gstreamer/gst/gstthread.c
Thomas Vander Stichele 8f0fda26d0 revert state change changes as agreed so we can rework them gradually
Original commit message from CVS:
revert state change changes as agreed so we can rework them gradually
2004-07-29 20:33:49 +00:00

637 lines
19 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* gstthread.c: Threaded container object
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "gst_private.h"
#include "gstthread.h"
#include "gstmarshal.h"
#include "gstscheduler.h"
#include "gstinfo.h"
#define GST_CAT_DEFAULT GST_CAT_THREAD
#define STACK_SIZE 0x200000
static GstElementDetails gst_thread_details =
GST_ELEMENT_DETAILS ("Threaded container",
"Generic/Bin",
"Container that creates/manages a thread",
"Erik Walthinsen <omega@cse.ogi.edu>, "
"Benjamin Otte <in7y118@informatik.uni-hamburg.de");
/* Thread signals and args */
enum
{
SHUTDOWN,
/* FILL ME */
LAST_SIGNAL
};
enum
{
SPINUP = 0,
STATECHANGE,
STARTUP
};
enum
{
ARG_0,
ARG_PRIORITY
};
static void gst_thread_base_init (gpointer g_class);
static void gst_thread_class_init (gpointer g_class, gpointer class_data);
static void gst_thread_init (GTypeInstance * instance, gpointer g_class);
static void gst_thread_dispose (GObject * object);
static void gst_thread_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_thread_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstElementStateReturn gst_thread_change_state (GstElement * element);
static void gst_thread_child_state_change (GstBin * bin,
GstElementState oldstate, GstElementState newstate, GstElement * element);
static void gst_thread_catch (GstThread * thread);
static void gst_thread_release (GstThread * thread);
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr gst_thread_save_thyself (GstObject * object,
xmlNodePtr parent);
static void gst_thread_restore_thyself (GstObject * object, xmlNodePtr self);
#endif
static void *gst_thread_main_loop (void *arg);
#define GST_TYPE_THREAD_PRIORITY (gst_thread_priority_get_type())
static GType
gst_thread_priority_get_type (void)
{
static GType thread_priority_type = 0;
static GEnumValue thread_priority[] = {
{G_THREAD_PRIORITY_LOW, "LOW", "Low Priority Scheduling"},
{G_THREAD_PRIORITY_NORMAL, "NORMAL", "Normal Scheduling"},
{G_THREAD_PRIORITY_HIGH, "HIGH", "High Priority Scheduling"},
{G_THREAD_PRIORITY_URGENT, "URGENT", "Urgent Scheduling"},
{0, NULL, NULL},
};
if (!thread_priority_type) {
thread_priority_type =
g_enum_register_static ("GstThreadPriority", thread_priority);
}
return thread_priority_type;
}
static GstBinClass *parent_class = NULL;
static guint gst_thread_signals[LAST_SIGNAL] = { 0 };
GPrivate *gst_thread_current;
GType
gst_thread_get_type (void)
{
static GType thread_type = 0;
if (!thread_type) {
static const GTypeInfo thread_info = {
sizeof (GstThreadClass),
gst_thread_base_init,
NULL,
gst_thread_class_init,
NULL,
NULL,
sizeof (GstThread),
0,
gst_thread_init,
NULL
};
thread_type = g_type_register_static (GST_TYPE_BIN, "GstThread",
&thread_info, 0);
}
return thread_type;
}
static void
gst_thread_base_init (gpointer g_class)
{
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_set_details (gstelement_class, &gst_thread_details);
}
static void
do_nothing (gpointer hi)
{
}
static void
gst_thread_class_init (gpointer g_class, gpointer class_data)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (g_class);
#ifndef GST_DISABLE_LOADSAVE
GstObjectClass *gstobject_class = GST_OBJECT_CLASS (g_class);
#endif
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
GstBinClass *gstbin_class = GST_BIN_CLASS (g_class);
GstThreadClass *klass = GST_THREAD_CLASS (g_class);
/* setup gst_thread_current */
gst_thread_current = g_private_new (do_nothing);
parent_class = g_type_class_peek_parent (g_class);
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PRIORITY,
g_param_spec_enum ("priority", "Scheduling Policy",
"The scheduling priority of the thread", GST_TYPE_THREAD_PRIORITY,
G_THREAD_PRIORITY_NORMAL, G_PARAM_READWRITE));
gst_thread_signals[SHUTDOWN] =
g_signal_new ("shutdown", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstThreadClass, shutdown), NULL, NULL,
gst_marshal_VOID__VOID, G_TYPE_NONE, 0);
