2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstthread.c: Threaded container object
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library 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.
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 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library 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.
25 /* #define GST_DEBUG_ENABLED */
26 #include "gst_private.h"
28 #include "gstthread.h"
29 #include "gstscheduler.h"
32 GstElementDetails gst_thread_details = {
35 "Container that creates/manages a thread",
37 "Erik Walthinsen <omega@cse.ogi.edu>",
42 /* Thread signals and args */
60 static void gst_thread_class_init (GstThreadClass *klass);
61 static void gst_thread_init (GstThread *thread);
63 static void gst_thread_dispose (GObject *object);
65 static void gst_thread_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
66 static void gst_thread_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
68 static GstElementStateReturn gst_thread_change_state (GstElement *element);
70 #ifndef GST_DISABLE_LOADSAVE
71 static xmlNodePtr gst_thread_save_thyself (GstObject *object, xmlNodePtr parent);
72 static void gst_thread_restore_thyself (GstObject *object, xmlNodePtr self);
75 static void* gst_thread_main_loop (void *arg);
77 static GstBinClass *parent_class = NULL;
78 /* static guint gst_thread_signals[LAST_SIGNAL] = { 0 }; */
81 gst_thread_get_type(void) {
82 static GType thread_type = 0;
85 static const GTypeInfo thread_info = {
86 sizeof(GstThreadClass),
89 (GClassInitFunc)gst_thread_class_init,
94 (GInstanceInitFunc)gst_thread_init,
97 thread_type = g_type_register_static(GST_TYPE_BIN, "GstThread", &thread_info, 0);
103 gst_thread_class_init (GstThreadClass *klass)
105 GObjectClass *gobject_class;
106 GstObjectClass *gstobject_class;
107 GstElementClass *gstelement_class;
108 GstBinClass *gstbin_class;
110 gobject_class = (GObjectClass*)klass;
111 gstobject_class = (GstObjectClass*)klass;
112 gstelement_class = (GstElementClass*)klass;
113 gstbin_class = (GstBinClass*)klass;
115 parent_class = g_type_class_ref (GST_TYPE_BIN);
117 gobject_class->dispose = gst_thread_dispose;
119 #ifndef GST_DISABLE_LOADSAVE
120 gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_thread_save_thyself);
121 gstobject_class->restore_thyself = GST_DEBUG_FUNCPTR (gst_thread_restore_thyself);
124 gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_thread_change_state);
126 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_thread_set_property);
127 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_thread_get_property);
132 gst_thread_init (GstThread *thread)
134 GstScheduler *scheduler;
136 GST_DEBUG (GST_CAT_THREAD, "initializing thread");
138 /* threads are managing bins and iterate themselves */
139 /* CR1: the GstBin code checks these flags */
140 GST_FLAG_SET (thread, GST_BIN_FLAG_MANAGER);
141 GST_FLAG_SET (thread, GST_BIN_SELF_SCHEDULABLE);
143 scheduler = gst_scheduler_factory_make (NULL, GST_ELEMENT (thread));
145 thread->lock = g_mutex_new ();
146 thread->cond = g_cond_new ();
148 thread->ppid = getpid ();
149 thread->thread_id = -1;
153 gst_thread_dispose (GObject *object)
155 GstThread *thread = GST_THREAD (object);
157 GST_DEBUG (GST_CAT_REFCOUNTING, "dispose");
159 g_mutex_free (thread->lock);
160 g_cond_free (thread->cond);
162 G_OBJECT_CLASS (parent_class)->dispose (object);
164 if (GST_ELEMENT_SCHED (thread)) {
165 gst_object_unref (GST_OBJECT (GST_ELEMENT_SCHED (thread)));
170 gst_thread_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
172 /* it's not null if we got it, but it might not be ours */
173 g_return_if_fail (GST_IS_THREAD (object));
177 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
183 gst_thread_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
185 /* it's not null if we got it, but it might not be ours */
186 g_return_if_fail (GST_IS_THREAD (object));
190 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
198 * @name: the name of the thread
200 * Create a new thread with the given name.
