2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
6 * gstthread.c: Threaded container object
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
24 #include "gst_private.h"
26 #include "gstthread.h"
27 #include "gstmarshal.h"
28 #include "gstscheduler.h"
31 #define GST_CAT_DEFAULT GST_CAT_THREAD
32 #define STACK_SIZE 0x200000
34 static GstElementDetails gst_thread_details =
35 GST_ELEMENT_DETAILS ("Threaded container",
37 "Container that creates/manages a thread",
38 "Erik Walthinsen <omega@cse.ogi.edu>, "
39 "Benjamin Otte <in7y118@informatik.uni-hamburg.de");
41 /* Thread signals and args */
63 static void gst_thread_base_init (gpointer g_class);
64 static void gst_thread_class_init (gpointer g_class, gpointer class_data);
65 static void gst_thread_init (GTypeInstance * instance, gpointer g_class);
67 static void gst_thread_dispose (GObject * object);
69 static void gst_thread_set_property (GObject * object, guint prop_id,
70 const GValue * value, GParamSpec * pspec);
71 static void gst_thread_get_property (GObject * object, guint prop_id,
72 GValue * value, GParamSpec * pspec);
73 static GstElementStateReturn gst_thread_change_state (GstElement * element);
74 static void gst_thread_child_state_change (GstBin * bin,
75 GstElementState oldstate, GstElementState newstate, GstElement * element);
77 static void gst_thread_catch (GstThread * thread);
78 static void gst_thread_release (GstThread * thread);
80 #ifndef GST_DISABLE_LOADSAVE
81 static xmlNodePtr gst_thread_save_thyself (GstObject * object,
83 static void gst_thread_restore_thyself (GstObject * object, xmlNodePtr self);
86 static void *gst_thread_main_loop (void *arg);
88 #define GST_TYPE_THREAD_PRIORITY (gst_thread_priority_get_type())
90 gst_thread_priority_get_type (void)
92 static GType thread_priority_type = 0;
93 static GEnumValue thread_priority[] = {
94 {G_THREAD_PRIORITY_LOW, "LOW", "Low Priority Scheduling"},
95 {G_THREAD_PRIORITY_NORMAL, "NORMAL", "Normal Scheduling"},
96 {G_THREAD_PRIORITY_HIGH, "HIGH", "High Priority Scheduling"},
97 {G_THREAD_PRIORITY_URGENT, "URGENT", "Urgent Scheduling"},
101 if (!thread_priority_type) {
102 thread_priority_type =
103 g_enum_register_static ("GstThreadPriority", thread_priority);
105 return thread_priority_type;
108 static GstBinClass *parent_class = NULL;
109 static guint gst_thread_signals[LAST_SIGNAL] = { 0 };
110 GPrivate *gst_thread_current;
113 gst_thread_get_type (void)
115 static GType thread_type = 0;
118 static const GTypeInfo thread_info = {
119 sizeof (GstThreadClass),
120 gst_thread_base_init,
122 gst_thread_class_init,
131 thread_type = g_type_register_static (GST_TYPE_BIN, "GstThread",
138 gst_thread_base_init (gpointer g_class)
140 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
142 gst_element_class_set_details (gstelement_class, &gst_thread_details);
145 do_nothing (gpointer hi)
149 gst_thread_class_init (gpointer g_class, gpointer class_data)
151 GObjectClass *gobject_class = G_OBJECT_CLASS (g_class);
153 #ifndef GST_DISABLE_LOADSAVE
154 GstObjectClass *gstobject_class = GST_OBJECT_CLASS (g_class);
156 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
157 GstBinClass *gstbin_class = GST_BIN_CLASS (g_class);
158 GstThreadClass *klass = GST_THREAD_CLASS (g_class);
160 /* setup gst_thread_current */
161 gst_thread_current = g_private_new (do_nothing);
163 parent_class = g_type_class_peek_parent (g_class);
165 g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PRIORITY,
166 g_param_spec_enum ("priority", "Scheduling Policy",
167 "The scheduling priority of the thread", GST_TYPE_THREAD_PRIORITY,
168 G_THREAD_PRIORITY_NORMAL, G_PARAM_READWRITE));
170 gst_thread_signals[SHUTDOWN] =
171 g_signal_new ("shutdown", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
172 G_STRUCT_OFFSET (GstThreadClass, shutdown), NULL, NULL,
173 gst_marshal_VOID__VOID, G_TYPE_NONE, 0);
175 gobject_class->dispose = gst_thread_dispose;
177 #ifndef GST_DISABLE_LOADSAVE
178 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_thread_save_thyself);
179 gstobject_class->restore_thyself =
180 GST_DEBUG_FUNCPTR (gst_thread_restore_thyself);