gobject_class->dispose = gst_thread_dispose;
#ifndef GST_DISABLE_LOADSAVE
gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_thread_save_thyself);
gstobject_class->restore_thyself =
GST_DEBUG_FUNCPTR (gst_thread_restore_thyself);
#endif
gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_thread_change_state);
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_thread_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_thread_get_property);
gstbin_class->child_state_change =
GST_DEBUG_FUNCPTR (gst_thread_child_state_change);
}
static void
gst_thread_init (GTypeInstance * instance, gpointer g_class)
{
GstScheduler *scheduler;
GstThread *thread = GST_THREAD (instance);
GST_DEBUG ("initializing thread");
/* threads are managing bins and iterate themselves */
/* CR1: the GstBin code checks these flags */
GST_FLAG_SET (thread, GST_BIN_FLAG_MANAGER);
GST_FLAG_SET (thread, GST_BIN_SELF_SCHEDULABLE);
scheduler = gst_scheduler_factory_make (NULL, GST_ELEMENT (thread));
g_assert (scheduler);
thread->lock = g_mutex_new ();
thread->cond = g_cond_new ();
thread->thread_id = (GThread *) NULL; /* set in NULL -> READY */
thread->priority = G_THREAD_PRIORITY_NORMAL;
}
static void
gst_thread_dispose (GObject * object)
{
GstThread *thread = GST_THREAD (object);
GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "GstThread: dispose");
G_OBJECT_CLASS (parent_class)->dispose (object);
g_assert (GST_STATE (thread) == GST_STATE_NULL);
GST_CAT_DEBUG (GST_CAT_REFCOUNTING, "GstThread: dispose, freeing locks");
g_mutex_free (thread->lock);
g_cond_free (thread->cond);
gst_object_replace ((GstObject **) & GST_ELEMENT_SCHED (thread), NULL);
}
/**
* gst_thread_set_priority:
* @thread: the thread to change
* @priority: the new priority for the thread
*
* change the thread's priority
*/
void
gst_thread_set_priority (GstThread * thread, GThreadPriority priority)
{
g_return_if_fail (GST_IS_THREAD (thread));
thread->priority = priority;
}
static void
gst_thread_set_property (GObject * object, guint prop_id, const GValue * value,
GParamSpec * pspec)
{
GstThread *thread;
thread = GST_THREAD (object);
switch (prop_id) {
case ARG_PRIORITY:
thread->priority = g_value_get_enum (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_thread_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstThread *thread;
thread = GST_THREAD (object);
switch (prop_id) {
case ARG_PRIORITY:
g_value_set_enum (value, thread->priority);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/**
* gst_thread_new:
* @name: the name of the thread
*
* Create a new thread with the given name.
*
* Returns: The new thread
*/
GstElement *
gst_thread_new (const gchar * name)
{
return gst_element_factory_make ("thread", name);
}
/**
* gst_thread_get_current:
*
* Gets the current GstThread.
*
* Returns: The current GstThread or NULL if you are not running inside a
* #GstThread.
*/
GstThread *
gst_thread_get_current (void)
{
return (GstThread *) g_private_get (gst_thread_current);
}
static inline void
gst_thread_release_children_locks (GstThread * thread)
{
GstRealPad *peer = NULL;
GstElement *peerelement;
GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread));
while (elements) {
GstElement *element = GST_ELEMENT (elements->data);
GList *pads;
g_assert (element);
GST_DEBUG_OBJECT (thread, "waking element \"%s\"",
GST_ELEMENT_NAME (element));
elements = g_list_next (elements);
if (!gst_element_release_locks (element))
g_warning ("element %s could not release locks",
GST_ELEMENT_NAME (element));
pads = GST_ELEMENT_PADS (element);
while (pads) {
if (GST_PAD_PEER (pads->data)) {
peer = GST_REAL_PAD (GST_PAD_PEER (pads->data));
pads = g_list_next (pads);
} else {
pads = g_list_next (pads);
continue;
}
if (!peer)
continue;
peerelement = GST_PAD_PARENT (peer);
if (!peerelement)
continue; /* FIXME: deal with case where there's no peer */
if (GST_ELEMENT_SCHED (peerelement) != GST_ELEMENT_SCHED (thread)) {
GST_LOG_OBJECT (thread, "element \"%s\" has pad cross sched boundary",
GST_ELEMENT_NAME (element));
GST_LOG_OBJECT (thread, "waking element \"%s\"",
GST_ELEMENT_NAME (peerelement));
if (!gst_element_release_locks (peerelement))
g_warning ("element %s could not release locks",
