result = TRUE;
3474 }
3475 else
3476 {
3477 gint timeout;
3478
3479 /* rounding down will lead to spinning, so always round up */
3480 timeout = (source->priv->ready_time - context->time + 999) / 1000;
3481
3482 if (source_timeout < 0 || timeout < source_timeout)
3483 source_timeout = timeout;
3484 }
3485 }
3486
3487 if (result)
3488 {
3489 GSource *ready_source = source;
3490
3491 while (ready_source)
3492 {
3493 ready_source->flags |= G_SOURCE_READY;
3494 ready_source = ready_source->priv->parent_source;
3495 }
3496 }
3497 }
3498
3499 if (source->flags & G_SOURCE_READY)
3500 {
3501 n_ready++;
3502 current_priority = source->priority;
3503 context->timeout = 0;
3504 }
3505
3506 if (source_timeout >= 0)
3507 {
3508 if (context->timeout < 0)
3509 context->timeout = source_timeout;
3510 else
3511 context->timeout = MIN (context->timeout, source_timeout);
3512 }
3513 }
3514 g_source_iter_clear (&iter);
3515
3516 UNLOCK_CONTEXT (context);
3517
3518 if (priority)
3519 *priority = current_priority;
3520
3521 return (n_ready > 0);
3522 }
3523
3524 /**
3525 * g_main_context_query:
3526 * @context: a #GMainContext
3527 * @max_priority: maximum priority source to check
3528 * @timeout_: (out): location to store timeout to be used in polling
3529 * @fds: (out caller-allocates) (array length=n_fds): location to
3530 * store #GPollFD records that need to be polled.
3531 * @n_fds: length of @fds.
3532 *
3533 * Determines information necessary to poll this main loop.
3534 *
3535 * You must have successfully acquired the context with
3536 * g_main_context_acquire() before you may call this function.
3537 *
3538 * Returns: the number of records actually stored in @fds,
3539 * or, if more than @n_fds records need to be stored, the number
3540 * of records that need to be stored.
3541 **/
3542 gint
3543 g_main_context_query (GMainContext *context,
3544 gint max_priority,
3545 gint *timeout,
3546 GPollFD *fds,
3547 gint n_fds)
3548 {
3549 gint n_poll;
3550 GPollRec *pollrec;
3551
3552 LOCK_CONTEXT (context);
3553
3554 pollrec = context->poll_records;
3555 n_poll = 0;
3556 while (pollrec && max_priority >= pollrec->priority)
3557 {
3558 /* We need to include entries with fd->events == 0 in the array because
3559 * otherwise if the application changes fd->events behind our back and
3560 * makes it non-zero, we'll be out of sync when we check the fds[] array.
3561 * (Changing fd->events after adding an FD wasn't an anticipated use of
3562 * this API, but it occurs in practice.) */
3563 if (n_poll < n_fds)
3564 {
3565 fds[n_poll].fd = pollrec->fd->fd;
3566 /* In direct contradiction to the Unix98 spec, IRIX runs into
3567 * difficulty if you pass in POLLERR, POLLHUP or POLLNVAL
3568 * flags in the events field of the pollfd while it should
3569 * just ignoring them. So we mask them out here.
3570 */
3571 fds[n_poll].events = pollrec->fd->events & ~(G_IO_ERR|G_IO_HUP|G_IO_NVAL);
3572 fds[n_poll].revents = 0;
3573 }
3574
3575 pollrec = pollrec->next;
3576 n_poll++;
3577 }
3578
3579 context->poll_changed = FALSE;
3580
3581 if (timeout)
3582 {
3583 *timeout = context->timeout;
3584 if (*timeout != 0)
3585 context->time_is_fresh = FALSE;
3586 }
3587
3588 UNLOCK_CONTEXT (context);
3589
3590 return n_poll;
3591 }
3592
3593 /**
3594 * g_main_context_check:
3595 * @context: a #GMainContext
3596 * @max_priority: the maximum numerical priority of sources to check
3597 * @fds: (array length=n_fds): array of #GPollFD's that was passed to
3598 * the last call to g_main_context_query()
3599 * @n_fds: return value of g_main_context_query()
3600 *
3601 * Passes the results of polling back to the main loop.
3602 *
3603 * You must have successfully acquired the context with
3604 * g_main_context_acquire() before you may call this function.
3605 *
3606 * Returns: %TRUE if some sources are ready to be dispatched.
3607 **/
3608 gboolean
3609 g_main_context_check (GMainContext *context,
3610 gint max_priority,
3611 GPollFD *fds,
3612 gint n_fds)
3613 {
3614 GSource *source;
3615 GSourceIter iter;
3616 GPollRec *pollrec;
3617 gint n_ready = 0;
3618 gint i;
3619
3620 LOCK_CONTEXT (context);
3621
3622 if (context->in_check_or_prepare)
3623 {
3624 g_warning ("g_main_context_check() called recursively from within a source's check() or "
3625 "prepare() member.");
3626 UNLOCK_CONTEXT (context);
3627 return FALSE;
3628 }
3629
3630 if (context->wake_up_rec.revents)
3631 g_wakeup_acknowledge (context->wakeup);
3632
3633 /* If the set of poll file descriptors changed, bail out
3634 * and let the main loop rerun
3635 */
3636 if (context->poll_changed)
3637 {
3638 UNLOCK_CONTEXT (context);
3639 return FALSE;
3640 }
3641
3642 pollrec = context->poll_records;
3643 i = 0;
3644 while (i < n_fds)
3645 {
3646 if (pollrec->fd->events)
3647 pollrec->fd->revents = fds[i].revents;
3648
3649 pollrec = pollrec->next;
3650 i++;
3651 }
3652
3653 g_source_iter_init (&iter, context, TRUE);
3654 while (g_source_iter_next (&iter, &source))
3655 {
3656 if (SOURCE_DESTROYED (source) || SOURCE_BLOCKED (source))
3657 continue;
3658 if ((n_ready > 0) && (source->priority > max_priority))
3659 break;
3660
3661 if (!(source->flags & G_SOURCE_READY))
3662 {
3663 gboolean result;
3664 gboolean (* check) (GSource *source);
3665
3666 check = source->source_funcs->check;
3667
3668 if (check)
3669 {
3670 /* If the check function is set, call it. */
3671 context->in_check_or_prepare++;
3672 UNLOCK_CONTEXT (context);
3673
3674 result = (* check) (source);
3675
3676 LOCK_CONTEXT (context);
3677 context->in_check_or_prepare--;
3678 }
3679 else
3680 result = FALSE;
3681
3682 if (result == FALSE)
3683 {
3684 GSList *tmp_list;
3685
3686 /* If not already explicitly flagged ready by ->check()
3687 * (or if we have no check) then we can still be ready if
3688 * any of our fds poll as ready.
3689 */
3690 for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next)
3691 {
3692 GPollFD *pollfd = tmp_list->data;
3693
3694 if (pollfd->revents)
3695 {
3696 result = TRUE;
3697 break;
3698 }
3699 }
3700 }
3701
3702 if (result == FALSE && source->priv->ready_time != -1)
3703 {
3704 if (!context->time_is_fresh)
3705 {
3706 context->time = g_get_monotonic_time ();
3707 context->time_is_fresh = TRUE;
3708 }
3709
3710 if (source->priv->ready_time <= context->time)
3711 result = TRUE;
3712 }
3713
3714 if (result)
3715 {
3716 GSource *ready_source = source;
3717
3718 while (ready_source)
3719 {
3720 ready_source->flags |= G_SOURCE_READY;
3721 ready_source = ready_source->priv->parent_source;
3722 }
3723 }
3724 }
3725
3726 if (source->flags & G_SOURCE_READY)
3727 {
3728 source->ref_count++;
3729 g_ptr_array_add (context->pending_dispatches, source);
3730
3731 n_ready++;
3732
3733 /* never dispatch sources with less priority than the first
3734 * one we choose to dispatch
3735 */
3736 max_priority = source->priority;
3737 }
3738 }
3739 g_source_iter_clear (&iter);
3740
3741 UNLOCK_CONTEXT (context);
3742
3743 return n_ready > 0;
3744 }
3745
3746 /**
3747 * g_main_context_dispatch:
3748 * @context: a #GMainContext
3749 *
3750 * Dispatches all pending sources.
3751 *
3752 * You must have successfully acquired the context with
3753 * g_main_context_acquire() before you may call this function.
