gstreamer/gst/gstthread.c
Thomas Vander Stichele 5a6cf24c16 code review
Original commit message from CVS:
code review
2002-04-12 09:38:47 +00:00

605 lines
19 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* 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 <unistd.h>
/* #define GST_DEBUG_ENABLED */
#include "gst_private.h"
#include "gstthread.h"
#include "gstscheduler.h"
#include "gstqueue.h"
GstElementDetails gst_thread_details = {
"Threaded container",
"Bin",
"Container that creates/manages a thread",
VERSION,
"Erik Walthinsen <omega@cse.ogi.edu>",
"(C) 1999, 2000",
};
/* Thread signals and args */
enum {
/* FILL ME */
LAST_SIGNAL
};
enum {
SPINUP=0,
STATECHANGE,
STARTUP
};
enum {
ARG_0,
};
static void gst_thread_class_init (GstThreadClass *klass);
static void gst_thread_init (GstThread *thread);
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);
#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);
static GstBinClass *parent_class = NULL;
/* static guint gst_thread_signals[LAST_SIGNAL] = { 0 }; */
GType
gst_thread_get_type(void) {
static GType thread_type = 0;
if (!thread_type) {
static const GTypeInfo thread_info = {
sizeof(GstThreadClass),
NULL,
NULL,
(GClassInitFunc)gst_thread_class_init,
NULL,
NULL,
sizeof(GstThread),
4,
(GInstanceInitFunc)gst_thread_init,
NULL
};
thread_type = g_type_register_static(GST_TYPE_BIN, "GstThread", &thread_info, 0);
}
return thread_type;
}
static void
gst_thread_class_init (GstThreadClass *klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
GstElementClass *gstelement_class;
GstBinClass *gstbin_class;
gobject_class = (GObjectClass*)klass;
gstobject_class = (GstObjectClass*)klass;
gstelement_class = (GstElementClass*)klass;
gstbin_class = (GstBinClass*)klass;
parent_class = g_type_class_ref (GST_TYPE_BIN);
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);
/* gstbin_class->schedule = gst_thread_schedule_dummy; */
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_thread_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_thread_get_property);
}
static void
gst_thread_init (GstThread *thread)
{
const gchar *schedname;
GstScheduler *scheduler;
GST_DEBUG (GST_CAT_THREAD, "initializing thread");
/* we're a manager by default */
/* CR1: the GstBin code checks these flags */
GST_FLAG_SET (thread, GST_BIN_FLAG_MANAGER);
GST_FLAG_SET (thread, GST_BIN_SELF_SCHEDULABLE);
schedname = gst_scheduler_factory_get_default_name ();
scheduler = gst_scheduler_factory_make (schedname, GST_ELEMENT (thread));
GST_ELEMENT_SCHED (thread) = scheduler;
gst_object_ref (GST_OBJECT (scheduler));
gst_object_sink (GST_OBJECT (scheduler));
thread->lock = g_mutex_new ();
thread->cond = g_cond_new ();
thread->ppid = getpid ();
thread->thread_id = -1;
}
static void
gst_thread_dispose (GObject *object)
{
GstThread *thread = GST_THREAD (object);
GST_DEBUG (GST_CAT_REFCOUNTING, "dispose");
g_mutex_free (thread->lock);
g_cond_free (thread->cond);
G_OBJECT_CLASS (parent_class)->dispose (object);
if (GST_ELEMENT_SCHED (thread)) {
gst_object_unref (GST_OBJECT (GST_ELEMENT_SCHED (thread)));
}
}
static void
gst_thread_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
/* it's not null if we got it, but it might not be ours */
g_return_if_fail (GST_IS_THREAD (object));