183 gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_thread_change_state);
185 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_thread_set_property);
186 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_thread_get_property);
188 gstbin_class->child_state_change =
189 GST_DEBUG_FUNCPTR (gst_thread_child_state_change);
193 gst_thread_init (GTypeInstance * instance, gpointer g_class)
195 GstScheduler *scheduler;
196 GstThread *thread = GST_THREAD (instance);
198 GST_DEBUG ("initializing thread");
200 /* threads are managing bins and iterate themselves */
201 /* CR1: the GstBin code checks these flags */
202 GST_FLAG_SET (thread, GST_BIN_FLAG_MANAGER);
203 GST_FLAG_SET (thread, GST_BIN_SELF_SCHEDULABLE);
205 scheduler = gst_scheduler_factory_make (NULL, GST_ELEMENT (thread));
206 g_assert (scheduler);
208 thread->lock = g_mutex_new ();
209 thread->cond = g_cond_new ();
211 thread->thread_id = (GThread *) NULL; /* set in NULL -> READY */
212 thread->priority = G_THREAD_PRIORITY_NORMAL;
216 gst_thread_dispose (GObject * object)
218 GstThread *thread = GST_THREAD (object);
220 GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "GstThread: dispose");
222 G_OBJECT_CLASS (parent_class)->dispose (object);
224 g_assert (GST_STATE (thread) == GST_STATE_NULL);
226 g_mutex_free (thread->lock);
227 g_cond_free (thread->cond);
229 gst_object_replace ((GstObject **) & GST_ELEMENT_SCHED (thread), NULL);
233 * gst_thread_set_priority:
234 * @thread: the thread to change
235 * @priority: the new priority for the thread
237 * change the thread's priority
240 gst_thread_set_priority (GstThread * thread, GThreadPriority priority)
242 g_return_if_fail (GST_IS_THREAD (thread));
244 thread->priority = priority;
248 gst_thread_set_property (GObject * object, guint prop_id, const GValue * value,
253 thread = GST_THREAD (object);
257 thread->priority = g_value_get_enum (value);
260 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
266 gst_thread_get_property (GObject * object, guint prop_id, GValue * value,
271 thread = GST_THREAD (object);
275 g_value_set_enum (value, thread->priority);
278 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
286 * @name: the name of the thread
288 * Create a new thread with the given name.
290 * Returns: The new thread
293 gst_thread_new (const gchar * name)
295 return gst_element_factory_make ("thread", name);
299 * gst_thread_get_current:
301 * Gets the current GstThread.
303 * Returns: The current GstThread or NULL if you are not running inside a
307 gst_thread_get_current (void)
309 return (GstThread *) g_private_get (gst_thread_current);
313 gst_thread_release_children_locks (GstThread * thread)
315 GstRealPad *peer = NULL;
316 GstElement *peerelement;
317 GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread));
320 GstElement *element = GST_ELEMENT (elements->data);
324 GST_DEBUG_OBJECT (thread, "waking element \"%s\"",
325 GST_ELEMENT_NAME (element));
326 elements = g_list_next (elements);
328 if (!gst_element_release_locks (element))
329 g_warning ("element %s could not release locks",
330 GST_ELEMENT_NAME (element));
332 pads = GST_ELEMENT_PADS (element);
335 if (GST_PAD_PEER (pads->data)) {
336 peer = GST_REAL_PAD (GST_PAD_PEER (pads->data));
337 pads = g_list_next (pads);
339 pads = g_list_next (pads);
346 peerelement = GST_PAD_PARENT (peer);
348 continue; /* FIXME: deal with case where there's no peer */
350 if (GST_ELEMENT_SCHED (peerelement) != GST_ELEMENT_SCHED (thread)) {
351 GST_LOG_OBJECT (thread, "element \"%s\" has pad cross sched boundary",
352 GST_ELEMENT_NAME (element));
353 GST_LOG_OBJECT (thread, "waking element \"%s\"",
354 GST_ELEMENT_NAME (peerelement));
355 if (!gst_element_release_locks (peerelement))
356 g_warning ("element %s could not release locks",
357 GST_ELEMENT_NAME (peerelement));
363 /* stops the main thread, if there is one and grabs the thread's mutex */
365 gst_thread_catch (GstThread * thread)
369 if (thread == gst_thread_get_current ()) {
370 /* we're trying to catch ourself */
371 if (!GST_FLAG_IS_SET (thread, GST_THREAD_MUTEX_LOCKED)) {