3754 **/
3755 void
3756 g_main_context_dispatch (GMainContext *context)
3757 {
3758 LOCK_CONTEXT (context);
3759
3760 if (context->pending_dispatches->len > 0)
3761 {
3762 g_main_dispatch (context);
3763 }
3764
3765 UNLOCK_CONTEXT (context);
3766 }
3767
3768 /* HOLDS context lock */
3769 static gboolean
3770 g_main_context_iterate (GMainContext *context,
3771 gboolean block,
3772 gboolean dispatch,
3773 GThread *self)
3774 {
3775 gint max_priority;
3776 gint timeout;
3777 gboolean some_ready;
3778 gint nfds, allocated_nfds;
3779 GPollFD *fds = NULL;
3780
3781 UNLOCK_CONTEXT (context);
3782
3783 if (!g_main_context_acquire (context))
3784 {
3785 gboolean got_ownership;
3786
3787 LOCK_CONTEXT (context);
3788
3789 if (!block)
3790 return FALSE;
3791
3792 got_ownership = g_main_context_wait (context,
3793 &context->cond,
3794 &context->mutex);
3795
3796 if (!got_ownership)
3797 return FALSE;
3798 }
3799 else
3800 LOCK_CONTEXT (context);
3801
3802 if (!context->cached_poll_array)
3803 {
3804 context->cached_poll_array_size = context->n_poll_records;
3805 context->cached_poll_array = g_new (GPollFD, context->n_poll_records);
3806 }
3807
3808 allocated_nfds = context->cached_poll_array_size;
3809 fds = context->cached_poll_array;
3810
3811 UNLOCK_CONTEXT (context);
3812
3813 g_main_context_prepare (context, &max_priority);
3814
3815 while ((nfds = g_main_context_query (context, max_priority, &timeout, fds,
3816 allocated_nfds)) > allocated_nfds)
3817 {
3818 LOCK_CONTEXT (context);
3819 g_free (fds);
3820 context->cached_poll_array_size = allocated_nfds = nfds;
3821 context->cached_poll_array = fds = g_new (GPollFD, nfds);
3822 UNLOCK_CONTEXT (context);
3823 }
3824
3825 if (!block)
3826 timeout = 0;
3827
3828 g_main_context_poll (context, timeout, max_priority, fds, nfds);
3829
3830 some_ready = g_main_context_check (context, max_priority, fds, nfds);
3831
3832 if (dispatch)
3833 g_main_context_dispatch (context);
3834
3835 g_main_context_release (context);
3836
3837 LOCK_CONTEXT (context);
3838
3839 return some_ready;
3840 }
3841
3842 /**
3843 * g_main_context_pending:
3844 * @context: (allow-none): a #GMainContext (if %NULL, the default context will be used)
3845 *
3846 * Checks if any sources have pending events for the given context.
3847 *
3848 * Returns: %TRUE if events are pending.
3849 **/
3850 gboolean
3851 g_main_context_pending (GMainContext *context)
3852 {
3853 gboolean retval;
3854
3855 if (!context)
3856 context = g_main_context_default();
3857
3858 LOCK_CONTEXT (context);
3859 retval = g_main_context_iterate (context, FALSE, FALSE, G_THREAD_SELF);
3860 UNLOCK_CONTEXT (context);
3861
3862 return retval;
3863 }
3864
3865 /**
3866 * g_main_context_iteration:
3867 * @context: (allow-none): a #GMainContext (if %NULL, the default context will be used)
3868 * @may_block: whether the call may block.
3869 *
3870 * Runs a single iteration for the given main loop. This involves
3871 * checking to see if any event sources are ready to be processed,
3872 * then if no events sources are ready and @may_block is %TRUE, waiting
3873 * for a source to become ready, then dispatching the highest priority
3874 * events sources that are ready. Otherwise, if @may_block is %FALSE
3875 * sources are not waited to become ready, only those highest priority
3876 * events sources will be dispatched (if any), that are ready at this
3877 * given moment without further waiting.
3878 *
3879 * Note that even when @may_block is %TRUE, it is still possible for
3880 * g_main_context_iteration() to return %FALSE, since the wait may
3881 * be interrupted for other reasons than an event source becoming ready.
3882 *
3883 * Returns: %TRUE if events were dispatched.
3884 **/
3885 gboolean
3886 g_main_context_iteration (GMainContext *context, gboolean may_block)
3887 {
3888 gboolean retval;
3889
3890 if (!context)
3891 context = g_main_context_default();
3892
3893 LOCK_CONTEXT (context);
3894 retval = g_main_context_iterate (context, may_block, TRUE, G_THREAD_SELF);
3895 UNLOCK_CONTEXT (context);
3896
3897 return retval;
3898 }
3899
3900 /**
3901 * g_main_loop_new:
3902 * @context: (allow-none): a #GMainContext (if %NULL, the default context will be used).
3903 * @is_running: set to %TRUE to indicate that the loop is running. This
3904 * is not very important since calling g_main_loop_run() will set this to
3905 * %TRUE anyway.
3906 *
3907 * Creates a new #GMainLoop structure.
3908 *
3909 * Returns: a new #GMainLoop.
3910 **/
3911 GMainLoop *
3912 g_main_loop_new (GMainContext *context,
3913 gboolean is_running)
3914 {
3915 GMainLoop *loop;
3916
3917 if (!context)
3918 context = g_main_context_default();
3919
3920 g_main_context_ref (context);
3921
3922 loop = g_new0 (GMainLoop, 1);
3923 loop->context = context;
3924 loop->is_running = is_running != FALSE;
3925 loop->ref_count = 1;
3926
3927 return loop;
3928 }
3929
3930 /**
3931 * g_main_loop_ref:
3932 * @loop: a #GMainLoop
3933 *
3934 * Increases the reference count on a #GMainLoop object by one.
3935 *
3936 * Returns: @loop
3937 **/
3938 GMainLoop *
3939 g_main_loop_ref (GMainLoop *loop)
3940 {
3941 g_return_val_if_fail (loop != NULL, NULL);
3942 g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL);
3943
3944 g_atomic_int_inc (&loop->ref_count);
3945
3946 return loop;
3947 }
3948
3949 /**
3950 * g_main_loop_unref:
3951 * @loop: a #GMainLoop
3952 *
3953 * Decreases the reference count on a #GMainLoop object by one. If
3954 * the result is zero, free the loop and free all associated memory.
3955 **/
3956 void
3957 g_main_loop_unref (GMainLoop *loop)
3958 {
3959 g_return_if_fail (loop != NULL);
3960 g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);
3961
3962 if (!g_atomic_int_dec_and_test (&loop->ref_count))
3963 return;
3964
3965 g_main_context_unref (loop->context);
3966 g_free (loop);
3967 }
3968
3969 /**
3970 * g_main_loop_run:
3971 * @loop: a #GMainLoop
3972 *
3973 * Runs a main loop until g_main_loop_quit() is called on the loop.
3974 * If this is called for the thread of the loop's #GMainContext,
3975 * it will process events from the loop, otherwise it will
3976 * simply wait.
3977 **/
3978 void
3979 g_main_loop_run (GMainLoop *loop)
3980 {
3981 GThread *self = G_THREAD_SELF;
3982
3983 g_return_if_fail (loop != NULL);
3984 g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);
3985
3986 if (!g_main_context_acquire (loop->context))
3987 {
3988 gboolean got_ownership = FALSE;
3989
3990 /* Another thread owns this context */
3991 LOCK_CONTEXT (loop->context);
3992
3993 g_atomic_int_inc (&loop->ref_count);
3994
3995 if (!loop->is_running)
3996 loop->is_running = TRUE;
3997
3998 while (loop->is_running && !got_ownership)
3999 got_ownership = g_main_context_wait (loop->context,
4000 &loop->context->cond,
4001 &loop->context->mutex);
4002
4003 if (!loop->is_running)
4004 {
4005 UNLOCK_CONTEXT (loop->context);
4006 if (got_ownership)
4007 g_main_context_release (loop->context);
4008 g_main_loop_unref (loop);
4009 return;
4010 }
4011
4012 g_assert (got_ownership);
4013 }
4014 else
4015 LOCK_CONTEXT (loop->context);
4016
4017 if (loop->context->in_check_or_prepare)
4018 {
4019 g_warning ("g_main_loop_run(): called recursively from within a source's "
4020 "check() or prepare() member, iteration not possible.");
4021 return;
4022 }
4023
4024 g_atomic_int_inc (&loop->ref_count);
4025 loop->is_running = TRUE;
4026 while (loop->is_running)
4027 g_main_context_iterate (loop->context, TRUE, TRUE, self);
4028
4029 UNLOCK_CONTEXT (loop->context);
4030
4031 g_main_context_release (loop->context);
4032
4033 g_main_loop_unref (loop);
4034 }
4035
4036 /**
4037 * g_main_loop_quit:
4038 * @loop: a #GMainLoop
4039 *
4040 * Stops a #GMainLoop from running. Any calls to g_main_loop_run()
4041 * for the loop will return.
4042 *
4043 * Note that sources that have already been dispatched when
4044 * g_main_loop_quit() is called will still be executed.
4045 **/
4046 void
4047 g_main_loop_quit (GMainLoop *loop)
4048 {
4049 g_return_if_fail (loop != NULL);
4050 g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);
4051
4052 LOCK_CONTEXT (loop->context);
4053 loop->is_running = FALSE;
4054 g_wakeup_signal (loop->context->wakeup);
4055
4056 g_cond_broadcast (&loop->context->cond);
4057
4058 UNLOCK_CONTEXT (loop->context);
4059 }
4060
4061 /**
4062 * g_main_loop_is_running:
4063 * @loop: a #GMainLoop.
4064 *
4065 * Checks to see if the main loop is currently being run via g_main_loop_run().
4066 *
4067 * Returns: %TRUE if the mainloop is currently being run.
