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, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
21 */
22
23 /*
24 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
25 * file for a list of people on the GLib Team. See the ChangeLog
26 * files for a list of changes. These files are distributed with
27 * GLib at ftp://ftp.gtk.org/pub/gtk/.
28 */
29
30 /*
31 * MT safe
32 */
33
34 #ifndef _WIN32
35 /* for pipe2; need to define it first to avoid
36 * other headers pulling in unistd.h
37 */
38 /* The meaning of_GNU_SOURCE that is intended here is present only on
39 * Linux; avoid the possibility that some misguided header in MinGW
40 * looks at it. Ideally we should define _GNU_SOURCE only on platforms
41 * where we know what it means and that is what we want here
42 * (i.e. Linux with glibc). After all, there might be some other POSIX
43 * platform even where _GNU_SOURCE is used for some unrelated change
44 * in semantics that isn't wanted. Sigh.
45 */
46 #define _GNU_SOURCE
47 #endif
48
49 #include "config.h"
50 #include "glibconfig.h"
51
52 /* Uncomment the next line (and the corresponding line in gpoll.c) to
53 * enable debugging printouts if the environment variable
54 * G_MAIN_POLL_DEBUG is set to some value.
55 */
56 /* #define G_MAIN_POLL_DEBUG */
57
58 #ifdef _WIN32
59 /* Always enable debugging printout on Windows, as it is more often
60 * needed there...
61 */
62 #define G_MAIN_POLL_DEBUG
63 #endif
64
65 #include <signal.h>
66 #include <sys/types.h>
67 #include <time.h>
68 #include <stdlib.h>
69 #ifdef HAVE_SYS_TIME_H
70 #include <sys/time.h>
71 #endif /* HAVE_SYS_TIME_H */
72 #ifdef HAVE_UNISTD_H
73 #include <unistd.h>
74 #endif /* HAVE_UNISTD_H */
75 #include <errno.h>
76
77 #ifdef G_OS_WIN32
78 #define STRICT
79 #include <windows.h>
80 #endif /* G_OS_WIN32 */
81
82 #ifdef G_OS_BEOS
83 #include <sys/socket.h>
84 #include <sys/wait.h>
85 #endif /* G_OS_BEOS */
86
87 #ifdef G_OS_UNIX
88 #include <fcntl.h>
89 #include <sys/wait.h>
90 #endif
91
92 #include "gmain.h"
93
94 #include "garray.h"
95 #include "giochannel.h"
96 #include "ghash.h"
97 #include "ghook.h"
98 #include "gqueue.h"
99 #include "gstrfuncs.h"
100 #include "gtestutils.h"
101 #include "gthreadprivate.h"
102
103 #ifdef G_OS_WIN32
104 #include "gwin32.h"
105 #endif
106
107 #ifdef G_MAIN_POLL_DEBUG
108 #include "gtimer.h"
109 #endif
110
111 /**
112 * SECTION:main
113 * @title: The Main Event Loop
114 * @short_description: manages all available sources of events
115 *
116 * The main event loop manages all the available sources of events for
117 * GLib and GTK+ applications. These events can come from any number of
118 * different types of sources such as file descriptors (plain files,
119 * pipes or sockets) and timeouts. New types of event sources can also
120 * be added using g_source_attach().
121 *
122 * To allow multiple independent sets of sources to be handled in
123 * different threads, each source is associated with a #GMainContext.
124 * A GMainContext can only be running in a single thread, but
125 * sources can be added to it and removed from it from other threads.
126 *
127 * Each event source is assigned a priority. The default priority,
128 * #G_PRIORITY_DEFAULT, is 0. Values less than 0 denote higher priorities.
129 * Values greater than 0 denote lower priorities. Events from high priority
130 * sources are always processed before events from lower priority sources.
131 *
132 * Idle functions can also be added, and assigned a priority. These will
133 * be run whenever no events with a higher priority are ready to be processed.
134 *
135 * The #GMainLoop data type represents a main event loop. A GMainLoop is
136 * created with g_main_loop_new(). After adding the initial event sources,
137 * g_main_loop_run() is called. This continuously checks for new events from
138 * each of the event sources and dispatches them. Finally, the processing of
139 * an event from one of the sources leads to a call to g_main_loop_quit() to
140 * exit the main loop, and g_main_loop_run() returns.
141 *
142 * It is possible to create new instances of #GMainLoop recursively.
143 * This is often used in GTK+ applications when showing modal dialog
144 * boxes. Note that event sources are associated with a particular
145 * #GMainContext, and will be checked and dispatched for all main
146 * loops associated with that GMainContext.
147 *
148 * GTK+ contains wrappers of some of these functions, e.g. gtk_main(),
149 * gtk_main_quit() and gtk_events_pending().
150 *
151 * <refsect2><title>Creating new source types</title>
152 * <para>One of the unusual features of the #GMainLoop functionality
153 * is that new types of event source can be created and used in
154 * addition to the builtin type of event source. A new event source
155 * type is used for handling GDK events. A new source type is created
156 * by <firstterm>deriving</firstterm> from the #GSource structure.
157 * The derived type of source is represented by a structure that has
158 * the #GSource structure as a first element, and other elements specific
159 * to the new source type. To create an instance of the new source type,
160 * call g_source_new() passing in the size of the derived structure and
161 * a table of functions. These #GSourceFuncs determine the behavior of
162 * the new source type.</para>
163 * <para>New source types basically interact with the main context
164 * in two ways. Their prepare function in #GSourceFuncs can set a timeout
165 * to determine the maximum amount of time that the main loop will sleep
166 * before checking the source again. In addition, or as well, the source
167 * can add file descriptors to the set that the main context checks using
168 * g_source_add_poll().</para>
169 * </refsect2>
170 * <refsect2><title>Customizing the main loop iteration</title>
171 * <para>Single iterations of a #GMainContext can be run with
172 * g_main_context_iteration(). In some cases, more detailed control
173 * of exactly how the details of the main loop work is desired, for
174 * instance, when integrating the #GMainLoop with an external main loop.
175 * In such cases, you can call the component functions of
176 * g_main_context_iteration() directly. These functions are
177 * g_main_context_prepare(), g_main_context_query(),
178 * g_main_context_check() and g_main_context_dispatch().</para>
179 * <para>The operation of these functions can best be seen in terms
180 * of a state diagram, as shown in <xref linkend="mainloop-states"/>.</para>
181 * <figure id="mainloop-states"><title>States of a Main Context</title>
182 * <graphic fileref="mainloop-states.gif" format="GIF"></graphic>
183 * </figure>
184 * </refsect2>
185 */
186
187 /* Types */
188
189 typedef struct _GTimeoutSource GTimeoutSource;
190 typedef struct _GChildWatchSource GChildWatchSource;
191 typedef struct _GPollRec GPollRec;
192 typedef struct _GSourceCallback GSourceCallback;
193
194 typedef enum
195 {
196 G_SOURCE_READY = 1 << G_HOOK_FLAG_USER_SHIFT,
197 G_SOURCE_CAN_RECURSE = 1 << (G_HOOK_FLAG_USER_SHIFT + 1)
198 } GSourceFlags;
199
200 #ifdef G_THREADS_ENABLED
201 typedef struct _GMainWaiter GMainWaiter;
202
203 struct _GMainWaiter
204 {
205 GCond *cond;
206 GMutex *mutex;
207 };
208 #endif
209
210 typedef struct _GMainDispatch GMainDispatch;
211
212 struct _GMainDispatch
213 {
214 gint depth;
215 GSList *dispatching_sources; /* stack of current sources */
216 };
217
218 #ifdef G_MAIN_POLL_DEBUG
219 gboolean _g_main_poll_debug = FALSE;
220 #endif
221
222 struct _GMainContext
223 {
224 #ifdef G_THREADS_ENABLED
225 /* The following lock is used for both the list of sources
226 * and the list of poll records
227 */
228 GStaticMutex mutex;
229 GCond *cond;
230 GThread *owner;
231 guint owner_count;
232 GSList *waiters;
233 #endif
234
235 gint ref_count;
236
237 GPtrArray *pending_dispatches;
238 gint timeout; /* Timeout for current iteration */
239
240 guint next_id;
241 GSource *source_list;
242 gint in_check_or_prepare;
243
244 GPollRec *poll_records, *poll_records_tail;
245 guint n_poll_records;
246 GPollFD *cached_poll_array;
247 guint cached_poll_array_size;
248
249 #ifdef G_THREADS_ENABLED
250 #ifndef G_OS_WIN32
251 /* this pipe is used to wake up the main loop when a source is added.
252 */
253 gint wake_up_pipe[2];
254 #else /* G_OS_WIN32 */
255 HANDLE wake_up_semaphore;
256 #endif /* G_OS_WIN32 */
257
258 GPollFD wake_up_rec;
259 gboolean poll_waiting;
260
261 /* Flag indicating whether the set of fd's changed during a poll */
262 gboolean poll_changed;
263 #endif /* G_THREADS_ENABLED */
264
265 GPollFunc poll_func;
266
267 gint64 time;
268 gboolean time_is_fresh;
269 gint64 real_time;
270 gboolean real_time_is_fresh;
271 };
272
273 struct _GSourceCallback
274 {
275 guint ref_count;
276 GSourceFunc func;
277 gpointer data;
278 GDestroyNotify notify;
279 };
280
281 struct _GMainLoop
282 {
283 GMainContext *context;
284 gboolean is_running;
285 gint ref_count;
286 };
287
288 struct _GTimeoutSource
289 {
290 GSource source;
291 gint64 expiration;
292 guint interval;
293 gboolean seconds;
294 };
295
296 struct _GChildWatchSource
297 {
298 GSource source;
299 GPid pid;
300 gint child_status;
301 #ifdef G_OS_WIN32
302 GPollFD poll;
303 #else /* G_OS_WIN32 */
304 gint count;
305 gboolean child_exited;
306 #endif /* G_OS_WIN32 */
307 };
308
309 struct _GPollRec
310 {
311 GPollFD *fd;
312 GPollRec *prev;
313 GPollRec *next;
314 gint priority;
315 };
316
317 struct _GSourcePrivate
318 {
319 GSList *child_sources;
320 GSource *parent_source;
321 };
322
323 #ifdef G_THREADS_ENABLED
324 #define LOCK_CONTEXT(context) g_static_mutex_lock (&context->mutex)
325 #define UNLOCK_CONTEXT(context) g_static_mutex_unlock (&context->mutex)
326 #define G_THREAD_SELF g_thread_self ()
327 #else
328 #define LOCK_CONTEXT(context) (void)0
329 #define UNLOCK_CONTEXT(context) (void)0
330 #define G_THREAD_SELF NULL
331 #endif
332
333 #define SOURCE_DESTROYED(source) (((source)->flags & G_HOOK_FLAG_ACTIVE) == 0)
334 #define SOURCE_BLOCKED(source) (((source)->flags & G_HOOK_FLAG_IN_CALL) != 0 && \
335 ((source)->flags & G_SOURCE_CAN_RECURSE) == 0)
336
337 #define SOURCE_UNREF(source, context) \
338 G_STMT_START { \
339 if ((source)->ref_count > 1) \
340 (source)->ref_count--; \
341 else \
342 g_source_unref_internal ((source), (context), TRUE); \
343 } G_STMT_END
344
345
346 /* Forward declarations */
347
348 static void g_source_unref_internal (GSource *source,
349 GMainContext *context,
350 gboolean have_lock);
351 static void g_source_destroy_internal (GSource *source,
352 GMainContext *context,
353 gboolean have_lock);
354 static void g_source_set_priority_unlocked (GSource *source,
355 GMainContext *context,
356 gint priority);
357 static void g_main_context_poll (GMainContext *context,
358 gint timeout,
359 gint priority,
360 GPollFD *fds,
361 gint n_fds);
362 static void g_main_context_add_poll_unlocked (GMainContext *context,
363 gint priority,
364 GPollFD *fd);
365 static void g_main_context_remove_poll_unlocked (GMainContext *context,
366 GPollFD *fd);
367 static void g_main_context_wakeup_unlocked (GMainContext *context);
368
369 static gboolean g_timeout_prepare (GSource *source,
370 gint *timeout);
371 static gboolean g_timeout_check (GSource *source);
372 static gboolean g_timeout_dispatch (GSource *source,
373 GSourceFunc callback,
374 gpointer user_data);
375 static gboolean g_child_watch_prepare (GSource *source,
376 gint *timeout);
377 static gboolean g_child_watch_check (GSource *source);
378 static gboolean g_child_watch_dispatch (GSource *source,
379 GSourceFunc callback,
380 gpointer user_data);
381 static gboolean g_idle_prepare (GSource *source,
382 gint *timeout);
383 static gboolean g_idle_check (GSource *source);
384 static gboolean g_idle_dispatch (GSource *source,
385 GSourceFunc callback,
386 gpointer user_data);
387
388 G_LOCK_DEFINE_STATIC (main_loop);
389 static GMainContext *default_main_context;
390 static GSList *main_contexts_without_pipe = NULL;
391
392 #ifndef G_OS_WIN32
393 /* Child status monitoring code */
394 enum {
395 CHILD_WATCH_UNINITIALIZED,
396 CHILD_WATCH_INITIALIZED_SINGLE,
397 CHILD_WATCH_INITIALIZED_THREADED
398 };
399 static gint child_watch_init_state = CHILD_WATCH_UNINITIALIZED;
400 static gint child_watch_count = 1;
401 static gint child_watch_wake_up_pipe[2] = {0, 0};
402 #endif /* !G_OS_WIN32 */
403 G_LOCK_DEFINE_STATIC (main_context_list);
404 static GSList *main_context_list = NULL;
405
406 GSourceFuncs g_timeout_funcs =
407 {
408 g_timeout_prepare,
409 g_timeout_check,
410 g_timeout_dispatch,
411 NULL
412 };
413
414 GSourceFuncs g_child_watch_funcs =
415 {
416 g_child_watch_prepare,
417 g_child_watch_check,
418 g_child_watch_dispatch,
419 NULL
420 };
421
422 GSourceFuncs g_idle_funcs =
423 {
424 g_idle_prepare,
425 g_idle_check,
426 g_idle_dispatch,
427 NULL
428 };
429
430 /**
431 * g_main_context_ref:
432 * @context: a #GMainContext
433 *
434 * Increases the reference count on a #GMainContext object by one.
435 *
436 * Returns: the @context that was passed in (since 2.6)
437 **/
438 GMainContext *
439 g_main_context_ref (GMainContext *context)
440 {
441 g_return_val_if_fail (context != NULL, NULL);
442 g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL);
443
444 g_atomic_int_inc (&context->ref_count);
445
446 return context;
447 }
448
449 static inline void
450 poll_rec_list_free (GMainContext *context,
451 GPollRec *list)
452 {
453 g_slice_free_chain (GPollRec, list, next);
454 }
455
456 /**
457 * g_main_context_unref:
458 * @context: a #GMainContext
459 *
460 * Decreases the reference count on a #GMainContext object by one. If
461 * the result is zero, free the context and free all associated memory.
462 **/
463 void
464 g_main_context_unref (GMainContext *context)
465 {
466 GSource *source;
467 g_return_if_fail (context != NULL);
468 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
469
470 if (!g_atomic_int_dec_and_test (&context->ref_count))
471 return;
472
473 G_LOCK (main_context_list);
474 main_context_list = g_slist_remove (main_context_list, context);
475 G_UNLOCK (main_context_list);
476
477 source = context->source_list;
478 while (source)
479 {
480 GSource *next = source->next;
481 g_source_destroy_internal (source, context, FALSE);
482 source = next;
483 }
484
485 #ifdef G_THREADS_ENABLED
486 g_static_mutex_free (&context->mutex);
487 #endif
488
489 g_ptr_array_free (context->pending_dispatches, TRUE);
490 g_free (context->cached_poll_array);
491
492 poll_rec_list_free (context, context->poll_records);
493
494 #ifdef G_THREADS_ENABLED
495 if (g_thread_supported())
496 {
497 #ifndef G_OS_WIN32
498 close (context->wake_up_pipe[0]);
499 close (context->wake_up_pipe[1]);
500 #else
501 CloseHandle (context->wake_up_semaphore);
502 #endif
503 }
504 else
505 main_contexts_without_pipe = g_slist_remove (main_contexts_without_pipe,
506 context);
507
508 if (context->cond != NULL)
509 g_cond_free (context->cond);
510 #endif
511
512 g_free (context);
513 }
514
515 #ifdef G_THREADS_ENABLED
516 static void
517 g_main_context_init_pipe (GMainContext *context)
518 {
519 # ifndef G_OS_WIN32
520 if (context->wake_up_pipe[0] != -1)
521 return;
522
523 #ifdef HAVE_PIPE2
524 /* if this fails, we fall through and try pipe */
525 pipe2 (context->wake_up_pipe, O_CLOEXEC);
526 #endif
527 if (context->wake_up_pipe[0] == -1)
528 {
529 if (pipe (context->wake_up_pipe) < 0)
530 g_error ("Cannot create pipe main loop wake-up: %s\n",
531 g_strerror (errno));
532
533 fcntl (context->wake_up_pipe[0], F_SETFD, FD_CLOEXEC);
534 fcntl (context->wake_up_pipe[1], F_SETFD, FD_CLOEXEC);
535 }
536
537 context->wake_up_rec.fd = context->wake_up_pipe[0];
538 context->wake_up_rec.events = G_IO_IN;
539 # else
540 if (context->wake_up_semaphore != NULL)
541 return;
542 context->wake_up_semaphore = CreateSemaphore (NULL, 0, 100, NULL);
543 if (context->wake_up_semaphore == NULL)
544 g_error ("Cannot create wake-up semaphore: %s",
545 g_win32_error_message (GetLastError ()));
546 context->wake_up_rec.fd = (gintptr) context->wake_up_semaphore;
547 context->wake_up_rec.events = G_IO_IN;
548
549 if (_g_main_poll_debug)
550 g_print ("wake-up semaphore: %p\n", context->wake_up_semaphore);
551 # endif
552 g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec);
553 }
554
555 void
556 _g_main_thread_init (void)
557 {
558 GSList *curr = main_contexts_without_pipe;
559 while (curr)
560 {
561 g_main_context_init_pipe ((GMainContext *)curr->data);
562 curr = curr->next;
563 }
564 g_slist_free (main_contexts_without_pipe);
565 main_contexts_without_pipe = NULL;
566 }
567 #endif /* G_THREADS_ENABLED */
568
569 /**
570 * g_main_context_new:
571 *
572 * Creates a new #GMainContext structure.
