gstreamer/gst/gstclock.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstclock.c: Clock subsystem for maintaining time sync
*
* 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 <sys/time.h>
/* #define GST_DEBUG_ENABLED */
#include "gst_private.h"
#include "gstclock.h"
#define CLASS(clock) GST_CLOCK_CLASS (G_OBJECT_GET_CLASS (clock))
static GMemChunk *_gst_clock_entries_chunk;
static GMutex *_gst_clock_entries_chunk_lock;
static GList *_gst_clock_entries_pool;
static void gst_clock_class_init (GstClockClass *klass);
static void gst_clock_init (GstClock *clock);
static GstObjectClass *parent_class = NULL;
/* static guint gst_clock_signals[LAST_SIGNAL] = { 0 }; */
typedef struct _GstClockEntry GstClockEntry;
static void gst_clock_free_entry (GstClock *clock, GstClockEntry *entry);
typedef enum {
GST_ENTRY_OK,
GST_ENTRY_RESTART,
} GstEntryStatus;
struct _GstClockEntry {
GstClockTime time;
GstEntryStatus status;
GstClockCallback func;
gpointer user_data;
GMutex *lock;
GCond *cond;
};
#define GST_CLOCK_ENTRY(entry) ((GstClockEntry *)(entry))
#define GST_CLOCK_ENTRY_TIME(entry) (((GstClockEntry *)(entry))->time)
#define GST_CLOCK_ENTRY_LOCK(entry) (g_mutex_lock ((entry)->lock))
#define GST_CLOCK_ENTRY_UNLOCK(entry) (g_mutex_unlock ((entry)->lock))
#define GST_CLOCK_ENTRY_SIGNAL(entry) (g_cond_signal ((entry)->cond))
#define GST_CLOCK_ENTRY_WAIT(entry) (g_cond_wait (entry->cond, entry->lock))
#define GST_CLOCK_ENTRY_TIMED_WAIT(entry, time) (g_cond_timed_wait (entry->cond, entry->lock, (time)))
static GstClockEntry*
gst_clock_entry_new (GstClockTime time,
GstClockCallback func, gpointer user_data)
{
GstClockEntry *entry;
g_mutex_lock (_gst_clock_entries_chunk_lock);
if (_gst_clock_entries_pool) {
entry = GST_CLOCK_ENTRY (_gst_clock_entries_pool->data);
_gst_clock_entries_pool = g_list_remove (_gst_clock_entries_pool, entry);
g_mutex_unlock (_gst_clock_entries_chunk_lock);
}
else {
entry = g_mem_chunk_alloc (_gst_clock_entries_chunk);
g_mutex_unlock (_gst_clock_entries_chunk_lock);
entry->lock = g_mutex_new ();
entry->cond = g_cond_new ();
}
entry->time = time;
entry->func = func;
entry->user_data = user_data;
return entry;
}
static gint
clock_compare_func (gconstpointer a,
gconstpointer b)
{
GstClockEntry *entry1 = (GstClockEntry *)a;
GstClockEntry *entry2 = (GstClockEntry *)b;
return (entry1->time - entry2->time);
}
GType
gst_clock_get_type (void)
{
static GType clock_type = 0;
if (!clock_type) {
static const GTypeInfo clock_info = {
sizeof (GstClockClass),
NULL,
NULL,
(GClassInitFunc) gst_clock_class_init,
NULL,
NULL,
sizeof (GstClock),
4,
(GInstanceInitFunc) gst_clock_init,
NULL
};
clock_type = g_type_register_static (GST_TYPE_OBJECT, "GstClock",
&clock_info, G_TYPE_FLAG_ABSTRACT);
}
return clock_type;
}
static void
gst_clock_class_init (GstClockClass *klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
gobject_class = (GObjectClass*) klass;
gstobject_class = (GstObjectClass*) klass;
parent_class = g_type_class_ref (GST_TYPE_OBJECT);
if (!g_thread_supported ())
g_thread_init (NULL);
_gst_clock_entries_chunk = g_mem_chunk_new ("GstClockEntries",
sizeof (GstClockEntry), sizeof (GstClockEntry) * 32,
G_ALLOC_AND_FREE);
_gst_clock_entries_chunk_lock = g_mutex_new ();
_gst_clock_entries_pool = NULL;
}
static void
gst_clock_init (GstClock *clock)
{
clock->speed = 1.0;
clock->active = FALSE;
clock->start_time = 0;
clock->last_time = 0;
clock->entries = NULL;
clock->async_supported = FALSE;
clock->active_mutex = g_mutex_new ();
clock->active_cond = g_cond_new ();
}
/**
* gst_clock_async_supported
* @clock: a #GstClock to query
*
* Checks if this clock can support asynchronous notification.