202 * Returns: The new thread
205 gst_thread_new (const gchar *name)
207 return gst_element_factory_make ("thread", name);
211 #define THR_INFO(format,args...) \
212 GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
213 GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
214 #define THR_DEBUG(format,args...) \
215 GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
216 GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
218 #define THR_INFO_MAIN(format,args...) \
219 GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
220 GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
221 #define THR_DEBUG_MAIN(format,args...) \
222 GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
223 GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
225 static GstElementStateReturn
226 gst_thread_update_state (GstThread *thread)
228 /* check for state change */
229 if (GST_STATE_PENDING(thread) != GST_STATE_VOID_PENDING) {
230 /* punt and change state on all the children */
231 if (GST_ELEMENT_CLASS (parent_class)->change_state)
232 return GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
235 return GST_STATE_SUCCESS;
239 static GstElementStateReturn
240 gst_thread_change_state (GstElement * element)
243 gboolean stateset = GST_STATE_SUCCESS;
245 pthread_t self = pthread_self ();
247 g_return_val_if_fail (GST_IS_THREAD (element), FALSE);
249 thread = GST_THREAD (element);
251 transition = GST_STATE_TRANSITION (element);
253 THR_INFO ("changing state from %s to %s",
254 gst_element_state_get_name (GST_STATE (element)),
255 gst_element_state_get_name (GST_STATE_PENDING (element)));
257 if (pthread_equal (self, thread->thread_id)) {
258 GST_DEBUG (GST_CAT_THREAD,
259 "no sync(" GST_DEBUG_THREAD_FORMAT "): setting own thread's state to spinning",
260 GST_DEBUG_THREAD_ARGS (thread->pid));
261 return gst_thread_update_state (thread);
264 switch (transition) {
265 case GST_STATE_NULL_TO_READY:
266 /* set the state to idle */
267 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
269 THR_DEBUG ("creating thread \"%s\"", GST_ELEMENT_NAME (element));
271 g_mutex_lock (thread->lock);
273 /* create the thread */
274 if (pthread_create (&thread->thread_id, NULL, gst_thread_main_loop, thread) != 0) {
275 g_mutex_unlock (thread->lock);
276 THR_DEBUG ("could not create thread \"%s\"", GST_ELEMENT_NAME (element));
277 return GST_STATE_FAILURE;
280 /* wait for it to 'spin up' */
281 THR_DEBUG ("waiting for child thread spinup");
282 g_cond_wait (thread->cond, thread->lock);
283 THR_DEBUG ("thread claims to be up");
284 g_mutex_unlock (thread->lock);
286 case GST_STATE_READY_TO_PAUSED:
287 THR_INFO ("readying thread");
288 g_mutex_lock (thread->lock);
289 THR_DEBUG ("signaling");
290 g_cond_signal (thread->cond);
291 THR_DEBUG ("waiting for ack");
292 g_cond_wait (thread->cond, thread->lock);
293 THR_DEBUG ("got ack");
294 g_mutex_unlock (thread->lock);
296 case GST_STATE_PAUSED_TO_PLAYING:
298 /* fixme: recurse into sub-bins */
299 const GList *elements = gst_bin_get_list (GST_BIN (thread));
301 gst_element_enable_threadsafe_properties ((GstElement*)elements->data);
302 elements = g_list_next (elements);
305 THR_DEBUG ("telling thread to start spinning");
306 g_mutex_lock (thread->lock);
307 THR_DEBUG ("signaling");
308 g_cond_signal (thread->cond);
309 THR_DEBUG ("waiting for ack");
310 g_cond_wait (thread->cond, thread->lock);
311 THR_DEBUG ("got ack");
312 g_mutex_unlock (thread->lock);
315 case GST_STATE_PLAYING_TO_PAUSED:
317 const GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread));
319 THR_INFO ("pausing thread");
321 /* the following code ensures that the bottom half of thread will run
322 * to perform each elements' change_state() (by calling gstbin.c::
324 * + the pending state was already set by gstelement.c::set_state()
325 * + unlock all elements so the bottom half can start the state change.