4068 **/
4069 gboolean
4070 g_main_loop_is_running (GMainLoop *loop)
4071 {
4072 g_return_val_if_fail (loop != NULL, FALSE);
4073 g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, FALSE);
4074
4075 return loop->is_running;
4076 }
4077
4078 /**
4079 * g_main_loop_get_context:
4080 * @loop: a #GMainLoop.
4081 *
4082 * Returns the #GMainContext of @loop.
4083 *
4084 * Returns: (transfer none): the #GMainContext of @loop
4085 **/
4086 GMainContext *
4087 g_main_loop_get_context (GMainLoop *loop)
4088 {
4089 g_return_val_if_fail (loop != NULL, NULL);
4090 g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL);
4091
4092 return loop->context;
4093 }
4094
4095 /* HOLDS: context's lock */
4096 static void
4097 g_main_context_poll (GMainContext *context,
4098 gint timeout,
4099 gint priority,
4100 GPollFD *fds,
4101 gint n_fds)
4102 {
4103 #ifdef G_MAIN_POLL_DEBUG
4104 GTimer *poll_timer;
4105 GPollRec *pollrec;
4106 gint i;
4107 #endif
4108
4109 GPollFunc poll_func;
4110
4111 if (n_fds || timeout != 0)
4112 {
4113 #ifdef G_MAIN_POLL_DEBUG
4114 poll_timer = NULL;
4115 if (_g_main_poll_debug)
4116 {
4117 g_print ("polling context=%p n=%d timeout=%d\n",
4118 context, n_fds, timeout);
4119 poll_timer = g_timer_new ();
4120 }
4121 #endif
4122
4123 LOCK_CONTEXT (context);
4124
4125 poll_func = context->poll_func;
4126
4127 UNLOCK_CONTEXT (context);
4128 if ((*poll_func) (fds, n_fds, timeout) < 0 && errno != EINTR)
4129 {
4130 #ifndef G_OS_WIN32
4131 g_warning ("poll(2) failed due to: %s.",
4132 g_strerror (errno));
4133 #else
4134 /* If g_poll () returns -1, it has already called g_warning() */
4135 #endif
4136 }
4137
4138 #ifdef G_MAIN_POLL_DEBUG
4139 if (_g_main_poll_debug)
4140 {
4141 LOCK_CONTEXT (context);
4142
4143 g_print ("g_main_poll(%d) timeout: %d - elapsed %12.10f seconds",
4144 n_fds,
4145 timeout,
4146 g_timer_elapsed (poll_timer, NULL));
4147 g_timer_destroy (poll_timer);
4148 pollrec = context->poll_records;
4149
4150 while (pollrec != NULL)
4151 {
4152 i = 0;
4153 while (i < n_fds)
4154 {
4155 if (fds[i].fd == pollrec->fd->fd &&
4156 pollrec->fd->events &&
4157 fds[i].revents)
4158 {
4159 g_print (" [" G_POLLFD_FORMAT " :", fds[i].fd);
4160 if (fds[i].revents & G_IO_IN)
4161 g_print ("i");
4162 if (fds[i].revents & G_IO_OUT)
4163 g_print ("o");
4164 if (fds[i].revents & G_IO_PRI)
4165 g_print ("p");
4166 if (fds[i].revents & G_IO_ERR)
4167 g_print ("e");
4168 if (fds[i].revents & G_IO_HUP)
4169 g_print ("h");
4170 if (fds[i].revents & G_IO_NVAL)
4171 g_print ("n");
4172 g_print ("]");
4173 }
4174 i++;
4175 }
4176 pollrec = pollrec->next;
4177 }
4178 g_print ("\n");
4179
4180 UNLOCK_CONTEXT (context);
4181 }
4182 #endif
4183 } /* if (n_fds || timeout != 0) */
4184 }
4185
4186 /**
4187 * g_main_context_add_poll:
4188 * @context: (allow-none): a #GMainContext (or %NULL for the default context)
4189 * @fd: a #GPollFD structure holding information about a file
4190 * descriptor to watch.
4191 * @priority: the priority for this file descriptor which should be
4192 * the same as the priority used for g_source_attach() to ensure that the
4193 * file descriptor is polled whenever the results may be needed.
4194 *
4195 * Adds a file descriptor to the set of file descriptors polled for
4196 * this context. This will very seldom be used directly. Instead
4197 * a typical event source will use g_source_add_unix_fd() instead.
4198 **/
4199 void
4200 g_main_context_add_poll (GMainContext *context,
4201 GPollFD *fd,
4202 gint priority)
4203 {
4204 if (!context)
4205 context = g_main_context_default ();
4206
4207 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
4208 g_return_if_fail (fd);
4209
4210 LOCK_CONTEXT (context);
4211 g_main_context_add_poll_unlocked (context, priority, fd);
4212 UNLOCK_CONTEXT (context);
4213 }
4214
4215 /* HOLDS: main_loop_lock */
4216 static void
4217 g_main_context_add_poll_unlocked (GMainContext *context,
4218 gint priority,
4219 GPollFD *fd)
4220 {
4221 GPollRec *prevrec, *nextrec;
4222 GPollRec *newrec = g_slice_new (GPollRec);
4223 #ifdef GSTREAMER_LITE
4224 if (newrec == NULL) {
4225 return;
4226 }
4227 #endif // GSTREAMER_LITE
4228
4229 /* This file descriptor may be checked before we ever poll */
4230 fd->revents = 0;
4231 newrec->fd = fd;
4232 newrec->priority = priority;
4233
4234 prevrec = context->poll_records_tail;
4235 nextrec = NULL;
4236 while (prevrec && priority < prevrec->priority)
4237 {
4238 nextrec = prevrec;
4239 prevrec = prevrec->prev;
4240 }
4241
4242 if (prevrec)
4243 prevrec->next = newrec;
4244 else
4245 context->poll_records = newrec;
4246
4247 newrec->prev = prevrec;
4248 newrec->next = nextrec;
4249
4250 if (nextrec)
4251 nextrec->prev = newrec;
4252 else
4253 context->poll_records_tail = newrec;
4254
4255 context->n_poll_records++;
4256
4257 context->poll_changed = TRUE;
4258
4259 /* Now wake up the main loop if it is waiting in the poll() */
4260 g_wakeup_signal (context->wakeup);
4261 }
4262
4263 /**
4264 * g_main_context_remove_poll:
4265 * @context:a #GMainContext
4266 * @fd: a #GPollFD descriptor previously added with g_main_context_add_poll()
4267 *
4268 * Removes file descriptor from the set of file descriptors to be
4269 * polled for a particular context.
4270 **/
4271 void
4272 g_main_context_remove_poll (GMainContext *context,
4273 GPollFD *fd)
4274 {
4275 if (!context)
4276 context = g_main_context_default ();
4277
4278 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
4279 g_return_if_fail (fd);
4280
4281 LOCK_CONTEXT (context);
4282 g_main_context_remove_poll_unlocked (context, fd);
4283 UNLOCK_CONTEXT (context);
4284 }
4285
4286 static void
4287 g_main_context_remove_poll_unlocked (GMainContext *context,
4288 GPollFD *fd)
4289 {
4290 GPollRec *pollrec, *prevrec, *nextrec;
4291
4292 prevrec = NULL;
4293 pollrec = context->poll_records;
4294
4295 while (pollrec)
4296 {
4297 nextrec = pollrec->next;
4298 if (pollrec->fd == fd)
4299 {
4300 if (prevrec != NULL)
4301 prevrec->next = nextrec;
4302 else
4303 context->poll_records = nextrec;
4304
4305 if (nextrec != NULL)
4306 nextrec->prev = prevrec;
4307 else
4308 context->poll_records_tail = prevrec;
4309
4310 g_slice_free (GPollRec, pollrec);
4311
4312 context->n_poll_records--;
4313 break;
4314 }
4315 prevrec = pollrec;
4316 pollrec = nextrec;
4317 }
4318
4319 context->poll_changed = TRUE;
4320
4321 /* Now wake up the main loop if it is waiting in the poll() */
4322 g_wakeup_signal (context->wakeup);
4323 }
4324
4325 /**
4326 * g_source_get_current_time:
4327 * @source: a #GSource
4328 * @timeval: #GTimeVal structure in which to store current time.
4329 *
4330 * This function ignores @source and is otherwise the same as
4331 * g_get_current_time().
4332 *
4333 * Deprecated: 2.28: use g_source_get_time() instead
4334 **/
4335 void
4336 g_source_get_current_time (GSource *source,
4337 GTimeVal *timeval)
4338 {
4339 g_get_current_time (timeval);
4340 }
4341
4342 /**
4343 * g_source_get_time:
4344 * @source: a #GSource
4345 *
4346 * Gets the time to be used when checking this source. The advantage of
4347 * calling this function over calling g_get_monotonic_time() directly is
4348 * that when checking multiple sources, GLib can cache a single value
4349 * instead of having to repeatedly get the system monotonic time.
4350 *
4351 * The time here is the system monotonic time, if available, or some
4352 * other reasonable alternative otherwise. See g_get_monotonic_time().