*
* Returns: TRUE if async notification is supported.
*/
gboolean
gst_clock_async_supported (GstClock *clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
return clock->async_supported;
}
/**
* gst_clock_set_speed
* @clock: a #GstClock to modify
* @speed: the speed to set on the clock
*
* Sets the speed on the given clock. 1.0 is the default
* speed.
*/
void
gst_clock_set_speed (GstClock *clock, gdouble speed)
{
g_return_if_fail (GST_IS_CLOCK (clock));
clock->speed = speed;
}
/**
* gst_clock_get_speed
* @clock: a #GstClock to query
*
* Gets the speed of the given clock.
*
* Returns: the speed of the clock.
*/
gdouble
gst_clock_get_speed (GstClock *clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), 0.0);
return clock->speed;
}
/**
* gst_clock_reset
* @clock: a #GstClock to reset
*
* Reset the clock to time 0.
*/
void
gst_clock_reset (GstClock *clock)
{
GstClockTime time = 0LL;
g_return_if_fail (GST_IS_CLOCK (clock));
if (CLASS (clock)->get_internal_time) {
time = CLASS (clock)->get_internal_time (clock);
}
GST_LOCK (clock);
clock->active = FALSE;
clock->start_time = time;
clock->last_time = 0LL;
GST_UNLOCK (clock);
}
/**
* gst_clock_set_active
* @clock: a #GstClock to set state of
* @active: flag indicating if the clock should be activated (TRUE) or deactivated
*
* Activates or deactivates the clock based on the active parameter.
* As soon as the clock is activated, the time will start ticking.
*/
void
gst_clock_set_active (GstClock *clock, gboolean active)
{
GstClockTime time = 0LL;
g_return_if_fail (GST_IS_CLOCK (clock));
clock->active = active;
if (CLASS (clock)->get_internal_time) {
time = CLASS (clock)->get_internal_time (clock);
}
GST_LOCK (clock);
if (active) {
clock->start_time = time - clock->last_time;
clock->accept_discont = TRUE;
}
else {
clock->last_time = time - clock->start_time;
clock->accept_discont = FALSE;
}
GST_UNLOCK (clock);
g_mutex_lock (clock->active_mutex);
g_cond_broadcast (clock->active_cond);
g_mutex_unlock (clock->active_mutex);
}
/**
* gst_clock_is_active
* @clock: a #GstClock to query
*
* Checks if the given clock is active.
*
* Returns: TRUE if the clock is active.
*/
gboolean
gst_clock_is_active (GstClock *clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
return clock->active;
}
gboolean
gst_clock_handle_discont (GstClock *clock, guint64 time)
{
GstClockTime itime = 0LL;
GST_DEBUG (GST_CAT_CLOCK, "clock discont %llu %llu %d\n", time, clock->start_time, clock->accept_discont);
GST_LOCK (clock);
if (clock->accept_discont) {
if (CLASS (clock)->get_internal_time) {
itime = CLASS (clock)->get_internal_time (clock);
}
}
else {
GST_UNLOCK (clock);
GST_DEBUG (GST_CAT_CLOCK, "clock discont refused %llu %llu\n", time, clock->start_time);
return FALSE;
}
clock->start_time = itime - time;
clock->last_time = time;
clock->accept_discont = FALSE;
GST_UNLOCK (clock);
GST_DEBUG (GST_CAT_CLOCK, "new time %llu\n", gst_clock_get_time (clock));
g_mutex_lock (clock->active_mutex);
g_cond_broadcast (clock->active_cond);
g_mutex_unlock (clock->active_mutex);
return TRUE;
}
/**
* gst_clock_get_time
* @clock: a #GstClock to query
*
* Gets the current time of the given clock. The time is always
* monotonically increasing.