327 g_mutex_lock (thread->lock);
329 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
332 GstElement *element = GST_ELEMENT (elements->data);
337 THR_DEBUG (" waking element \"%s\"", GST_ELEMENT_NAME (element));
338 elements = g_list_next (elements);
340 if (!gst_element_release_locks (element)) {
341 g_warning ("element %s could not release locks", GST_ELEMENT_NAME (element));
344 pads = GST_ELEMENT_PADS (element);
347 GstRealPad *peer = GST_REAL_PAD (GST_PAD_PEER (pads->data));
348 GstElement *peerelement;
350 pads = g_list_next (pads);
355 peerelement = GST_PAD_PARENT (peer);
357 continue; /* deal with case where there's no peer */
359 if (!GST_FLAG_IS_SET (peerelement, GST_ELEMENT_DECOUPLED)) {
360 GST_DEBUG (GST_CAT_THREAD, "peer element isn't DECOUPLED");
364 if (GST_ELEMENT_SCHED (peerelement) != GST_ELEMENT_SCHED (thread)) {
365 THR_DEBUG (" element \"%s\" has pad cross sched boundary", GST_ELEMENT_NAME (element));
366 THR_DEBUG (" waking element \"%s\"", GST_ELEMENT_NAME (peerelement));
367 if (!gst_element_release_locks (peerelement)) {
368 g_warning ("element %s could not release locks", GST_ELEMENT_NAME (peerelement));
374 THR_DEBUG ("telling thread to pause, signaling");
375 g_cond_signal (thread->cond);
376 THR_DEBUG ("waiting for ack");
377 g_cond_wait (thread->cond, thread->lock);
378 THR_DEBUG ("got ack");
379 g_mutex_unlock (thread->lock);
381 elements = gst_bin_get_list (GST_BIN (thread));
383 gst_element_disable_threadsafe_properties ((GstElement*)elements->data);
384 elements = g_list_next (elements);
388 case GST_STATE_READY_TO_NULL:
389 THR_DEBUG ("telling thread to pause (null) - and joining");
390 /* MattH FIXME revisit */
391 g_mutex_lock (thread->lock);
392 THR_DEBUG ("signaling");
393 g_cond_signal (thread->cond);
394 THR_DEBUG ("waiting for ack");
395 g_cond_wait (thread->cond, thread->lock);
396 THR_DEBUG ("got ack");
397 pthread_join (thread->thread_id, NULL);
398 thread->thread_id = -1;
399 g_mutex_unlock (thread->lock);
401 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
402 GST_FLAG_UNSET (thread, GST_THREAD_STATE_STARTED);
403 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
406 case GST_STATE_PAUSED_TO_READY:
407 THR_DEBUG ("telling thread to stop spinning");
408 g_mutex_lock (thread->lock);
409 THR_DEBUG ("signaling");
410 g_cond_signal (thread->cond);
411 THR_DEBUG ("waiting for ack");
412 g_cond_wait (thread->cond, thread->lock);
413 THR_DEBUG ("got ack");
414 g_mutex_unlock (thread->lock);
418 GST_DEBUG_ELEMENT (GST_CAT_THREAD, element, "UNHANDLED STATE CHANGE! %x", transition);
426 * gst_thread_main_loop:
427 * @arg: the thread to start
429 * The main loop of the thread. The thread will iterate
430 * while the state is GST_THREAD_STATE_SPINNING.
433 gst_thread_main_loop (void *arg)
435 GstThread *thread = GST_THREAD (arg);
438 g_mutex_lock (thread->lock);
440 gst_scheduler_setup (GST_ELEMENT_SCHED (thread));
441 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
443 thread->pid = getpid();
444 THR_INFO_MAIN("thread is running");
446 /* first we need to change the state of all the children */
447 if (GST_ELEMENT_CLASS (parent_class)->change_state) {
448 stateset = GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
450 if (stateset != GST_STATE_SUCCESS) {
451 THR_DEBUG_MAIN ("state change of children failed");
456 THR_DEBUG_MAIN ("indicating spinup");
457 g_cond_signal (thread->cond);
458 /* don't unlock the mutex because we hold it into the top of the while loop */
459 THR_DEBUG_MAIN ("thread has indicated spinup to parent process");
461 /***** THREAD IS NOW IN READY STATE *****/
463 /* CR1: most of this code is handshaking */
464 /* do this while the thread lives */
465 while (!GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING)) {
466 /* NOTE we hold the thread lock at this point */
467 /* what we do depends on what state we're in */
468 switch (GST_STATE (thread)) {
469 /* NOTE: cannot be in NULL, we're not running in that state at all */
470 case GST_STATE_READY:
471 /* wait to be set to either the NULL or PAUSED states */
472 THR_DEBUG_MAIN ("thread in %s state, waiting for either %s or %s",