GST_ELEMENT_NAME (peerelement));
}
}
}
}
/* stops the main thread, if there is one and grabs the thread's mutex */
static void
gst_thread_catch (GstThread * thread)
{
gboolean wait;
if (thread == gst_thread_get_current ()) {
/* we're trying to catch ourself */
if (!GST_FLAG_IS_SET (thread, GST_THREAD_MUTEX_LOCKED)) {
GST_DEBUG_OBJECT (thread, "catching itself, grabbing lock");
g_mutex_lock (thread->lock);
GST_FLAG_SET (thread, GST_THREAD_MUTEX_LOCKED);
}
GST_DEBUG_OBJECT (thread, "catching itself");
GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
} else {
GST_DEBUG_OBJECT (thread, "catching thread, grabbing lock");
/* another thread is trying to catch us */
g_mutex_lock (thread->lock);
wait = !GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING);
while (!wait) {
GTimeVal tv;
GST_LOG_OBJECT (thread, "catching thread...");
GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
g_cond_signal (thread->cond);
gst_thread_release_children_locks (thread);
g_get_current_time (&tv);
g_time_val_add (&tv, 1000); /* wait a millisecond to catch the thread */
wait = g_cond_timed_wait (thread->cond, thread->lock, &tv);
}
GST_LOG_OBJECT (thread, "caught thread");
}
g_assert (!GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING));
}
static void
gst_thread_release (GstThread * thread)
{
if (thread != gst_thread_get_current ()) {
g_cond_signal (thread->cond);
g_mutex_unlock (thread->lock);
}
}
static GstElementStateReturn
gst_thread_change_state (GstElement * element)
{
GstThread *thread;
GstElementStateReturn ret;
gint transition;
g_return_val_if_fail (GST_IS_THREAD (element), GST_STATE_FAILURE);
transition = GST_STATE_TRANSITION (element);
thread = GST_THREAD (element);
GST_DEBUG_OBJECT (element, "changing state from %s to %s",
gst_element_state_get_name (GST_STATE (element)),
gst_element_state_get_name (GST_STATE_PENDING (element)));
gst_thread_catch (thread);
/* FIXME: (or GStreamers ideas about "threading"): the element variables are
commonly accessed by multiple threads at the same time (see bug #111146
for an example) */
if (transition != GST_STATE_TRANSITION (element)) {
g_warning ("inconsistent state information, fix threading please");
}
switch (transition) {
case GST_STATE_NULL_TO_READY:
/* create the thread */
GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
thread->thread_id = g_thread_create_full (gst_thread_main_loop,
thread, STACK_SIZE, FALSE, TRUE, thread->priority, NULL);
if (!thread->thread_id) {
GST_ERROR_OBJECT (element, "g_thread_create_full failed");
goto error_out;
}
GST_LOG_OBJECT (element, "GThread created");
/* wait for it to 'spin up' */
g_cond_wait (thread->cond, thread->lock);
break;
case GST_STATE_READY_TO_PAUSED:
break;
case GST_STATE_PAUSED_TO_PLAYING:
{
/* FIXME: recurse into sub-bins */
GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread));
while (elements) {
gst_element_enable_threadsafe_properties ((GstElement *) elements->
data);
elements = g_list_next (elements);
}
/* reset self to spinning */
if (thread == gst_thread_get_current ())
GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
break;
}
case GST_STATE_PLAYING_TO_PAUSED:
{
GList *elements = (GList *) gst_bin_get_list (GST_BIN (thread));
while (elements) {
gst_element_disable_threadsafe_properties ((GstElement *) elements->
data);
elements = g_list_next (elements);
}
break;
}
case GST_STATE_PAUSED_TO_READY:
break;
case GST_STATE_READY_TO_NULL:
/* we can't join the threads here, because this could have been triggered
by ourself (ouch) */
GST_LOG_OBJECT (thread, "destroying GThread %p", thread->thread_id);
GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
thread->thread_id = NULL;
if (thread == gst_thread_get_current ()) {
/* or should we continue? */
g_warning
("Thread %s is destroying itself. Function call will not return!",
GST_ELEMENT_NAME (thread));
gst_scheduler_reset (GST_ELEMENT_SCHED (thread));
/* unlock and signal - we are out */
gst_thread_release (thread);
GST_INFO_OBJECT (thread, "GThread %p is exiting", g_thread_self ());
g_signal_emit (G_OBJECT (thread), gst_thread_signals[SHUTDOWN], 0);
g_thread_exit (NULL);
}
/* now wait for the thread to destroy itself */
