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)
137 GST_DEBUG (GST_CAT_THREAD,"initializing thread\n");
139 /* we're a manager by default */
140 GST_FLAG_SET (thread, GST_BIN_FLAG_MANAGER);
142 thread->lock = g_mutex_new();
143 thread->cond = g_cond_new();
145 GST_ELEMENT_SCHED(thread) = gst_schedulerfactory_make ("basic", GST_ELEMENT(thread));
146 GST_DEBUG(GST_CAT_THREAD, "thread's scheduler is %p\n",GST_ELEMENT_SCHED(thread));
148 thread->ppid = getpid();
149 thread->thread_id = -1;
151 /* gst_element_set_manager(GST_ELEMENT(thread),GST_ELEMENT(thread)); */
155 gst_thread_dispose (GObject *object)
157 GstThread *thread = GST_THREAD (object);
159 GST_DEBUG (GST_CAT_REFCOUNTING,"dispose\n");
161 g_mutex_free (thread->lock);
162 g_cond_free (thread->cond);
164 G_OBJECT_CLASS (parent_class)->dispose (object);
166 gst_object_destroy (GST_OBJECT (GST_ELEMENT_SCHED (thread)));
167 gst_object_unref (GST_OBJECT (GST_ELEMENT_SCHED (thread)));
172 gst_thread_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
174 /* it's not null if we got it, but it might not be ours */
175 g_return_if_fail (GST_IS_THREAD (object));
179 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
185 gst_thread_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
187 /* it's not null if we got it, but it might not be ours */
188 g_return_if_fail (GST_IS_THREAD (object));
192 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
200 * @name: the name of the thread
202 * Create a new thread with the given name.
204 * Returns: The new thread
207 gst_thread_new (const gchar *name)
209 return gst_elementfactory_make ("thread", name);
213 #define THR_INFO(format,args...) \
214 GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
215 GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
216 #define THR_DEBUG(format,args...) \
217 GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
218 GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
220 #define THR_INFO_MAIN(format,args...) \
221 GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
222 GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
223 #define THR_DEBUG_MAIN(format,args...) \
224 GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
225 GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
227 static GstElementStateReturn
228 gst_thread_update_state (GstThread *thread)
230 /* check for state change */
231 if (GST_STATE_PENDING(thread) != GST_STATE_VOID_PENDING) {
232 /* punt and change state on all the children */
233 if (GST_ELEMENT_CLASS (parent_class)->change_state)
234 return GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
237 return GST_STATE_SUCCESS;
241 static GstElementStateReturn
242 gst_thread_change_state (GstElement * element)
245 gboolean stateset = GST_STATE_SUCCESS;
247 pthread_t self = pthread_self ();
249 g_return_val_if_fail (GST_IS_THREAD (element), FALSE);
251 thread = GST_THREAD (element);
253 transition = GST_STATE_TRANSITION (element);
255 THR_INFO ("changing state from %s to %s",
256 gst_element_statename (GST_STATE (element)),
257 gst_element_statename (GST_STATE_PENDING (element)));
259 if (pthread_equal (self, thread->thread_id)) {
260 GST_DEBUG (GST_CAT_THREAD,
261 "no sync(" GST_DEBUG_THREAD_FORMAT "): setting own thread's state to spinning\n",
262 GST_DEBUG_THREAD_ARGS (thread->pid));
263 return gst_thread_update_state (thread);
266 switch (transition) {
267 case GST_STATE_NULL_TO_READY:
268 /* set the state to idle */
269 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
271 THR_DEBUG ("creating thread \"%s\"\n", GST_ELEMENT_NAME (element));
273 g_mutex_lock (thread->lock);
275 /* create the thread */
276 pthread_create (&thread->thread_id, NULL, gst_thread_main_loop, thread);
278 /* wait for it to 'spin up' */
279 THR_DEBUG ("waiting for child thread spinup\n");
280 g_cond_wait (thread->cond, thread->lock);
281 THR_DEBUG ("thread claims to be up\n");
282 g_mutex_unlock (thread->lock);
284 case GST_STATE_READY_TO_PAUSED:
285 THR_INFO ("readying thread");
286 g_mutex_lock (thread->lock);
287 THR_DEBUG ("signaling\n");
288 g_cond_signal (thread->cond);
289 THR_DEBUG ("waiting for ack\n");
290 g_cond_wait (thread->cond, thread->lock);
291 THR_DEBUG ("got ack\n");
292 g_mutex_unlock (thread->lock);
294 case GST_STATE_PAUSED_TO_PLAYING:
295 THR_DEBUG ("telling thread to start spinning\n");
296 g_mutex_lock (thread->lock);
297 THR_DEBUG ("signaling\n");