473 gst_element_state_get_name (GST_STATE_READY),
474 gst_element_state_get_name (GST_STATE_NULL),
475 gst_element_state_get_name (GST_STATE_PAUSED));
476 g_cond_wait (thread->cond,thread->lock);
478 /* this must have happened by a state change in the thread context */
479 if (GST_STATE_PENDING (thread) != GST_STATE_NULL &&
480 GST_STATE_PENDING (thread) != GST_STATE_PAUSED) {
481 g_cond_signal (thread->cond);
485 /* been signaled, we need to state transition now and signal back */
486 gst_thread_update_state (thread);
487 THR_DEBUG_MAIN ("done with state transition, signaling back to parent process");
488 g_cond_signal (thread->cond);
489 /* now we decide what to do next */
490 if (GST_STATE (thread) == GST_STATE_NULL) {
491 /* REAPING must be set, we can simply break this iteration */
492 GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
495 case GST_STATE_PAUSED:
496 /* wait to be set to either the READY or PLAYING states */
497 THR_DEBUG_MAIN("thread in %s state, waiting for either %s or %s",
498 gst_element_state_get_name (GST_STATE_PAUSED),
499 gst_element_state_get_name (GST_STATE_READY),
500 gst_element_state_get_name (GST_STATE_PLAYING));
501 g_cond_wait (thread->cond, thread->lock);
503 /* this must have happened by a state change in the thread context */
504 if (GST_STATE_PENDING (thread) != GST_STATE_READY &&
505 GST_STATE_PENDING (thread) != GST_STATE_PLAYING) {
506 g_cond_signal (thread->cond);
510 /* been signaled, we need to state transition now and signal back */
511 gst_thread_update_state (thread);
512 /* now we decide what to do next */
513 if (GST_STATE (thread) != GST_STATE_PLAYING) {
514 /* either READY or the state change failed for some reason */
515 g_cond_signal (thread->cond);
519 GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
520 /* PLAYING is coming up, so we can now start spinning */
521 while (GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING)) {
524 g_cond_signal (thread->cond);
525 g_mutex_unlock (thread->lock);
526 status = gst_bin_iterate (GST_BIN (thread));
527 g_mutex_lock (thread->lock);
528 /* g_cond_signal(thread->cond); */
530 if (!status || GST_STATE_PENDING (thread) != GST_STATE_VOID_PENDING)
531 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
533 /* looks like we were stopped because of a statechange */
534 if (GST_STATE_PENDING (thread)) {
535 gst_thread_update_state (thread);
537 /* once we're here, SPINNING has stopped, we should signal that we're done */
538 THR_DEBUG_MAIN ("SPINNING stopped, signaling back to parent process");
539 g_cond_signal (thread->cond);
540 /* now we can wait for PAUSED */
543 case GST_STATE_PLAYING:
544 /* wait to be set to PAUSED */
545 THR_DEBUG_MAIN ("thread in %s state, waiting for %s",
546 gst_element_state_get_name(GST_STATE_PLAYING),
547 gst_element_state_get_name(GST_STATE_PAUSED));
548 g_cond_wait (thread->cond,thread->lock);
550 /* been signaled, we need to state transition now and signal back */
551 gst_thread_update_state (thread);
552 g_cond_signal (thread->cond);
553 /* now we decide what to do next */
554 /* there's only PAUSED, we we just wait for it */
557 THR_DEBUG_MAIN ("thread in %s state, preparing to die",
558 gst_element_state_get_name(GST_STATE_NULL));
559 GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
562 g_assert_not_reached ();
566 /* we need to destroy the scheduler here because it has mapped it's
567 * stack into the threads stack space */
568 gst_scheduler_reset (GST_ELEMENT_SCHED (thread));
570 /* since we don't unlock at the end of the while loop, do it here */
571 g_mutex_unlock (thread->lock);
573 GST_INFO (GST_CAT_THREAD, "gstthread: thread \"%s\" is stopped",
574 GST_ELEMENT_NAME (thread));
578 #ifndef GST_DISABLE_LOADSAVE
580 gst_thread_save_thyself (GstObject *object,
583 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
584 GST_OBJECT_CLASS (parent_class)->save_thyself (object, self);
589 gst_thread_restore_thyself (GstObject *object,
592 GST_DEBUG (GST_CAT_THREAD,"gstthread: restore");
594 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
595 GST_OBJECT_CLASS (parent_class)->restore_thyself (object, self);
597 #endif /* GST_DISABLE_LOADSAVE */