-
Notifications
You must be signed in to change notification settings - Fork 527
/
gmain.c
5653 lines (4818 loc) · 151 KB
/
gmain.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* gmain.c: Main loop abstraction, timeouts, and idle functions
* Copyright 1998 Owen Taylor
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
/*
* MT safe
*/
#include "config.h"
#include "glibconfig.h"
/* Uncomment the next line (and the corresponding line in gpoll.c) to
* enable debugging printouts if the environment variable
* G_MAIN_POLL_DEBUG is set to some value.
*/
/* #define G_MAIN_POLL_DEBUG */
#ifdef _WIN32
/* Always enable debugging printout on Windows, as it is more often
* needed there...
*/
#define G_MAIN_POLL_DEBUG
#endif
#ifdef G_OS_UNIX
#include "glib-unix.h"
#include <pthread.h>
#ifdef HAVE_EVENTFD
#include <sys/eventfd.h>
#endif
#endif
#include <signal.h>
#include <sys/types.h>
#include <time.h>
#include <stdlib.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif /* HAVE_SYS_TIME_H */
#ifdef G_OS_UNIX
#include <unistd.h>
#endif /* G_OS_UNIX */
#include <errno.h>
#include <string.h>
#ifdef G_OS_WIN32
#define STRICT
#include <windows.h>
#endif /* G_OS_WIN32 */
#ifdef HAVE_MACH_MACH_TIME_H
#include <mach/mach_time.h>
#endif
#include "glib_trace.h"
#include "gmain.h"
#include "garray.h"
#include "giochannel.h"
#include "ghash.h"
#include "ghook.h"
#include "gqueue.h"
#include "gstrfuncs.h"
#include "gtestutils.h"
#ifdef G_OS_WIN32
#include "gwin32.h"
#endif
#ifdef G_MAIN_POLL_DEBUG
#include "gtimer.h"
#endif
#include "gwakeup.h"
#include "gmain-internal.h"
#include "glib-init.h"
#include "glib-private.h"
/**
* SECTION:main
* @title: The Main Event Loop
* @short_description: manages all available sources of events
*
* The main event loop manages all the available sources of events for
* GLib and GTK+ applications. These events can come from any number of
* different types of sources such as file descriptors (plain files,
* pipes or sockets) and timeouts. New types of event sources can also
* be added using g_source_attach().
*
* To allow multiple independent sets of sources to be handled in
* different threads, each source is associated with a #GMainContext.
* A GMainContext can only be running in a single thread, but
* sources can be added to it and removed from it from other threads.
*
* Each event source is assigned a priority. The default priority,
* #G_PRIORITY_DEFAULT, is 0. Values less than 0 denote higher priorities.
* Values greater than 0 denote lower priorities. Events from high priority
* sources are always processed before events from lower priority sources.
*
* Idle functions can also be added, and assigned a priority. These will
* be run whenever no events with a higher priority are ready to be processed.
*
* The #GMainLoop data type represents a main event loop. A GMainLoop is
* created with g_main_loop_new(). After adding the initial event sources,
* g_main_loop_run() is called. This continuously checks for new events from
* each of the event sources and dispatches them. Finally, the processing of
* an event from one of the sources leads to a call to g_main_loop_quit() to
* exit the main loop, and g_main_loop_run() returns.
*
* It is possible to create new instances of #GMainLoop recursively.
* This is often used in GTK+ applications when showing modal dialog
* boxes. Note that event sources are associated with a particular
* #GMainContext, and will be checked and dispatched for all main
* loops associated with that GMainContext.
*
* GTK+ contains wrappers of some of these functions, e.g. gtk_main(),
* gtk_main_quit() and gtk_events_pending().
*
* ## Creating new source types
*
* One of the unusual features of the #GMainLoop functionality
* is that new types of event source can be created and used in
* addition to the builtin type of event source. A new event source
* type is used for handling GDK events. A new source type is created
* by "deriving" from the #GSource structure. The derived type of
* source is represented by a structure that has the #GSource structure
* as a first element, and other elements specific to the new source
* type. To create an instance of the new source type, call
* g_source_new() passing in the size of the derived structure and
* a table of functions. These #GSourceFuncs determine the behavior of
* the new source type.