*
* Returns: the time of the clock.
*/
GstClockTime
gst_clock_get_time (GstClock *clock)
{
GstClockTime ret = 0LL;
g_return_val_if_fail (GST_IS_CLOCK (clock), 0LL);
if (!clock->active) {
/* clock is not activen return previous time */
ret = clock->last_time;
}
else {
if (CLASS (clock)->get_internal_time) {
ret = CLASS (clock)->get_internal_time (clock) - clock->start_time;
}
/* make sure the time is increasing, else return last_time */
if ((gint64) ret < (gint64) clock->last_time) {
ret = clock->last_time;
}
else {
clock->last_time = ret;
}
}
return ret;
}
static GstClockID
gst_clock_wait_async_func (GstClock *clock, GstClockTime time,
GstClockCallback func, gpointer user_data)
{
GstClockEntry *entry = NULL;
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
if (!clock->active) {
GST_DEBUG (GST_CAT_CLOCK, "blocking on clock\n");
g_mutex_lock (clock->active_mutex);
g_cond_wait (clock->active_cond, clock->active_mutex);
g_mutex_unlock (clock->active_mutex);
}
entry = gst_clock_entry_new (time, func, user_data);
GST_LOCK (clock);
clock->entries = g_list_insert_sorted (clock->entries, entry, clock_compare_func);
GST_UNLOCK (clock);
return entry;
}
/**
* gst_clock_wait
* @clock: a #GstClock to wait on
* @time: The #GstClockTime to wait for
*
* Wait and block till the clock reaches the specified time.
*
* Returns: the #GstClockReturn result of the operation.
*/
GstClockReturn
gst_clock_wait (GstClock *clock, GstClockTime time, GstClockTimeDiff *jitter)
{
GstClockID id;
GstClockReturn res;
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_STOPPED);
id = gst_clock_wait_async_func (clock, time, NULL, NULL);
res = gst_clock_wait_id (clock, id, jitter);
return res;
}
/**
* gst_clock_wait_async
* @clock: a #GstClock to wait on
* @time: The #GstClockTime to wait for
* @func: The callback function
* @user_data: User data passed in the calback
*
* Register a callback on the given clock that will be triggered
* when the clock has reached the given time. A ClockID is returned
* that can be used to cancel the request.
*
* Returns: the clock id or NULL when async notification is not supported.
*/
GstClockID
gst_clock_wait_async (GstClock *clock, GstClockTime time,
GstClockCallback func, gpointer user_data)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
if (clock->async_supported) {
return gst_clock_wait_async_func (clock, time, func, user_data);
}
return NULL;
}
/**
* gst_clock_cancel_wait_async
* @clock: The clock to cancel the request on
* @id: The id to cancel
*
* Cancel an outstanding async notification request with the given ID.
*/
void
gst_clock_cancel_wait_async (GstClock *clock, GstClockID id)
{
g_warning ("not supported");
}
/**
* gst_clock_notify_async
* @clock: The clock to wait on
* @interval: The interval between notifications
* @func: The callback function
* @user_data: User data passed in the calback
*
* Register a callback on the given clock that will be periodically
* triggered with the specified interval. A ClockID is returned
* that can be used to cancel the request.
*
* Returns: the clock id or NULL when async notification is not supported.
*/
GstClockID
gst_clock_notify_async (GstClock *clock, GstClockTime interval,
GstClockCallback func, gpointer user_data)
{
g_warning ("not supported");
return NULL;
}
/**
* gst_clock_remove_notify_async
* @clock: The clock to cancel the request on
* @id: The id to cancel
*
* Cancel an outstanding async notification request with the given ID.