switch (prop_id) {
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)
{
/* it's not null if we got it, but it might not be ours */
g_return_if_fail (GST_IS_THREAD (object));
switch (prop_id) {
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);
}
#define THR_INFO(format,args...) \
GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
#define THR_DEBUG(format,args...) \
GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync(" GST_DEBUG_THREAD_FORMAT "): " format , \
GST_DEBUG_THREAD_ARGS(thread->pid) , ## args )
#define THR_INFO_MAIN(format,args...) \
GST_INFO_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
#define THR_DEBUG_MAIN(format,args...) \
GST_DEBUG_ELEMENT(GST_CAT_THREAD, thread, "sync-main(" GST_DEBUG_THREAD_FORMAT "): " format , \
GST_DEBUG_THREAD_ARGS(thread->ppid) , ## args )
static GstElementStateReturn
gst_thread_update_state (GstThread *thread)
{
/* check for state change */
if (GST_STATE_PENDING(thread) != GST_STATE_VOID_PENDING) {
/* punt and change state on all the children */
if (GST_ELEMENT_CLASS (parent_class)->change_state)
return GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
}
return GST_STATE_SUCCESS;
}
static GstElementStateReturn
gst_thread_change_state (GstElement * element)
{
GstThread *thread;
gboolean stateset = GST_STATE_SUCCESS;
gint transition;
pthread_t self = pthread_self ();
g_return_val_if_fail (GST_IS_THREAD (element), FALSE);
thread = GST_THREAD (element);
transition = GST_STATE_TRANSITION (element);
THR_INFO ("changing state from %s to %s",
gst_element_statename (GST_STATE (element)),
gst_element_statename (GST_STATE_PENDING (element)));
if (pthread_equal (self, thread->thread_id)) {
GST_DEBUG (GST_CAT_THREAD,
"no sync(" GST_DEBUG_THREAD_FORMAT "): setting own thread's state to spinning",
GST_DEBUG_THREAD_ARGS (thread->pid));
return gst_thread_update_state (thread);
}
switch (transition) {
case GST_STATE_NULL_TO_READY:
/* set the state to idle */
GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
THR_DEBUG ("creating thread \"%s\"", GST_ELEMENT_NAME (element));
g_mutex_lock (thread->lock);
/* create the thread */
pthread_create (&thread->thread_id, NULL, gst_thread_main_loop, thread);
/* wait for it to 'spin up' */
THR_DEBUG ("waiting for child thread spinup");
g_cond_wait (thread->cond, thread->lock);
THR_DEBUG ("thread claims to be up");
g_mutex_unlock (thread->lock);
break;
case GST_STATE_READY_TO_PAUSED:
THR_INFO ("readying thread");
g_mutex_lock (thread->lock);
THR_DEBUG ("signaling");
g_cond_signal (thread->cond);
THR_DEBUG ("waiting for ack");
g_cond_wait (thread->cond, thread->lock);
THR_DEBUG ("got ack");
g_mutex_unlock (thread->lock);
break;
case GST_STATE_PAUSED_TO_PLAYING:
THR_DEBUG ("telling thread to start spinning");
g_mutex_lock (thread->lock);
THR_DEBUG ("signaling");
g_cond_signal (thread->cond);
THR_DEBUG ("waiting for ack");
g_cond_wait (thread->cond, thread->lock);
THR_DEBUG ("got ack");
g_mutex_unlock (thread->lock);
break;
case GST_STATE_PLAYING_TO_PAUSED:
{
GList *elements = gst_bin_get_list (GST_BIN (thread));
THR_INFO ("pausing thread");
/* the following code ensures that the bottom half of thread will run
* to perform each elements' change_state() (by calling gstbin.c::
* change_state()).