*
* New source types basically interact with the main context
* in two ways. Their prepare function in #GSourceFuncs can set a timeout
* to determine the maximum amount of time that the main loop will sleep
* before checking the source again. In addition, or as well, the source
* can add file descriptors to the set that the main context checks using
* g_source_add_poll().
*
* ## Customizing the main loop iteration
*
* Single iterations of a #GMainContext can be run with
* g_main_context_iteration(). In some cases, more detailed control
* of exactly how the details of the main loop work is desired, for
* instance, when integrating the #GMainLoop with an external main loop.
* In such cases, you can call the component functions of
* g_main_context_iteration() directly. These functions are
* g_main_context_prepare(), g_main_context_query(),
* g_main_context_check() and g_main_context_dispatch().
*
* ## State of a Main Context # {#mainloop-states}
*
* The operation of these functions can best be seen in terms
* of a state diagram, as shown in this image.
*
* 
*
* On UNIX, the GLib mainloop is incompatible with fork(). Any program
* using the mainloop must either exec() or exit() from the child
* without returning to the mainloop.
*/
/* Types */
typedef struct _GTimeoutSource GTimeoutSource;
typedef struct _GChildWatchSource GChildWatchSource;
typedef struct _GUnixSignalWatchSource GUnixSignalWatchSource;
typedef struct _GPollRec GPollRec;
typedef struct _GSourceCallback GSourceCallback;
typedef enum
{
G_SOURCE_READY = 1 << G_HOOK_FLAG_USER_SHIFT,
G_SOURCE_CAN_RECURSE = 1 << (G_HOOK_FLAG_USER_SHIFT + 1),
G_SOURCE_BLOCKED = 1 << (G_HOOK_FLAG_USER_SHIFT + 2)
} GSourceFlags;
typedef struct _GSourceList GSourceList;
struct _GSourceList
{
GSource *head, *tail;
gint priority;
};
typedef struct _GMainWaiter GMainWaiter;
struct _GMainWaiter
{
GCond *cond;
GMutex *mutex;
};
typedef struct _GMainDispatch GMainDispatch;
struct _GMainDispatch
{
gint depth;
GSource *source;
};
#ifdef G_MAIN_POLL_DEBUG
gboolean _g_main_poll_debug = FALSE;
#endif
struct _GMainContext
{
/* The following lock is used for both the list of sources
* and the list of poll records
*/
GMutex mutex;
GCond cond;
GThread *owner;
guint owner_count;
GSList *waiters;
gint ref_count;
GHashTable *sources; /* guint -> GSource */
GPtrArray *pending_dispatches;
gint timeout; /* Timeout for current iteration */
guint next_id;
GList *source_lists;
gint in_check_or_prepare;
GPollRec *poll_records;
guint n_poll_records;
GPollFD *cached_poll_array;
guint cached_poll_array_size;
GWakeup *wakeup;
GPollFD wake_up_rec;
/* Flag indicating whether the set of fd's changed during a poll */
gboolean poll_changed;
GPollFunc poll_func;
gint64 time;
gboolean time_is_fresh;
};
struct _GSourceCallback
{
guint ref_count;
GSourceFunc func;
gpointer data;
GDestroyNotify notify;
};
struct _GMainLoop
{
GMainContext *context;
gboolean is_running;
gint ref_count;
};
struct _GTimeoutSource
{
GSource source;
guint interval;
gboolean seconds;
};
struct _GChildWatchSource
{
GSource source;
GPid pid;
gint child_status;
#ifdef G_OS_WIN32
GPollFD poll;
#else /* G_OS_WIN32 */
gboolean child_exited;
#endif /* G_OS_WIN32 */
};
struct _GUnixSignalWatchSource
{
GSource source;
int signum;
gboolean pending;
};
struct _GPollRec
{
GPollFD *fd;
GPollRec *prev;
GPollRec *next;
gint priority;
};
struct _GSourcePrivate
{
GSList *child_sources;
GSource *parent_source;
gint64 ready_time;
/* This is currently only used on UNIX, but we always declare it (and
* let it remain empty on Windows) to avoid #ifdef all over the place.