573 *
574 * Return value: the new #GMainContext
575 **/
576 GMainContext *
577 g_main_context_new (void)
578 {
579 GMainContext *context = g_new0 (GMainContext, 1);
580
581 #ifdef G_MAIN_POLL_DEBUG
582 {
583 static gboolean beenhere = FALSE;
584
585 if (!beenhere)
586 {
587 if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
588 _g_main_poll_debug = TRUE;
589 beenhere = TRUE;
590 }
591 }
592 #endif
593
594 #ifdef G_THREADS_ENABLED
595 g_static_mutex_init (&context->mutex);
596
597 context->owner = NULL;
598 context->waiters = NULL;
599
600 # ifndef G_OS_WIN32
601 context->wake_up_pipe[0] = -1;
602 context->wake_up_pipe[1] = -1;
603 # else
604 context->wake_up_semaphore = NULL;
605 # endif
606 #endif
607
608 context->ref_count = 1;
609
610 context->next_id = 1;
611
612 context->source_list = NULL;
613
614 context->poll_func = g_poll;
615
616 context->cached_poll_array = NULL;
617 context->cached_poll_array_size = 0;
618
619 context->pending_dispatches = g_ptr_array_new ();
620
621 context->time_is_fresh = FALSE;
622 context->real_time_is_fresh = FALSE;
623
624 #ifdef G_THREADS_ENABLED
625 if (g_thread_supported ())
626 g_main_context_init_pipe (context);
627 else
628 main_contexts_without_pipe = g_slist_prepend (main_contexts_without_pipe,
629 context);
630 #endif
631
632 G_LOCK (main_context_list);
633 main_context_list = g_slist_append (main_context_list, context);
634
635 #ifdef G_MAIN_POLL_DEBUG
636 if (_g_main_poll_debug)
637 g_print ("created context=%p\n", context);
638 #endif
639
640 G_UNLOCK (main_context_list);
641
642 return context;
643 }
644
645 /**
646 * g_main_context_default:
647 *
648 * Returns the global default main context. This is the main context
649 * used for main loop functions when a main loop is not explicitly
650 * specified, and corresponds to the "main" main loop. See also
651 * g_main_context_get_thread_default().
652 *
653 * Return value: the global default main context.
654 **/
655 GMainContext *
656 g_main_context_default (void)
657 {
658 /* Slow, but safe */
659
660 G_LOCK (main_loop);
661
662 if (!default_main_context)
663 {
664 default_main_context = g_main_context_new ();
665 #ifdef G_MAIN_POLL_DEBUG
666 if (_g_main_poll_debug)
667 g_print ("default context=%p\n", default_main_context);
668 #endif
669 }
670
671 G_UNLOCK (main_loop);
672
673 return default_main_context;
674 }
675
676 static GStaticPrivate thread_context_stack = G_STATIC_PRIVATE_INIT;
677
678 static void
679 free_context_stack (gpointer data)
680 {
681 GQueue *stack = data;
682 GMainContext *context;
683
684 while (!g_queue_is_empty (stack))
685 {
686 context = g_queue_pop_head (stack);
687 g_main_context_release (context);
688 if (context)
689 g_main_context_unref (context);
690 }
691 g_queue_free (stack);
692 }
693
694 /**
695 * g_main_context_push_thread_default:
696 * @context: a #GMainContext, or %NULL for the global default context
697 *
698 * Acquires @context and sets it as the thread-default context for the
699 * current thread. This will cause certain asynchronous operations
700 * (such as most <link linkend="gio">gio</link>-based I/O) which are
701 * started in this thread to run under @context and deliver their
702 * results to its main loop, rather than running under the global
703 * default context in the main thread. Note that calling this function
704 * changes the context returned by
705 * g_main_context_get_thread_default(), <emphasis>not</emphasis> the
706 * one returned by g_main_context_default(), so it does not affect the
707 * context used by functions like g_idle_add().
708 *
709 * Normally you would call this function shortly after creating a new
710 * thread, passing it a #GMainContext which will be run by a
711 * #GMainLoop in that thread, to set a new default context for all
712 * async operations in that thread. (In this case, you don't need to
713 * ever call g_main_context_pop_thread_default().) In some cases
714 * however, you may want to schedule a single operation in a
715 * non-default context, or temporarily use a non-default context in
716 * the main thread. In that case, you can wrap the call to the
717 * asynchronous operation inside a
718 * g_main_context_push_thread_default() /
719 * g_main_context_pop_thread_default() pair, but it is up to you to
720 * ensure that no other asynchronous operations accidentally get
721 * started while the non-default context is active.
722 *
723 * Beware that libraries that predate this function may not correctly
724 * handle being used from a thread with a thread-default context. Eg,
725 * see g_file_supports_thread_contexts().
726 *
727 * Since: 2.22
728 **/
729 void
730 g_main_context_push_thread_default (GMainContext *context)
731 {
732 GQueue *stack;
733 gboolean acquired_context;
734
735 acquired_context = g_main_context_acquire (context);
736 g_return_if_fail (acquired_context);
737
738 if (context == g_main_context_default ())
739 context = NULL;
740 else if (context)
741 g_main_context_ref (context);
742
743 stack = g_static_private_get (&thread_context_stack);
744 if (!stack)
745 {
746 stack = g_queue_new ();
747 g_static_private_set (&thread_context_stack, stack,
748 free_context_stack);
749 }
750
751 g_queue_push_head (stack, context);
752 }
753
754 /**
755 * g_main_context_pop_thread_default:
756 * @context: a #GMainContext object, or %NULL
757 *
758 * Pops @context off the thread-default context stack (verifying that
759 * it was on the top of the stack).
760 *
761 * Since: 2.22
762 **/
763 void
764 g_main_context_pop_thread_default (GMainContext *context)
765 {
766 GQueue *stack;
767
768 if (context == g_main_context_default ())
769 context = NULL;
770
771 stack = g_static_private_get (&thread_context_stack);
772
773 g_return_if_fail (stack != NULL);
774 g_return_if_fail (g_queue_peek_head (stack) == context);
775
776 g_queue_pop_head (stack);
777
778 g_main_context_release (context);
779 if (context)
780 g_main_context_unref (context);
781 }
782
783 /**
784 * g_main_context_get_thread_default:
785 *
786 * Gets the thread-default #GMainContext for this thread. Asynchronous
787 * operations that want to be able to be run in contexts other than
788 * the default one should call this method to get a #GMainContext to
789 * add their #GSource<!-- -->s to. (Note that even in single-threaded
790 * programs applications may sometimes want to temporarily push a
791 * non-default context, so it is not safe to assume that this will
792 * always return %NULL if threads are not initialized.)
793 *
794 * Returns: the thread-default #GMainContext, or %NULL if the
795 * thread-default context is the global default context.
796 *
797 * Since: 2.22
798 **/
799 GMainContext *
800 g_main_context_get_thread_default (void)
801 {
802 GQueue *stack;
803
804 stack = g_static_private_get (&thread_context_stack);
805 if (stack)
806 return g_queue_peek_head (stack);
807 else
808 return NULL;
809 }
810
811 /* Hooks for adding to the main loop */
812
813 /**
814 * g_source_new:
815 * @source_funcs: structure containing functions that implement
816 * the sources behavior.
817 * @struct_size: size of the #GSource structure to create.
818 *
819 * Creates a new #GSource structure. The size is specified to
820 * allow creating structures derived from #GSource that contain
821 * additional data. The size passed in must be at least
822 * <literal>sizeof (GSource)</literal>.
823 *
824 * The source will not initially be associated with any #GMainContext
825 * and must be added to one with g_source_attach() before it will be
826 * executed.
827 *
828 * Return value: the newly-created #GSource.
829 **/
830 GSource *
831 g_source_new (GSourceFuncs *source_funcs,
832 guint struct_size)
833 {
834 GSource *source;
835
836 g_return_val_if_fail (source_funcs != NULL, NULL);
837 g_return_val_if_fail (struct_size >= sizeof (GSource), NULL);
838
839 source = (GSource*) g_malloc0 (struct_size);
840 #ifdef GSTREAMER_LITE
841 if (source == NULL)
842 return NULL;
843 #endif // GSTREAMER_LITE
844
845 source->source_funcs = source_funcs;
846 source->ref_count = 1;
847
848 source->priority = G_PRIORITY_DEFAULT;
849
850 source->flags = G_HOOK_FLAG_ACTIVE;
851
852 /* NULL/0 initialization for all other fields */
853
854 return source;
855 }
856
857 /* Holds context's lock
858 */
859 static void
860 g_source_list_add (GSource *source,
861 GMainContext *context)
862 {
863 GSource *tmp_source, *last_source;
864
865 if (source->priv && source->priv->parent_source)
866 {
867 /* Put the source immediately before its parent */
868 tmp_source = source->priv->parent_source;
869 last_source = source->priv->parent_source->prev;
870 }
871 else
872 {
873 last_source = NULL;
874 tmp_source = context->source_list;
875 while (tmp_source && tmp_source->priority <= source->priority)
876 {
877 last_source = tmp_source;
878 tmp_source = tmp_source->next;
879 }
880 }
881
882 source->next = tmp_source;
883 if (tmp_source)
884 tmp_source->prev = source;
885
886 source->prev = last_source;
887 if (last_source)
888 last_source->next = source;
889 else
890 context->source_list = source;
891 }
892
893 /* Holds context's lock
894 */
895 static void
896 g_source_list_remove (GSource *source,
897 GMainContext *context)
898 {
899 if (source->prev)
900 source->prev->next = source->next;
901 else
902 context->source_list = source->next;
903
904 if (source->next)
905 source->next->prev = source->prev;
906
907 source->prev = NULL;
908 source->next = NULL;
909 }
910
911 static guint
912 g_source_attach_unlocked (GSource *source,
913 GMainContext *context)
914 {
915 guint result = 0;
916 GSList *tmp_list;
917
918 source->context = context;
919 result = source->source_id = context->next_id++;
920
921 source->ref_count++;
922 g_source_list_add (source, context);
923
924 tmp_list = source->poll_fds;
925 while (tmp_list)
926 {
927 g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data);
928 tmp_list = tmp_list->next;
929 }
930
931 if (source->priv)
932 {
933 tmp_list = source->priv->child_sources;
934 while (tmp_list)
935 {
936 g_source_attach_unlocked (tmp_list->data, context);
937 tmp_list = tmp_list->next;
938 }
939 }
940
941 return result;
942 }
943
944 /**
945 * g_source_attach:
946 * @source: a #GSource
947 * @context: a #GMainContext (if %NULL, the default context will be used)
948 *
949 * Adds a #GSource to a @context so that it will be executed within
950 * that context. Remove it by calling g_source_destroy().
951 *
952 * Return value: the ID (greater than 0) for the source within the
953 * #GMainContext.
954 **/
955 guint
956 g_source_attach (GSource *source,
957 GMainContext *context)
958 {
959 guint result = 0;
960
961 #ifdef GSTREAMER_LITE
962 if (source == NULL) {
963 return 0;
964 }
965 #endif // GSTREAMER_LITE
966
967 g_return_val_if_fail (source->context == NULL, 0);
968 g_return_val_if_fail (!SOURCE_DESTROYED (source), 0);
969
970 if (!context)
971 context = g_main_context_default ();
972
973 LOCK_CONTEXT (context);
974
975 result = g_source_attach_unlocked (source, context);
976
977 #ifdef G_THREADS_ENABLED
978 /* Now wake up the main loop if it is waiting in the poll() */
979 g_main_context_wakeup_unlocked (context);
980 #endif
981
982 UNLOCK_CONTEXT (context);
983
984 return result;
985 }
986
987 static void
988 g_source_destroy_internal (GSource *source,
989 GMainContext *context,
990 gboolean have_lock)
991 {
992 if (!have_lock)
993 LOCK_CONTEXT (context);
994
995 if (!SOURCE_DESTROYED (source))
996 {
997 GSList *tmp_list;
998 gpointer old_cb_data;
999 GSourceCallbackFuncs *old_cb_funcs;
1000
1001 source->flags &= ~G_HOOK_FLAG_ACTIVE;
1002
1003 old_cb_data = source->callback_data;
1004 old_cb_funcs = source->callback_funcs;
1005
1006 source->callback_data = NULL;
1007 source->callback_funcs = NULL;
1008
1009 if (old_cb_funcs)
1010 {
1011 UNLOCK_CONTEXT (context);
1012 old_cb_funcs->unref (old_cb_data);
1013 LOCK_CONTEXT (context);
1014 }
1015
1016 if (!SOURCE_BLOCKED (source))
1017 {
1018 tmp_list = source->poll_fds;
1019 while (tmp_list)
1020 {
1021 g_main_context_remove_poll_unlocked (context, tmp_list->data);
1022 tmp_list = tmp_list->next;
1023 }
1024 }
1025
1026 if (source->priv && source->priv->child_sources)
1027 {
1028 /* This is safe because even if a child_source finalizer or
1029 * closure notify tried to modify source->priv->child_sources
1030 * from outside the lock, it would fail since
1031 * SOURCE_DESTROYED(source) is now TRUE.
1032 */
1033 tmp_list = source->priv->child_sources;
1034 while (tmp_list)
1035 {
1036 g_source_destroy_internal (tmp_list->data, context, TRUE);
1037 g_source_unref_internal (tmp_list->data, context, TRUE);
1038 tmp_list = tmp_list->next;
1039 }
1040 g_slist_free (source->priv->child_sources);
1041 source->priv->child_sources = NULL;
1042 }
1043
1044 g_source_unref_internal (source, context, TRUE);
1045 }
1046
1047 if (!have_lock)
1048 UNLOCK_CONTEXT (context);
1049 }
1050
1051 /**
1052 * g_source_destroy:
1053 * @source: a #GSource
1054 *
1055 * Removes a source from its #GMainContext, if any, and mark it as
1056 * destroyed. The source cannot be subsequently added to another
1057 * context.
1058 **/
1059 void
1060 g_source_destroy (GSource *source)
1061 {
1062 GMainContext *context;
1063
1064 g_return_if_fail (source != NULL);
1065
1066 context = source->context;
1067
1068 if (context)
1069 g_source_destroy_internal (source, context, FALSE);
1070 else
1071 source->flags &= ~G_HOOK_FLAG_ACTIVE;
1072 }
1073
1074 /**
1075 * g_source_get_id:
1076 * @source: a #GSource
1077 *
1078 * Returns the numeric ID for a particular source. The ID of a source
1079 * is a positive integer which is unique within a particular main loop
1080 * context. The reverse
1081 * mapping from ID to source is done by g_main_context_find_source_by_id().
1082 *
1083 * Return value: the ID (greater than 0) for the source
1084 **/
1085 guint
1086 g_source_get_id (GSource *source)
1087 {
1088 guint result;
1089
1090 g_return_val_if_fail (source != NULL, 0);
1091 g_return_val_if_fail (source->context != NULL, 0);
1092
1093 LOCK_CONTEXT (source->context);
1094 result = source->source_id;
1095 UNLOCK_CONTEXT (source->context);
1096
1097 return result;
1098 }
1099
1100 /**
1101 * g_source_get_context:
1102 * @source: a #GSource
1103 *
1104 * Gets the #GMainContext with which the source is associated.
1105 * Calling this function on a destroyed source is an error.
1106 *
1107 * Return value: the #GMainContext with which the source is associated,
1108 * or %NULL if the context has not yet been added
1109 * to a source.
1110 **/
1111 GMainContext *
1112 g_source_get_context (GSource *source)
1113 {
1114 g_return_val_if_fail (!SOURCE_DESTROYED (source), NULL);
1115
1116 return source->context;
1117 }
1118
1119 /**
1120 * g_source_add_poll:
1121 * @source:a #GSource
1122 * @fd: a #GPollFD structure holding information about a file
1123 * descriptor to watch.
1124 *
1125 * Adds a file descriptor to the set of file descriptors polled for
1126 * this source. This is usually combined with g_source_new() to add an
1127 * event source. The event source's check function will typically test
1128 * the @revents field in the #GPollFD struct and return %TRUE if events need
1129 * to be processed.
1130 **/
1131 void
1132 g_source_add_poll (GSource *source,
1133 GPollFD *fd)
1134 {
1135 GMainContext *context;
1136
1137 g_return_if_fail (source != NULL);
1138 g_return_if_fail (fd != NULL);
1139 g_return_if_fail (!SOURCE_DESTROYED (source));
1140
1141 #ifdef GSTREAMER_LITE
1142 if (source == NULL)
1143 return;
1144 #endif // GSTREAMER_LITE
1145
1146 context = source->context;
1147
1148 if (context)
1149 LOCK_CONTEXT (context);
1150
1151 source->poll_fds = g_slist_prepend (source->poll_fds, fd);
1152
1153 if (context)
1154 {
1155 if (!SOURCE_BLOCKED (source))
1156 g_main_context_add_poll_unlocked (context, source->priority, fd);
1157 UNLOCK_CONTEXT (context);
1158 }
1159 }
1160
1161 /**
1162 * g_source_remove_poll:
1163 * @source:a #GSource
1164 * @fd: a #GPollFD structure previously passed to g_source_add_poll().
1165 *
1166 * Removes a file descriptor from the set of file descriptors polled for
1167 * this source.
1168 **/
1169 void
1170 g_source_remove_poll (GSource *source,
1171 GPollFD *fd)
1172 {
1173 GMainContext *context;
1174
1175 g_return_if_fail (source != NULL);
1176 g_return_if_fail (fd != NULL);
1177 g_return_if_fail (!SOURCE_DESTROYED (source));
1178
1179 #ifdef GSTREAMER_LITE
1180 if (source == NULL)
1181 return;
1182 #endif // GSTREAMER_LITE
1183
1184 context = source->context;
1185
1186 if (context)
1187 LOCK_CONTEXT (context);
1188
1189 source->poll_fds = g_slist_remove (source->poll_fds, fd);
1190
1191 if (context)
1192 {
1193 if (!SOURCE_BLOCKED (source))
1194 g_main_context_remove_poll_unlocked (context, fd);
1195 UNLOCK_CONTEXT (context);
1196 }
1197 }
1198
1199 /**
1200 * g_source_add_child_source:
1201 * @source:a #GSource
1202 * @child_source: a second #GSource that @source should "poll"
1203 *
1204 * Adds @child_source to @source as a "polled" source; when @source is
1205 * added to a #GMainContext, @child_source will be automatically added
1206 * with the same priority, when @child_source is triggered, it will
1207 * cause @source to dispatch (in addition to calling its own
1208 * callback), and when @source is destroyed, it will destroy
1209 * @child_source as well. (@source will also still be dispatched if
1210 * its own prepare/check functions indicate that it is ready.)
1211 *
1212 * If you don't need @child_source to do anything on its own when it
1213 * triggers, you can call g_source_set_dummy_callback() on it to set a
1214 * callback that does nothing (except return %TRUE if appropriate).
1215 *
1216 * @source will hold a reference on @child_source while @child_source
1217 * is attached to it.