* + the pending state was already set by gstelement.c::set_state()
* + find every queue we manage, and signal its empty and full conditions
*/
g_mutex_lock (thread->lock);
GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
while (elements) {
GstElement *element = GST_ELEMENT (elements->data);
g_assert (element);
THR_DEBUG (" element \"%s\"", GST_ELEMENT_NAME (element));
elements = g_list_next (elements);
if (GST_IS_QUEUE (element)) {
GstQueue *queue = GST_QUEUE (element);
/* FIXME make this more efficient by only waking queues that are asleep
* FIXME and only waking the appropriate condition (depending on if it's
* FIXME on up- or down-stream side)
* FIXME also make this more efficient by keeping list of managed queues
*/
THR_DEBUG ("waking queue \"%s\"", GST_ELEMENT_NAME (element));
g_mutex_lock (queue->qlock);
GST_STATE_PENDING (element) = GST_STATE_PAUSED;
g_cond_signal (queue->not_full);
g_cond_signal (queue->not_empty);
g_mutex_unlock (queue->qlock);
}
else {
GList *pads = GST_ELEMENT_PADS (element);
while (pads) {
GstRealPad *peer = GST_REAL_PAD (GST_PAD_PEER (pads->data));
GstElement *peerelement;
pads = g_list_next (pads);
if (!peer)
continue;
peerelement = GST_PAD_PARENT (peer);
if (!peerelement)
continue; /* deal with case where there's no peer */
if (!GST_FLAG_IS_SET (peerelement, GST_ELEMENT_DECOUPLED)) {
GST_DEBUG (GST_CAT_THREAD, "peer element isn't DECOUPLED");
continue;
}
/* FIXME this needs to go away eventually */
if (!GST_IS_QUEUE (peerelement)) {
GST_DEBUG (GST_CAT_THREAD, "peer element isn't a Queue");
continue;
}
if (GST_ELEMENT_SCHED (peerelement) != GST_ELEMENT_SCHED (thread)) {
GstQueue *queue = GST_QUEUE (peerelement);
THR_DEBUG (" element \"%s\" has pad cross sched boundary", GST_ELEMENT_NAME (element));
/* FIXME!! */
g_mutex_lock (queue->qlock);
g_cond_signal (queue->not_full);
g_cond_signal (queue->not_empty);
g_mutex_unlock (queue->qlock);
}
}
}
}
THR_DEBUG ("telling thread to pause, signaling");
g_cond_signal (thread->cond);
THR_DEBUG ("waiting for ack");
g_cond_wait (thread->cond, thread->lock);
THR_DEBUG ("got ack");
g_mutex_unlock (thread->lock);
break;
}
case GST_STATE_READY_TO_NULL:
THR_DEBUG ("telling thread to pause (null) - and joining");
/* MattH FIXME revisit */
g_mutex_lock (thread->lock);
THR_DEBUG ("signaling");
g_cond_signal (thread->cond);
THR_DEBUG ("waiting for ack");
g_cond_wait (thread->cond, thread->lock);
THR_DEBUG ("got ack");
pthread_join (thread->thread_id, NULL);
thread->thread_id = -1;
g_mutex_unlock (thread->lock);
GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
GST_FLAG_UNSET (thread, GST_THREAD_STATE_STARTED);
GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
break;
case GST_STATE_PAUSED_TO_READY:
THR_DEBUG ("telling thread to stop spinning");
g_mutex_lock (thread->lock);
THR_DEBUG ("signaling");
g_cond_signal (thread->cond);
THR_DEBUG ("waiting for ack");
g_cond_wait (thread->cond, thread->lock);
THR_DEBUG ("got ack");
g_mutex_unlock (thread->lock);
break;
default:
GST_DEBUG_ELEMENT (GST_CAT_THREAD, element, "UNHANDLED STATE CHANGE! %x", transition);
break;
}
return stateset;
}
/**
* 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 = GST_THREAD (arg);
gint stateset;
g_mutex_lock (thread->lock);
gst_scheduler_setup (GST_ELEMENT_SCHED (thread));
GST_FLAG_UNSET (thread, GST_THREAD_STATE_REAPING);
thread->pid = getpid();
THR_INFO_MAIN("thread is running");
/* first we need to change the state of all the children */
if (GST_ELEMENT_CLASS (parent_class)->change_state) {
stateset = GST_ELEMENT_CLASS (parent_class)->change_state (GST_ELEMENT(thread));
if (stateset != GST_STATE_SUCCESS) {
THR_DEBUG_MAIN ("state change of children failed");
}
}
THR_DEBUG_MAIN ("indicating spinup");
g_cond_signal (thread->cond);
/* don't unlock the mutex because we hold it into the top of the while loop */
THR_DEBUG_MAIN ("thread has indicated spinup to parent process");
/***** THREAD IS NOW IN READY STATE *****/
/* CR1: most of this code is handshaking */
/* do this while the thread lives */
while (!GST_FLAG_IS_SET (thread, GST_THREAD_STATE_REAPING)) {