*/
GSList *fds;
};
typedef struct _GSourceIter
{
GMainContext *context;
gboolean may_modify;
GList *current_list;
GSource *source;
} GSourceIter;
#define LOCK_CONTEXT(context) g_mutex_lock (&context->mutex)
#define UNLOCK_CONTEXT(context) g_mutex_unlock (&context->mutex)
#define G_THREAD_SELF g_thread_self ()
#define SOURCE_DESTROYED(source) (((source)->flags & G_HOOK_FLAG_ACTIVE) == 0)
#define SOURCE_BLOCKED(source) (((source)->flags & G_SOURCE_BLOCKED) != 0)
#define SOURCE_UNREF(source, context) \
G_STMT_START { \
if ((source)->ref_count > 1) \
(source)->ref_count--; \
else \
g_source_unref_internal ((source), (context), TRUE); \
} G_STMT_END
/* Forward declarations */
static void g_source_unref_internal (GSource *source,
GMainContext *context,
gboolean have_lock);
static void g_source_destroy_internal (GSource *source,
GMainContext *context,
gboolean have_lock);
static void g_source_set_priority_unlocked (GSource *source,
GMainContext *context,
gint priority);
static void g_child_source_remove_internal (GSource *child_source,
GMainContext *context);
static void g_main_context_poll (GMainContext *context,
gint timeout,
gint priority,
GPollFD *fds,
gint n_fds);
static void g_main_context_add_poll_unlocked (GMainContext *context,
gint priority,
GPollFD *fd);
static void g_main_context_remove_poll_unlocked (GMainContext *context,
GPollFD *fd);
static void g_source_iter_init (GSourceIter *iter,
GMainContext *context,
gboolean may_modify);
static gboolean g_source_iter_next (GSourceIter *iter,
GSource **source);
static void g_source_iter_clear (GSourceIter *iter);
static gboolean g_timeout_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data);
static gboolean g_child_watch_prepare (GSource *source,
gint *timeout);
static gboolean g_child_watch_check (GSource *source);
static gboolean g_child_watch_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data);
static void g_child_watch_finalize (GSource *source);
#ifdef G_OS_UNIX
static void g_unix_signal_handler (int signum);
static gboolean g_unix_signal_watch_prepare (GSource *source,
gint *timeout);
static gboolean g_unix_signal_watch_check (GSource *source);
static gboolean g_unix_signal_watch_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data);
static void g_unix_signal_watch_finalize (GSource *source);
#endif
static gboolean g_idle_prepare (GSource *source,
gint *timeout);
static gboolean g_idle_check (GSource *source);
static gboolean g_idle_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data);
static void block_source (GSource *source);
static GMainContext *glib_worker_context;
G_LOCK_DEFINE_STATIC (main_loop);
static GMainContext *default_main_context;
#ifndef G_OS_WIN32
/* UNIX signals work by marking one of these variables then waking the
* worker context to check on them and dispatch accordingly.
*/
#ifdef HAVE_SIG_ATOMIC_T
static volatile sig_atomic_t unix_signal_pending[NSIG];
static volatile sig_atomic_t any_unix_signal_pending;
#else
static volatile int unix_signal_pending[NSIG];
static volatile int any_unix_signal_pending;
#endif
static volatile guint unix_signal_refcount[NSIG];
/* Guards all the data below */
G_LOCK_DEFINE_STATIC (unix_signal_lock);
static GSList *unix_signal_watches;
static GSList *unix_child_watches;
GSourceFuncs g_unix_signal_funcs =
{
g_unix_signal_watch_prepare,
g_unix_signal_watch_check,
g_unix_signal_watch_dispatch,
g_unix_signal_watch_finalize
};
#endif /* !G_OS_WIN32 */
G_LOCK_DEFINE_STATIC (main_context_list);
static GSList *main_context_list = NULL;
GSourceFuncs g_timeout_funcs =
{
NULL, /* prepare */
NULL, /* check */
g_timeout_dispatch,
NULL
};
GSourceFuncs g_child_watch_funcs =
{
g_child_watch_prepare,
g_child_watch_check,
g_child_watch_dispatch,
g_child_watch_finalize
};
GSourceFuncs g_idle_funcs =
{
g_idle_prepare,
g_idle_check,
g_idle_dispatch,
NULL
};
/**
* g_main_context_ref:
* @context: a #GMainContext
*
* Increases the reference count on a #GMainContext object by one.