1218 *
1219 * Since: 2.28
1220 **/
1221 void
1222 g_source_add_child_source (GSource *source,
1223 GSource *child_source)
1224 {
1225 GMainContext *context;
1226
1227 g_return_if_fail (source != NULL);
1228 g_return_if_fail (child_source != NULL);
1229 g_return_if_fail (!SOURCE_DESTROYED (source));
1230 g_return_if_fail (!SOURCE_DESTROYED (child_source));
1231 g_return_if_fail (child_source->context == NULL);
1232 g_return_if_fail (child_source->priv == NULL || child_source->priv->parent_source == NULL);
1233
1234 context = source->context;
1235
1236 if (context)
1237 LOCK_CONTEXT (context);
1238
1239 if (!source->priv)
1240 source->priv = g_slice_new0 (GSourcePrivate);
1241 if (!child_source->priv)
1242 child_source->priv = g_slice_new0 (GSourcePrivate);
1243
1244 source->priv->child_sources = g_slist_prepend (source->priv->child_sources,
1245 g_source_ref (child_source));
1246 child_source->priv->parent_source = source;
1247 g_source_set_priority_unlocked (child_source, context, source->priority);
1248
1249 if (context)
1250 {
1251 UNLOCK_CONTEXT (context);
1252 g_source_attach (child_source, context);
1253 }
1254 }
1255
1256 /**
1257 * g_source_remove_child_source:
1258 * @source:a #GSource
1259 * @child_source: a #GSource previously passed to
1260 * g_source_add_child_source().
1261 *
1262 * Detaches @child_source from @source and destroys it.
1263 *
1264 * Since: 2.28
1265 **/
1266 void
1267 g_source_remove_child_source (GSource *source,
1268 GSource *child_source)
1269 {
1270 GMainContext *context;
1271
1272 g_return_if_fail (source != NULL);
1273 g_return_if_fail (child_source != NULL);
1274 g_return_if_fail (child_source->priv != NULL && child_source->priv->parent_source == source);
1275 g_return_if_fail (!SOURCE_DESTROYED (source));
1276 g_return_if_fail (!SOURCE_DESTROYED (child_source));
1277
1278 context = source->context;
1279
1280 if (context)
1281 LOCK_CONTEXT (context);
1282
1283 source->priv->child_sources = g_slist_remove (source->priv->child_sources, child_source);
1284 g_source_destroy_internal (child_source, context, TRUE);
1285 g_source_unref_internal (child_source, context, TRUE);
1286
1287 if (context)
1288 UNLOCK_CONTEXT (context);
1289 }
1290
1291 /**
1292 * g_source_set_callback_indirect:
1293 * @source: the source
1294 * @callback_data: pointer to callback data "object"
1295 * @callback_funcs: functions for reference counting @callback_data
1296 * and getting the callback and data
1297 *
1298 * Sets the callback function storing the data as a refcounted callback
1299 * "object". This is used internally. Note that calling
1300 * g_source_set_callback_indirect() assumes
1301 * an initial reference count on @callback_data, and thus
1302 * @callback_funcs->unref will eventually be called once more
1303 * than @callback_funcs->ref.
1304 **/
1305 void
1306 g_source_set_callback_indirect (GSource *source,
1307 gpointer callback_data,
1308 GSourceCallbackFuncs *callback_funcs)
1309 {
1310 GMainContext *context;
1311 gpointer old_cb_data;
1312 GSourceCallbackFuncs *old_cb_funcs;
1313
1314 g_return_if_fail (source != NULL);
1315 g_return_if_fail (callback_funcs != NULL || callback_data == NULL);
1316
1317 context = source->context;
1318
1319 if (context)
1320 LOCK_CONTEXT (context);
1321
1322 old_cb_data = source->callback_data;
1323 old_cb_funcs = source->callback_funcs;
1324
1325 source->callback_data = callback_data;
1326 source->callback_funcs = callback_funcs;
1327
1328 if (context)
1329 UNLOCK_CONTEXT (context);
1330
1331 if (old_cb_funcs)
1332 old_cb_funcs->unref (old_cb_data);
1333 }
1334
1335 static void
1336 g_source_callback_ref (gpointer cb_data)
1337 {
1338 GSourceCallback *callback = cb_data;
1339
1340 callback->ref_count++;
1341 }
1342
1343
1344 static void
1345 g_source_callback_unref (gpointer cb_data)
1346 {
1347 GSourceCallback *callback = cb_data;
1348
1349 callback->ref_count--;
1350 if (callback->ref_count == 0)
1351 {
1352 if (callback->notify)
1353 callback->notify (callback->data);
1354 g_free (callback);
1355 }
1356 }
1357
1358 static void
1359 g_source_callback_get (gpointer cb_data,
1360 GSource *source,
1361 GSourceFunc *func,
1362 gpointer *data)
1363 {
1364 GSourceCallback *callback = cb_data;
1365
1366 *func = callback->func;
1367 *data = callback->data;
1368 }
1369
1370 static GSourceCallbackFuncs g_source_callback_funcs = {
1371 g_source_callback_ref,
1372 g_source_callback_unref,
1373 g_source_callback_get,
1374 };
1375
1376 /**
1377 * g_source_set_callback:
1378 * @source: the source
1379 * @func: a callback function
1380 * @data: the data to pass to callback function
1381 * @notify: a function to call when @data is no longer in use, or %NULL.
1382 *
1383 * Sets the callback function for a source. The callback for a source is
1384 * called from the source's dispatch function.
1385 *
1386 * The exact type of @func depends on the type of source; ie. you
1387 * should not count on @func being called with @data as its first
1388 * parameter.
1389 *
1390 * Typically, you won't use this function. Instead use functions specific
1391 * to the type of source you are using.
1392 **/
1393 void
1394 g_source_set_callback (GSource *source,
1395 GSourceFunc func,
1396 gpointer data,
1397 GDestroyNotify notify)
1398 {
1399 GSourceCallback *new_callback;
1400
1401 g_return_if_fail (source != NULL);
1402 #ifdef GSTREAMER_LITE
1403 if (source == NULL)
1404 return;
1405 #endif // GSTREAMER_LITE
1406
1407 new_callback = g_new (GSourceCallback, 1);
1408
1409 new_callback->ref_count = 1;
1410 new_callback->func = func;
1411 new_callback->data = data;
1412 new_callback->notify = notify;
1413
1414 g_source_set_callback_indirect (source, new_callback, &g_source_callback_funcs);
1415 }
1416
1417
1418 /**
1419 * g_source_set_funcs:
1420 * @source: a #GSource
1421 * @funcs: the new #GSourceFuncs
1422 *
1423 * Sets the source functions (can be used to override
1424 * default implementations) of an unattached source.
1425 *
1426 * Since: 2.12
1427 */
1428 void
1429 g_source_set_funcs (GSource *source,
1430 GSourceFuncs *funcs)
1431 {
1432 g_return_if_fail (source != NULL);
1433 g_return_if_fail (source->context == NULL);
1434 g_return_if_fail (source->ref_count > 0);
1435 g_return_if_fail (funcs != NULL);
1436
1437 source->source_funcs = funcs;
1438 }
1439
1440 static void
1441 g_source_set_priority_unlocked (GSource *source,
1442 GMainContext *context,
1443 gint priority)
1444 {
1445 GSList *tmp_list;
1446
1447 source->priority = priority;
1448
1449 if (context)
1450 {
1451 /* Remove the source from the context's source and then
1452 * add it back so it is sorted in the correct place
1453 */
1454 g_source_list_remove (source, source->context);
1455 g_source_list_add (source, source->context);
1456
1457 if (!SOURCE_BLOCKED (source))
1458 {
1459 tmp_list = source->poll_fds;
1460 while (tmp_list)
1461 {
1462 g_main_context_remove_poll_unlocked (context, tmp_list->data);
1463 g_main_context_add_poll_unlocked (context, priority, tmp_list->data);
1464
1465 tmp_list = tmp_list->next;
1466 }
1467 }
1468 }
1469
1470 if (source->priv && source->priv->child_sources)
1471 {
1472 tmp_list = source->priv->child_sources;
1473 while (tmp_list)
1474 {
1475 g_source_set_priority_unlocked (tmp_list->data, context, priority);
1476 tmp_list = tmp_list->next;
1477 }
1478 }
1479 }
1480
1481 /**
1482 * g_source_set_priority:
1483 * @source: a #GSource
1484 * @priority: the new priority.
1485 *
1486 * Sets the priority of a source. While the main loop is being run, a
1487 * source will be dispatched if it is ready to be dispatched and no
1488 * sources at a higher (numerically smaller) priority are ready to be
1489 * dispatched.
1490 **/
1491 void
1492 g_source_set_priority (GSource *source,
1493 gint priority)
1494 {
1495 GMainContext *context;
1496
1497 #ifdef GSTREAMER_LITE
1498 if (source == NULL || source->priv == NULL || source->priv->parent_source == NULL)
1499 return;
1500 #endif // GSTREAMER_LITE
1501
1502 g_return_if_fail (source != NULL);
1503
1504 context = source->context;
1505
1506 if (context)
1507 LOCK_CONTEXT (context);
1508 g_source_set_priority_unlocked (source, context, priority);
1509 if (context)
1510 UNLOCK_CONTEXT (source->context);
1511 }
1512
1513 /**
1514 * g_source_get_priority:
1515 * @source: a #GSource
1516 *
1517 * Gets the priority of a source.
1518 *
1519 * Return value: the priority of the source
1520 **/
1521 gint
1522 g_source_get_priority (GSource *source)
1523 {
1524 g_return_val_if_fail (source != NULL, 0);
1525
1526 return source->priority;
1527 }
1528
1529 /**
1530 * g_source_set_can_recurse:
1531 * @source: a #GSource
1532 * @can_recurse: whether recursion is allowed for this source
1533 *
1534 * Sets whether a source can be called recursively. If @can_recurse is
1535 * %TRUE, then while the source is being dispatched then this source
1536 * will be processed normally. Otherwise, all processing of this
1537 * source is blocked until the dispatch function returns.
1538 **/
1539 void
1540 g_source_set_can_recurse (GSource *source,
1541 gboolean can_recurse)
1542 {
1543 GMainContext *context;
1544
1545 g_return_if_fail (source != NULL);
1546
1547 context = source->context;
1548
1549 if (context)
1550 LOCK_CONTEXT (context);
1551
1552 if (can_recurse)
1553 source->flags |= G_SOURCE_CAN_RECURSE;
1554 else
1555 source->flags &= ~G_SOURCE_CAN_RECURSE;
1556
1557 if (context)
1558 UNLOCK_CONTEXT (context);
1559 }
1560
1561 /**
1562 * g_source_get_can_recurse:
1563 * @source: a #GSource
1564 *
1565 * Checks whether a source is allowed to be called recursively.
1566 * see g_source_set_can_recurse().
1567 *
1568 * Return value: whether recursion is allowed.
1569 **/
1570 gboolean
1571 g_source_get_can_recurse (GSource *source)
1572 {
1573 g_return_val_if_fail (source != NULL, FALSE);
1574
1575 return (source->flags & G_SOURCE_CAN_RECURSE) != 0;
1576 }
1577
1578
1579 /**
1580 * g_source_set_name:
1581 * @source: a #GSource
1582 * @name: debug name for the source
1583 *
1584 * Sets a name for the source, used in debugging and profiling.
1585 * The name defaults to #NULL.
1586 *
1587 * The source name should describe in a human-readable way
1588 * what the source does. For example, "X11 event queue"
1589 * or "GTK+ repaint idle handler" or whatever it is.
1590 *
1591 * It is permitted to call this function multiple times, but is not
1592 * recommended due to the potential performance impact. For example,
1593 * one could change the name in the "check" function of a #GSourceFuncs
1594 * to include details like the event type in the source name.
1595 *
1596 * Since: 2.26
1597 **/
1598 void
1599 g_source_set_name (GSource *source,
1600 const char *name)
1601 {
1602 g_return_if_fail (source != NULL);
1603
1604 /* setting back to NULL is allowed, just because it's
1605 * weird if get_name can return NULL but you can't
1606 * set that.
1607 */
1608
1609 g_free (source->name);
1610 source->name = g_strdup (name);
1611 }
1612
1613 /**
1614 * g_source_get_name:
1615 * @source: a #GSource
1616 *
1617 * Gets a name for the source, used in debugging and profiling.
1618 * The name may be #NULL if it has never been set with
1619 * g_source_set_name().
1620 *
1621 * Return value: the name of the source
1622 * Since: 2.26
1623 **/
1624 G_CONST_RETURN char*
1625 g_source_get_name (GSource *source)
1626 {
1627 g_return_val_if_fail (source != NULL, NULL);
1628
1629 return source->name;
1630 }
1631
1632 /**
1633 * g_source_set_name_by_id:
1634 * @tag: a #GSource ID
1635 * @name: debug name for the source
1636 *
1637 * Sets the name of a source using its ID.
1638 *
1639 * This is a convenience utility to set source names from the return
1640 * value of g_idle_add(), g_timeout_add(), etc.
1641 *
1642 * Since: 2.26
1643 **/
1644 void
1645 g_source_set_name_by_id (guint tag,
1646 const char *name)
1647 {
1648 GSource *source;
1649
1650 g_return_if_fail (tag > 0);
1651
1652 source = g_main_context_find_source_by_id (NULL, tag);
1653 if (source == NULL)
1654 return;
1655
1656 g_source_set_name (source, name);
1657 }
1658
1659
1660 /**
1661 * g_source_ref:
1662 * @source: a #GSource
1663 *
1664 * Increases the reference count on a source by one.
1665 *
1666 * Return value: @source
1667 **/
1668 GSource *
1669 g_source_ref (GSource *source)
1670 {
1671 GMainContext *context;
1672
1673 g_return_val_if_fail (source != NULL, NULL);
1674
1675 context = source->context;
1676
1677 if (context)
1678 LOCK_CONTEXT (context);
1679
1680 source->ref_count++;
1681
1682 if (context)
1683 UNLOCK_CONTEXT (context);
1684
1685 return source;
1686 }
1687
1688 /* g_source_unref() but possible to call within context lock
1689 */
1690 static void
1691 g_source_unref_internal (GSource *source,
1692 GMainContext *context,
1693 gboolean have_lock)
1694 {
1695 gpointer old_cb_data = NULL;
1696 GSourceCallbackFuncs *old_cb_funcs = NULL;
1697
1698 g_return_if_fail (source != NULL);
1699
1700 if (!have_lock && context)
1701 LOCK_CONTEXT (context);
1702
1703 source->ref_count--;
1704 if (source->ref_count == 0)
1705 {
1706 old_cb_data = source->callback_data;
1707 old_cb_funcs = source->callback_funcs;
1708
1709 source->callback_data = NULL;
1710 source->callback_funcs = NULL;
1711
1712 if (context)
1713 {
1714 if (!SOURCE_DESTROYED (source))
1715 g_warning (G_STRLOC ": ref_count == 0, but source was still attached to a context!");
1716 g_source_list_remove (source, context);
1717 }
1718
1719 if (source->source_funcs->finalize)
1720 {
1721 if (context)
1722 UNLOCK_CONTEXT (context);
1723 source->source_funcs->finalize (source);
1724 if (context)
1725 LOCK_CONTEXT (context);
1726 }
1727
1728 g_free (source->name);
1729 source->name = NULL;
1730
1731 g_slist_free (source->poll_fds);
1732 source->poll_fds = NULL;
1733 g_free (source);
1734 }
1735
1736 if (!have_lock && context)
1737 UNLOCK_CONTEXT (context);
1738
1739 if (old_cb_funcs)
1740 {
1741 if (have_lock)
1742 UNLOCK_CONTEXT (context);
1743
1744 old_cb_funcs->unref (old_cb_data);
1745
1746 if (have_lock)
1747 LOCK_CONTEXT (context);
1748 }
1749 }
1750
1751 /**
1752 * g_source_unref:
1753 * @source: a #GSource
1754 *
1755 * Decreases the reference count of a source by one. If the
1756 * resulting reference count is zero the source and associated
1757 * memory will be destroyed.
1758 **/
1759 void
1760 g_source_unref (GSource *source)
1761 {
1762 g_return_if_fail (source != NULL);
1763 #ifdef GSTREAMER_LITE
1764 if (source == NULL)
1765 return;
1766 #endif // GSTREAMER_LITE
1767
1768 g_source_unref_internal (source, source->context, FALSE);
1769 }
1770
1771 /**
1772 * g_main_context_find_source_by_id:
1773 * @context: a #GMainContext (if %NULL, the default context will be used)
1774 * @source_id: the source ID, as returned by g_source_get_id().
1775 *
1776 * Finds a #GSource given a pair of context and ID.
1777 *
1778 * Return value: the #GSource if found, otherwise, %NULL
1779 **/
1780 GSource *
1781 g_main_context_find_source_by_id (GMainContext *context,
1782 guint source_id)
1783 {
1784 GSource *source;
1785
1786 g_return_val_if_fail (source_id > 0, NULL);
1787
1788 if (context == NULL)
1789 context = g_main_context_default ();
1790
1791 LOCK_CONTEXT (context);
1792
1793 source = context->source_list;
1794 while (source)
1795 {
1796 if (!SOURCE_DESTROYED (source) &&
1797 source->source_id == source_id)
1798 break;
1799 source = source->next;
1800 }
1801
1802 UNLOCK_CONTEXT (context);
1803
1804 return source;
1805 }
1806
1807 /**
1808 * g_main_context_find_source_by_funcs_user_data:
1809 * @context: a #GMainContext (if %NULL, the default context will be used).
1810 * @funcs: the @source_funcs passed to g_source_new().
1811 * @user_data: the user data from the callback.
1812 *
1813 * Finds a source with the given source functions and user data. If
1814 * multiple sources exist with the same source function and user data,
1815 * the first one found will be returned.
1816 *
1817 * Return value: the source, if one was found, otherwise %NULL
1818 **/
1819 GSource *
1820 g_main_context_find_source_by_funcs_user_data (GMainContext *context,
1821 GSourceFuncs *funcs,
1822 gpointer user_data)
1823 {
1824 GSource *source;
1825
1826 g_return_val_if_fail (funcs != NULL, NULL);
1827
1828 if (context == NULL)
1829 context = g_main_context_default ();
1830
1831 LOCK_CONTEXT (context);
1832
1833 source = context->source_list;
1834 while (source)
1835 {
1836 if (!SOURCE_DESTROYED (source) &&
1837 source->source_funcs == funcs &&
1838 source->callback_funcs)
1839 {
1840 GSourceFunc callback;
1841 gpointer callback_data;
1842
1843 source->callback_funcs->get (source->callback_data, source, &callback, &callback_data);
1844
1845 if (callback_data == user_data)
1846 break;
1847 }
1848 source = source->next;
1849 }
1850
1851 UNLOCK_CONTEXT (context);
1852
1853 return source;
1854 }
1855
1856 /**
1857 * g_main_context_find_source_by_user_data:
1858 * @context: a #GMainContext
1859 * @user_data: the user_data for the callback.
1860 *
1861 * Finds a source with the given user data for the callback. If
1862 * multiple sources exist with the same user data, the first
1863 * one found will be returned.