4353 *
4354 * Returns: the monotonic time in microseconds
4355 *
4356 * Since: 2.28
4357 **/
4358 gint64
4359 g_source_get_time (GSource *source)
4360 {
4361 GMainContext *context;
4362 gint64 result;
4363
4364 g_return_val_if_fail (source->context != NULL, 0);
4365
4366 context = source->context;
4367
4368 LOCK_CONTEXT (context);
4369
4370 if (!context->time_is_fresh)
4371 {
4372 context->time = g_get_monotonic_time ();
4373 context->time_is_fresh = TRUE;
4374 }
4375
4376 result = context->time;
4377
4378 UNLOCK_CONTEXT (context);
4379
4380 return result;
4381 }
4382
4383 /**
4384 * g_main_context_set_poll_func:
4385 * @context: a #GMainContext
4386 * @func: the function to call to poll all file descriptors
4387 *
4388 * Sets the function to use to handle polling of file descriptors. It
4389 * will be used instead of the poll() system call
4390 * (or GLib's replacement function, which is used where
4391 * poll() isn't available).
4392 *
4393 * This function could possibly be used to integrate the GLib event
4394 * loop with an external event loop.
4395 **/
4396 void
4397 g_main_context_set_poll_func (GMainContext *context,
4398 GPollFunc func)
4399 {
4400 if (!context)
4401 context = g_main_context_default ();
4402
4403 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
4404
4405 LOCK_CONTEXT (context);
4406
4407 if (func)
4408 context->poll_func = func;
4409 else
4410 context->poll_func = g_poll;
4411
4412 UNLOCK_CONTEXT (context);
4413 }
4414
4415 /**
4416 * g_main_context_get_poll_func:
4417 * @context: a #GMainContext
4418 *
4419 * Gets the poll function set by g_main_context_set_poll_func().
4420 *
4421 * Returns: the poll function
4422 **/
4423 GPollFunc
4424 g_main_context_get_poll_func (GMainContext *context)
4425 {
4426 GPollFunc result;
4427
4428 if (!context)
4429 context = g_main_context_default ();
4430
4431 g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL);
4432
4433 LOCK_CONTEXT (context);
4434 result = context->poll_func;
4435 UNLOCK_CONTEXT (context);
4436
4437 return result;
4438 }
4439
4440 /**
4441 * g_main_context_wakeup:
4442 * @context: a #GMainContext
4443 *
4444 * If @context is currently blocking in g_main_context_iteration()
4445 * waiting for a source to become ready, cause it to stop blocking
4446 * and return. Otherwise, cause the next invocation of
4447 * g_main_context_iteration() to return without blocking.
4448 *
4449 * This API is useful for low-level control over #GMainContext; for
4450 * example, integrating it with main loop implementations such as
4451 * #GMainLoop.
4452 *
4453 * Another related use for this function is when implementing a main
4454 * loop with a termination condition, computed from multiple threads:
4455 *
4456 * |[<!-- language="C" -->
4457 * #define NUM_TASKS 10
4458 * static volatile gint tasks_remaining = NUM_TASKS;
4459 * ...
4460 *
4461 * while (g_atomic_int_get (&tasks_remaining) != 0)
4462 * g_main_context_iteration (NULL, TRUE);
4463 * ]|
4464 *
4465 * Then in a thread:
4466 * |[<!-- language="C" -->
4467 * perform_work();
4468 *
4469 * if (g_atomic_int_dec_and_test (&tasks_remaining))
4470 * g_main_context_wakeup (NULL);
4471 * ]|
4472 **/
4473 void
4474 g_main_context_wakeup (GMainContext *context)
4475 {
4476 if (!context)
4477 context = g_main_context_default ();
4478
4479 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
4480
4481 g_wakeup_signal (context->wakeup);
4482 }
4483
4484 /**
4485 * g_main_context_is_owner:
4486 * @context: a #GMainContext
4487 *
4488 * Determines whether this thread holds the (recursive)
4489 * ownership of this #GMainContext. This is useful to
4490 * know before waiting on another thread that may be
4491 * blocking to get ownership of @context.
4492 *
4493 * Returns: %TRUE if current thread is owner of @context.
4494 *
4495 * Since: 2.10
4496 **/
4497 gboolean
4498 g_main_context_is_owner (GMainContext *context)
4499 {
4500 gboolean is_owner;
4501
4502 if (!context)
4503 context = g_main_context_default ();
4504
4505 LOCK_CONTEXT (context);
4506 is_owner = context->owner == G_THREAD_SELF;
4507 UNLOCK_CONTEXT (context);
4508
4509 return is_owner;
4510 }
4511
4512 /* Timeouts */
4513
4514 static void
4515 g_timeout_set_expiration (GTimeoutSource *timeout_source,
4516 gint64 current_time)
4517 {
4518 gint64 expiration;
4519
4520 expiration = current_time + (guint64) timeout_source->interval * 1000;
4521
4522 if (timeout_source->seconds)
4523 {
4524 gint64 remainder;
4525 static gint timer_perturb = -1;
4526
4527 if (timer_perturb == -1)
4528 {
4529 /*
4530 * we want a per machine/session unique 'random' value; try the dbus
4531 * address first, that has a UUID in it. If there is no dbus, use the
4532 * hostname for hashing.
4533 */
4534 const char *session_bus_address = g_getenv ("DBUS_SESSION_BUS_ADDRESS");
4535 if (!session_bus_address)
4536 session_bus_address = g_getenv ("HOSTNAME");
4537 if (session_bus_address)
4538 timer_perturb = ABS ((gint) g_str_hash (session_bus_address)) % 1000000;
4539 else
4540 timer_perturb = 0;
4541 }
4542
4543 /* We want the microseconds part of the timeout to land on the
4544 * 'timer_perturb' mark, but we need to make sure we don't try to
4545 * set the timeout in the past. We do this by ensuring that we
4546 * always only *increase* the expiration time by adding a full
4547 * second in the case that the microsecond portion decreases.
4548 */
4549 expiration -= timer_perturb;
4550
4551 remainder = expiration % 1000000;
4552 if (remainder >= 1000000/4)
4553 expiration += 1000000;
4554
4555 expiration -= remainder;
4556 expiration += timer_perturb;
4557 }
4558
4559 g_source_set_ready_time ((GSource *) timeout_source, expiration);
4560 }
4561
4562 static gboolean
4563 g_timeout_dispatch (GSource *source,
4564 GSourceFunc callback,
4565 gpointer user_data)
4566 {
4567 GTimeoutSource *timeout_source = (GTimeoutSource *)source;
4568 gboolean again;
4569
4570 if (!callback)
4571 {
4572 g_warning ("Timeout source dispatched without callback\n"
4573 "You must call g_source_set_callback().");
4574 return FALSE;
4575 }
4576
4577 again = callback (user_data);
4578
4579 if (again)
4580 g_timeout_set_expiration (timeout_source, g_source_get_time (source));
4581
4582 return again;
4583 }
4584
4585 /**
4586 * g_timeout_source_new:
4587 * @interval: the timeout interval in milliseconds.
4588 *
4589 * Creates a new timeout source.
4590 *
4591 * The source will not initially be associated with any #GMainContext
4592 * and must be added to one with g_source_attach() before it will be
4593 * executed.
4594 *
4595 * The interval given is in terms of monotonic time, not wall clock
4596 * time. See g_get_monotonic_time().
4597 *
4598 * Returns: the newly-created timeout source
4599 **/
4600 GSource *
4601 g_timeout_source_new (guint interval)
4602 {
4603 GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource));
4604 #ifdef GSTREAMER_LITE
4605 if (source == NULL)
4606 return NULL;
4607 #endif // GSTREAMER_LITE
4608 GTimeoutSource *timeout_source = (GTimeoutSource *)source;
4609
4610 timeout_source->interval = interval;
4611 g_timeout_set_expiration (timeout_source, g_get_monotonic_time ());
4612
4613 return source;
4614 }
4615
4616 #ifndef GSTREAMER_LITE
4617 /**
4618 * g_timeout_source_new_seconds:
4619 * @interval: the timeout interval in seconds
4620 *
4621 * Creates a new timeout source.
4622 *
4623 * The source will not initially be associated with any #GMainContext
4624 * and must be added to one with g_source_attach() before it will be
4625 * executed.
4626 *
4627 * The scheduling granularity/accuracy of this timeout source will be
4628 * in seconds.
4629 *
4630 * The interval given in terms of monotonic time, not wall clock time.
4631 * See g_get_monotonic_time().