/* NOTE we hold the thread lock at this point */
/* what we do depends on what state we're in */
switch (GST_STATE (thread)) {
/* NOTE: cannot be in NULL, we're not running in that state at all */
case GST_STATE_READY:
/* wait to be set to either the NULL or PAUSED states */
THR_DEBUG_MAIN ("thread in %s state, waiting for either %s or %s",
gst_element_statename (GST_STATE_READY),
gst_element_statename (GST_STATE_NULL),
gst_element_statename (GST_STATE_PAUSED));
g_cond_wait (thread->cond,thread->lock);
/* this must have happened by a state change in the thread context */
if (GST_STATE_PENDING (thread) != GST_STATE_NULL &&
GST_STATE_PENDING (thread) != GST_STATE_PAUSED) {
g_cond_signal (thread->cond);
continue;
}
/* been signaled, we need to state transition now and signal back */
gst_thread_update_state (thread);
THR_DEBUG_MAIN ("done with state transition, signaling back to parent process");
g_cond_signal (thread->cond);
/* now we decide what to do next */
if (GST_STATE (thread) == GST_STATE_NULL) {
/* REAPING must be set, we can simply break this iteration */
GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
}
continue;
case GST_STATE_PAUSED:
/* wait to be set to either the READY or PLAYING states */
THR_DEBUG_MAIN("thread in %s state, waiting for either %s or %s",
gst_element_statename (GST_STATE_PAUSED),
gst_element_statename (GST_STATE_READY),
gst_element_statename (GST_STATE_PLAYING));
g_cond_wait (thread->cond, thread->lock);
/* this must have happened by a state change in the thread context */
if (GST_STATE_PENDING (thread) != GST_STATE_READY &&
GST_STATE_PENDING (thread) != GST_STATE_PLAYING) {
g_cond_signal (thread->cond);
continue;
}
/* been signaled, we need to state transition now and signal back */
gst_thread_update_state (thread);
/* now we decide what to do next */
if (GST_STATE (thread) != GST_STATE_PLAYING) {
/* either READY or the state change failed for some reason */
g_cond_signal (thread->cond);
continue;
}
else {
GST_FLAG_SET (thread, GST_THREAD_STATE_SPINNING);
/* PLAYING is coming up, so we can now start spinning */
while (GST_FLAG_IS_SET (thread, GST_THREAD_STATE_SPINNING)) {
gboolean status;
g_cond_signal (thread->cond);
g_mutex_unlock (thread->lock);
status = gst_bin_iterate (GST_BIN (thread));
g_mutex_lock (thread->lock);
/* g_cond_signal(thread->cond); */
if (!status || GST_STATE_PENDING (thread) != GST_STATE_VOID_PENDING)
GST_FLAG_UNSET (thread, GST_THREAD_STATE_SPINNING);
}
/* looks like we were stopped because of a statechange */
if (GST_STATE_PENDING (thread)) {
gst_thread_update_state (thread);
}
/* once we're here, SPINNING has stopped, we should signal that we're done */
THR_DEBUG_MAIN ("SPINNING stopped, signaling back to parent process");
g_cond_signal (thread->cond);
/* now we can wait for PAUSED */
continue;
}
case GST_STATE_PLAYING:
/* wait to be set to PAUSED */
THR_DEBUG_MAIN ("thread in %s state, waiting for %s",
gst_element_statename(GST_STATE_PLAYING),
gst_element_statename(GST_STATE_PAUSED));
g_cond_wait (thread->cond,thread->lock);
/* been signaled, we need to state transition now and signal back */
gst_thread_update_state (thread);
g_cond_signal (thread->cond);
/* now we decide what to do next */
/* there's only PAUSED, we we just wait for it */
continue;
case GST_STATE_NULL:
THR_DEBUG_MAIN ("thread in %s state, preparing to die",
gst_element_statename(GST_STATE_NULL));
GST_FLAG_SET (thread, GST_THREAD_STATE_REAPING);
break;
default:
g_assert_not_reached ();
break;
}
}
/* we need to destroy the scheduler here because it has mapped it's
* stack into the threads stack space */
gst_scheduler_reset (GST_ELEMENT_SCHED (thread));
/* since we don't unlock at the end of the while loop, do it here */
g_mutex_unlock (thread->lock);
GST_INFO (GST_CAT_THREAD, "gstthread: thread \"%s\" is stopped",
GST_ELEMENT_NAME (thread));
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_DEBUG (GST_CAT_THREAD,"gstthread: restore");
if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
GST_OBJECT_CLASS (parent_class)->restore_thyself (object, self);
}
#endif /* GST_DISABLE_LOADSAVE */