1864 *
1865 * Return value: the source, if one was found, otherwise %NULL
1866 **/
1867 GSource *
1868 g_main_context_find_source_by_user_data (GMainContext *context,
1869 gpointer user_data)
1870 {
1871 GSource *source;
1872
1873 if (context == NULL)
1874 context = g_main_context_default ();
1875
1876 LOCK_CONTEXT (context);
1877
1878 source = context->source_list;
1879 while (source)
1880 {
1881 if (!SOURCE_DESTROYED (source) &&
1882 source->callback_funcs)
1883 {
1884 GSourceFunc callback;
1885 gpointer callback_data = NULL;
1886
1887 source->callback_funcs->get (source->callback_data, source, &callback, &callback_data);
1888
1889 if (callback_data == user_data)
1890 break;
1891 }
1892 source = source->next;
1893 }
1894
1895 UNLOCK_CONTEXT (context);
1896
1897 return source;
1898 }
1899
1900 /**
1901 * g_source_remove:
1902 * @tag: the ID of the source to remove.
1903 *
1904 * Removes the source with the given id from the default main context.
1905 * The id of
1906 * a #GSource is given by g_source_get_id(), or will be returned by the
1907 * functions g_source_attach(), g_idle_add(), g_idle_add_full(),
1908 * g_timeout_add(), g_timeout_add_full(), g_child_watch_add(),
1909 * g_child_watch_add_full(), g_io_add_watch(), and g_io_add_watch_full().
1910 *
1911 * See also g_source_destroy(). You must use g_source_destroy() for sources
1912 * added to a non-default main context.
1913 *
1914 * Return value: %TRUE if the source was found and removed.
1915 **/
1916 gboolean
1917 g_source_remove (guint tag)
1918 {
1919 GSource *source;
1920
1921 g_return_val_if_fail (tag > 0, FALSE);
1922
1923 source = g_main_context_find_source_by_id (NULL, tag);
1924 if (source)
1925 g_source_destroy (source);
1926
1927 return source != NULL;
1928 }
1929
1930 /**
1931 * g_source_remove_by_user_data:
1932 * @user_data: the user_data for the callback.
1933 *
1934 * Removes a source from the default main loop context given the user
1935 * data for the callback. If multiple sources exist with the same user
1936 * data, only one will be destroyed.
1937 *
1938 * Return value: %TRUE if a source was found and removed.
1939 **/
1940 gboolean
1941 g_source_remove_by_user_data (gpointer user_data)
1942 {
1943 GSource *source;
1944
1945 source = g_main_context_find_source_by_user_data (NULL, user_data);
1946 if (source)
1947 {
1948 g_source_destroy (source);
1949 return TRUE;
1950 }
1951 else
1952 return FALSE;
1953 }
1954
1955 /**
1956 * g_source_remove_by_funcs_user_data:
1957 * @funcs: The @source_funcs passed to g_source_new()
1958 * @user_data: the user data for the callback
1959 *
1960 * Removes a source from the default main loop context given the
1961 * source functions and user data. If multiple sources exist with the
1962 * same source functions and user data, only one will be destroyed.
1963 *
1964 * Return value: %TRUE if a source was found and removed.
1965 **/
1966 gboolean
1967 g_source_remove_by_funcs_user_data (GSourceFuncs *funcs,
1968 gpointer user_data)
1969 {
1970 GSource *source;
1971
1972 g_return_val_if_fail (funcs != NULL, FALSE);
1973
1974 source = g_main_context_find_source_by_funcs_user_data (NULL, funcs, user_data);
1975 if (source)
1976 {
1977 g_source_destroy (source);
1978 return TRUE;
1979 }
1980 else
1981 return FALSE;
1982 }
1983
1984 /**
1985 * g_get_current_time:
1986 * @result: #GTimeVal structure in which to store current time.
1987 *
1988 * Equivalent to the UNIX gettimeofday() function, but portable.
1989 *
1990 * You may find g_get_real_time() to be more convenient.
1991 **/
1992 void
1993 g_get_current_time (GTimeVal *result)
1994 {
1995 #ifndef G_OS_WIN32
1996 struct timeval r;
1997
1998 g_return_if_fail (result != NULL);
1999
2000 /*this is required on alpha, there the timeval structs are int's
2001 not longs and a cast only would fail horribly*/
2002 gettimeofday (&r, NULL);
2003 result->tv_sec = r.tv_sec;
2004 result->tv_usec = r.tv_usec;
2005 #else
2006 FILETIME ft;
2007 guint64 time64;
2008
2009 g_return_if_fail (result != NULL);
2010
2011 GetSystemTimeAsFileTime (&ft);
2012 memmove (&time64, &ft, sizeof (FILETIME));
2013
2014 /* Convert from 100s of nanoseconds since 1601-01-01
2015 * to Unix epoch. Yes, this is Y2038 unsafe.
2016 */
2017 time64 -= G_GINT64_CONSTANT (116444736000000000);
2018 time64 /= 10;
2019
2020 result->tv_sec = time64 / 1000000;
2021 result->tv_usec = time64 % 1000000;
2022 #endif
2023 }
2024
2025 /**
2026 * g_get_real_time:
2027 *
2028 * Queries the system wall-clock time.
2029 *
2030 * This call is functionally equivalent to g_get_current_time() except
2031 * that the return value is often more convenient than dealing with a
2032 * #GTimeVal.
2033 *
2034 * You should only use this call if you are actually interested in the real
2035 * wall-clock time. g_get_monotonic_time() is probably more useful for
2036 * measuring intervals.
2037 *
2038 * Returns: the number of microseconds since January 1, 1970 UTC.
2039 *
2040 * Since: 2.28
2041 **/
2042 gint64
2043 g_get_real_time (void)
2044 {
2045 GTimeVal tv;
2046
2047 g_get_current_time (&tv);
2048
2049 return (((gint64) tv.tv_sec) * 1000000) + tv.tv_usec;
2050 }
2051
2052 /**
2053 * g_get_monotonic_time:
2054 *
2055 * Queries the system monotonic time, if available.
2056 *
2057 * On POSIX systems with clock_gettime() and %CLOCK_MONOTONIC this call
2058 * is a very shallow wrapper for that. Otherwise, we make a best effort
2059 * that probably involves returning the wall clock time (with at least
2060 * microsecond accuracy, subject to the limitations of the OS kernel).
2061 *
2062 * Note that, on Windows, "limitations of the OS kernel" is a rather
2063 * substantial statement. Depending on the configuration of the system,
2064 * the wall clock time is updated as infrequently as 64 times a second
2065 * (which is approximately every 16ms).
2066 *
2067 * Returns: the monotonic time, in microseconds
2068 *
2069 * Since: 2.28
2070 **/
2071 gint64
2072 g_get_monotonic_time (void)
2073 {
2074 #ifdef HAVE_CLOCK_GETTIME
2075 /* librt clock_gettime() is our first choice */
2076 {
2077 static int clockid = CLOCK_REALTIME;
2078 struct timespec ts;
2079
2080 #ifdef HAVE_MONOTONIC_CLOCK
2081 /* We have to check if we actually have monotonic clock support.
2082 *
2083 * There is no thread safety issue here since there is no harm if we
2084 * check twice.
2085 */
2086 {
2087 static gboolean checked;
2088
2089 if G_UNLIKELY (!checked)
2090 {
2091 if (sysconf (_SC_MONOTONIC_CLOCK) >= 0)
2092 clockid = CLOCK_MONOTONIC;
2093 checked = TRUE;
2094 }
2095 }
2096 #endif
2097
2098 clock_gettime (clockid, &ts);
2099
2100 /* In theory monotonic time can have any epoch.
2101 *
2102 * glib presently assumes the following:
2103 *
2104 * 1) The epoch comes some time after the birth of Jesus of Nazareth, but
2105 * not more than 10000 years later.
2106 *
2107 * 2) The current time also falls sometime within this range.
2108 *
2109 * These two reasonable assumptions leave us with a maximum deviation from
2110 * the epoch of 10000 years, or 315569520000000000 seconds.
2111 *
2112 * If we restrict ourselves to this range then the number of microseconds
2113 * will always fit well inside the constraints of a int64 (by a factor of
2114 * about 29).
2115 *
2116 * If you actually hit the following assertion, probably you should file a
2117 * bug against your operating system for being excessively silly.
2118 **/
2119 g_assert (G_GINT64_CONSTANT (-315569520000000000) < ts.tv_sec &&
2120 ts.tv_sec < G_GINT64_CONSTANT (315569520000000000));
2121
2122 return (((gint64) ts.tv_sec) * 1000000) + (ts.tv_nsec / 1000);
2123 }
2124 #else
2125 /* It may look like we are discarding accuracy on Windows (since its
2126 * current time is expressed in 100s of nanoseconds) but according to
2127 * many sources, the time is only updated 64 times per second, so
2128 * microsecond accuracy is more than enough.
2129 */
2130 {
2131 GTimeVal tv;
2132
2133 g_get_current_time (&tv);
2134
2135 return (((gint64) tv.tv_sec) * 1000000) + tv.tv_usec;
2136 }
2137 #endif
2138 }
2139
2140 static void
2141 g_main_dispatch_free (gpointer dispatch)
2142 {
2143 g_slice_free (GMainDispatch, dispatch);
2144 }
2145
2146 /* Running the main loop */
2147
2148 static GMainDispatch *
2149 get_dispatch (void)
2150 {
2151 static GStaticPrivate depth_private = G_STATIC_PRIVATE_INIT;
2152 GMainDispatch *dispatch = g_static_private_get (&depth_private);
2153 if (!dispatch)
2154 {
2155 dispatch = g_slice_new0 (GMainDispatch);
2156 g_static_private_set (&depth_private, dispatch, g_main_dispatch_free);
2157 }
2158
2159 return dispatch;
2160 }
2161
2162 /**
2163 * g_main_depth:
2164 *
2165 * Returns the depth of the stack of calls to
2166 * g_main_context_dispatch() on any #GMainContext in the current thread.
2167 * That is, when called from the toplevel, it gives 0. When
2168 * called from within a callback from g_main_context_iteration()
2169 * (or g_main_loop_run(), etc.) it returns 1. When called from within
2170 * a callback to a recursive call to g_main_context_iteration(),
2171 * it returns 2. And so forth.
2172 *
2173 * This function is useful in a situation like the following:
2174 * Imagine an extremely simple "garbage collected" system.
2175 *
2176 * |[
2177 * static GList *free_list;
2178 *
2179 * gpointer
2180 * allocate_memory (gsize size)
2181 * {
2182 * gpointer result = g_malloc (size);
2183 * free_list = g_list_prepend (free_list, result);
2184 * return result;
2185 * }
2186 *
2187 * void
2188 * free_allocated_memory (void)
2189 * {
2190 * GList *l;
2191 * for (l = free_list; l; l = l->next);
2192 * g_free (l->data);
2193 * g_list_free (free_list);
2194 * free_list = NULL;
2195 * }
2196 *
2197 * [...]
2198 *
2199 * while (TRUE);
2200 * {
2201 * g_main_context_iteration (NULL, TRUE);
2202 * free_allocated_memory();
2203 * }
2204 * ]|
2205 *
2206 * This works from an application, however, if you want to do the same
2207 * thing from a library, it gets more difficult, since you no longer
2208 * control the main loop. You might think you can simply use an idle
2209 * function to make the call to free_allocated_memory(), but that
2210 * doesn't work, since the idle function could be called from a
2211 * recursive callback. This can be fixed by using g_main_depth()
2212 *
2213 * |[
2214 * gpointer
2215 * allocate_memory (gsize size)
2216 * {
2217 * FreeListBlock *block = g_new (FreeListBlock, 1);
2218 * block->mem = g_malloc (size);
2219 * block->depth = g_main_depth ();
2220 * free_list = g_list_prepend (free_list, block);
2221 * return block->mem;
2222 * }
2223 *
2224 * void
2225 * free_allocated_memory (void)
2226 * {
2227 * GList *l;
2228 *
2229 * int depth = g_main_depth ();
2230 * for (l = free_list; l; );
2231 * {
2232 * GList *next = l->next;
2233 * FreeListBlock *block = l->data;
2234 * if (block->depth > depth)
2235 * {
2236 * g_free (block->mem);
2237 * g_free (block);
2238 * free_list = g_list_delete_link (free_list, l);
2239 * }
2240 *
2241 * l = next;
2242 * }
2243 * }
2244 * ]|
2245 *
2246 * There is a temptation to use g_main_depth() to solve
2247 * problems with reentrancy. For instance, while waiting for data
2248 * to be received from the network in response to a menu item,
2249 * the menu item might be selected again. It might seem that
2250 * one could make the menu item's callback return immediately
2251 * and do nothing if g_main_depth() returns a value greater than 1.
2252 * However, this should be avoided since the user then sees selecting
2253 * the menu item do nothing. Furthermore, you'll find yourself adding
2254 * these checks all over your code, since there are doubtless many,
2255 * many things that the user could do. Instead, you can use the
2256 * following techniques:
2257 *
2258 * <orderedlist>
2259 * <listitem>
2260 * <para>
2261 * Use gtk_widget_set_sensitive() or modal dialogs to prevent
2262 * the user from interacting with elements while the main
2263 * loop is recursing.
2264 * </para>
2265 * </listitem>
2266 * <listitem>
2267 * <para>
2268 * Avoid main loop recursion in situations where you can't handle
2269 * arbitrary callbacks. Instead, structure your code so that you
2270 * simply return to the main loop and then get called again when
2271 * there is more work to do.
2272 * </para>
2273 * </listitem>
2274 * </orderedlist>
2275 *
2276 * Return value: The main loop recursion level in the current thread
2277 **/
2278 int
2279 g_main_depth (void)
2280 {
2281 GMainDispatch *dispatch = get_dispatch ();
2282 return dispatch->depth;
2283 }
2284
2285 /**
2286 * g_main_current_source:
2287 *
2288 * Returns the currently firing source for this thread.
2289 *
2290 * Return value: The currently firing source or %NULL.
2291 *
2292 * Since: 2.12
2293 */
2294 GSource *
2295 g_main_current_source (void)
2296 {
2297 GMainDispatch *dispatch = get_dispatch ();
2298 return dispatch->dispatching_sources ? dispatch->dispatching_sources->data : NULL;
2299 }
2300
2301 /**
2302 * g_source_is_destroyed:
2303 * @source: a #GSource
2304 *
2305 * Returns whether @source has been destroyed.
2306 *
2307 * This is important when you operate upon your objects
2308 * from within idle handlers, but may have freed the object
2309 * before the dispatch of your idle handler.
2310 *
2311 * |[
2312 * static gboolean
2313 * idle_callback (gpointer data)
2314 * {
2315 * SomeWidget *self = data;
2316 *
2317 * GDK_THREADS_ENTER (<!-- -->);
2318 * /<!-- -->* do stuff with self *<!-- -->/
2319 * self->idle_id = 0;
2320 * GDK_THREADS_LEAVE (<!-- -->);
2321 *
2322 * return FALSE;
2323 * }
2324 *
2325 * static void
2326 * some_widget_do_stuff_later (SomeWidget *self)
2327 * {
2328 * self->idle_id = g_idle_add (idle_callback, self);
2329 * }
2330 *
2331 * static void
2332 * some_widget_finalize (GObject *object)
2333 * {
2334 * SomeWidget *self = SOME_WIDGET (object);
2335 *
2336 * if (self->idle_id)
2337 * g_source_remove (self->idle_id);
2338 *
2339 * G_OBJECT_CLASS (parent_class)->finalize (object);
2340 * }
2341 * ]|
2342 *
2343 * This will fail in a multi-threaded application if the
2344 * widget is destroyed before the idle handler fires due
2345 * to the use after free in the callback. A solution, to
2346 * this particular problem, is to check to if the source
2347 * has already been destroy within the callback.
2348 *
2349 * |[
2350 * static gboolean
2351 * idle_callback (gpointer data)
2352 * {
2353 * SomeWidget *self = data;
2354 *
2355 * GDK_THREADS_ENTER ();
2356 * if (!g_source_is_destroyed (g_main_current_source ()))
2357 * {
2358 * /<!-- -->* do stuff with self *<!-- -->/
2359 * }
2360 * GDK_THREADS_LEAVE ();
2361 *
2362 * return FALSE;
2363 * }
2364 * ]|
2365 *
2366 * Return value: %TRUE if the source has been destroyed
2367 *
2368 * Since: 2.12
2369 */
2370 gboolean
2371 g_source_is_destroyed (GSource *source)
2372 {
2373 return SOURCE_DESTROYED (source);
2374 }
2375
2376 /* Temporarily remove all this source's file descriptors from the
2377 * poll(), so that if data comes available for one of the file descriptors
2378 * we don't continually spin in the poll()
2379 */
2380 /* HOLDS: source->context's lock */
2381 static void
2382 block_source (GSource *source)
2383 {
2384 GSList *tmp_list;
2385
2386 g_return_if_fail (!SOURCE_BLOCKED (source));
2387
2388 tmp_list = source->poll_fds;
2389 while (tmp_list)
2390 {
2391 g_main_context_remove_poll_unlocked (source->context, tmp_list->data);
2392 tmp_list = tmp_list->next;
2393 }
2394 }
2395
2396 /* HOLDS: source->context's lock */
2397 static void
2398 unblock_source (GSource *source)
2399 {
2400 GSList *tmp_list;
2401
2402 g_return_if_fail (!SOURCE_BLOCKED (source)); /* Source already unblocked */
2403 g_return_if_fail (!SOURCE_DESTROYED (source));
2404
2405 tmp_list = source->poll_fds;
2406 while (tmp_list)
2407 {
2408 g_main_context_add_poll_unlocked (source->context, source->priority, tmp_list->data);
2409 tmp_list = tmp_list->next;
2410 }
2411 }
2412
2413 /* HOLDS: context's lock */
2414 static void
2415 g_main_dispatch (GMainContext *context)
2416 {
2417 GMainDispatch *current = get_dispatch ();
2418 guint i;
2419
2420 for (i = 0; i < context->pending_dispatches->len; i++)
2421 {
2422 GSource *source = context->pending_dispatches->pdata[i];
2423
2424 context->pending_dispatches->pdata[i] = NULL;
2425 g_assert (source);
2426
2427 source->flags &= ~G_SOURCE_READY;
2428
2429 if (!SOURCE_DESTROYED (source))
2430 {
2431 gboolean was_in_call;
2432 gpointer user_data = NULL;
2433 GSourceFunc callback = NULL;
2434 GSourceCallbackFuncs *cb_funcs;
2435 gpointer cb_data;
2436 gboolean need_destroy;
2437
2438 gboolean (*dispatch) (GSource *,
2439 GSourceFunc,
2440 gpointer);
2441 GSList current_source_link;
2442
2443 dispatch = source->source_funcs->dispatch;
2444 cb_funcs = source->callback_funcs;
2445 cb_data = source->callback_data;
2446
2447 if (cb_funcs)
2448 cb_funcs->ref (cb_data);
2449
2450 if ((source->flags & G_SOURCE_CAN_RECURSE) == 0)
2451 block_source (source);
2452
2453 was_in_call = source->flags & G_HOOK_FLAG_IN_CALL;
2454 source->flags |= G_HOOK_FLAG_IN_CALL;
2455
2456 if (cb_funcs)
2457 cb_funcs->get (cb_data, source, &callback, &user_data);
2458
2459 UNLOCK_CONTEXT (context);
2460
2461 current->depth++;
2462 /* The on-stack allocation of the GSList is unconventional, but
2463 * we know that the lifetime of the link is bounded to this
2464 * function as the link is kept in a thread specific list and
2465 * not manipulated outside of this function and its descendants.
