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 /* gstbin_class->schedule = gst_thread_schedule_dummy; */
128 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_thread_set_property);
129 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_thread_get_property);
134 gst_thread_init (GstThread *thread)
136 const gchar *schedname;
137 GstScheduler *scheduler;
139 GST_DEBUG (GST_CAT_THREAD, "initializing thread");
141 /* we're a manager by default */
142 GST_FLAG_SET (thread, GST_BIN_FLAG_MANAGER);
143 GST_FLAG_SET (thread, GST_BIN_SELF_SCHEDULABLE);
145 schedname = gst_schedulerfactory_get_default_name ();
147 scheduler = gst_schedulerfactory_make (schedname, GST_ELEMENT (thread));
149 GST_ELEMENT_SCHED (thread) = scheduler;
151 gst_object_ref (GST_OBJECT (scheduler));
152 gst_object_sink (GST_OBJECT (scheduler));
154 thread->lock = g_mutex_new ();
155 thread->cond = g_cond_new ();
157 thread->ppid = getpid ();
158 thread->thread_id = -1;
162 gst_thread_dispose (GObject *object)
164 GstThread *thread = GST_THREAD (object);
166 GST_DEBUG (GST_CAT_REFCOUNTING, "dispose");
168 g_mutex_free (thread->lock);
169 g_cond_free (thread->cond);
171 G_OBJECT_CLASS (parent_class)->dispose (object);
173 if (GST_ELEMENT_SCHED (thread)) {
174 gst_object_unref (GST_OBJECT (GST_ELEMENT_SCHED (thread)));
179 gst_thread_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
181 /* it's not null if we got it, but it might not be ours */
182 g_return_if_fail (GST_IS_THREAD (object));
186 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
192 gst_thread_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
194 /* it's not null if we got it, but it might not be ours */
195 g_return_if_fail (GST_IS_THREAD (object));
199 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
207 * @name: the name of the thread
209 * Create a new thread with the given name.
211 * Returns: The new thread
214 gst_thread_new (const gchar *name)
216 return gst_elementfactory_make ("thread", name);
220 #define THR_INFO(format,args...) \
221 GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
222 GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
223 #define THR_DEBUG(format,args...) \
224 GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
225 GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
227 #define THR_INFO_MAIN(format,args...) \
228 GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
229 GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
230 #define THR_DEBUG_MAIN(format,args...) \
231 GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
232 GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
234 static GstElementStateReturn
235 gst_thread_update_state (GstThread *thread)
237 /* check for state change */
238 if (GST_STATE_PENDING(thread) != GST_STATE_VOID_PENDING) {
239 /* punt and change state on all the children */
240 if (GST_ELEMENT_CLASS (parent_class)->change_state)
241 return GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
244 return GST_STATE_SUCCESS;
248 static GstElementStateReturn
249 gst_thread_change_state (GstElement * element)
252 gboolean stateset = GST_STATE_SUCCESS;
254 pthread_t self = pthread_self ();
256 g_return_val_if_fail (GST_IS_THREAD (element), FALSE);
258 thread = GST_THREAD (element);
260 transition = GST_STATE_TRANSITION (element);
262 THR_INFO ("changing state from %s to %s",
263 gst_element_statename (GST_STATE (element)),
264 gst_element_statename (GST_STATE_PENDING (element)));
266 if (pthread_equal (self, thread->thread_id)) {
267 GST_DEBUG (GST_CAT_THREAD,
268 "no sync(" GST_DEBUG_THREAD_FORMAT "): setting own thread's state to spinning",
269 GST_DEBUG_THREAD_ARGS (thread->pid));
270 return gst_thread_update_state (thread);
273 switch (transition) {
274 case GST_STATE_NULL_TO_READY:
275 /* set the state to idle */
276 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
278 THR_DEBUG ("creating thread \"%s\"", GST_ELEMENT_NAME (element));
280 g_mutex_lock (thread->lock);
282 /* create the thread */
283 pthread_create (&thread->thread_id, NULL, gst_thread_main_loop, thread);
285 /* wait for it to 'spin up' */
286 THR_DEBUG ("waiting for child thread spinup");
287 g_cond_wait (thread->cond, thread->lock);
288 THR_DEBUG ("thread claims to be up");
289 g_mutex_unlock (thread->lock);
291 case GST_STATE_READY_TO_PAUSED:
292 THR_INFO ("readying thread");
293 g_mutex_lock (thread->lock);
294 THR_DEBUG ("signaling");
295 g_cond_signal (thread->cond);
296 THR_DEBUG ("waiting for ack");
297 g_cond_wait (thread->cond, thread->lock);
298 THR_DEBUG ("got ack");
299 g_mutex_unlock (thread->lock);
301 case GST_STATE_PAUSED_TO_PLAYING:
302 THR_DEBUG ("telling thread to start spinning");
303 g_mutex_lock (thread->lock);
304 THR_DEBUG ("signaling");
305 g_cond_signal (thread->cond);
306 THR_DEBUG ("waiting for ack");
307 g_cond_wait (thread->cond, thread->lock);
308 THR_DEBUG ("got ack");
309 g_mutex_unlock (thread->lock);
311 case GST_STATE_PLAYING_TO_PAUSED:
313 GList *elements = gst_bin_get_list (GST_BIN (thread));
315 THR_INFO ("pausing thread");
317 /* the following code ensures that the bottom half of thread will run
318 * to perform each elements' change_state() (by calling gstbin.c::
320 * + the pending state was already set by gstelement.c::set_state()
321 * + find every queue we manage, and signal its empty and full conditions
323 g_mutex_lock (thread->lock);
325 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
328 GstElement *element = GST_ELEMENT (elements->data);
331 THR_DEBUG (" element \"%s\"", GST_ELEMENT_NAME (element));
332 elements = g_list_next (elements);
333 if (GST_IS_QUEUE (element)) {
334 GstQueue *queue = GST_QUEUE (element);
335 /* FIXME make this more efficient by only waking queues that are asleep
336 * FIXME and only waking the appropriate condition (depending on if it's
337 * FIXME on up- or down-stream side)
338 * FIXME also make this more efficient by keeping list of managed queues
340 THR_DEBUG ("waking queue \"%s\"", GST_ELEMENT_NAME (element));
341 g_mutex_lock (queue->qlock);
342 GST_STATE_PENDING (element) = GST_STATE_PAUSED;
343 g_cond_signal (queue->not_full);
344 g_cond_signal (queue->not_empty);
345 g_mutex_unlock (queue->qlock);
348 GList *pads = GST_ELEMENT_PADS (element);
351 GstRealPad *peer = GST_REAL_PAD (GST_PAD_PEER (pads->data));
352 GstElement *peerelement;
354 pads = g_list_next (pads);
359 peerelement = GST_PAD_PARENT (peer);
361 continue; /* deal with case where there's no peer */
363 if (!GST_FLAG_IS_SET (peerelement, GST_ELEMENT_DECOUPLED)) {
364 GST_DEBUG (GST_CAT_THREAD, "peer element isn't DECOUPLED");
368 /* FIXME this needs to go away eventually */
369 if (!GST_IS_QUEUE (peerelement)) {
370 GST_DEBUG (GST_CAT_THREAD, "peer element isn't a Queue");
374 if (GST_ELEMENT_SCHED (peerelement) != GST_ELEMENT_SCHED (thread)) {
375 GstQueue *queue = GST_QUEUE (peerelement);
377 THR_DEBUG (" element \"%s\" has pad cross sched boundary", GST_ELEMENT_NAME (element));
379 g_mutex_lock (queue->qlock);
380 g_cond_signal (queue->not_full);
381 g_cond_signal (queue->not_empty);
382 g_mutex_unlock (queue->qlock);
387 THR_DEBUG ("telling thread to pause, signaling");
388 g_cond_signal (thread->cond);
389 THR_DEBUG ("waiting for ack");
390 g_cond_wait (thread->cond, thread->lock);
391 THR_DEBUG ("got ack");
392 g_mutex_unlock (thread->lock);
395 case GST_STATE_READY_TO_NULL:
396 THR_DEBUG ("telling thread to pause (null) - and joining");
397 /* MattH FIXME revisit */
398 g_mutex_lock (thread->lock);
399 THR_DEBUG ("signaling");
400 g_cond_signal (thread->cond);
401 THR_DEBUG ("waiting for ack");
402 g_cond_wait (thread->cond, thread->lock);
403 THR_DEBUG ("got ack");
404 pthread_join (thread->thread_id, NULL);
405 thread->thread_id = -1;
406 g_mutex_unlock (thread->lock);
408 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
409 GST_FLAG_UNSET (thread, GST_THREAD_STATE_STARTED);
410 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
413 case GST_STATE_PAUSED_TO_READY:
414 THR_DEBUG ("telling thread to stop spinning");
415 g_mutex_lock (thread->lock);
416 THR_DEBUG ("signaling");
417 g_cond_signal (thread->cond);
418 THR_DEBUG ("waiting for ack");
419 g_cond_wait (thread->cond, thread->lock);
420 THR_DEBUG ("got ack");
421 g_mutex_unlock (thread->lock);
425 GST_DEBUG_ELEMENT (GST_CAT_THREAD, element, "UNHANDLED STATE CHANGE! %x", transition);
433 * gst_thread_main_loop:
434 * @arg: the thread to start
436 * The main loop of the thread. The thread will iterate
437 * while the state is GST_THREAD_STATE_SPINNING
440 gst_thread_main_loop (void *arg)
442 GstThread *thread = GST_THREAD (arg);
445 g_mutex_lock (thread->lock);
447 gst_scheduler_setup (GST_ELEMENT_SCHED (thread));
448 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
450 thread->pid = getpid();
451 THR_INFO_MAIN("thread is running");
453 /* first we need to change the state of all the children */
454 if (GST_ELEMENT_CLASS (parent_class)->change_state) {
455 stateset = GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
457 if (stateset != GST_STATE_SUCCESS) {
458 THR_DEBUG_MAIN ("state change of children failed");
463 THR_DEBUG_MAIN ("indicating spinup");
464 g_cond_signal (thread->cond);
465 /* don't unlock the mutex because we hold it into the top of the while loop */