g_cond_signal (thread->cond);
g_cond_wait (thread->cond, thread->lock);
/* it should be dead now */
break;
default:
break;
}
if (GST_ELEMENT_CLASS (parent_class)->change_state) {
ret = GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT (thread));
} else {
ret = GST_STATE_SUCCESS;
}
gst_thread_release (thread);
return ret;
error_out:
GST_CAT_DEBUG (GST_CAT_STATES, "changing state from %s to %s failed for %s",
gst_element_state_get_name (GST_STATE (element)),
gst_element_state_get_name (GST_STATE_PENDING (element)),
GST_ELEMENT_NAME (element));
gst_thread_release (thread);
return GST_STATE_FAILURE;
}
/* state changes work this way: We grab the lock and stop the thread from
spinning (via gst_thread_catch) - then we change the state. After that the
thread may spin on. */
static void
gst_thread_child_state_change (GstBin * bin, GstElementState oldstate,
GstElementState newstate, GstElement * element)
{
GST_LOG_OBJECT (bin, "(from thread %s) child %s changed state from %s to %s",
gst_thread_get_current ()? GST_ELEMENT_NAME (gst_thread_get_current ()) :
"(none)", GST_ELEMENT_NAME (element),
gst_element_state_get_name (oldstate),
gst_element_state_get_name (newstate));
if (parent_class->child_state_change)
parent_class->child_state_change (bin, oldstate, newstate, element);
/* We'll wake up the main thread now. Note that we can't lock the thread here,
because we might be called from inside gst_thread_change_state when holding
the lock. But this doesn't cause any problems. */
if (newstate == GST_STATE_PLAYING)
g_cond_signal (GST_THREAD (bin)->cond);
}
/**
* gst_thread_main_loop:
* @arg: the thread to start
*
* The main loop of the thread. The thread will iterate
* while the state is GST_THREAD_STATE_SPINNING.
*/
static void *
gst_thread_main_loop (void *arg)
{
GstThread *thread = NULL;
gboolean status;
GstScheduler *sched;
thread = GST_THREAD (arg);
g_mutex_lock (thread->lock);
GST_LOG_OBJECT (thread, "Started main loop");
/* initialize gst_thread_current */
g_private_set (gst_thread_current, thread);
/* set up the element's scheduler */
gst_scheduler_setup (GST_ELEMENT_SCHED (thread));
GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
g_cond_signal (thread->cond);
while (!(GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING))) {
if (GST_STATE (thread) == GST_STATE_PLAYING) {
GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
status = TRUE;
GST_LOG_OBJECT (thread, "starting to iterate");
while (status && GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING)) {
g_mutex_unlock (thread->lock);
status = gst_bin_iterate (GST_BIN (thread));
if (!status)
GST_DEBUG_OBJECT (thread, "iterate returned false");
if (GST_FLAG_IS_SET (thread, GST_THREAD_MUTEX_LOCKED)) {
GST_FLAG_UNSET (thread, GST_THREAD_MUTEX_LOCKED);
} else {
g_mutex_lock (thread->lock);
}
}
GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
}
if (GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING))
break;
GST_LOG_OBJECT (thread, "we're caught");
g_cond_signal (thread->cond);
g_cond_wait (thread->cond, thread->lock);
}
/* we need to destroy the scheduler here because it has mapped it's
* stack into the threads stack space */
sched = GST_ELEMENT_SCHED (thread);
if (sched)
gst_scheduler_reset (sched);
/* must do that before releasing the lock - we might get disposed before being done */
g_signal_emit (G_OBJECT (thread), gst_thread_signals[SHUTDOWN], 0);
/* unlock and signal - we are out */
GST_LOG_OBJECT (thread, "Thread %p exits main loop", g_thread_self ());
g_cond_signal (thread->cond);
g_mutex_unlock (thread->lock);
/* don't assume the GstThread object exists anymore now */
return NULL;
}
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr
gst_thread_save_thyself (GstObject * object, xmlNodePtr self)
{
if (GST_OBJECT_CLASS (parent_class)->save_thyself)
GST_OBJECT_CLASS (parent_class)->save_thyself (object, self);
return NULL;
}
static void
gst_thread_restore_thyself (GstObject * object, xmlNodePtr self)
{
GST_LOG_OBJECT (object, "restoring");
if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
GST_OBJECT_CLASS (parent_class)->restore_thyself (object, self);
}
#endif /* GST_DISABLE_LOADSAVE */