2466 * Avoiding the overhead of a g_slist_alloc() is useful as many
2467 * applications do little more than dispatch events.
2468 *
2469 * This is a performance hack - do not revert to g_slist_prepend()!
2470 */
2471 current_source_link.data = source;
2472 current_source_link.next = current->dispatching_sources;
2473 current->dispatching_sources = ¤t_source_link;
2474 need_destroy = ! dispatch (source,
2475 callback,
2476 user_data);
2477 g_assert (current->dispatching_sources == ¤t_source_link);
2478 current->dispatching_sources = current_source_link.next;
2479 current->depth--;
2480
2481 if (cb_funcs)
2482 cb_funcs->unref (cb_data);
2483
2484 LOCK_CONTEXT (context);
2485
2486 if (!was_in_call)
2487 source->flags &= ~G_HOOK_FLAG_IN_CALL;
2488
2489 if ((source->flags & G_SOURCE_CAN_RECURSE) == 0 &&
2490 !SOURCE_DESTROYED (source))
2491 unblock_source (source);
2492
2493 /* Note: this depends on the fact that we can't switch
2494 * sources from one main context to another
2495 */
2496 if (need_destroy && !SOURCE_DESTROYED (source))
2497 {
2498 g_assert (source->context == context);
2499 g_source_destroy_internal (source, context, TRUE);
2500 }
2501 }
2502
2503 SOURCE_UNREF (source, context);
2504 }
2505
2506 g_ptr_array_set_size (context->pending_dispatches, 0);
2507 }
2508
2509 /* Holds context's lock */
2510 static inline GSource *
2511 next_valid_source (GMainContext *context,
2512 GSource *source)
2513 {
2514 GSource *new_source = source ? source->next : context->source_list;
2515
2516 while (new_source)
2517 {
2518 if (!SOURCE_DESTROYED (new_source))
2519 {
2520 new_source->ref_count++;
2521 break;
2522 }
2523
2524 new_source = new_source->next;
2525 }
2526
2527 if (source)
2528 SOURCE_UNREF (source, context);
2529
2530 return new_source;
2531 }
2532
2533 /**
2534 * g_main_context_acquire:
2535 * @context: a #GMainContext
2536 *
2537 * Tries to become the owner of the specified context.
2538 * If some other thread is the owner of the context,
2539 * returns %FALSE immediately. Ownership is properly
2540 * recursive: the owner can require ownership again
2541 * and will release ownership when g_main_context_release()
2542 * is called as many times as g_main_context_acquire().
2543 *
2544 * You must be the owner of a context before you
2545 * can call g_main_context_prepare(), g_main_context_query(),
2546 * g_main_context_check(), g_main_context_dispatch().
2547 *
2548 * Return value: %TRUE if the operation succeeded, and
2549 * this thread is now the owner of @context.
2550 **/
2551 gboolean
2552 g_main_context_acquire (GMainContext *context)
2553 {
2554 #ifdef G_THREADS_ENABLED
2555 gboolean result = FALSE;
2556 GThread *self = G_THREAD_SELF;
2557
2558 if (context == NULL)
2559 context = g_main_context_default ();
2560
2561 LOCK_CONTEXT (context);
2562
2563 if (!context->owner)
2564 {
2565 context->owner = self;
2566 g_assert (context->owner_count == 0);
2567 }
2568
2569 if (context->owner == self)
2570 {
2571 context->owner_count++;
2572 result = TRUE;
2573 }
2574
2575 UNLOCK_CONTEXT (context);
2576
2577 return result;
2578 #else /* !G_THREADS_ENABLED */
2579 return TRUE;
2580 #endif /* G_THREADS_ENABLED */
2581 }
2582
2583 /**
2584 * g_main_context_release:
2585 * @context: a #GMainContext
2586 *
2587 * Releases ownership of a context previously acquired by this thread
2588 * with g_main_context_acquire(). If the context was acquired multiple
2589 * times, the ownership will be released only when g_main_context_release()
2590 * is called as many times as it was acquired.
2591 **/
2592 void
2593 g_main_context_release (GMainContext *context)
2594 {
2595 #ifdef G_THREADS_ENABLED
2596 if (context == NULL)
2597 context = g_main_context_default ();
2598
2599 LOCK_CONTEXT (context);
2600
2601 context->owner_count--;
2602 if (context->owner_count == 0)
2603 {
2604 context->owner = NULL;
2605
2606 if (context->waiters)
2607 {
2608 GMainWaiter *waiter = context->waiters->data;
2609 gboolean loop_internal_waiter =
2610 (waiter->mutex == g_static_mutex_get_mutex (&context->mutex));
2611 context->waiters = g_slist_delete_link (context->waiters,
2612 context->waiters);
2613 if (!loop_internal_waiter)
2614 g_mutex_lock (waiter->mutex);
2615
2616 g_cond_signal (waiter->cond);
2617
2618 if (!loop_internal_waiter)
2619 g_mutex_unlock (waiter->mutex);
2620 }
2621 }
2622
2623 UNLOCK_CONTEXT (context);
2624 #endif /* G_THREADS_ENABLED */
2625 }
2626
2627 /**
2628 * g_main_context_wait:
2629 * @context: a #GMainContext
2630 * @cond: a condition variable
2631 * @mutex: a mutex, currently held
2632 *
2633 * Tries to become the owner of the specified context,
2634 * as with g_main_context_acquire(). But if another thread
2635 * is the owner, atomically drop @mutex and wait on @cond until
2636 * that owner releases ownership or until @cond is signaled, then
2637 * try again (once) to become the owner.
2638 *
2639 * Return value: %TRUE if the operation succeeded, and
2640 * this thread is now the owner of @context.
2641 **/
2642 gboolean
2643 g_main_context_wait (GMainContext *context,
2644 GCond *cond,
2645 GMutex *mutex)
2646 {
2647 #ifdef G_THREADS_ENABLED
2648 gboolean result = FALSE;
2649 GThread *self = G_THREAD_SELF;
2650 gboolean loop_internal_waiter;
2651
2652 if (context == NULL)
2653 context = g_main_context_default ();
2654
2655 loop_internal_waiter = (mutex == g_static_mutex_get_mutex (&context->mutex));
2656
2657 if (!loop_internal_waiter)
2658 LOCK_CONTEXT (context);
2659
2660 if (context->owner && context->owner != self)
2661 {
2662 GMainWaiter waiter;
2663
2664 waiter.cond = cond;
2665 waiter.mutex = mutex;
2666
2667 context->waiters = g_slist_append (context->waiters, &waiter);
2668
2669 if (!loop_internal_waiter)
2670 UNLOCK_CONTEXT (context);
2671 g_cond_wait (cond, mutex);
2672 if (!loop_internal_waiter)
2673 LOCK_CONTEXT (context);
2674
2675 context->waiters = g_slist_remove (context->waiters, &waiter);
2676 }
2677
2678 if (!context->owner)
2679 {
2680 context->owner = self;
2681 g_assert (context->owner_count == 0);
2682 }
2683
2684 if (context->owner == self)
2685 {
2686 context->owner_count++;
2687 result = TRUE;
2688 }
2689
2690 if (!loop_internal_waiter)
2691 UNLOCK_CONTEXT (context);
2692
2693 return result;
2694 #else /* !G_THREADS_ENABLED */
2695 return TRUE;
2696 #endif /* G_THREADS_ENABLED */
2697 }
2698
2699 /**
2700 * g_main_context_prepare:
2701 * @context: a #GMainContext
2702 * @priority: location to store priority of highest priority
2703 * source already ready.
2704 *
2705 * Prepares to poll sources within a main loop. The resulting information
2706 * for polling is determined by calling g_main_context_query ().
2707 *
2708 * Return value: %TRUE if some source is ready to be dispatched
2709 * prior to polling.
2710 **/
2711 gboolean
2712 g_main_context_prepare (GMainContext *context,
2713 gint *priority)
2714 {
2715 gint i;
2716 gint n_ready = 0;
2717 gint current_priority = G_MAXINT;
2718 GSource *source;
2719
2720 if (context == NULL)
2721 context = g_main_context_default ();
2722
2723 LOCK_CONTEXT (context);
2724
2725 context->time_is_fresh = FALSE;
2726 context->real_time_is_fresh = FALSE;
2727
2728 if (context->in_check_or_prepare)
2729 {
2730 g_warning ("g_main_context_prepare() called recursively from within a source's check() or "
2731 "prepare() member.");
2732 UNLOCK_CONTEXT (context);
2733 return FALSE;
2734 }
2735
2736 #ifdef G_THREADS_ENABLED
2737 if (context->poll_waiting)
2738 {
2739 g_warning("g_main_context_prepare(): main loop already active in another thread");
2740 UNLOCK_CONTEXT (context);
2741 return FALSE;
2742 }
2743
2744 context->poll_waiting = TRUE;
2745 #endif /* G_THREADS_ENABLED */
2746
2747 #if 0
2748 /* If recursing, finish up current dispatch, before starting over */
2749 if (context->pending_dispatches)
2750 {
2751 if (dispatch)
2752 g_main_dispatch (context, ¤t_time);
2753
2754 UNLOCK_CONTEXT (context);
2755 return TRUE;
2756 }
2757 #endif
2758
2759 /* If recursing, clear list of pending dispatches */
2760
2761 for (i = 0; i < context->pending_dispatches->len; i++)
2762 {
2763 if (context->pending_dispatches->pdata[i])
2764 SOURCE_UNREF ((GSource *)context->pending_dispatches->pdata[i], context);
2765 }
2766 g_ptr_array_set_size (context->pending_dispatches, 0);
2767
2768 /* Prepare all sources */
2769
2770 context->timeout = -1;
2771
2772 source = next_valid_source (context, NULL);
2773 while (source)
2774 {
2775 gint source_timeout = -1;
2776
2777 if ((n_ready > 0) && (source->priority > current_priority))
2778 {
2779 SOURCE_UNREF (source, context);
2780 break;
2781 }
2782 if (SOURCE_BLOCKED (source))
2783 goto next;
2784
2785 if (!(source->flags & G_SOURCE_READY))
2786 {
2787 gboolean result;
2788 gboolean (*prepare) (GSource *source,
2789 gint *timeout);
2790
2791 prepare = source->source_funcs->prepare;
2792 context->in_check_or_prepare++;
2793 UNLOCK_CONTEXT (context);
2794
2795 result = (*prepare) (source, &source_timeout);
2796
2797 LOCK_CONTEXT (context);
2798 context->in_check_or_prepare--;
2799
2800 if (result)
2801 {
2802 GSource *ready_source = source;
2803
2804 while (ready_source)
2805 {
2806 ready_source->flags |= G_SOURCE_READY;
2807 ready_source = ready_source->priv ? ready_source->priv->parent_source : NULL;
2808 }
2809 }
2810 }
2811
2812 if (source->flags & G_SOURCE_READY)
2813 {
2814 n_ready++;
2815 current_priority = source->priority;
2816 context->timeout = 0;
2817 }
2818
2819 if (source_timeout >= 0)
2820 {
2821 if (context->timeout < 0)
2822 context->timeout = source_timeout;
2823 else
2824 context->timeout = MIN (context->timeout, source_timeout);
2825 }
2826
2827 next:
2828 source = next_valid_source (context, source);
2829 }
2830
2831 UNLOCK_CONTEXT (context);
2832
2833 if (priority)
2834 *priority = current_priority;
2835
2836 return (n_ready > 0);
2837 }
2838
2839 /**
2840 * g_main_context_query:
2841 * @context: a #GMainContext
2842 * @max_priority: maximum priority source to check
2843 * @timeout_: location to store timeout to be used in polling
2844 * @fds: location to store #GPollFD records that need to be polled.
2845 * @n_fds: length of @fds.
2846 *
2847 * Determines information necessary to poll this main loop.
2848 *
2849 * Return value: the number of records actually stored in @fds,
2850 * or, if more than @n_fds records need to be stored, the number
2851 * of records that need to be stored.
2852 **/
2853 gint
2854 g_main_context_query (GMainContext *context,
2855 gint max_priority,
2856 gint *timeout,
2857 GPollFD *fds,
2858 gint n_fds)
2859 {
2860 gint n_poll;
2861 GPollRec *pollrec;
2862
2863 LOCK_CONTEXT (context);
2864
2865 pollrec = context->poll_records;
2866 n_poll = 0;
2867 while (pollrec && max_priority >= pollrec->priority)
2868 {
2869 /* We need to include entries with fd->events == 0 in the array because
2870 * otherwise if the application changes fd->events behind our back and
2871 * makes it non-zero, we'll be out of sync when we check the fds[] array.
2872 * (Changing fd->events after adding an FD wasn't an anticipated use of
2873 * this API, but it occurs in practice.) */
2874 if (n_poll < n_fds)
2875 {
2876 fds[n_poll].fd = pollrec->fd->fd;
2877 /* In direct contradiction to the Unix98 spec, IRIX runs into
2878 * difficulty if you pass in POLLERR, POLLHUP or POLLNVAL
2879 * flags in the events field of the pollfd while it should
2880 * just ignoring them. So we mask them out here.
2881 */
2882 fds[n_poll].events = pollrec->fd->events & ~(G_IO_ERR|G_IO_HUP|G_IO_NVAL);
2883 fds[n_poll].revents = 0;
2884 }
2885
2886 pollrec = pollrec->next;
2887 n_poll++;
2888 }
2889
2890 #ifdef G_THREADS_ENABLED
2891 context->poll_changed = FALSE;
2892 #endif
2893
2894 if (timeout)
2895 {
2896 *timeout = context->timeout;
2897 if (*timeout != 0)
2898 {
2899 context->time_is_fresh = FALSE;
2900 context->real_time_is_fresh = FALSE;
2901 }
2902 }
2903
2904 UNLOCK_CONTEXT (context);
2905
2906 return n_poll;
2907 }
2908
2909 /**
2910 * g_main_context_check:
2911 * @context: a #GMainContext
2912 * @max_priority: the maximum numerical priority of sources to check
2913 * @fds: array of #GPollFD's that was passed to the last call to
2914 * g_main_context_query()
2915 * @n_fds: return value of g_main_context_query()
2916 *
2917 * Passes the results of polling back to the main loop.
2918 *
2919 * Return value: %TRUE if some sources are ready to be dispatched.
2920 **/
2921 gboolean
2922 g_main_context_check (GMainContext *context,
2923 gint max_priority,
2924 GPollFD *fds,
2925 gint n_fds)
2926 {
2927 GSource *source;
2928 GPollRec *pollrec;
2929 gint n_ready = 0;
2930 gint i;
2931
2932 LOCK_CONTEXT (context);
2933
2934 if (context->in_check_or_prepare)
2935 {
2936 g_warning ("g_main_context_check() called recursively from within a source's check() or "
2937 "prepare() member.");
2938 UNLOCK_CONTEXT (context);
2939 return FALSE;
2940 }
2941
2942 #ifdef G_THREADS_ENABLED
2943 if (!context->poll_waiting)
2944 {
2945 #ifndef G_OS_WIN32
2946 gchar a;
2947 read (context->wake_up_pipe[0], &a, 1);
2948 #endif
2949 }
2950 else
2951 context->poll_waiting = FALSE;
2952
2953 /* If the set of poll file descriptors changed, bail out
2954 * and let the main loop rerun
2955 */
2956 if (context->poll_changed)
2957 {
2958 UNLOCK_CONTEXT (context);
2959 return FALSE;
2960 }
2961 #endif /* G_THREADS_ENABLED */
2962
2963 pollrec = context->poll_records;
2964 i = 0;
2965 while (i < n_fds)
2966 {
2967 if (pollrec->fd->events)
2968 pollrec->fd->revents = fds[i].revents;
2969
2970 pollrec = pollrec->next;
2971 i++;
2972 }
2973
2974 source = next_valid_source (context, NULL);
2975 while (source)
2976 {
2977 if ((n_ready > 0) && (source->priority > max_priority))
2978 {
2979 SOURCE_UNREF (source, context);
2980 break;
2981 }
2982 if (SOURCE_BLOCKED (source))
2983 goto next;
2984
2985 if (!(source->flags & G_SOURCE_READY))
2986 {
2987 gboolean result;
2988 gboolean (*check) (GSource *source);
2989
2990 check = source->source_funcs->check;
2991
2992 context->in_check_or_prepare++;
2993 UNLOCK_CONTEXT (context);
2994
2995 result = (*check) (source);
2996
2997 LOCK_CONTEXT (context);
2998 context->in_check_or_prepare--;
2999
3000 if (result)
3001 {
3002 GSource *ready_source = source;
3003
3004 while (ready_source)
3005 {
3006 ready_source->flags |= G_SOURCE_READY;
3007 ready_source = ready_source->priv ? ready_source->priv->parent_source : NULL;
3008 }
3009 }
3010 }
3011
3012 if (source->flags & G_SOURCE_READY)
3013 {
3014 source->ref_count++;
3015 g_ptr_array_add (context->pending_dispatches, source);
3016
3017 n_ready++;
3018
3019 /* never dispatch sources with less priority than the first
3020 * one we choose to dispatch
3021 */
3022 max_priority = source->priority;
3023 }
3024
3025 next:
3026 source = next_valid_source (context, source);
3027 }
3028
3029 UNLOCK_CONTEXT (context);
3030
3031 return n_ready > 0;
3032 }
3033
3034 /**
3035 * g_main_context_dispatch:
3036 * @context: a #GMainContext
3037 *
3038 * Dispatches all pending sources.