298 g_cond_signal (thread->cond);
299 THR_DEBUG ("waiting for ack\n");
300 g_cond_wait (thread->cond, thread->lock);
301 THR_DEBUG ("got ack\n");
302 g_mutex_unlock (thread->lock);
304 case GST_STATE_PLAYING_TO_PAUSED:
306 GList *elements = (element->sched)->elements;
308 THR_INFO ("pausing thread");
310 /* the following code ensures that the bottom half of thread will run
311 * to perform each elements' change_state() (by calling gstbin.c::
313 * + the pending state was already set by gstelement.c::set_state()
314 * + find every queue we manage, and signal its empty and full conditions
316 g_mutex_lock (thread->lock);
318 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
321 GstElement *e = GST_ELEMENT (elements->data);
324 THR_DEBUG (" element \"%s\"\n", GST_ELEMENT_NAME (e));
325 elements = g_list_next (elements);
326 if (GST_IS_QUEUE (e)) {
327 /* FIXME make this more efficient by only waking queues that are asleep
328 * FIXME and only waking the appropriate condition (depending on if it's
329 * FIXME on up- or down-stream side)
330 * FIXME also make this more efficient by keeping list of managed queues
332 THR_DEBUG ("waking queue \"%s\"\n", GST_ELEMENT_NAME (e));
333 gst_element_set_state (e, GST_STATE_PAUSED);
336 GList *pads = GST_ELEMENT_PADS (e);
340 GstElement *peerelement;
341 GstPad *p = GST_PAD (pads->data);
343 pads = g_list_next (pads);
345 peer = GST_PAD_PEER (p);
349 peerelement = GST_PAD_PARENT (peer);
351 continue; /* deal with case where there's no peer */
353 if (!GST_FLAG_IS_SET (peerelement, GST_ELEMENT_DECOUPLED)) {
354 GST_DEBUG (GST_CAT_THREAD, "peer element isn't DECOUPLED\n");
358 /* FIXME this needs to go away eventually */
359 if (!GST_IS_QUEUE (peerelement)) {
360 GST_DEBUG (GST_CAT_THREAD, "peer element isn't a Queue\n");
364 if (GST_ELEMENT_SCHED (peerelement) != GST_ELEMENT_SCHED (thread)) {
365 GstQueue *queue = GST_QUEUE (peerelement);
367 THR_DEBUG (" element \"%s\" has pad cross sched boundary\n", GST_ELEMENT_NAME (e));
369 g_mutex_lock (queue->qlock);
370 g_cond_signal (queue->not_full);
371 g_cond_signal (queue->not_empty);
372 g_mutex_unlock (queue->qlock);
377 THR_DEBUG ("telling thread to pause, signaling\n");
378 g_cond_signal (thread->cond);
379 THR_DEBUG ("waiting for ack\n");
380 g_cond_wait (thread->cond, thread->lock);
381 THR_DEBUG ("got ack\n");
382 g_mutex_unlock (thread->lock);
385 case GST_STATE_READY_TO_NULL:
386 THR_DEBUG ("telling thread to pause (null) - and joining\n");
387 /* MattH FIXME revisit */
388 g_mutex_lock (thread->lock);
389 THR_DEBUG ("signaling\n");
390 g_cond_signal (thread->cond);
391 THR_DEBUG ("waiting for ack\n");
392 g_cond_wait (thread->cond, thread->lock);
393 THR_DEBUG ("got ack\n");
394 pthread_join (thread->thread_id, NULL);
395 thread->thread_id = -1;
396 g_mutex_unlock (thread->lock);
398 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
399 GST_FLAG_UNSET (thread, GST_THREAD_STATE_STARTED);
400 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
403 case GST_STATE_PAUSED_TO_READY:
404 THR_DEBUG ("telling thread to stop spinning\n");
405 g_mutex_lock (thread->lock);
406 THR_DEBUG ("signaling\n");
407 g_cond_signal (thread->cond);
408 THR_DEBUG ("waiting for ack\n");
409 g_cond_wait (thread->cond, thread->lock);
410 THR_DEBUG ("got ack\n");
411 g_mutex_unlock (thread->lock);
415 GST_DEBUG_ELEMENT (GST_CAT_THREAD, element, "UNHANDLED STATE CHANGE! %x\n", transition);
423 * gst_thread_main_loop:
424 * @arg: the thread to start
426 * The main loop of the thread. The thread will iterate
427 * while the state is GST_THREAD_STATE_SPINNING
430 gst_thread_main_loop (void *arg)
432 GstThread *thread = GST_THREAD (arg);
435 g_mutex_lock (thread->lock);
437 gst_scheduler_setup (GST_ELEMENT_SCHED (thread));
438 GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
440 thread->pid = getpid();
441 THR_INFO_MAIN("thread is running");
443 /* first we need to change the state of all the children */
444 if (GST_ELEMENT_CLASS (parent_class)->change_state) {
445 stateset = GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
447 if (stateset != GST_STATE_SUCCESS) {
448 THR_DEBUG_MAIN ("state change of children failed\n");
453 THR_DEBUG_MAIN ("indicating spinup\n");
454 g_cond_signal (thread->cond);
455 /* don't unlock the mutex because we hold it into the top of the while loop */
456 THR_DEBUG_MAIN ("thread has indicated spinup to parent process\n");