4632 *
4633 * Returns: the newly-created timeout source
4634 *
4635 * Since: 2.14
4636 **/
4637 GSource *
4638 g_timeout_source_new_seconds (guint interval)
4639 {
4640 GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource));
4641 GTimeoutSource *timeout_source = (GTimeoutSource *)source;
4642
4643 timeout_source->interval = 1000 * interval;
4644 timeout_source->seconds = TRUE;
4645
4646 g_timeout_set_expiration (timeout_source, g_get_monotonic_time ());
4647
4648 return source;
4649 }
4650 #endif // GSTREAMER_LITE
4651
4652 /**
4653 * g_timeout_add_full:
4654 * @priority: the priority of the timeout source. Typically this will be in
4655 * the range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
4656 * @interval: the time between calls to the function, in milliseconds
4657 * (1/1000ths of a second)
4658 * @function: function to call
4659 * @data: data to pass to @function
4660 * @notify: (allow-none): function to call when the timeout is removed, or %NULL
4661 *
4662 * Sets a function to be called at regular intervals, with the given
4663 * priority. The function is called repeatedly until it returns
4664 * %FALSE, at which point the timeout is automatically destroyed and
4665 * the function will not be called again. The @notify function is
4666 * called when the timeout is destroyed. The first call to the
4667 * function will be at the end of the first @interval.
4668 *
4669 * Note that timeout functions may be delayed, due to the processing of other
4670 * event sources. Thus they should not be relied on for precise timing.
4671 * After each call to the timeout function, the time of the next
4672 * timeout is recalculated based on the current time and the given interval
4673 * (it does not try to 'catch up' time lost in delays).
4674 *
4675 * This internally creates a main loop source using g_timeout_source_new()
4676 * and attaches it to the main loop context using g_source_attach(). You can
4677 * do these steps manually if you need greater control.
4678 *
4679 * The interval given in terms of monotonic time, not wall clock time.
4680 * See g_get_monotonic_time().
4681 *
4682 * Returns: the ID (greater than 0) of the event source.
4683 * Rename to: g_timeout_add
4684 **/
4685 guint
4686 g_timeout_add_full (gint priority,
4687 guint interval,
4688 GSourceFunc function,
4689 gpointer data,
4690 GDestroyNotify notify)
4691 {
4692 GSource *source;
4693 guint id;
4694
4695 g_return_val_if_fail (function != NULL, 0);
4696
4697 source = g_timeout_source_new (interval);
4698 #ifdef GSTREAMER_LITE
4699 if (source == NULL)
4700 return 0;
4701 #endif // GSTREAMER_LITE
4702
4703 if (priority != G_PRIORITY_DEFAULT)
4704 g_source_set_priority (source, priority);
4705
4706 g_source_set_callback (source, function, data, notify);
4707 id = g_source_attach (source, NULL);
4708 g_source_unref (source);
4709
4710 return id;
4711 }
4712
4713 /**
4714 * g_timeout_add:
4715 * @interval: the time between calls to the function, in milliseconds
4716 * (1/1000ths of a second)
4717 * @function: function to call
4718 * @data: data to pass to @function
4719 *
4720 * Sets a function to be called at regular intervals, with the default
4721 * priority, #G_PRIORITY_DEFAULT. The function is called repeatedly
4722 * until it returns %FALSE, at which point the timeout is automatically
4723 * destroyed and the function will not be called again. The first call
4724 * to the function will be at the end of the first @interval.
4725 *
4726 * Note that timeout functions may be delayed, due to the processing of other
4727 * event sources. Thus they should not be relied on for precise timing.
4728 * After each call to the timeout function, the time of the next
4729 * timeout is recalculated based on the current time and the given interval
4730 * (it does not try to 'catch up' time lost in delays).
4731 *
4732 * If you want to have a timer in the "seconds" range and do not care
4733 * about the exact time of the first call of the timer, use the
4734 * g_timeout_add_seconds() function; this function allows for more
4735 * optimizations and more efficient system power usage.
4736 *
4737 * This internally creates a main loop source using g_timeout_source_new()
4738 * and attaches it to the main loop context using g_source_attach(). You can
4739 * do these steps manually if you need greater control.
4740 *
4741 * The interval given is in terms of monotonic time, not wall clock
4742 * time. See g_get_monotonic_time().
4743 *
4744 * Returns: the ID (greater than 0) of the event source.
4745 **/
4746 guint
4747 g_timeout_add (guint32 interval,
4748 GSourceFunc function,
4749 gpointer data)
4750 {
4751 return g_timeout_add_full (G_PRIORITY_DEFAULT,
4752 interval, function, data, NULL);
4753 }
4754
4755 #ifndef GSTREAMER_LITE
4756 /**
4757 * g_timeout_add_seconds_full:
4758 * @priority: the priority of the timeout source. Typically this will be in
4759 * the range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
4760 * @interval: the time between calls to the function, in seconds
4761 * @function: function to call
4762 * @data: data to pass to @function
4763 * @notify: (allow-none): function to call when the timeout is removed, or %NULL
4764 *
4765 * Sets a function to be called at regular intervals, with @priority.
4766 * The function is called repeatedly until it returns %FALSE, at which
4767 * point the timeout is automatically destroyed and the function will
4768 * not be called again.
4769 *
4770 * Unlike g_timeout_add(), this function operates at whole second granularity.
4771 * The initial starting point of the timer is determined by the implementation
4772 * and the implementation is expected to group multiple timers together so that
4773 * they fire all at the same time.
4774 * To allow this grouping, the @interval to the first timer is rounded
4775 * and can deviate up to one second from the specified interval.
4776 * Subsequent timer iterations will generally run at the specified interval.
4777 *
4778 * Note that timeout functions may be delayed, due to the processing of other
4779 * event sources. Thus they should not be relied on for precise timing.
4780 * After each call to the timeout function, the time of the next
4781 * timeout is recalculated based on the current time and the given @interval
4782 *
4783 * If you want timing more precise than whole seconds, use g_timeout_add()
4784 * instead.
4785 *
4786 * The grouping of timers to fire at the same time results in a more power
4787 * and CPU efficient behavior so if your timer is in multiples of seconds
4788 * and you don't require the first timer exactly one second from now, the
4789 * use of g_timeout_add_seconds() is preferred over g_timeout_add().
4790 *
4791 * This internally creates a main loop source using
4792 * g_timeout_source_new_seconds() and attaches it to the main loop context
4793 * using g_source_attach(). You can do these steps manually if you need
4794 * greater control.
4795 *
4796 * The interval given is in terms of monotonic time, not wall clock
4797 * time. See g_get_monotonic_time().
4798 *
4799 * Returns: the ID (greater than 0) of the event source.
4800 *
4801 * Rename to: g_timeout_add_seconds
4802 * Since: 2.14
4803 **/
4804 guint
4805 g_timeout_add_seconds_full (gint priority,
4806 guint32 interval,
4807 GSourceFunc function,
4808 gpointer data,
4809 GDestroyNotify notify)
4810 {
4811 GSource *source;
4812 guint id;
4813
4814 g_return_val_if_fail (function != NULL, 0);
4815
4816 source = g_timeout_source_new_seconds (interval);
4817
4818 if (priority != G_PRIORITY_DEFAULT)
4819 g_source_set_priority (source, priority);
4820
4821 g_source_set_callback (source, function, data, notify);
4822 id = g_source_attach (source, NULL);
4823 g_source_unref (source);
4824
4825 return id;
4826 }
4827
4828 /**
4829 * g_timeout_add_seconds:
4830 * @interval: the time between calls to the function, in seconds
4831 * @function: function to call
4832 * @data: data to pass to @function
4833 *
4834 * Sets a function to be called at regular intervals with the default
4835 * priority, #G_PRIORITY_DEFAULT. The function is called repeatedly until
4836 * it returns %FALSE, at which point the timeout is automatically destroyed
4837 * and the function will not be called again.
4838 *
4839 * This internally creates a main loop source using
4840 * g_timeout_source_new_seconds() and attaches it to the main loop context
4841 * using g_source_attach(). You can do these steps manually if you need
4842 * greater control. Also see g_timeout_add_seconds_full().
4843 *
4844 * Note that the first call of the timer may not be precise for timeouts
4845 * of one second. If you need finer precision and have such a timeout,
4846 * you may want to use g_timeout_add() instead.
4847 *
4848 * The interval given is in terms of monotonic time, not wall clock
4849 * time. See g_get_monotonic_time().
4850 *
4851 * Returns: the ID (greater than 0) of the event source.
4852 *
4853 * Since: 2.14
4854 **/
4855 guint
4856 g_timeout_add_seconds (guint interval,
4857 GSourceFunc function,
4858 gpointer data)
4859 {
4860 g_return_val_if_fail (function != NULL, 0);
4861
4862 return g_timeout_add_seconds_full (G_PRIORITY_DEFAULT, interval, function, data, NULL);
4863 }
4864 #endif // GSTREAMER_LITE
4865
4866 /* Child watch functions */
4867
4868 #ifdef G_OS_WIN32
4869
4870 static gboolean
4871 g_child_watch_prepare (GSource *source,
4872 gint *timeout)
4873 {
4874 *timeout = -1;
4875 return FALSE;
4876 }
4877
4878 static gboolean
4879 g_child_watch_check (GSource *source)
4880 {
4881 GChildWatchSource *child_watch_source;
4882 gboolean child_exited;
4883
4884 child_watch_source = (GChildWatchSource *) source;
4885
4886 child_exited = child_watch_source->poll.revents & G_IO_IN;
4887
4888 if (child_exited)
4889 {
4890 DWORD child_status;
4891
4892 /*
4893 * Note: We do _not_ check for the special value of STILL_ACTIVE
4894 * since we know that the process has exited and doing so runs into
4895 * problems if the child process "happens to return STILL_ACTIVE(259)"
4896 * as Microsoft's Platform SDK puts it.