*
* Returns: the @context that was passed in (since 2.6)
**/
GMainContext *
g_main_context_ref (GMainContext *context)
{
g_return_val_if_fail (context != NULL, NULL);
g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL);
g_atomic_int_inc (&context->ref_count);
return context;
}
static inline void
poll_rec_list_free (GMainContext *context,
GPollRec *list)
{
g_slice_free_chain (GPollRec, list, next);
}
/**
* g_main_context_unref:
* @context: a #GMainContext
*
* Decreases the reference count on a #GMainContext object by one. If
* the result is zero, free the context and free all associated memory.
**/
void
g_main_context_unref (GMainContext *context)
{
GSourceIter iter;
GSource *source;
GList *sl_iter;
GSourceList *list;
guint i;
g_return_if_fail (context != NULL);
g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
if (!g_atomic_int_dec_and_test (&context->ref_count))
return;
G_LOCK (main_context_list);
main_context_list = g_slist_remove (main_context_list, context);
G_UNLOCK (main_context_list);
/* Free pending dispatches */
for (i = 0; i < context->pending_dispatches->len; i++)
g_source_unref_internal (context->pending_dispatches->pdata[i], context, FALSE);
/* g_source_iter_next() assumes the context is locked. */
LOCK_CONTEXT (context);
g_source_iter_init (&iter, context, TRUE);
while (g_source_iter_next (&iter, &source))
{
source->context = NULL;
g_source_destroy_internal (source, context, TRUE);
}
UNLOCK_CONTEXT (context);
for (sl_iter = context->source_lists; sl_iter; sl_iter = sl_iter->next)
{
list = sl_iter->data;
g_slice_free (GSourceList, list);
}
g_list_free (context->source_lists);
g_hash_table_destroy (context->sources);
g_mutex_clear (&context->mutex);
g_ptr_array_free (context->pending_dispatches, TRUE);
g_free (context->cached_poll_array);
poll_rec_list_free (context, context->poll_records);
g_wakeup_free (context->wakeup);
g_cond_clear (&context->cond);
g_free (context);
}
/* Helper function used by mainloop/overflow test.
*/
GMainContext *
g_main_context_new_with_next_id (guint next_id)
{
GMainContext *ret = g_main_context_new ();
ret->next_id = next_id;
return ret;
}
/**
* g_main_context_new:
*
* Creates a new #GMainContext structure.
*
* Returns: the new #GMainContext
**/
GMainContext *
g_main_context_new (void)
{
static gsize initialised;
GMainContext *context;
if (g_once_init_enter (&initialised))
{
#ifdef G_MAIN_POLL_DEBUG
if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
_g_main_poll_debug = TRUE;
#endif
g_once_init_leave (&initialised, TRUE);
}
context = g_new0 (GMainContext, 1);
g_mutex_init (&context->mutex);
g_cond_init (&context->cond);
context->sources = g_hash_table_new (NULL, NULL);
context->owner = NULL;
context->waiters = NULL;
context->ref_count = 1;
context->next_id = 1;
context->source_lists = NULL;
context->poll_func = g_poll;
context->cached_poll_array = NULL;
context->cached_poll_array_size = 0;
context->pending_dispatches = g_ptr_array_new ();
context->time_is_fresh = FALSE;
context->wakeup = g_wakeup_new ();
g_wakeup_get_pollfd (context->wakeup, &context->wake_up_rec);
g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec);
G_LOCK (main_context_list);
main_context_list = g_slist_append (main_context_list, context);
#ifdef G_MAIN_POLL_DEBUG
if (_g_main_poll_debug)
g_print ("created context=%p\n", context);
#endif
G_UNLOCK (main_context_list);
return context;
}
/**
* g_main_context_default:
*
* Returns the global default main context. This is the main context
* used for main loop functions when a main loop is not explicitly
* specified, and corresponds to the "main" main loop. See also
* g_main_context_get_thread_default().
*
* Returns: (transfer none): the global default main context.