458 /***** THREAD IS NOW IN READY STATE *****/
460 while (!GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING)) {
461 /* NOTE we hold the thread lock at this point */
462 /* what we do depends on what state we're in */
463 switch (GST_STATE (thread)) {
464 /* NOTE: cannot be in NULL, we're not running in that state at all */
465 case GST_STATE_READY:
466 /* wait to be set to either the NULL or PAUSED states */
467 THR_DEBUG_MAIN ("thread in %s state, waiting for either %s or %s\n",
468 gst_element_statename (GST_STATE_READY),
469 gst_element_statename (GST_STATE_NULL),
470 gst_element_statename (GST_STATE_PAUSED));
471 g_cond_wait (thread->cond,thread->lock);
473 g_assert (GST_STATE_PENDING (thread) == GST_STATE_NULL ||
474 GST_STATE_PENDING (thread) == GST_STATE_PAUSED);
476 /* been signaled, we need to state transition now and signal back */
477 gst_thread_update_state (thread);
478 THR_DEBUG_MAIN ("done with state transition, signaling back to parent process\n");
479 g_cond_signal (thread->cond);
480 /* now we decide what to do next */
481 if (GST_STATE (thread) == GST_STATE_NULL) {
482 /* REAPING must be set, we can simply break this iteration */
483 GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
486 case GST_STATE_PAUSED:
487 /* wait to be set to either the READY or PLAYING states */
488 THR_DEBUG_MAIN("thread in %s state, waiting for either %s or %s\n",
489 gst_element_statename (GST_STATE_PAUSED),
490 gst_element_statename (GST_STATE_READY),
491 gst_element_statename (GST_STATE_PLAYING));
492 g_cond_wait (thread->cond,thread->lock);
494 g_assert (GST_STATE_PENDING (thread) == GST_STATE_READY ||
495 GST_STATE_PENDING (thread) == GST_STATE_PLAYING);
497 /* been signaled, we need to state transition now and signal back */
498 gst_thread_update_state (thread);
499 /* now we decide what to do next */
500 if (GST_STATE (thread) != GST_STATE_PLAYING) {
501 /* either READY or the state change failed for some reason */
502 g_cond_signal (thread->cond);
506 GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
507 /* PLAYING is coming up, so we can now start spinning */
508 while (GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING)) {
511 g_cond_signal (thread->cond);
512 g_mutex_unlock (thread->lock);
513 status = gst_bin_iterate (GST_BIN (thread));
514 g_mutex_lock (thread->lock);
515 /* g_cond_signal(thread->cond); */
517 if (!status || GST_STATE_PENDING (thread) != GST_STATE_VOID_PENDING)
518 GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
520 /* looks like we were stopped because of a statechange */
521 if (GST_STATE_PENDING (thread)) {
522 gst_thread_update_state (thread);
524 /* once we're here, SPINNING has stopped, we should signal that we're done */
525 THR_DEBUG_MAIN ("SPINNING stopped, signaling back to parent process\n");
526 g_cond_signal (thread->cond);
527 /* now we can wait for PAUSED */
530 case GST_STATE_PLAYING:
531 /* wait to be set to PAUSED */
532 THR_DEBUG_MAIN ("thread in %s state, waiting for %s\n",
533 gst_element_statename(GST_STATE_PLAYING),
534 gst_element_statename(GST_STATE_PAUSED));
535 g_cond_wait (thread->cond,thread->lock);
537 /* been signaled, we need to state transition now and signal back */
538 gst_thread_update_state (thread);
539 g_cond_signal (thread->cond);
540 /* now we decide what to do next */
541 /* there's only PAUSED, we we just wait for it */
544 THR_DEBUG_MAIN ("thread in %s state, preparing to die\n",
545 gst_element_statename(GST_STATE_NULL));
546 GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
549 g_assert_not_reached ();
553 /* we need to destroy the scheduler here bacause it has mapped it's
554 * stack into the threads stack space */
555 gst_scheduler_reset (GST_ELEMENT_SCHED (thread));
557 /* since we don't unlock at the end of the while loop, do it here */
558 g_mutex_unlock (thread->lock);
560 GST_INFO (GST_CAT_THREAD, "gstthread: thread \"%s\" is stopped",
561 GST_ELEMENT_NAME (thread));
565 #ifndef GST_DISABLE_LOADSAVE
567 gst_thread_save_thyself (GstObject *object,
570 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
571 GST_OBJECT_CLASS (parent_class)->save_thyself (object, self);
576 gst_thread_restore_thyself (GstObject *object,
579 GST_DEBUG (GST_CAT_THREAD,"gstthread: restore\n");
581 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
582 GST_OBJECT_CLASS (parent_class)->restore_thyself (object, self);
584 #endif /* GST_DISABLE_LOADSAVE */