4897 */
4898 if (!GetExitCodeProcess (child_watch_source->pid, &child_status))
4899 {
4900 gchar *emsg = g_win32_error_message (GetLastError ());
4901 g_warning (G_STRLOC ": GetExitCodeProcess() failed: %s", emsg);
4902 g_free (emsg);
4903
4904 child_watch_source->child_status = -1;
4905 }
4906 else
4907 child_watch_source->child_status = child_status;
4908 }
4909
4910 return child_exited;
4911 }
4912
4913 static void
4914 g_child_watch_finalize (GSource *source)
4915 {
4916 }
4917
4918 #else /* G_OS_WIN32 */
4919
4920 static void
4921 wake_source (GSource *source)
4922 {
4923 GMainContext *context;
4924
4925 /* This should be thread-safe:
4926 *
4927 * - if the source is currently being added to a context, that
4928 * context will be woken up anyway
4929 *
4930 * - if the source is currently being destroyed, we simply need not
4931 * to crash:
4932 *
4933 * - the memory for the source will remain valid until after the
4934 * source finalize function was called (which would remove the
4935 * source from the global list which we are currently holding the
4936 * lock for)
4937 *
4938 * - the GMainContext will either be NULL or point to a live
4939 * GMainContext
4940 *
4941 * - the GMainContext will remain valid since we hold the
4942 * main_context_list lock
4943 *
4944 * Since we are holding a lot of locks here, don't try to enter any
4945 * more GMainContext functions for fear of dealock -- just hit the
4946 * GWakeup and run. Even if that's safe now, it could easily become
4947 * unsafe with some very minor changes in the future, and signal
4948 * handling is not the most well-tested codepath.
4949 */
4950 G_LOCK(main_context_list);
4951 context = source->context;
4952 if (context)
4953 g_wakeup_signal (context->wakeup);
4954 G_UNLOCK(main_context_list);
4955 }
4956
4957 static void
4958 dispatch_unix_signals_unlocked (void)
4959 {
4960 gboolean pending[NSIG];
4961 GSList *node;
4962 gint i;
4963
4964 /* clear this first incase another one arrives while we're processing */
4965 any_unix_signal_pending = FALSE;
4966
4967 /* We atomically test/clear the bit from the global array in case
4968 * other signals arrive while we are dispatching.
4969 *
4970 * We then can safely use our own array below without worrying about
4971 * races.
4972 */
4973 for (i = 0; i < NSIG; i++)
4974 {
4975 /* Be very careful with (the volatile) unix_signal_pending.
4976 *
4977 * We must ensure that it's not possible that we clear it without
4978 * handling the signal. We therefore must ensure that our pending
4979 * array has a field set (ie: we will do something about the
4980 * signal) before we clear the item in unix_signal_pending.
4981 *
4982 * Note specifically: we must check _our_ array.
4983 */
4984 pending[i] = unix_signal_pending[i];
4985 if (pending[i])
4986 unix_signal_pending[i] = FALSE;
4987 }
4988
4989 /* handle GChildWatchSource instances */
4990 if (pending[SIGCHLD])
4991 {
4992 /* The only way we can do this is to scan all of the children.
4993 *
4994 * The docs promise that we will not reap children that we are not
4995 * explicitly watching, so that ties our hands from calling
4996 * waitpid(-1). We also can't use siginfo's si_pid field since if
4997 * multiple SIGCHLD arrive at the same time, one of them can be
4998 * dropped (since a given UNIX signal can only be pending once).
4999 */
5000 for (node = unix_child_watches; node; node = node->next)
5001 {
5002 GChildWatchSource *source = node->data;
5003
5004 if (!source->child_exited)
5005 {
5006 pid_t pid;
5007 do
5008 {
5009 g_assert (source->pid > 0);
5010
5011 pid = waitpid (source->pid, &source->child_status, WNOHANG);
5012 if (pid > 0)
5013 {
5014 source->child_exited = TRUE;
5015 wake_source ((GSource *) source);
5016 }
5017 else if (pid == -1 && errno == ECHILD)
5018 {
5019 g_warning ("GChildWatchSource: Exit status of a child process was requested but ECHILD was received by waitpid(). Most likely the process is ignoring SIGCHLD, or some other thread is invoking waitpid() with a nonpositive first argument; either behavior can break applications that use g_child_watch_add()/g_spawn_sync() either directly or indirectly.");
5020 source->child_exited = TRUE;
5021 source->child_status = 0;
5022 wake_source ((GSource *) source);
5023 }
5024 }
5025 while (pid == -1 && errno == EINTR);
5026 }
5027 }
5028 }
5029
5030 /* handle GUnixSignalWatchSource instances */
5031 for (node = unix_signal_watches; node; node = node->next)
5032 {
5033 GUnixSignalWatchSource *source = node->data;
5034
5035 if (!source->pending)
5036 {
5037 if (pending[source->signum])
5038 {
5039 source->pending = TRUE;
5040
5041 wake_source ((GSource *) source);
5042 }
5043 }
5044 }
5045
5046 }
5047
5048 static void
5049 dispatch_unix_signals (void)
5050 {
5051 G_LOCK(unix_signal_lock);
5052 dispatch_unix_signals_unlocked ();
5053 G_UNLOCK(unix_signal_lock);
5054 }
5055
5056 static gboolean
5057 g_child_watch_prepare (GSource *source,
5058 gint *timeout)
5059 {
5060 GChildWatchSource *child_watch_source;
5061
5062 child_watch_source = (GChildWatchSource *) source;
5063
5064 return child_watch_source->child_exited;
5065 }
5066
5067 static gboolean
5068 g_child_watch_check (GSource *source)
5069 {
5070 GChildWatchSource *child_watch_source;
5071
5072 child_watch_source = (GChildWatchSource *) source;
5073
5074 return child_watch_source->child_exited;
5075 }
5076
5077 static gboolean
5078 g_unix_signal_watch_prepare (GSource *source,
5079 gint *timeout)
5080 {
5081 GUnixSignalWatchSource *unix_signal_source;
5082
5083 unix_signal_source = (GUnixSignalWatchSource *) source;
5084
5085 return unix_signal_source->pending;
5086 }
5087
5088 static gboolean
5089 g_unix_signal_watch_check (GSource *source)
5090 {
5091 GUnixSignalWatchSource *unix_signal_source;
5092
5093 unix_signal_source = (GUnixSignalWatchSource *) source;
5094
5095 return unix_signal_source->pending;
5096 }
5097
5098 static gboolean
5099 g_unix_signal_watch_dispatch (GSource *source,
5100 GSourceFunc callback,
5101 gpointer user_data)
5102 {
5103 GUnixSignalWatchSource *unix_signal_source;
5104 gboolean again;
5105
5106 unix_signal_source = (GUnixSignalWatchSource *) source;
5107
5108 if (!callback)
5109 {
5110 g_warning ("Unix signal source dispatched without callback\n"
5111 "You must call g_source_set_callback().");
5112 return FALSE;
5113 }
5114
5115 again = (callback) (user_data);
5116
5117 unix_signal_source->pending = FALSE;
5118
5119 return again;
5120 }
5121
5122 static void
5123 ref_unix_signal_handler_unlocked (int signum)
5124 {
5125 /* Ensure we have the worker context */
5126 g_get_worker_context ();
5127 unix_signal_refcount[signum]++;
5128 if (unix_signal_refcount[signum] == 1)
5129 {
5130 struct sigaction action;
5131 action.sa_handler = g_unix_signal_handler;
5132 sigemptyset (&action.sa_mask);
5133 #ifdef SA_RESTART
5134 action.sa_flags = SA_RESTART | SA_NOCLDSTOP;
5135 #else
5136 action.sa_flags = SA_NOCLDSTOP;
5137 #endif
5138 sigaction (signum, &action, NULL);
5139 }
5140 }
5141
5142 static void
5143 unref_unix_signal_handler_unlocked (int signum)
5144 {
5145 unix_signal_refcount[signum]--;
5146 if (unix_signal_refcount[signum] == 0)
5147 {
5148 struct sigaction action;
5149 memset (&action, 0, sizeof (action));
5150 action.sa_handler = SIG_DFL;
5151 sigemptyset (&action.sa_mask);
5152 sigaction (signum, &action, NULL);
5153 }
5154 }
5155
5156 GSource *
5157 _g_main_create_unix_signal_watch (int signum)
5158 {
5159 GSource *source;
5160 GUnixSignalWatchSource *unix_signal_source;
5161
5162 source = g_source_new (&g_unix_signal_funcs, sizeof (GUnixSignalWatchSource));
5163 unix_signal_source = (GUnixSignalWatchSource *) source;
5164
5165 unix_signal_source->signum = signum;
5166 unix_signal_source->pending = FALSE;
5167
5168 G_LOCK (unix_signal_lock);
5169 ref_unix_signal_handler_unlocked (signum);
5170 unix_signal_watches = g_slist_prepend (unix_signal_watches, unix_signal_source);
5171 dispatch_unix_signals_unlocked ();
5172 G_UNLOCK (unix_signal_lock);
5173
5174 return source;
5175 }
5176
5177 static void
5178 g_unix_signal_watch_finalize (GSource *source)
5179 {
5180 GUnixSignalWatchSource *unix_signal_source;
5181
5182 unix_signal_source = (GUnixSignalWatchSource *) source;
5183
5184 G_LOCK (unix_signal_lock);
5185 unref_unix_signal_handler_unlocked (unix_signal_source->signum);
5186 unix_signal_watches = g_slist_remove (unix_signal_watches, source);
5187 G_UNLOCK (unix_signal_lock);
5188 }
5189
5190 static void
5191 g_child_watch_finalize (GSource *source)
5192 {
5193 G_LOCK (unix_signal_lock);
5194 unix_child_watches = g_slist_remove (unix_child_watches, source);
5195 unref_unix_signal_handler_unlocked (SIGCHLD);
5196 G_UNLOCK (unix_signal_lock);
5197 }
5198
5199 #endif /* G_OS_WIN32 */
5200
5201 static gboolean
5202 g_child_watch_dispatch (GSource *source,
5203 GSourceFunc callback,
5204 gpointer user_data)
5205 {
5206 GChildWatchSource *child_watch_source;
5207 GChildWatchFunc child_watch_callback = (GChildWatchFunc) callback;
5208
5209 child_watch_source = (GChildWatchSource *) source;
5210
5211 if (!callback)
5212 {
5213 g_warning ("Child watch source dispatched without callback\n"
5214 "You must call g_source_set_callback().");
5215 return FALSE;
5216 }
5217
5218 (child_watch_callback) (child_watch_source->pid, child_watch_source->child_status, user_data);
5219
5220 /* We never keep a child watch source around as the child is gone */
5221 return FALSE;
5222 }
5223
5224 #ifndef G_OS_WIN32
5225
5226 static void
5227 g_unix_signal_handler (int signum)
5228 {
5229 unix_signal_pending[signum] = TRUE;
5230 any_unix_signal_pending = TRUE;
5231
5232 g_wakeup_signal (glib_worker_context->wakeup);
5233 }
5234
5235 #endif /* !G_OS_WIN32 */
5236
5237 /**
5238 * g_child_watch_source_new:
5239 * @pid: process to watch. On POSIX the positive pid of a child process. On
5240 * Windows a handle for a process (which doesn't have to be a child).