466 THR_DEBUG_MAIN ("thread has indicated spinup to parent process");
468 /***** THREAD IS NOW IN READY STATE *****/
470 while (!GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING)) {
471 /* NOTE we hold the thread lock at this point */
472 /* what we do depends on what state we're in */
473 switch (GST_STATE (thread)) {
474 /* NOTE: cannot be in NULL, we're not running in that state at all */
475 case GST_STATE_READY:
476 /* wait to be set to either the NULL or PAUSED states */
477 THR_DEBUG_MAIN ("thread in %s state, waiting for either %s or %s",
478 gst_element_statename (GST_STATE_READY),
479 gst_element_statename (GST_STATE_NULL),
480 gst_element_statename (GST_STATE_PAUSED));
481 g_cond_wait (thread->cond,thread->lock);
483 /* this must have happened by a state change in the thread context */
484 if (GST_STATE_PENDING (thread) != GST_STATE_NULL &&
485 GST_STATE_PENDING (thread) != GST_STATE_PAUSED) {
486 g_cond_signal (thread->cond);
490 /* been signaled, we need to state transition now and signal back */
491 gst_thread_update_state (thread);
492 THR_DEBUG_MAIN ("done with state transition, signaling back to parent process");
493 g_cond_signal (thread->cond);
494 /* now we decide what to do next */
495 if (GST_STATE (thread) == GST_STATE_NULL) {
496 /* REAPING must be set, we can simply break this iteration */
497 GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
500 case GST_STATE_PAUSED:
501 /* wait to be set to either the READY or PLAYING states */
502 THR_DEBUG_MAIN("thread in %s state, waiting for either %s or %s",
503 gst_element_statename (GST_STATE_PAUSED),
504 gst_element_statename (GST_STATE_READY),
505 gst_element_statename (GST_STATE_PLAYING));
506 g_cond_wait (thread->cond,thread->lock);
508 /* this must have happened by a state change in the thread context */
509 if (GST_STATE_PENDING (thread) != GST_STATE_READY &&
510 GST_STATE_PENDING (thread) != GST_STATE_PLAYING) {
511 g_cond_signal (thread->cond);
515 /* been signaled, we need to state transition now and signal back */
516 gst_thread_update_state (thread);
517 /* now we decide what to do next */
518 if (GST_STATE (thread) != GST_STATE_PLAYING) {
519 /* either READY or the state change failed for some reason */
520 g_cond_signal (thread->cond);
524 GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
525 /* PLAYING is coming up, so we can now start spinning */
526 while (GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING)) {
529 g_cond_signal (thread->cond);
530 g_mutex_unlock (thread->lock);
531 status = gst_bin_iterate (GST_BIN (thread));
532 g_mutex_lock (thread->lock);
533 /* g_cond_signal(thread->cond); */
535 if (!status || GST_STATE_PENDING (thread) != GST_STATE_VOID_PENDING)
536 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
538 /* looks like we were stopped because of a statechange */
539 if (GST_STATE_PENDING (thread)) {
540 gst_thread_update_state (thread);
542 /* once we're here, SPINNING has stopped, we should signal that we're done */
543 THR_DEBUG_MAIN ("SPINNING stopped, signaling back to parent process");
544 g_cond_signal (thread->cond);
545 /* now we can wait for PAUSED */
548 case GST_STATE_PLAYING:
549 /* wait to be set to PAUSED */
550 THR_DEBUG_MAIN ("thread in %s state, waiting for %s",
551 gst_element_statename(GST_STATE_PLAYING),
552 gst_element_statename(GST_STATE_PAUSED));
553 g_cond_wait (thread->cond,thread->lock);
555 /* been signaled, we need to state transition now and signal back */
556 gst_thread_update_state (thread);
557 g_cond_signal (thread->cond);
558 /* now we decide what to do next */
559 /* there's only PAUSED, we we just wait for it */
562 THR_DEBUG_MAIN ("thread in %s state, preparing to die",
563 gst_element_statename(GST_STATE_NULL));
564 GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
567 g_assert_not_reached ();
571 /* we need to destroy the scheduler here bacause it has mapped it's
572 * stack into the threads stack space */
573 gst_scheduler_reset (GST_ELEMENT_SCHED (thread));
575 /* since we don't unlock at the end of the while loop, do it here */
576 g_mutex_unlock (thread->lock);
578 GST_INFO (GST_CAT_THREAD, "gstthread: thread \"%s\" is stopped",
579 GST_ELEMENT_NAME (thread));
583 #ifndef GST_DISABLE_LOADSAVE
585 gst_thread_save_thyself (GstObject *object,
588 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
589 GST_OBJECT_CLASS (parent_class)->save_thyself (object, self);
594 gst_thread_restore_thyself (GstObject *object,
597 GST_DEBUG (GST_CAT_THREAD,"gstthread: restore");
599 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
600 GST_OBJECT_CLASS (parent_class)->restore_thyself (object, self);
602 #endif /* GST_DISABLE_LOADSAVE */