3039 **/
3040 void
3041 g_main_context_dispatch (GMainContext *context)
3042 {
3043 LOCK_CONTEXT (context);
3044
3045 if (context->pending_dispatches->len > 0)
3046 {
3047 g_main_dispatch (context);
3048 }
3049
3050 UNLOCK_CONTEXT (context);
3051 }
3052
3053 /* HOLDS context lock */
3054 static gboolean
3055 g_main_context_iterate (GMainContext *context,
3056 gboolean block,
3057 gboolean dispatch,
3058 GThread *self)
3059 {
3060 gint max_priority;
3061 gint timeout;
3062 gboolean some_ready;
3063 gint nfds, allocated_nfds;
3064 GPollFD *fds = NULL;
3065
3066 UNLOCK_CONTEXT (context);
3067
3068 #ifdef G_THREADS_ENABLED
3069 if (!g_main_context_acquire (context))
3070 {
3071 gboolean got_ownership;
3072
3073 LOCK_CONTEXT (context);
3074
3075 g_return_val_if_fail (g_thread_supported (), FALSE);
3076
3077 if (!block)
3078 return FALSE;
3079
3080 if (!context->cond)
3081 context->cond = g_cond_new ();
3082
3083 got_ownership = g_main_context_wait (context,
3084 context->cond,
3085 g_static_mutex_get_mutex (&context->mutex));
3086
3087 if (!got_ownership)
3088 return FALSE;
3089 }
3090 else
3091 LOCK_CONTEXT (context);
3092 #endif /* G_THREADS_ENABLED */
3093
3094 if (!context->cached_poll_array)
3095 {
3096 context->cached_poll_array_size = context->n_poll_records;
3097 context->cached_poll_array = g_new (GPollFD, context->n_poll_records);
3098 }
3099
3100 allocated_nfds = context->cached_poll_array_size;
3101 fds = context->cached_poll_array;
3102
3103 UNLOCK_CONTEXT (context);
3104
3105 g_main_context_prepare (context, &max_priority);
3106
3107 while ((nfds = g_main_context_query (context, max_priority, &timeout, fds,
3108 allocated_nfds)) > allocated_nfds)
3109 {
3110 LOCK_CONTEXT (context);
3111 g_free (fds);
3112 context->cached_poll_array_size = allocated_nfds = nfds;
3113 context->cached_poll_array = fds = g_new (GPollFD, nfds);
3114 UNLOCK_CONTEXT (context);
3115 }
3116
3117 if (!block)
3118 timeout = 0;
3119
3120 g_main_context_poll (context, timeout, max_priority, fds, nfds);
3121
3122 some_ready = g_main_context_check (context, max_priority, fds, nfds);
3123
3124 if (dispatch)
3125 g_main_context_dispatch (context);
3126
3127 #ifdef G_THREADS_ENABLED
3128 g_main_context_release (context);
3129 #endif /* G_THREADS_ENABLED */
3130
3131 LOCK_CONTEXT (context);
3132
3133 return some_ready;
3134 }
3135
3136 /**
3137 * g_main_context_pending:
3138 * @context: a #GMainContext (if %NULL, the default context will be used)
3139 *
3140 * Checks if any sources have pending events for the given context.
3141 *
3142 * Return value: %TRUE if events are pending.
3143 **/
3144 gboolean
3145 g_main_context_pending (GMainContext *context)
3146 {
3147 gboolean retval;
3148
3149 if (!context)
3150 context = g_main_context_default();
3151
3152 LOCK_CONTEXT (context);
3153 retval = g_main_context_iterate (context, FALSE, FALSE, G_THREAD_SELF);
3154 UNLOCK_CONTEXT (context);
3155
3156 return retval;
3157 }
3158
3159 /**
3160 * g_main_context_iteration:
3161 * @context: a #GMainContext (if %NULL, the default context will be used)
3162 * @may_block: whether the call may block.
3163 *
3164 * Runs a single iteration for the given main loop. This involves
3165 * checking to see if any event sources are ready to be processed,
3166 * then if no events sources are ready and @may_block is %TRUE, waiting
3167 * for a source to become ready, then dispatching the highest priority
3168 * events sources that are ready. Otherwise, if @may_block is %FALSE
3169 * sources are not waited to become ready, only those highest priority
3170 * events sources will be dispatched (if any), that are ready at this
3171 * given moment without further waiting.
3172 *
3173 * Note that even when @may_block is %TRUE, it is still possible for
3174 * g_main_context_iteration() to return %FALSE, since the the wait may
3175 * be interrupted for other reasons than an event source becoming ready.
3176 *
3177 * Return value: %TRUE if events were dispatched.
3178 **/
3179 gboolean
3180 g_main_context_iteration (GMainContext *context, gboolean may_block)
3181 {
3182 gboolean retval;
3183
3184 if (!context)
3185 context = g_main_context_default();
3186
3187 LOCK_CONTEXT (context);
3188 retval = g_main_context_iterate (context, may_block, TRUE, G_THREAD_SELF);
3189 UNLOCK_CONTEXT (context);
3190
3191 return retval;
3192 }
3193
3194 /**
3195 * g_main_loop_new:
3196 * @context: a #GMainContext (if %NULL, the default context will be used).
3197 * @is_running: set to %TRUE to indicate that the loop is running. This
3198 * is not very important since calling g_main_loop_run() will set this to
3199 * %TRUE anyway.
3200 *
3201 * Creates a new #GMainLoop structure.
3202 *
3203 * Return value: a new #GMainLoop.
3204 **/
3205 GMainLoop *
3206 g_main_loop_new (GMainContext *context,
3207 gboolean is_running)
3208 {
3209 GMainLoop *loop;
3210
3211 if (!context)
3212 context = g_main_context_default();
3213
3214 g_main_context_ref (context);
3215
3216 loop = g_new0 (GMainLoop, 1);
3217 loop->context = context;
3218 loop->is_running = is_running != FALSE;
3219 loop->ref_count = 1;
3220
3221 return loop;
3222 }
3223
3224 /**
3225 * g_main_loop_ref:
3226 * @loop: a #GMainLoop
3227 *
3228 * Increases the reference count on a #GMainLoop object by one.
3229 *
3230 * Return value: @loop
3231 **/
3232 GMainLoop *
3233 g_main_loop_ref (GMainLoop *loop)
3234 {
3235 g_return_val_if_fail (loop != NULL, NULL);
3236 g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL);
3237
3238 g_atomic_int_inc (&loop->ref_count);
3239
3240 return loop;
3241 }
3242
3243 /**
3244 * g_main_loop_unref:
3245 * @loop: a #GMainLoop
3246 *
3247 * Decreases the reference count on a #GMainLoop object by one. If
3248 * the result is zero, free the loop and free all associated memory.
3249 **/
3250 void
3251 g_main_loop_unref (GMainLoop *loop)
3252 {
3253 g_return_if_fail (loop != NULL);
3254 g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);
3255
3256 if (!g_atomic_int_dec_and_test (&loop->ref_count))
3257 return;
3258
3259 g_main_context_unref (loop->context);
3260 g_free (loop);
3261 }
3262
3263 /**
3264 * g_main_loop_run:
3265 * @loop: a #GMainLoop
3266 *
3267 * Runs a main loop until g_main_loop_quit() is called on the loop.
3268 * If this is called for the thread of the loop's #GMainContext,
3269 * it will process events from the loop, otherwise it will
3270 * simply wait.
3271 **/
3272 void
3273 g_main_loop_run (GMainLoop *loop)
3274 {
3275 GThread *self = G_THREAD_SELF;
3276
3277 g_return_if_fail (loop != NULL);
3278 g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);
3279
3280 #ifdef G_THREADS_ENABLED
3281 if (!g_main_context_acquire (loop->context))
3282 {
3283 gboolean got_ownership = FALSE;
3284
3285 /* Another thread owns this context */
3286 if (!g_thread_supported ())
3287 {
3288 g_warning ("g_main_loop_run() was called from second thread but "
3289 "g_thread_init() was never called.");
3290 return;
3291 }
3292
3293 LOCK_CONTEXT (loop->context);
3294
3295 g_atomic_int_inc (&loop->ref_count);
3296
3297 if (!loop->is_running)
3298 loop->is_running = TRUE;
3299
3300 if (!loop->context->cond)
3301 loop->context->cond = g_cond_new ();
3302
3303 while (loop->is_running && !got_ownership)
3304 got_ownership = g_main_context_wait (loop->context,
3305 loop->context->cond,
3306 g_static_mutex_get_mutex (&loop->context->mutex));
3307
3308 if (!loop->is_running)
3309 {
3310 UNLOCK_CONTEXT (loop->context);
3311 if (got_ownership)
3312 g_main_context_release (loop->context);
3313 g_main_loop_unref (loop);
3314 return;
3315 }
3316
3317 g_assert (got_ownership);
3318 }
3319 else
3320 LOCK_CONTEXT (loop->context);
3321 #endif /* G_THREADS_ENABLED */
3322
3323 if (loop->context->in_check_or_prepare)
3324 {
3325 g_warning ("g_main_loop_run(): called recursively from within a source's "
3326 "check() or prepare() member, iteration not possible.");
3327 return;
3328 }
3329
3330 g_atomic_int_inc (&loop->ref_count);
3331 loop->is_running = TRUE;
3332 while (loop->is_running)
3333 g_main_context_iterate (loop->context, TRUE, TRUE, self);
3334
3335 UNLOCK_CONTEXT (loop->context);
3336
3337 #ifdef G_THREADS_ENABLED
3338 g_main_context_release (loop->context);
3339 #endif /* G_THREADS_ENABLED */
3340
3341 g_main_loop_unref (loop);
3342 }
3343
3344 /**
3345 * g_main_loop_quit:
3346 * @loop: a #GMainLoop
3347 *
3348 * Stops a #GMainLoop from running. Any calls to g_main_loop_run()
3349 * for the loop will return.
3350 *
3351 * Note that sources that have already been dispatched when
3352 * g_main_loop_quit() is called will still be executed.
3353 **/
3354 void
3355 g_main_loop_quit (GMainLoop *loop)
3356 {
3357 g_return_if_fail (loop != NULL);
3358 g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0);
3359
3360 LOCK_CONTEXT (loop->context);
3361 loop->is_running = FALSE;
3362 g_main_context_wakeup_unlocked (loop->context);
3363
3364 #ifdef G_THREADS_ENABLED
3365 if (loop->context->cond)
3366 g_cond_broadcast (loop->context->cond);
3367 #endif /* G_THREADS_ENABLED */
3368
3369 UNLOCK_CONTEXT (loop->context);
3370 }
3371
3372 /**
3373 * g_main_loop_is_running:
3374 * @loop: a #GMainLoop.
3375 *
3376 * Checks to see if the main loop is currently being run via g_main_loop_run().
3377 *
3378 * Return value: %TRUE if the mainloop is currently being run.
3379 **/
3380 gboolean
3381 g_main_loop_is_running (GMainLoop *loop)
3382 {
3383 g_return_val_if_fail (loop != NULL, FALSE);
3384 g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, FALSE);
3385
3386 return loop->is_running;
3387 }
3388
3389 /**
3390 * g_main_loop_get_context:
3391 * @loop: a #GMainLoop.
3392 *
3393 * Returns the #GMainContext of @loop.
3394 *
3395 * Return value: the #GMainContext of @loop
3396 **/
3397 GMainContext *
3398 g_main_loop_get_context (GMainLoop *loop)
3399 {
3400 g_return_val_if_fail (loop != NULL, NULL);
3401 g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL);
3402
3403 return loop->context;
3404 }
3405
3406 /* HOLDS: context's lock */
3407 static void
3408 g_main_context_poll (GMainContext *context,
3409 gint timeout,
3410 gint priority,
3411 GPollFD *fds,
3412 gint n_fds)
3413 {
3414 #ifdef G_MAIN_POLL_DEBUG
3415 GTimer *poll_timer;
3416 GPollRec *pollrec;
3417 gint i;
3418 #endif
3419
3420 GPollFunc poll_func;
3421
3422 if (n_fds || timeout != 0)
3423 {
3424 #ifdef G_MAIN_POLL_DEBUG
3425 if (_g_main_poll_debug)
3426 {
3427 g_print ("polling context=%p n=%d timeout=%d\n",
3428 context, n_fds, timeout);
3429 poll_timer = g_timer_new ();
3430 }
3431 #endif
3432
3433 LOCK_CONTEXT (context);
3434
3435 poll_func = context->poll_func;
3436
3437 UNLOCK_CONTEXT (context);
3438 if ((*poll_func) (fds, n_fds, timeout) < 0 && errno != EINTR)
3439 {
3440 #ifndef G_OS_WIN32
3441 g_warning ("poll(2) failed due to: %s.",
3442 g_strerror (errno));
3443 #else
3444 /* If g_poll () returns -1, it has already called g_warning() */
3445 #endif
3446 }
3447
3448 #ifdef G_MAIN_POLL_DEBUG
3449 if (_g_main_poll_debug)
3450 {
3451 LOCK_CONTEXT (context);
3452
3453 g_print ("g_main_poll(%d) timeout: %d - elapsed %12.10f seconds",
3454 n_fds,
3455 timeout,
3456 g_timer_elapsed (poll_timer, NULL));
3457 g_timer_destroy (poll_timer);
3458 pollrec = context->poll_records;
3459
3460 while (pollrec != NULL)
3461 {
3462 i = 0;
3463 while (i < n_fds)
3464 {
3465 if (fds[i].fd == pollrec->fd->fd &&
3466 pollrec->fd->events &&
3467 fds[i].revents)
3468 {
3469 g_print (" [" G_POLLFD_FORMAT " :", fds[i].fd);
3470 if (fds[i].revents & G_IO_IN)
3471 g_print ("i");
3472 if (fds[i].revents & G_IO_OUT)
3473 g_print ("o");
3474 if (fds[i].revents & G_IO_PRI)
3475 g_print ("p");
3476 if (fds[i].revents & G_IO_ERR)
3477 g_print ("e");
3478 if (fds[i].revents & G_IO_HUP)
3479 g_print ("h");
3480 if (fds[i].revents & G_IO_NVAL)
3481 g_print ("n");
3482 g_print ("]");
3483 }
3484 i++;
3485 }
3486 pollrec = pollrec->next;
3487 }
3488 g_print ("\n");
3489
3490 UNLOCK_CONTEXT (context);
3491 }
3492 #endif
3493 } /* if (n_fds || timeout != 0) */
3494 }
3495
3496 /**
3497 * g_main_context_add_poll:
3498 * @context: a #GMainContext (or %NULL for the default context)
3499 * @fd: a #GPollFD structure holding information about a file
3500 * descriptor to watch.
3501 * @priority: the priority for this file descriptor which should be
3502 * the same as the priority used for g_source_attach() to ensure that the
3503 * file descriptor is polled whenever the results may be needed.
3504 *
3505 * Adds a file descriptor to the set of file descriptors polled for
3506 * this context. This will very seldomly be used directly. Instead
3507 * a typical event source will use g_source_add_poll() instead.
3508 **/
3509 void
3510 g_main_context_add_poll (GMainContext *context,
3511 GPollFD *fd,
3512 gint priority)
3513 {
3514 if (!context)
3515 context = g_main_context_default ();
3516
3517 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
3518 g_return_if_fail (fd);
3519
3520 LOCK_CONTEXT (context);
3521 g_main_context_add_poll_unlocked (context, priority, fd);
3522 UNLOCK_CONTEXT (context);
3523 }
3524
3525 /* HOLDS: main_loop_lock */
3526 static void
3527 g_main_context_add_poll_unlocked (GMainContext *context,
3528 gint priority,
3529 GPollFD *fd)
3530 {
3531 GPollRec *prevrec, *nextrec;
3532 GPollRec *newrec = g_slice_new (GPollRec);
3533 #ifdef GSTREAMER_LITE
3534 if (newrec == NULL) {
3535 return;
3536 }
3537 #endif // GSTREAMER_LITE
3538
3539 /* This file descriptor may be checked before we ever poll */
3540 fd->revents = 0;
3541 newrec->fd = fd;
3542 newrec->priority = priority;
3543
3544 prevrec = context->poll_records_tail;
3545 nextrec = NULL;
3546 while (prevrec && priority < prevrec->priority)
3547 {
3548 nextrec = prevrec;
3549 prevrec = prevrec->prev;
3550 }
3551
3552 if (prevrec)
3553 prevrec->next = newrec;
3554 else
3555 context->poll_records = newrec;
3556
3557 newrec->prev = prevrec;
3558 newrec->next = nextrec;
3559
3560 if (nextrec)
3561 nextrec->prev = newrec;
3562 else
3563 context->poll_records_tail = newrec;
3564
3565 context->n_poll_records++;
3566
3567 #ifdef G_THREADS_ENABLED
3568 context->poll_changed = TRUE;
3569
3570 /* Now wake up the main loop if it is waiting in the poll() */
3571 g_main_context_wakeup_unlocked (context);
3572 #endif
3573 }
3574
3575 /**
3576 * g_main_context_remove_poll:
3577 * @context:a #GMainContext
3578 * @fd: a #GPollFD descriptor previously added with g_main_context_add_poll()
3579 *
3580 * Removes file descriptor from the set of file descriptors to be
3581 * polled for a particular context.
3582 **/
3583 void
3584 g_main_context_remove_poll (GMainContext *context,
3585 GPollFD *fd)
3586 {
3587 if (!context)
3588 context = g_main_context_default ();
3589
3590 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
3591 g_return_if_fail (fd);
3592
3593 LOCK_CONTEXT (context);
3594 g_main_context_remove_poll_unlocked (context, fd);
3595 UNLOCK_CONTEXT (context);
3596 }
3597
3598 static void
3599 g_main_context_remove_poll_unlocked (GMainContext *context,
3600 GPollFD *fd)
3601 {
3602 GPollRec *pollrec, *prevrec, *nextrec;
3603
3604 prevrec = NULL;
3605 pollrec = context->poll_records;
3606
3607 while (pollrec)
3608 {
3609 nextrec = pollrec->next;
3610 if (pollrec->fd == fd)
3611 {
3612 if (prevrec != NULL)
3613 prevrec->next = nextrec;
3614 else
3615 context->poll_records = nextrec;
3616
3617 if (nextrec != NULL)
3618 nextrec->prev = prevrec;
3619 else
3620 context->poll_records_tail = prevrec;
3621
3622 g_slice_free (GPollRec, pollrec);
3623
3624 context->n_poll_records--;
3625 break;
3626 }
3627 prevrec = pollrec;
3628 pollrec = nextrec;
3629 }
3630
3631 #ifdef G_THREADS_ENABLED
3632 context->poll_changed = TRUE;
3633
3634 /* Now wake up the main loop if it is waiting in the poll() */
3635 g_main_context_wakeup_unlocked (context);
3636 #endif
3637 }
3638
3639 /**
3640 * g_source_get_current_time:
3641 * @source: a #GSource
3642 * @timeval: #GTimeVal structure in which to store current time.
3643 *
3644 * Gets the "current time" to be used when checking
3645 * this source. The advantage of calling this function over
3646 * calling g_get_current_time() directly is that when
3647 * checking multiple sources, GLib can cache a single value
3648 * instead of having to repeatedly get the system time.
3649 *
3650 * Deprecated: 2.28: use g_source_get_time() instead
3651 **/
3652 void
3653 g_source_get_current_time (GSource *source,
3654 GTimeVal *timeval)
3655 {
3656 GMainContext *context;
3657
3658 g_return_if_fail (source->context != NULL);
3659
3660 context = source->context;
3661
3662 LOCK_CONTEXT (context);
3663
3664 if (!context->real_time_is_fresh)
3665 {
3666 context->real_time = g_get_real_time ();
3667 context->real_time_is_fresh = TRUE;
3668 }
3669
3670 timeval->tv_sec = context->real_time / 1000000;
3671 timeval->tv_usec = context->real_time % 1000000;
3672
3673 UNLOCK_CONTEXT (context);
3674 }
3675
3676 /**
3677 * g_source_get_time:
3678 * @source: a #GSource
3679 *
3680 * Gets the time to be used when checking this source. The advantage of
3681 * calling this function over calling g_get_monotonic_time() directly is
3682 * that when checking multiple sources, GLib can cache a single value
3683 * instead of having to repeatedly get the system monotonic time.