5241 *
5242 * Creates a new child_watch source.
5243 *
5244 * The source will not initially be associated with any #GMainContext
5245 * and must be added to one with g_source_attach() before it will be
5246 * executed.
5247 *
5248 * Note that child watch sources can only be used in conjunction with
5249 * `g_spawn...` when the %G_SPAWN_DO_NOT_REAP_CHILD flag is used.
5250 *
5251 * Note that on platforms where #GPid must be explicitly closed
5252 * (see g_spawn_close_pid()) @pid must not be closed while the
5253 * source is still active. Typically, you will want to call
5254 * g_spawn_close_pid() in the callback function for the source.
5255 *
5256 * Note further that using g_child_watch_source_new() is not
5257 * compatible with calling `waitpid` with a nonpositive first
5258 * argument in the application. Calling waitpid() for individual
5259 * pids will still work fine.
5260 *
5261 * Similarly, on POSIX platforms, the @pid passed to this function must
5262 * be greater than 0 (i.e. this function must wait for a specific child,
5263 * and cannot wait for one of many children by using a nonpositive argument).
5264 *
5265 * Returns: the newly-created child watch source
5266 *
5267 * Since: 2.4
5268 **/
5269 GSource *
5270 g_child_watch_source_new (GPid pid)
5271 {
5272 GSource *source;
5273 GChildWatchSource *child_watch_source;
5274
5275 #ifndef G_OS_WIN32
5276 g_return_val_if_fail (pid > 0, NULL);
5277 #endif
5278
5279 source = g_source_new (&g_child_watch_funcs, sizeof (GChildWatchSource));
5280 #ifdef GSTREAMER_LITE
5281 if (source == NULL)
5282 return NULL;
5283 #endif // GSTREAMER_LITE
5284 child_watch_source = (GChildWatchSource *)source;
5285
5286 child_watch_source->pid = pid;
5287
5288 #ifdef G_OS_WIN32
5289 child_watch_source->poll.fd = (gintptr) pid;
5290 child_watch_source->poll.events = G_IO_IN;
5291
5292 g_source_add_poll (source, &child_watch_source->poll);
5293 #else /* G_OS_WIN32 */
5294 G_LOCK (unix_signal_lock);
5295 ref_unix_signal_handler_unlocked (SIGCHLD);
5296 unix_child_watches = g_slist_prepend (unix_child_watches, child_watch_source);
5297 if (waitpid (pid, &child_watch_source->child_status, WNOHANG) > 0)
5298 child_watch_source->child_exited = TRUE;
5299 G_UNLOCK (unix_signal_lock);
5300 #endif /* G_OS_WIN32 */
5301
5302 return source;
5303 }
5304
5305 /**
5306 * g_child_watch_add_full:
5307 * @priority: the priority of the idle source. Typically this will be in the
5308 * range between #G_PRIORITY_DEFAULT_IDLE and #G_PRIORITY_HIGH_IDLE.
5309 * @pid: process to watch. On POSIX the positive pid of a child process. On
5310 * Windows a handle for a process (which doesn't have to be a child).
5311 * @function: function to call
5312 * @data: data to pass to @function
5313 * @notify: (allow-none): function to call when the idle is removed, or %NULL
5314 *
5315 * Sets a function to be called when the child indicated by @pid
5316 * exits, at the priority @priority.
5317 *
5318 * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes()
5319 * you will need to pass #G_SPAWN_DO_NOT_REAP_CHILD as flag to
5320 * the spawn function for the child watching to work.
5321 *
5322 * In many programs, you will want to call g_spawn_check_exit_status()
5323 * in the callback to determine whether or not the child exited
5324 * successfully.
5325 *
5326 * Also, note that on platforms where #GPid must be explicitly closed
5327 * (see g_spawn_close_pid()) @pid must not be closed while the source
5328 * is still active. Typically, you should invoke g_spawn_close_pid()
5329 * in the callback function for the source.
5330 *
5331 * GLib supports only a single callback per process id.
5332 *
5333 * This internally creates a main loop source using
5334 * g_child_watch_source_new() and attaches it to the main loop context
5335 * using g_source_attach(). You can do these steps manually if you
5336 * need greater control.
5337 *
5338 * Returns: the ID (greater than 0) of the event source.
5339 *
5340 * Rename to: g_child_watch_add
5341 * Since: 2.4
5342 **/
5343 guint
5344 g_child_watch_add_full (gint priority,
5345 GPid pid,
5346 GChildWatchFunc function,
5347 gpointer data,
5348 GDestroyNotify notify)
5349 {
5350 GSource *source;
5351 guint id;
5352
5353 g_return_val_if_fail (function != NULL, 0);
5354 #ifndef G_OS_WIN32
5355 g_return_val_if_fail (pid > 0, 0);
5356 #endif
5357
5358 source = g_child_watch_source_new (pid);
5359
5360 if (priority != G_PRIORITY_DEFAULT)
5361 g_source_set_priority (source, priority);
5362
5363 g_source_set_callback (source, (GSourceFunc) function, data, notify);
5364 id = g_source_attach (source, NULL);
5365 g_source_unref (source);
5366
5367 return id;
5368 }
5369
5370 /**
5371 * g_child_watch_add:
5372 * @pid: process id to watch. On POSIX the positive pid of a child
5373 * process. On Windows a handle for a process (which doesn't have to be
5374 * a child).
5375 * @function: function to call
5376 * @data: data to pass to @function
5377 *
5378 * Sets a function to be called when the child indicated by @pid
5379 * exits, at a default priority, #G_PRIORITY_DEFAULT.
5380 *
5381 * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes()
5382 * you will need to pass #G_SPAWN_DO_NOT_REAP_CHILD as flag to
5383 * the spawn function for the child watching to work.
5384 *
5385 * Note that on platforms where #GPid must be explicitly closed
5386 * (see g_spawn_close_pid()) @pid must not be closed while the
5387 * source is still active. Typically, you will want to call
5388 * g_spawn_close_pid() in the callback function for the source.
5389 *
5390 * GLib supports only a single callback per process id.
5391 *
5392 * This internally creates a main loop source using
5393 * g_child_watch_source_new() and attaches it to the main loop context
5394 * using g_source_attach(). You can do these steps manually if you
5395 * need greater control.
5396 *
5397 * Returns: the ID (greater than 0) of the event source.