372 g_mutex_lock (thread->lock);
373 GST_FLAG_SET (thread, GST_THREAD_MUTEX_LOCKED);
375 GST_DEBUG_OBJECT (thread, "catching itself");
376 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
378 /* another thread is trying to catch us */
379 g_mutex_lock (thread->lock);
380 wait = !GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING);
384 GST_LOG_OBJECT (thread, "catching thread...");
385 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
386 g_cond_signal (thread->cond);
387 gst_thread_release_children_locks (thread);
388 g_get_current_time (&tv);
389 g_time_val_add (&tv, 1000); /* wait a millisecond to catch the thread */
390 wait = g_cond_timed_wait (thread->cond, thread->lock, &tv);
392 GST_LOG_OBJECT (thread, "caught thread");
394 g_assert (!GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING));
398 gst_thread_release (GstThread * thread)
400 if (thread != gst_thread_get_current ()) {
401 g_cond_signal (thread->cond);
402 g_mutex_unlock (thread->lock);
406 static GstElementStateReturn
407 gst_thread_change_state (GstElement * element)
410 GstElementStateReturn ret;
413 g_return_val_if_fail (GST_IS_THREAD (element), GST_STATE_FAILURE);
414 transition = GST_STATE_TRANSITION (element);
416 thread = GST_THREAD (element);
418 GST_DEBUG_OBJECT (element, "changing state from %s to %s",
419 gst_element_state_get_name (GST_STATE (element)),
420 gst_element_state_get_name (GST_STATE_PENDING (element)));
422 gst_thread_catch (thread);
424 /* FIXME: (or GStreamers ideas about "threading"): the element variables are
425 commonly accessed by multiple threads at the same time (see bug #111146
427 if (transition != GST_STATE_TRANSITION (element)) {
428 g_warning ("inconsistent state information, fix threading please");
431 switch (transition) {
432 case GST_STATE_NULL_TO_READY:
433 /* create the thread */
434 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
435 thread->thread_id = g_thread_create_full (gst_thread_main_loop,
436 thread, STACK_SIZE, FALSE, TRUE, thread->priority, NULL);
437 if (!thread->thread_id) {
438 GST_ERROR_OBJECT (element, "g_thread_create_full failed");
441 GST_LOG_OBJECT (element, "GThread created");
443 /* wait for it to 'spin up' */
444 g_cond_wait (thread->cond, thread->lock);
446 case GST_STATE_READY_TO_PAUSED:
448 case GST_STATE_PAUSED_TO_PLAYING:
450 /* FIXME: recurse into sub-bins */
451 GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread));
454 gst_element_enable_threadsafe_properties ((GstElement *) elements->
456 elements = g_list_next (elements);
458 /* reset self to spinning */
459 if (thread == gst_thread_get_current ())
460 GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
463 case GST_STATE_PLAYING_TO_PAUSED:
465 GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread));
468 gst_element_disable_threadsafe_properties ((GstElement *) elements->
470 elements = g_list_next (elements);
474 case GST_STATE_PAUSED_TO_READY:
476 case GST_STATE_READY_TO_NULL:
477 /* we can't join the threads here, because this could have been triggered
479 GST_LOG_OBJECT (thread, "destroying GThread %p", thread->thread_id);
480 GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
481 thread->thread_id = NULL;
482 if (thread == gst_thread_get_current ()) {
483 /* or should we continue? */
485 ("Thread %s is destroying itself. Function call will not return!",
486 GST_ELEMENT_NAME (thread));
487 gst_scheduler_reset (GST_ELEMENT_SCHED (thread));
489 /* unlock and signal - we are out */
490 gst_thread_release (thread);
492 GST_INFO_OBJECT (thread, "GThread %p is exiting", g_thread_self ());
494 g_signal_emit (G_OBJECT (thread), gst_thread_signals[SHUTDOWN], 0);
496 g_thread_exit (NULL);
498 /* now wait for the thread to destroy itself */
499 g_cond_signal (thread->cond);
500 g_cond_wait (thread->cond, thread->lock);
501 /* it should be dead now */
504 GST_ERROR_OBJECT (element, "unhandled state change! %x",
505 GST_STATE_TRANSITION (element));
506 g_warning ("thread %s: UNHANDLED STATE CHANGE! %x",
507 GST_STR_NULL (GST_OBJECT_NAME (element)),
508 GST_STATE_TRANSITION (element));
509 /* FIXME: not doable with current threading mess:
510 g_assert_not_reached ();
515 if (GST_ELEMENT_CLASS (parent_class)->change_state) {
516 ret = GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT (thread));
518 ret = GST_STATE_SUCCESS;
521 gst_thread_release (thread);
525 GST_CAT_DEBUG (GST_CAT_STATES, "changing state from %s to %s failed for %s",
526 gst_element_state_get_name (GST_STATE (element)),
527 gst_element_state_get_name (GST_STATE_PENDING (element)),
528 GST_ELEMENT_NAME (element));
529 gst_thread_release (thread);
530 return GST_STATE_FAILURE;
533 /* state changes work this way: We grab the lock and stop the thread from
534 spinning (via gst_thread_catch) - then we change the state. After that the
535 thread may spin on. */
537 gst_thread_child_state_change (GstBin * bin, GstElementState oldstate,
538 GstElementState newstate, GstElement * element)
540 GST_LOG_OBJECT (bin, "(from thread %s) child %s changed state from %s to %s",
541 gst_thread_get_current ()? GST_ELEMENT_NAME (gst_thread_get_current ()) :
542 "(none)", GST_ELEMENT_NAME (element),
543 gst_element_state_get_name (oldstate),
544 gst_element_state_get_name (newstate));
545 if (parent_class->child_state_change)
546 parent_class->child_state_change (bin, oldstate, newstate, element);
547 /* We'll wake up the main thread now. Note that we can't lock the thread here,
548 because we might be called from inside gst_thread_change_state when holding
549 the lock. But this doesn't cause any problems. */
550 if (newstate == GST_STATE_PLAYING)
551 g_cond_signal (GST_THREAD (bin)->cond);
555 * gst_thread_main_loop:
556 * @arg: the thread to start
558 * The main loop of the thread. The thread will iterate
559 * while the state is GST_THREAD_STATE_SPINNING.
562 gst_thread_main_loop (void *arg)
564 GstThread *thread = NULL;
567 thread = GST_THREAD (arg);
568 g_mutex_lock (thread->lock);
569 GST_LOG_OBJECT (thread, "Started main loop");
571 /* initialize gst_thread_current */
572 g_private_set (gst_thread_current, thread);
574 /* set up the element's scheduler */
575 gst_scheduler_setup (GST_ELEMENT_SCHED (thread));
576 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
578 g_cond_signal (thread->cond);
579 while (!(GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING))) {
580 if (GST_STATE (thread) == GST_STATE_PLAYING) {
581 GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
583 GST_LOG_OBJECT (thread, "starting to iterate");
584 while (status && GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING)) {
585 g_mutex_unlock (thread->lock);
586 status = gst_bin_iterate (GST_BIN (thread));
588 GST_DEBUG_OBJECT (thread, "iterate returned false");
589 if (GST_FLAG_IS_SET (thread, GST_THREAD_MUTEX_LOCKED)) {
590 GST_FLAG_UNSET (thread, GST_THREAD_MUTEX_LOCKED);
592 g_mutex_lock (thread->lock);
595 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
597 if (GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING))
599 GST_LOG_OBJECT (thread, "we're caught");
600 g_cond_signal (thread->cond);
601 g_cond_wait (thread->cond, thread->lock);
604 /* we need to destroy the scheduler here because it has mapped it's
605 * stack into the threads stack space */
606 gst_scheduler_reset (GST_ELEMENT_SCHED (thread));
608 /* must do that before releasing the lock - we might get disposed before being done */
609 g_signal_emit (G_OBJECT (thread), gst_thread_signals[SHUTDOWN], 0);
611 /* unlock and signal - we are out */
613 GST_LOG_OBJECT (thread, "Thread %p exits main loop", g_thread_self ());
614 g_cond_signal (thread->cond);
615 g_mutex_unlock (thread->lock);
616 /* don't assume the GstThread object exists anymore now */
621 #ifndef GST_DISABLE_LOADSAVE
623 gst_thread_save_thyself (GstObject * object, xmlNodePtr self)
625 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
626 GST_OBJECT_CLASS (parent_class)->save_thyself (object, self);
631 gst_thread_restore_thyself (GstObject * object, xmlNodePtr self)
633 GST_LOG_OBJECT (object, "restoring");
635 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
636 GST_OBJECT_CLASS (parent_class)->restore_thyself (object, self);
638 #endif /* GST_DISABLE_LOADSAVE */