**/
GMainContext *
g_main_context_default (void)
{
/* Slow, but safe */
G_LOCK (main_loop);
if (!default_main_context)
{
default_main_context = g_main_context_new ();
#ifdef G_MAIN_POLL_DEBUG
if (_g_main_poll_debug)
g_print ("default context=%p\n", default_main_context);
#endif
}
G_UNLOCK (main_loop);
return default_main_context;
}
static void
free_context (gpointer data)
{
GMainContext *context = data;
g_main_context_release (context);
if (context)
g_main_context_unref (context);
}
static void
free_context_stack (gpointer data)
{
g_queue_free_full((GQueue *) data, (GDestroyNotify) free_context);
}
static GPrivate thread_context_stack = G_PRIVATE_INIT (free_context_stack);
/**
* g_main_context_push_thread_default:
* @context: (allow-none): a #GMainContext, or %NULL for the global default context
*
* Acquires @context and sets it as the thread-default context for the
* current thread. This will cause certain asynchronous operations
* (such as most [gio][gio]-based I/O) which are
* started in this thread to run under @context and deliver their
* results to its main loop, rather than running under the global
* default context in the main thread. Note that calling this function
* changes the context returned by g_main_context_get_thread_default(),
* not the one returned by g_main_context_default(), so it does not affect
* the context used by functions like g_idle_add().
*
* Normally you would call this function shortly after creating a new
* thread, passing it a #GMainContext which will be run by a
* #GMainLoop in that thread, to set a new default context for all
* async operations in that thread. (In this case, you don't need to
* ever call g_main_context_pop_thread_default().) In some cases
* however, you may want to schedule a single operation in a
* non-default context, or temporarily use a non-default context in
* the main thread. In that case, you can wrap the call to the
* asynchronous operation inside a
* g_main_context_push_thread_default() /
* g_main_context_pop_thread_default() pair, but it is up to you to
* ensure that no other asynchronous operations accidentally get
* started while the non-default context is active.
*
* Beware that libraries that predate this function may not correctly
* handle being used from a thread with a thread-default context. Eg,
* see g_file_supports_thread_contexts().
*
* Since: 2.22
**/
void
g_main_context_push_thread_default (GMainContext *context)
{
GQueue *stack;
gboolean acquired_context;
acquired_context = g_main_context_acquire (context);
g_return_if_fail (acquired_context);
if (context == g_main_context_default ())
context = NULL;
else if (context)
g_main_context_ref (context);
stack = g_private_get (&thread_context_stack);
if (!stack)
{
stack = g_queue_new ();
g_private_set (&thread_context_stack, stack);
}
g_queue_push_head (stack, context);
}
/**
* g_main_context_pop_thread_default:
* @context: (allow-none): a #GMainContext object, or %NULL
*
* Pops @context off the thread-default context stack (verifying that
* it was on the top of the stack).
*
* Since: 2.22
**/
void
g_main_context_pop_thread_default (GMainContext *context)
{
GQueue *stack;
if (context == g_main_context_default ())
context = NULL;
stack = g_private_get (&thread_context_stack);
g_return_if_fail (stack != NULL);
g_return_if_fail (g_queue_peek_head (stack) == context);
g_queue_pop_head (stack);
g_main_context_release (context);
if (context)
g_main_context_unref (context);
}
/**
* g_main_context_get_thread_default:
*
* Gets the thread-default #GMainContext for this thread. Asynchronous
* operations that want to be able to be run in contexts other than
* the default one should call this method or
* g_main_context_ref_thread_default() to get a #GMainContext to add
* their #GSources to. (Note that even in single-threaded
* programs applications may sometimes want to temporarily push a
* non-default context, so it is not safe to assume that this will
* always return %NULL if you are running in the default thread.)
*
* If you need to hold a reference on the context, use
* g_main_context_ref_thread_default() instead.
*
* Returns: (transfer none): the thread-default #GMainContext, or
* %NULL if the thread-default context is the global default context.
*
* Since: 2.22
**/
GMainContext *
g_main_context_get_thread_default (void)
{
GQueue *stack;
stack = g_private_get (&thread_context_stack);
if (stack)
return g_queue_peek_head (stack);
else
return NULL;
}
/**
* g_main_context_ref_thread_default:
*
* Gets the thread-default #GMainContext for this thread, as with
* g_main_context_get_thread_default(), but also adds a reference to
* it with g_main_context_ref(). In addition, unlike
* g_main_context_get_thread_default(), if the thread-default context
* is the global default context, this will return that #GMainContext
* (with a ref added to it) rather than returning %NULL.