3684 *
3685 * The time here is the system monotonic time, if available, or some
3686 * other reasonable alternative otherwise. See g_get_monotonic_time().
3687 *
3688 * Returns: the monotonic time in microseconds
3689 *
3690 * Since: 2.28
3691 **/
3692 gint64
3693 g_source_get_time (GSource *source)
3694 {
3695 GMainContext *context;
3696 gint64 result;
3697
3698 g_return_val_if_fail (source->context != NULL, 0);
3699
3700 context = source->context;
3701
3702 LOCK_CONTEXT (context);
3703
3704 if (!context->time_is_fresh)
3705 {
3706 context->time = g_get_monotonic_time ();
3707 context->time_is_fresh = TRUE;
3708 }
3709
3710 result = context->time;
3711
3712 UNLOCK_CONTEXT (context);
3713
3714 return result;
3715 }
3716
3717 /**
3718 * g_main_context_set_poll_func:
3719 * @context: a #GMainContext
3720 * @func: the function to call to poll all file descriptors
3721 *
3722 * Sets the function to use to handle polling of file descriptors. It
3723 * will be used instead of the poll() system call
3724 * (or GLib's replacement function, which is used where
3725 * poll() isn't available).
3726 *
3727 * This function could possibly be used to integrate the GLib event
3728 * loop with an external event loop.
3729 **/
3730 void
3731 g_main_context_set_poll_func (GMainContext *context,
3732 GPollFunc func)
3733 {
3734 if (!context)
3735 context = g_main_context_default ();
3736
3737 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
3738
3739 LOCK_CONTEXT (context);
3740
3741 if (func)
3742 context->poll_func = func;
3743 else
3744 context->poll_func = g_poll;
3745
3746 UNLOCK_CONTEXT (context);
3747 }
3748
3749 /**
3750 * g_main_context_get_poll_func:
3751 * @context: a #GMainContext
3752 *
3753 * Gets the poll function set by g_main_context_set_poll_func().
3754 *
3755 * Return value: the poll function
3756 **/
3757 GPollFunc
3758 g_main_context_get_poll_func (GMainContext *context)
3759 {
3760 GPollFunc result;
3761
3762 if (!context)
3763 context = g_main_context_default ();
3764
3765 g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL);
3766
3767 LOCK_CONTEXT (context);
3768 result = context->poll_func;
3769 UNLOCK_CONTEXT (context);
3770
3771 return result;
3772 }
3773
3774 /* HOLDS: context's lock */
3775 /* Wake the main loop up from a poll() */
3776 static void
3777 g_main_context_wakeup_unlocked (GMainContext *context)
3778 {
3779 #ifdef G_THREADS_ENABLED
3780 if (g_thread_supported() && context->poll_waiting)
3781 {
3782 context->poll_waiting = FALSE;
3783 #ifndef G_OS_WIN32
3784 write (context->wake_up_pipe[1], "A", 1);
3785 #else
3786 ReleaseSemaphore (context->wake_up_semaphore, 1, NULL);
3787 #endif
3788 }
3789 #endif
3790 }
3791
3792 /**
3793 * g_main_context_wakeup:
3794 * @context: a #GMainContext
3795 *
3796 * If @context is currently waiting in a poll(), interrupt
3797 * the poll(), and continue the iteration process.
3798 **/
3799 void
3800 g_main_context_wakeup (GMainContext *context)
3801 {
3802 if (!context)
3803 context = g_main_context_default ();
3804
3805 g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0);
3806
3807 LOCK_CONTEXT (context);
3808 g_main_context_wakeup_unlocked (context);
3809 UNLOCK_CONTEXT (context);
3810 }
3811
3812 /**
3813 * g_main_context_is_owner:
3814 * @context: a #GMainContext
3815 *
3816 * Determines whether this thread holds the (recursive)
3817 * ownership of this #GMaincontext. This is useful to
3818 * know before waiting on another thread that may be
3819 * blocking to get ownership of @context.
3820 *
3821 * Returns: %TRUE if current thread is owner of @context.
3822 *
3823 * Since: 2.10
3824 **/
3825 gboolean
3826 g_main_context_is_owner (GMainContext *context)
3827 {
3828 gboolean is_owner;
3829
3830 if (!context)
3831 context = g_main_context_default ();
3832
3833 #ifdef G_THREADS_ENABLED
3834 LOCK_CONTEXT (context);
3835 is_owner = context->owner == G_THREAD_SELF;
3836 UNLOCK_CONTEXT (context);
3837 #else
3838 is_owner = TRUE;
3839 #endif
3840
3841 return is_owner;
3842 }
3843
3844 /* Timeouts */
3845
3846 static void
3847 g_timeout_set_expiration (GTimeoutSource *timeout_source,
3848 gint64 current_time)
3849 {
3850 timeout_source->expiration = current_time +
3851 (guint64) timeout_source->interval * 1000;
3852
3853 if (timeout_source->seconds)
3854 {
3855 gint64 remainder;
3856 static gint timer_perturb = -1;
3857
3858 if (timer_perturb == -1)
3859 {
3860 /*
3861 * we want a per machine/session unique 'random' value; try the dbus
3862 * address first, that has a UUID in it. If there is no dbus, use the
3863 * hostname for hashing.
3864 */
3865 const char *session_bus_address = g_getenv ("DBUS_SESSION_BUS_ADDRESS");
3866 if (!session_bus_address)
3867 session_bus_address = g_getenv ("HOSTNAME");
3868 if (session_bus_address)
3869 timer_perturb = ABS ((gint) g_str_hash (session_bus_address)) % 1000000;
3870 else
3871 timer_perturb = 0;
3872 }
3873
3874 /* We want the microseconds part of the timeout to land on the
3875 * 'timer_perturb' mark, but we need to make sure we don't try to
3876 * set the timeout in the past. We do this by ensuring that we
3877 * always only *increase* the expiration time by adding a full
3878 * second in the case that the microsecond portion decreases.
3879 */
3880 timeout_source->expiration -= timer_perturb;
3881
3882 remainder = timeout_source->expiration % 1000000;
3883 if (remainder >= 1000000/4)
3884 timeout_source->expiration += 1000000;
3885
3886 timeout_source->expiration -= remainder;
3887 timeout_source->expiration += timer_perturb;
3888 }
3889 }
3890
3891 static gboolean
3892 g_timeout_prepare (GSource *source,
3893 gint *timeout)
3894 {
3895 GTimeoutSource *timeout_source = (GTimeoutSource *) source;
3896 gint64 now = g_source_get_time (source);
3897
3898 if (now < timeout_source->expiration)
3899 {
3900 /* Round up to ensure that we don't try again too early */
3901 *timeout = (timeout_source->expiration - now + 999) / 1000;
3902 return FALSE;
3903 }
3904
3905 *timeout = 0;
3906 return TRUE;
3907 }
3908
3909 static gboolean
3910 g_timeout_check (GSource *source)
3911 {
3912 GTimeoutSource *timeout_source = (GTimeoutSource *) source;
3913 gint64 now = g_source_get_time (source);
3914
3915 return timeout_source->expiration <= now;
3916 }
3917
3918 static gboolean
3919 g_timeout_dispatch (GSource *source,
3920 GSourceFunc callback,
3921 gpointer user_data)
3922 {
3923 GTimeoutSource *timeout_source = (GTimeoutSource *)source;
3924 gboolean again;
3925
3926 if (!callback)
3927 {
3928 g_warning ("Timeout source dispatched without callback\n"
3929 "You must call g_source_set_callback().");
3930 return FALSE;
3931 }
3932
3933 again = callback (user_data);
3934
3935 if (again)
3936 g_timeout_set_expiration (timeout_source, g_source_get_time (source));
3937
3938 return again;
3939 }
3940
3941 /**
3942 * g_timeout_source_new:
3943 * @interval: the timeout interval in milliseconds.
3944 *
3945 * Creates a new timeout source.
3946 *
3947 * The source will not initially be associated with any #GMainContext
3948 * and must be added to one with g_source_attach() before it will be
3949 * executed.
3950 *
3951 * Return value: the newly-created timeout source
3952 **/
3953 GSource *
3954 g_timeout_source_new (guint interval)
3955 {
3956 GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource));
3957 #ifdef GSTREAMER_LITE
3958 if (source == NULL)
3959 return NULL;
3960 #endif // GSTREAMER_LITE
3961 GTimeoutSource *timeout_source = (GTimeoutSource *)source;
3962
3963 timeout_source->interval = interval;
3964 g_timeout_set_expiration (timeout_source, g_get_monotonic_time ());
3965
3966 return source;
3967 }
3968
3969 #ifndef GSTREAMER_LITE
3970 /**
3971 * g_timeout_source_new_seconds:
3972 * @interval: the timeout interval in seconds
3973 *
3974 * Creates a new timeout source.
3975 *
3976 * The source will not initially be associated with any #GMainContext
3977 * and must be added to one with g_source_attach() before it will be
3978 * executed.
3979 *
3980 * The scheduling granularity/accuracy of this timeout source will be
3981 * in seconds.
3982 *
3983 * Return value: the newly-created timeout source
3984 *
3985 * Since: 2.14
3986 **/
3987 GSource *
3988 g_timeout_source_new_seconds (guint interval)
3989 {
3990 GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource));
3991 GTimeoutSource *timeout_source = (GTimeoutSource *)source;
3992
3993 timeout_source->interval = 1000 * interval;
3994 timeout_source->seconds = TRUE;
3995
3996 g_timeout_set_expiration (timeout_source, g_get_monotonic_time ());
3997
3998 return source;
3999 }
4000 #endif // GSTREAMER_LITE
4001
4002 /**
4003 * g_timeout_add_full:
4004 * @priority: the priority of the timeout source. Typically this will be in
4005 * the range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
4006 * @interval: the time between calls to the function, in milliseconds
4007 * (1/1000ths of a second)
4008 * @function: function to call
4009 * @data: data to pass to @function
4010 * @notify: function to call when the timeout is removed, or %NULL
4011 *
4012 * Sets a function to be called at regular intervals, with the given
4013 * priority. The function is called repeatedly until it returns
4014 * %FALSE, at which point the timeout is automatically destroyed and
4015 * the function will not be called again. The @notify function is
4016 * called when the timeout is destroyed. The first call to the
4017 * function will be at the end of the first @interval.
4018 *
4019 * Note that timeout functions may be delayed, due to the processing of other
4020 * event sources. Thus they should not be relied on for precise timing.
4021 * After each call to the timeout function, the time of the next
4022 * timeout is recalculated based on the current time and the given interval
4023 * (it does not try to 'catch up' time lost in delays).
4024 *
4025 * This internally creates a main loop source using g_timeout_source_new()
4026 * and attaches it to the main loop context using g_source_attach(). You can
4027 * do these steps manually if you need greater control.
4028 *
4029 * Return value: the ID (greater than 0) of the event source.
4030 **/
4031 guint
4032 g_timeout_add_full (gint priority,
4033 guint interval,
4034 GSourceFunc function,
4035 gpointer data,
4036 GDestroyNotify notify)
4037 {
4038 GSource *source;
4039 guint id;
4040
4041 g_return_val_if_fail (function != NULL, 0);
4042
4043 source = g_timeout_source_new (interval);
4044 #ifdef GSTREAMER_LITE
4045 if (source == NULL)
4046 return 0;
4047 #endif // GSTREAMER_LITE
4048
4049 if (priority != G_PRIORITY_DEFAULT)
4050 g_source_set_priority (source, priority);
4051
4052 g_source_set_callback (source, function, data, notify);
4053 id = g_source_attach (source, NULL);
4054 g_source_unref (source);
4055
4056 return id;
4057 }
4058
4059 /**
4060 * g_timeout_add:
4061 * @interval: the time between calls to the function, in milliseconds
4062 * (1/1000ths of a second)
4063 * @function: function to call
4064 * @data: data to pass to @function
4065 *
4066 * Sets a function to be called at regular intervals, with the default
4067 * priority, #G_PRIORITY_DEFAULT. The function is called repeatedly
4068 * until it returns %FALSE, at which point the timeout is automatically
4069 * destroyed and the function will not be called again. The first call
4070 * to the function will be at the end of the first @interval.
4071 *
4072 * Note that timeout functions may be delayed, due to the processing of other
4073 * event sources. Thus they should not be relied on for precise timing.
4074 * After each call to the timeout function, the time of the next
4075 * timeout is recalculated based on the current time and the given interval
4076 * (it does not try to 'catch up' time lost in delays).
4077 *
4078 * If you want to have a timer in the "seconds" range and do not care
4079 * about the exact time of the first call of the timer, use the
4080 * g_timeout_add_seconds() function; this function allows for more
4081 * optimizations and more efficient system power usage.
4082 *
4083 * This internally creates a main loop source using g_timeout_source_new()
4084 * and attaches it to the main loop context using g_source_attach(). You can
4085 * do these steps manually if you need greater control.
4086 *
4087 * Return value: the ID (greater than 0) of the event source.
4088 **/
4089 guint
4090 g_timeout_add (guint32 interval,
4091 GSourceFunc function,
4092 gpointer data)
4093 {
4094 return g_timeout_add_full (G_PRIORITY_DEFAULT,
4095 interval, function, data, NULL);
4096 }
4097
4098 #ifndef GSTREAMER_LITE
4099 /**
4100 * g_timeout_add_seconds_full:
4101 * @priority: the priority of the timeout source. Typically this will be in
4102 * the range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH.
4103 * @interval: the time between calls to the function, in seconds
4104 * @function: function to call
4105 * @data: data to pass to @function
4106 * @notify: function to call when the timeout is removed, or %NULL
4107 *
4108 * Sets a function to be called at regular intervals, with @priority.
4109 * The function is called repeatedly until it returns %FALSE, at which
4110 * point the timeout is automatically destroyed and the function will
4111 * not be called again.
4112 *
4113 * Unlike g_timeout_add(), this function operates at whole second granularity.
4114 * The initial starting point of the timer is determined by the implementation
4115 * and the implementation is expected to group multiple timers together so that
4116 * they fire all at the same time.
4117 * To allow this grouping, the @interval to the first timer is rounded
4118 * and can deviate up to one second from the specified interval.
4119 * Subsequent timer iterations will generally run at the specified interval.
4120 *
4121 * Note that timeout functions may be delayed, due to the processing of other
4122 * event sources. Thus they should not be relied on for precise timing.
4123 * After each call to the timeout function, the time of the next
4124 * timeout is recalculated based on the current time and the given @interval
4125 *
4126 * If you want timing more precise than whole seconds, use g_timeout_add()
4127 * instead.
4128 *
4129 * The grouping of timers to fire at the same time results in a more power
4130 * and CPU efficient behavior so if your timer is in multiples of seconds
4131 * and you don't require the first timer exactly one second from now, the
4132 * use of g_timeout_add_seconds() is preferred over g_timeout_add().
4133 *
4134 * This internally creates a main loop source using
4135 * g_timeout_source_new_seconds() and attaches it to the main loop context
4136 * using g_source_attach(). You can do these steps manually if you need
4137 * greater control.
4138 *
4139 * Return value: the ID (greater than 0) of the event source.
4140 *
4141 * Since: 2.14
4142 **/
4143 guint
4144 g_timeout_add_seconds_full (gint priority,
4145 guint32 interval,
4146 GSourceFunc function,
4147 gpointer data,
4148 GDestroyNotify notify)
4149 {
4150 GSource *source;
4151 guint id;
4152
4153 g_return_val_if_fail (function != NULL, 0);
4154
4155 source = g_timeout_source_new_seconds (interval);
4156
4157 if (priority != G_PRIORITY_DEFAULT)
4158 g_source_set_priority (source, priority);
4159
4160 g_source_set_callback (source, function, data, notify);
4161 id = g_source_attach (source, NULL);
4162 g_source_unref (source);
4163
4164 return id;
4165 }
4166
4167 /**
4168 * g_timeout_add_seconds:
4169 * @interval: the time between calls to the function, in seconds
4170 * @function: function to call
4171 * @data: data to pass to @function
4172 *
4173 * Sets a function to be called at regular intervals with the default
4174 * priority, #G_PRIORITY_DEFAULT. The function is called repeatedly until
4175 * it returns %FALSE, at which point the timeout is automatically destroyed
4176 * and the function will not be called again.
4177 *
4178 * This internally creates a main loop source using
4179 * g_timeout_source_new_seconds() and attaches it to the main loop context
4180 * using g_source_attach(). You can do these steps manually if you need
4181 * greater control. Also see g_timout_add_seconds_full().
4182 *
4183 * Note that the first call of the timer may not be precise for timeouts
4184 * of one second. If you need finer precision and have such a timeout,
4185 * you may want to use g_timeout_add() instead.
4186 *
4187 * Return value: the ID (greater than 0) of the event source.
4188 *
4189 * Since: 2.14
4190 **/
4191 guint
4192 g_timeout_add_seconds (guint interval,
4193 GSourceFunc function,
4194 gpointer data)
4195 {
4196 g_return_val_if_fail (function != NULL, 0);
4197
4198 return g_timeout_add_seconds_full (G_PRIORITY_DEFAULT, interval, function, data, NULL);
4199 }
4200 #endif // GSTREAMER_LITE
4201
4202 /* Child watch functions */
4203
4204 #ifdef G_OS_WIN32
4205
4206 static gboolean
4207 g_child_watch_prepare (GSource *source,
4208 gint *timeout)
4209 {
4210 *timeout = -1;
4211 return FALSE;
4212 }
4213
4214
4215 static gboolean
4216 g_child_watch_check (GSource *source)
4217 {
4218 GChildWatchSource *child_watch_source;
4219 gboolean child_exited;
4220
4221 child_watch_source = (GChildWatchSource *) source;
4222
4223 child_exited = child_watch_source->poll.revents & G_IO_IN;
4224
4225 if (child_exited)
4226 {
4227 DWORD child_status;
4228
4229 /*
4230 * Note: We do _not_ check for the special value of STILL_ACTIVE
4231 * since we know that the process has exited and doing so runs into
4232 * problems if the child process "happens to return STILL_ACTIVE(259)"
4233 * as Microsoft's Platform SDK puts it.