5398 *
5399 * Since: 2.4
5400 **/
5401 guint
5402 g_child_watch_add (GPid pid,
5403 GChildWatchFunc function,
5404 gpointer data)
5405 {
5406 return g_child_watch_add_full (G_PRIORITY_DEFAULT, pid, function, data, NULL);
5407 }
5408
5409
5410 /* Idle functions */
5411
5412 static gboolean
5413 g_idle_prepare (GSource *source,
5414 gint *timeout)
5415 {
5416 *timeout = 0;
5417
5418 return TRUE;
5419 }
5420
5421 static gboolean
5422 g_idle_check (GSource *source)
5423 {
5424 return TRUE;
5425 }
5426
5427 static gboolean
5428 g_idle_dispatch (GSource *source,
5429 GSourceFunc callback,
5430 gpointer user_data)
5431 {
5432 if (!callback)
5433 {
5434 g_warning ("Idle source dispatched without callback\n"
5435 "You must call g_source_set_callback().");
5436 return FALSE;
5437 }
5438
5439 return callback (user_data);
5440 }
5441
5442 /**
5443 * g_idle_source_new:
5444 *
5445 * Creates a new idle source.
5446 *
5447 * The source will not initially be associated with any #GMainContext
5448 * and must be added to one with g_source_attach() before it will be
5449 * executed. Note that the default priority for idle sources is
5450 * %G_PRIORITY_DEFAULT_IDLE, as compared to other sources which
5451 * have a default priority of %G_PRIORITY_DEFAULT.
5452 *
5453 * Returns: the newly-created idle source
5454 **/
5455 GSource *
5456 g_idle_source_new (void)
5457 {
5458 GSource *source;
5459
5460 source = g_source_new (&g_idle_funcs, sizeof (GSource));
5461 g_source_set_priority (source, G_PRIORITY_DEFAULT_IDLE);
5462
5463 return source;
5464 }
5465
5466 /**
5467 * g_idle_add_full:
5468 * @priority: the priority of the idle source. Typically this will be in the
5469 * range between #G_PRIORITY_DEFAULT_IDLE and #G_PRIORITY_HIGH_IDLE.
5470 * @function: function to call
5471 * @data: data to pass to @function
5472 * @notify: (allow-none): function to call when the idle is removed, or %NULL
5473 *
5474 * Adds a function to be called whenever there are no higher priority
5475 * events pending. If the function returns %FALSE it is automatically
5476 * removed from the list of event sources and will not be called again.
5477 *
5478 * This internally creates a main loop source using g_idle_source_new()
5479 * and attaches it to the main loop context using g_source_attach().
5480 * You can do these steps manually if you need greater control.
5481 *
5482 * Returns: the ID (greater than 0) of the event source.
5483 * Rename to: g_idle_add
5484 **/
5485 guint
5486 g_idle_add_full (gint priority,
5487 GSourceFunc function,
5488 gpointer data,
5489 GDestroyNotify notify)
5490 {
5491 GSource *source;
5492 guint id;
5493
5494 g_return_val_if_fail (function != NULL, 0);
5495
5496 source = g_idle_source_new ();
5497
5498 if (priority != G_PRIORITY_DEFAULT_IDLE)
5499 g_source_set_priority (source, priority);
5500
5501 g_source_set_callback (source, function, data, notify);
5502 id = g_source_attach (source, NULL);
5503 g_source_unref (source);
5504
5505 return id;
5506 }
5507
5508 /**
5509 * g_idle_add:
5510 * @function: function to call
5511 * @data: data to pass to @function.
5512 *
5513 * Adds a function to be called whenever there are no higher priority
5514 * events pending to the default main loop. The function is given the
5515 * default idle priority, #G_PRIORITY_DEFAULT_IDLE. If the function
5516 * returns %FALSE it is automatically removed from the list of event
5517 * sources and will not be called again.
5518 *
5519 * This internally creates a main loop source using g_idle_source_new()
5520 * and attaches it to the main loop context using g_source_attach().
5521 * You can do these steps manually if you need greater control.
5522 *
5523 * Returns: the ID (greater than 0) of the event source.
5524 **/
5525 guint
5526 g_idle_add (GSourceFunc function,
5527 gpointer data)
5528 {
5529 return g_idle_add_full (G_PRIORITY_DEFAULT_IDLE, function, data, NULL);
5530 }
5531
5532 /**
5533 * g_idle_remove_by_data:
5534 * @data: the data for the idle source's callback.
5535 *
5536 * Removes the idle function with the given data.
5537 *
5538 * Returns: %TRUE if an idle source was found and removed.
5539 **/
5540 gboolean
5541 g_idle_remove_by_data (gpointer data)
5542 {
5543 return g_source_remove_by_funcs_user_data (&g_idle_funcs, data);
5544 }
5545
5546 /**
5547 * g_main_context_invoke:
5548 * @context: (allow-none): a #GMainContext, or %NULL
5549 * @function: function to call
5550 * @data: data to pass to @function
5551 *
5552 * Invokes a function in such a way that @context is owned during the
5553 * invocation of @function.
5554 *
5555 * If @context is %NULL then the global default main context — as
5556 * returned by g_main_context_default() — is used.
5557 *
5558 * If @context is owned by the current thread, @function is called
5559 * directly. Otherwise, if @context is the thread-default main context
5560 * of the current thread and g_main_context_acquire() succeeds, then
5561 * @function is called and g_main_context_release() is called
5562 * afterwards.
5563 *
5564 * In any other case, an idle source is created to call @function and
5565 * that source is attached to @context (presumably to be run in another
5566 * thread). The idle source is attached with #G_PRIORITY_DEFAULT
5567 * priority. If you want a different priority, use
5568 * g_main_context_invoke_full().
5569 *
5570 * Note that, as with normal idle functions, @function should probably
5571 * return %FALSE. If it returns %TRUE, it will be continuously run in a
5572 * loop (and may prevent this call from returning).
5573 *
5574 * Since: 2.28
5575 **/
5576 void
5577 g_main_context_invoke (GMainContext *context,
5578 GSourceFunc function,
5579 gpointer data)
5580 {
5581 g_main_context_invoke_full (context,
5582 G_PRIORITY_DEFAULT,
5583 function, data, NULL);
5584 }
5585
5586 /**
5587 * g_main_context_invoke_full:
5588 * @context: (allow-none): a #GMainContext, or %NULL
5589 * @priority: the priority at which to run @function
5590 * @function: function to call
5591 * @data: data to pass to @function
5592 * @notify: (allow-none): a function to call when @data is no longer in use, or %NULL.
5593 *
5594 * Invokes a function in such a way that @context is owned during the
5595 * invocation of @function.
5596 *
5597 * This function is the same as g_main_context_invoke() except that it
5598 * lets you specify the priority incase @function ends up being
5599 * scheduled as an idle and also lets you give a #GDestroyNotify for @data.
5600 *
5601 * @notify should not assume that it is called from any particular
5602 * thread or with any particular context acquired.
5603 *
5604 * Since: 2.28
5605 **/
5606 void
5607 g_main_context_invoke_full (GMainContext *context,
5608 gint priority,
5609 GSourceFunc function,
5610 gpointer data,
5611 GDestroyNotify notify)
5612 {
5613 g_return_if_fail (function != NULL);
5614
5615 if (!context)
5616 context = g_main_context_default ();
5617
5618 if (g_main_context_is_owner (context))
5619 {
5620 while (function (data));
5621 if (notify != NULL)
5622 notify (data);
5623 }
5624
5625 else
5626 {
5627 GMainContext *thread_default;
5628
5629 thread_default = g_main_context_get_thread_default ();
5630
5631 if (!thread_default)
5632 thread_default = g_main_context_default ();
5633
5634 if (thread_default == context && g_main_context_acquire (context))
5635 {
5636 while (function (data));
5637
5638 g_main_context_release (context);
5639
5640 if (notify != NULL)
5641 notify (data);
5642 }
5643 else
5644 {
5645 GSource *source;
5646
5647 source = g_idle_source_new ();
5648 g_source_set_priority (source, priority);
5649 g_source_set_callback (source, function, data, notify);
5650 g_source_attach (source, context);
5651 g_source_unref (source);
5652 }
5653 }
5654 }
5655
5656 static gpointer
5657 glib_worker_main (gpointer data)
5658 {
5659 while (TRUE)
5660 {
5661 g_main_context_iteration (glib_worker_context, TRUE);
5662
5663 #ifdef G_OS_UNIX
5664 if (any_unix_signal_pending)
5665 dispatch_unix_signals ();
5666 #endif
5667 }
5668
5669 return NULL; /* worst GCC warning message ever... */
5670 }
5671
5672 GMainContext *
5673 g_get_worker_context (void)
5674 {
5675 static gsize initialised;
5676
5677 if (g_once_init_enter (&initialised))
5678 {
5679 /* mask all signals in the worker thread */
5680 #ifdef G_OS_UNIX
5681 sigset_t prev_mask;
5682 sigset_t all;
5683
5684 sigfillset (&all);
5685 pthread_sigmask (SIG_SETMASK, &all, &prev_mask);
5686 #endif
5687 glib_worker_context = g_main_context_new ();
5688 g_thread_new ("gmain", glib_worker_main, NULL);
5689 #ifdef G_OS_UNIX
5690 pthread_sigmask (SIG_SETMASK, &prev_mask, NULL);
5691 #endif
5692 g_once_init_leave (&initialised, TRUE);
5693 }
5694
5695 return glib_worker_context;
5696 }