*
* Returns: (transfer full): the thread-default #GMainContext. Unref
* with g_main_context_unref() when you are done with it.
*
* Since: 2.32
*/
GMainContext *
g_main_context_ref_thread_default (void)
{
GMainContext *context;
context = g_main_context_get_thread_default ();
if (!context)
context = g_main_context_default ();
return g_main_context_ref (context);
}
/* Hooks for adding to the main loop */
/**
* g_source_new:
* @source_funcs: structure containing functions that implement
* the sources behavior.
* @struct_size: size of the #GSource structure to create.
*
* Creates a new #GSource structure. The size is specified to
* allow creating structures derived from #GSource that contain
* additional data. The size passed in must be at least
* `sizeof (GSource)`.
*
* The source will not initially be associated with any #GMainContext
* and must be added to one with g_source_attach() before it will be
* executed.
*
* Returns: the newly-created #GSource.
**/
GSource *
g_source_new (GSourceFuncs *source_funcs,
guint struct_size)
{
GSource *source;
g_return_val_if_fail (source_funcs != NULL, NULL);
g_return_val_if_fail (struct_size >= sizeof (GSource), NULL);
source = (GSource*) g_malloc0 (struct_size);
source->priv = g_slice_new0 (GSourcePrivate);
source->source_funcs = source_funcs;
source->ref_count = 1;
source->priority = G_PRIORITY_DEFAULT;
source->flags = G_HOOK_FLAG_ACTIVE;
source->priv->ready_time = -1;
/* NULL/0 initialization for all other fields */
return source;
}
/* Holds context's lock */
static void
g_source_iter_init (GSourceIter *iter,
GMainContext *context,
gboolean may_modify)
{
iter->context = context;
iter->current_list = NULL;
iter->source = NULL;
iter->may_modify = may_modify;
}
/* Holds context's lock */
static gboolean
g_source_iter_next (GSourceIter *iter, GSource **source)
{
GSource *next_source;
if (iter->source)
next_source = iter->source->next;
else
next_source = NULL;
if (!next_source)
{
if (iter->current_list)
iter->current_list = iter->current_list->next;
else
iter->current_list = iter->context->source_lists;
if (iter->current_list)
{
GSourceList *source_list = iter->current_list->data;
next_source = source_list->head;
}
}
/* Note: unreffing iter->source could potentially cause its
* GSourceList to be removed from source_lists (if iter->source is
* the only source in its list, and it is destroyed), so we have to
* keep it reffed until after we advance iter->current_list, above.
*/
if (iter->source && iter->may_modify)
SOURCE_UNREF (iter->source, iter->context);
iter->source = next_source;
if (iter->source && iter->may_modify)
iter->source->ref_count++;
*source = iter->source;
return *source != NULL;
}
/* Holds context's lock. Only necessary to call if you broke out of
* the g_source_iter_next() loop early.
*/
static void
g_source_iter_clear (GSourceIter *iter)
{
if (iter->source && iter->may_modify)
{
SOURCE_UNREF (iter->source, iter->context);
iter->source = NULL;
}
}
/* Holds context's lock
*/
static GSourceList *
find_source_list_for_priority (GMainContext *context,
gint priority,
gboolean create)
{
GList *iter, *last;
GSourceList *source_list;
last = NULL;
for (iter = context->source_lists; iter != NULL; last = iter, iter = iter->next)
{
source_list = iter->data;
if (source_list->priority == priority)
return source_list;
if (source_list->priority > priority)
{
if (!create)
return NULL;
source_list = g_slice_new0 (GSourceList);
source_list->priority = priority;
context->source_lists = g_list_insert_before (context->source_lists,
iter,
source_list);
return source_list;
}
}
if (!create)
return NULL;
source_list = g_slice_new0 (GSourceList);
source_list->priority = priority;
if (!last)
context->source_lists = g_list_append (NULL, source_list);
else
{
/* This just appends source_list to the end of
* context->source_lists without having to walk the list again.
*/
last = g_list_append (last, source_list);
}
return source_list;
}
/* Holds context's lock
*/
static void
source_add_to_context (GSource *source,
GMainContext *context)