4234 */
4235 if (!GetExitCodeProcess (child_watch_source->pid, &child_status))
4236 {
4237 gchar *emsg = g_win32_error_message (GetLastError ());
4238 g_warning (G_STRLOC ": GetExitCodeProcess() failed: %s", emsg);
4239 g_free (emsg);
4240
4241 child_watch_source->child_status = -1;
4242 }
4243 else
4244 child_watch_source->child_status = child_status;
4245 }
4246
4247 return child_exited;
4248 }
4249
4250 #else /* G_OS_WIN32 */
4251
4252 static gboolean
4253 check_for_child_exited (GSource *source)
4254 {
4255 GChildWatchSource *child_watch_source;
4256 gint count;
4257
4258 /* protect against another SIGCHLD in the middle of this call */
4259 count = child_watch_count;
4260
4261 child_watch_source = (GChildWatchSource *) source;
4262
4263 if (child_watch_source->child_exited)
4264 return TRUE;
4265
4266 if (child_watch_source->count < count)
4267 {
4268 gint child_status;
4269
4270 if (waitpid (child_watch_source->pid, &child_status, WNOHANG) > 0)
4271 {
4272 child_watch_source->child_status = child_status;
4273 child_watch_source->child_exited = TRUE;
4274 }
4275 child_watch_source->count = count;
4276 }
4277
4278 return child_watch_source->child_exited;
4279 }
4280
4281 static gboolean
4282 g_child_watch_prepare (GSource *source,
4283 gint *timeout)
4284 {
4285 *timeout = -1;
4286
4287 return check_for_child_exited (source);
4288 }
4289
4290
4291 static gboolean
4292 g_child_watch_check (GSource *source)
4293 {
4294 return check_for_child_exited (source);
4295 }
4296
4297 #endif /* G_OS_WIN32 */
4298
4299 static gboolean
4300 g_child_watch_dispatch (GSource *source,
4301 GSourceFunc callback,
4302 gpointer user_data)
4303 {
4304 GChildWatchSource *child_watch_source;
4305 GChildWatchFunc child_watch_callback = (GChildWatchFunc) callback;
4306
4307 child_watch_source = (GChildWatchSource *) source;
4308
4309 if (!callback)
4310 {
4311 g_warning ("Child watch source dispatched without callback\n"
4312 "You must call g_source_set_callback().");
4313 return FALSE;
4314 }
4315
4316 (child_watch_callback) (child_watch_source->pid, child_watch_source->child_status, user_data);
4317
4318 /* We never keep a child watch source around as the child is gone */
4319 return FALSE;
4320 }
4321
4322 #ifndef G_OS_WIN32
4323
4324 static void
4325 g_child_watch_signal_handler (int signum)
4326 {
4327 child_watch_count ++;
4328
4329 if (child_watch_init_state == CHILD_WATCH_INITIALIZED_THREADED)
4330 {
4331 write (child_watch_wake_up_pipe[1], "B", 1);
4332 }
4333 else
4334 {
4335 /* We count on the signal interrupting the poll in the same thread.
4336 */
4337 }
4338 }
4339
4340 static void
4341 g_child_watch_source_init_single (void)
4342 {
4343 struct sigaction action;
4344
4345 g_assert (! g_thread_supported());
4346 g_assert (child_watch_init_state == CHILD_WATCH_UNINITIALIZED);
4347
4348 child_watch_init_state = CHILD_WATCH_INITIALIZED_SINGLE;
4349
4350 action.sa_handler = g_child_watch_signal_handler;
4351 sigemptyset (&action.sa_mask);
4352 action.sa_flags = SA_NOCLDSTOP;
4353 sigaction (SIGCHLD, &action, NULL);
4354 }
4355
4356 G_GNUC_NORETURN static gpointer
4357 child_watch_helper_thread (gpointer data)
4358 {
4359 while (1)
4360 {
4361 gchar b[20];
4362 GSList *list;
4363
4364 read (child_watch_wake_up_pipe[0], b, 20);
4365
4366 /* We were woken up. Wake up all other contexts in all other threads */
4367 G_LOCK (main_context_list);
4368 for (list = main_context_list; list; list = list->next)
4369 {
4370 GMainContext *context;
4371
4372 context = list->data;
4373 if (g_atomic_int_get (&context->ref_count) > 0)
4374 /* Due to racing conditions we can find ref_count == 0, in
4375 * that case, however, the context is still not destroyed
4376 * and no poll can be active, otherwise the ref_count
4377 * wouldn't be 0 */
4378 g_main_context_wakeup (context);
4379 }
4380 G_UNLOCK (main_context_list);
4381 }
4382 }
4383
4384 static void
4385 g_child_watch_source_init_multi_threaded (void)
4386 {
4387 GError *error = NULL;
4388 struct sigaction action;
4389
4390 g_assert (g_thread_supported());
4391
4392 if (pipe (child_watch_wake_up_pipe) < 0)
4393 g_error ("Cannot create wake up pipe: %s\n", g_strerror (errno));
4394 fcntl (child_watch_wake_up_pipe[1], F_SETFL, O_NONBLOCK | fcntl (child_watch_wake_up_pipe[1], F_GETFL));
4395
4396 /* We create a helper thread that polls on the wakeup pipe indefinitely */
4397 /* FIXME: Think this through for races */
4398 if (g_thread_create (child_watch_helper_thread, NULL, FALSE, &error) == NULL)
4399 g_error ("Cannot create a thread to monitor child exit status: %s\n", error->message);
4400 child_watch_init_state = CHILD_WATCH_INITIALIZED_THREADED;
4401
4402 action.sa_handler = g_child_watch_signal_handler;
4403 sigemptyset (&action.sa_mask);
4404 action.sa_flags = SA_RESTART | SA_NOCLDSTOP;
4405 sigaction (SIGCHLD, &action, NULL);
4406 }
4407
4408 static void
4409 g_child_watch_source_init_promote_single_to_threaded (void)
4410 {
4411 g_child_watch_source_init_multi_threaded ();
4412 }
4413
4414 static void
4415 g_child_watch_source_init (void)
4416 {
4417 if (g_thread_supported())
4418 {
4419 if (child_watch_init_state == CHILD_WATCH_UNINITIALIZED)
4420 g_child_watch_source_init_multi_threaded ();
4421 else if (child_watch_init_state == CHILD_WATCH_INITIALIZED_SINGLE)
4422 g_child_watch_source_init_promote_single_to_threaded ();
4423 }
4424 else
4425 {
4426 if (child_watch_init_state == CHILD_WATCH_UNINITIALIZED)
4427 g_child_watch_source_init_single ();
4428 }
4429 }
4430
4431 #endif /* !G_OS_WIN32 */
4432
4433 /**
4434 * g_child_watch_source_new:
4435 * @pid: process to watch. On POSIX the pid of a child process. On
4436 * Windows a handle for a process (which doesn't have to be a child).
4437 *
4438 * Creates a new child_watch source.
4439 *
4440 * The source will not initially be associated with any #GMainContext
4441 * and must be added to one with g_source_attach() before it will be
4442 * executed.
4443 *
4444 * Note that child watch sources can only be used in conjunction with
4445 * <literal>g_spawn...</literal> when the %G_SPAWN_DO_NOT_REAP_CHILD
4446 * flag is used.
4447 *
4448 * Note that on platforms where #GPid must be explicitly closed
4449 * (see g_spawn_close_pid()) @pid must not be closed while the
4450 * source is still active. Typically, you will want to call
4451 * g_spawn_close_pid() in the callback function for the source.
4452 *
4453 * Note further that using g_child_watch_source_new() is not
4454 * compatible with calling <literal>waitpid(-1)</literal> in
4455 * the application. Calling waitpid() for individual pids will
4456 * still work fine.
4457 *
4458 * Return value: the newly-created child watch source
4459 *
4460 * Since: 2.4
4461 **/
4462 GSource *
4463 g_child_watch_source_new (GPid pid)
4464 {
4465 GSource *source = g_source_new (&g_child_watch_funcs, sizeof (GChildWatchSource));
4466 GChildWatchSource *child_watch_source = (GChildWatchSource *)source;
4467
4468 #ifdef GSTREAMER_LITE
4469 if (source == NULL)
4470 return NULL;
4471 #endif // GSTREAMER_LITE
4472
4473 #ifdef G_OS_WIN32
4474 child_watch_source->poll.fd = (gintptr) pid;
4475 child_watch_source->poll.events = G_IO_IN;
4476
4477 g_source_add_poll (source, &child_watch_source->poll);
4478 #else /* G_OS_WIN32 */
4479 g_child_watch_source_init ();
4480 #endif /* G_OS_WIN32 */
4481
4482 child_watch_source->pid = pid;
4483
4484 return source;
4485 }
4486
4487 /**
4488 * g_child_watch_add_full:
4489 * @priority: the priority of the idle source. Typically this will be in the
4490 * range between #G_PRIORITY_DEFAULT_IDLE and #G_PRIORITY_HIGH_IDLE.
4491 * @pid: process to watch. On POSIX the pid of a child process. On
4492 * Windows a handle for a process (which doesn't have to be a child).
4493 * @function: function to call
4494 * @data: data to pass to @function
4495 * @notify: function to call when the idle is removed, or %NULL
4496 *
4497 * Sets a function to be called when the child indicated by @pid
4498 * exits, at the priority @priority.
4499 *
4500 * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes()
4501 * you will need to pass #G_SPAWN_DO_NOT_REAP_CHILD as flag to
4502 * the spawn function for the child watching to work.
4503 *
4504 * Note that on platforms where #GPid must be explicitly closed
4505 * (see g_spawn_close_pid()) @pid must not be closed while the
4506 * source is still active. Typically, you will want to call
4507 * g_spawn_close_pid() in the callback function for the source.
4508 *
4509 * GLib supports only a single callback per process id.
4510 *
4511 * This internally creates a main loop source using
4512 * g_child_watch_source_new() and attaches it to the main loop context
4513 * using g_source_attach(). You can do these steps manually if you
4514 * need greater control.
4515 *
4516 * Return value: the ID (greater than 0) of the event source.
4517 *
4518 * Since: 2.4
4519 **/
4520 guint
4521 g_child_watch_add_full (gint priority,
4522 GPid pid,
4523 GChildWatchFunc function,
4524 gpointer data,
4525 GDestroyNotify notify)
4526 {
4527 GSource *source;
4528 guint id;
4529
4530 g_return_val_if_fail (function != NULL, 0);
4531
4532 source = g_child_watch_source_new (pid);
4533
4534 if (priority != G_PRIORITY_DEFAULT)
4535 g_source_set_priority (source, priority);
4536
4537 g_source_set_callback (source, (GSourceFunc) function, data, notify);
4538 id = g_source_attach (source, NULL);
4539 g_source_unref (source);
4540
4541 return id;
4542 }
4543
4544 /**
4545 * g_child_watch_add:
4546 * @pid: process id to watch. On POSIX the pid of a child process. On
4547 * Windows a handle for a process (which doesn't have to be a child).
4548 * @function: function to call
4549 * @data: data to pass to @function
4550 *
4551 * Sets a function to be called when the child indicated by @pid
4552 * exits, at a default priority, #G_PRIORITY_DEFAULT.
4553 *
4554 * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes()
4555 * you will need to pass #G_SPAWN_DO_NOT_REAP_CHILD as flag to
4556 * the spawn function for the child watching to work.
4557 *
4558 * Note that on platforms where #GPid must be explicitly closed
4559 * (see g_spawn_close_pid()) @pid must not be closed while the
4560 * source is still active. Typically, you will want to call
4561 * g_spawn_close_pid() in the callback function for the source.
4562 *
4563 * GLib supports only a single callback per process id.
4564 *
4565 * This internally creates a main loop source using
4566 * g_child_watch_source_new() and attaches it to the main loop context
4567 * using g_source_attach(). You can do these steps manually if you
4568 * need greater control.
4569 *
4570 * Return value: the ID (greater than 0) of the event source.
4571 *
4572 * Since: 2.4
4573 **/
4574 guint
4575 g_child_watch_add (GPid pid,
4576 GChildWatchFunc function,
4577 gpointer data)
4578 {
4579 return g_child_watch_add_full (G_PRIORITY_DEFAULT, pid, function, data, NULL);
4580 }
4581
4582
4583 /* Idle functions */
4584
4585 static gboolean
4586 g_idle_prepare (GSource *source,
4587 gint *timeout)
4588 {
4589 *timeout = 0;
4590
4591 return TRUE;
4592 }
4593
4594 static gboolean
4595 g_idle_check (GSource *source)
4596 {
4597 return TRUE;
4598 }
4599
4600 static gboolean
4601 g_idle_dispatch (GSource *source,
4602 GSourceFunc callback,
4603 gpointer user_data)
4604 {
4605 if (!callback)
4606 {
4607 g_warning ("Idle source dispatched without callback\n"
4608 "You must call g_source_set_callback().");
4609 return FALSE;
4610 }
4611
4612 return callback (user_data);
4613 }
4614
4615 /**
4616 * g_idle_source_new:
4617 *
4618 * Creates a new idle source.
4619 *
4620 * The source will not initially be associated with any #GMainContext
4621 * and must be added to one with g_source_attach() before it will be
4622 * executed. Note that the default priority for idle sources is
4623 * %G_PRIORITY_DEFAULT_IDLE, as compared to other sources which
4624 * have a default priority of %G_PRIORITY_DEFAULT.
4625 *
4626 * Return value: the newly-created idle source
4627 **/
4628 GSource *
4629 g_idle_source_new (void)
4630 {
4631 GSource *source;
4632
4633 source = g_source_new (&g_idle_funcs, sizeof (GSource));
4634 g_source_set_priority (source, G_PRIORITY_DEFAULT_IDLE);
4635
4636 return source;
4637 }
4638
4639 /**
4640 * g_idle_add_full:
4641 * @priority: the priority of the idle source. Typically this will be in the
4642 * range between #G_PRIORITY_DEFAULT_IDLE and #G_PRIORITY_HIGH_IDLE.
4643 * @function: function to call
4644 * @data: data to pass to @function
4645 * @notify: function to call when the idle is removed, or %NULL
4646 *
4647 * Adds a function to be called whenever there are no higher priority
4648 * events pending. If the function returns %FALSE it is automatically
4649 * removed from the list of event sources and will not be called again.
4650 *
4651 * This internally creates a main loop source using g_idle_source_new()
4652 * and attaches it to the main loop context using g_source_attach().
4653 * You can do these steps manually if you need greater control.
4654 *
4655 * Return value: the ID (greater than 0) of the event source.
4656 **/
4657 guint
4658 g_idle_add_full (gint priority,
4659 GSourceFunc function,
4660 gpointer data,
4661 GDestroyNotify notify)
4662 {
4663 GSource *source;
4664 guint id;
4665
4666 g_return_val_if_fail (function != NULL, 0);
4667
4668 source = g_idle_source_new ();
4669
4670 if (priority != G_PRIORITY_DEFAULT_IDLE)
4671 g_source_set_priority (source, priority);
4672
4673 g_source_set_callback (source, function, data, notify);
4674 id = g_source_attach (source, NULL);
4675 g_source_unref (source);
4676
4677 return id;
4678 }
4679
4680 /**
4681 * g_idle_add:
4682 * @function: function to call
4683 * @data: data to pass to @function.
4684 *
4685 * Adds a function to be called whenever there are no higher priority
4686 * events pending to the default main loop. The function is given the
4687 * default idle priority, #G_PRIORITY_DEFAULT_IDLE. If the function
4688 * returns %FALSE it is automatically removed from the list of event
4689 * sources and will not be called again.
4690 *
4691 * This internally creates a main loop source using g_idle_source_new()
4692 * and attaches it to the main loop context using g_source_attach().
4693 * You can do these steps manually if you need greater control.
4694 *
4695 * Return value: the ID (greater than 0) of the event source.
4696 **/
4697 guint
4698 g_idle_add (GSourceFunc function,
4699 gpointer data)
4700 {
4701 return g_idle_add_full (G_PRIORITY_DEFAULT_IDLE, function, data, NULL);
4702 }
4703
4704 /**
4705 * g_idle_remove_by_data:
4706 * @data: the data for the idle source's callback.
4707 *
4708 * Removes the idle function with the given data.
4709 *
4710 * Return value: %TRUE if an idle source was found and removed.
4711 **/
4712 gboolean
4713 g_idle_remove_by_data (gpointer data)
4714 {
4715 return g_source_remove_by_funcs_user_data (&g_idle_funcs, data);
4716 }
4717
4718 /**
4719 * g_main_context_invoke:
4720 * @context: a #GMainContext, or %NULL
4721 * @function: function to call
4722 * @data: data to pass to @function
4723 *
4724 * Invokes a function in such a way that @context is owned during the
4725 * invocation of @function.
4726 *
4727 * If @context is %NULL then the global default main context — as
4728 * returned by g_main_context_default() — is used.
4729 *
4730 * If @context is owned by the current thread, @function is called
4731 * directly. Otherwise, if @context is the thread-default main context
4732 * of the current thread and g_main_context_acquire() succeeds, then
4733 * @function is called and g_main_context_release() is called
4734 * afterwards.
4735 *
4736 * In any other case, an idle source is created to call @function and
4737 * that source is attached to @context (presumably to be run in another
4738 * thread). The idle source is attached with #G_PRIORITY_DEFAULT
4739 * priority. If you want a different priority, use
4740 * g_main_context_invoke_full().
4741 *
4742 * Note that, as with normal idle functions, @function should probably
4743 * return %FALSE. If it returns %TRUE, it will be continuously run in a
4744 * loop (and may prevent this call from returning).
4745 *
4746 * Since: 2.28
4747 **/
4748 void
4749 g_main_context_invoke (GMainContext *context,
4750 GSourceFunc function,
4751 gpointer data)
4752 {
4753 g_main_context_invoke_full (context,
4754 G_PRIORITY_DEFAULT,
4755 function, data, NULL);
4756 }
4757
4758 /**
4759 * g_main_context_invoke_full:
4760 * @context: a #GMainContext, or %NULL
4761 * @priority: the priority at which to run @function
4762 * @function: function to call
4763 * @data: data to pass to @function
4764 * @notify: a function to call when @data is no longer in use, or %NULL.
4765 *
4766 * Invokes a function in such a way that @context is owned during the
4767 * invocation of @function.
4768 *
4769 * This function is the same as g_main_context_invoke() except that it
4770 * lets you specify the priority incase @function ends up being
4771 * scheduled as an idle and also lets you give a #GDestroyNotify for @data.
4772 *
4773 * @notify should not assume that it is called from any particular
4774 * thread or with any particular context acquired.
4775 *
4776 * Since: 2.28
4777 **/
4778 void
4779 g_main_context_invoke_full (GMainContext *context,
4780 gint priority,
4781 GSourceFunc function,
4782 gpointer data,
4783 GDestroyNotify notify)
4784 {
4785 g_return_if_fail (function != NULL);
4786
4787 if (!context)
4788 context = g_main_context_default ();
4789
4790 if (g_main_context_is_owner (context))
4791 {
4792 while (function (data));
4793 if (notify != NULL)
4794 notify (data);
4795 }
4796
4797 else
4798 {
4799 GMainContext *thread_default;
4800
4801 thread_default = g_main_context_get_thread_default ();
4802
4803 if (!thread_default)
4804 thread_default = g_main_context_default ();
4805
4806 if (thread_default == context && g_main_context_acquire (context))
4807 {
4808 while (function (data));
4809
4810 g_main_context_release (context);
4811
4812 if (notify != NULL)
4813 notify (data);
4814 }
4815 else
4816 {
4817 GSource *source;
4818
4819 source = g_idle_source_new ();
4820 g_source_set_priority (source, priority);
4821 g_source_set_callback (source, function, data, notify);
4822 g_source_attach (source, context);
4823 g_source_unref (source);
4824 }
4825 }
4826 }