*/
void
gst_clock_remove_notify_async (GstClock *clock, GstClockID id)
{
g_warning ("not supported");
}
static void
gst_clock_unlock_func (GstClock *clock, GstClockTime time, GstClockID id, gpointer user_data)
{
GstClockEntry *entry = (GstClockEntry *) id;
GST_CLOCK_ENTRY_LOCK (entry);
GST_CLOCK_ENTRY_SIGNAL (entry);
GST_CLOCK_ENTRY_UNLOCK (entry);
}
/**
* gst_clock_wait_id
* @clock: The clock to wait on
* @id: The clock id to wait on
*
* Wait and block on the clockid obtained with gst_clock_wait_async.
*
* Returns: result of the operation.
*/
GstClockReturn
gst_clock_wait_id (GstClock *clock, GstClockID id, GstClockTimeDiff *jitter)
{
GstClockReturn res = GST_CLOCK_TIMEOUT;
GstClockEntry *entry = (GstClockEntry *) id;
GstClockTime current_real, current, target;
GTimeVal timeval;
GstClockTimeDiff this_jitter;
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_ERROR);
g_return_val_if_fail (entry, GST_CLOCK_ERROR);
current = gst_clock_get_time (clock);
g_get_current_time (&timeval);
current_real = GST_TIMEVAL_TO_TIME (timeval);
GST_CLOCK_ENTRY_LOCK (entry);
entry->func = gst_clock_unlock_func;
target = GST_CLOCK_ENTRY_TIME (entry) - current + current_real;
GST_DEBUG (GST_CAT_CLOCK, "real_target %llu, current_real %llu, target %llu, now %llu\n",
target, current_real, GST_CLOCK_ENTRY_TIME (entry), current);
if (target > current_real) {
GST_TIME_TO_TIMEVAL (target, timeval);
GST_CLOCK_ENTRY_TIMED_WAIT (entry, &timeval);
current = gst_clock_get_time (clock);
this_jitter = current - GST_CLOCK_ENTRY_TIME (entry);
}
else {
res = GST_CLOCK_EARLY;
this_jitter = target - current_real;
}
GST_CLOCK_ENTRY_UNLOCK (entry);
if (jitter)
*jitter = this_jitter;
gst_clock_free_entry (clock, entry);
return res;
}
/**
* gst_clock_get_next_id
* @clock: The clock to query
*
* Get the clockid of the next event.
*
* Returns: a clockid or NULL is no event is pending.
*/
GstClockID
gst_clock_get_next_id (GstClock *clock)
{
GstClockEntry *entry = NULL;
GST_LOCK (clock);
if (clock->entries)
entry = GST_CLOCK_ENTRY (clock->entries->data);
GST_UNLOCK (clock);
return (GstClockID *) entry;
}
/**
* gst_clock_id_get_time
* @id: The clockid to query
*
* Get the time of the clock ID
*
* Returns: the time of the given clock id
*/
GstClockTime
gst_clock_id_get_time (GstClockID id)
{
return GST_CLOCK_ENTRY_TIME (id);
}
static void
gst_clock_free_entry (GstClock *clock, GstClockEntry *entry)
{
GST_LOCK (clock);
clock->entries = g_list_remove (clock->entries, entry);
GST_UNLOCK (clock);
g_mutex_lock (_gst_clock_entries_chunk_lock);
_gst_clock_entries_pool = g_list_prepend (_gst_clock_entries_pool, entry);
g_mutex_unlock (_gst_clock_entries_chunk_lock);
}
/**
* gst_clock_unlock_id
* @clock: The clock that own the id
* @id: The clockid to unlock
*
* Unlock the ClockID.
*/
void
gst_clock_unlock_id (GstClock *clock, GstClockID id)
{
GstClockEntry *entry = (GstClockEntry *) id;
if (entry->func)
entry->func (clock, gst_clock_get_time (clock), id, entry->user_data);
gst_clock_free_entry (clock, entry);
}
/**
* gst_clock_set_resolution
* @clock: The clock set the resolution on
* @resolution: The resolution to set
*
* Set the accuracy of the clock.
*/
void
gst_clock_set_resolution (GstClock *clock, guint64 resolution)
{
g_return_if_fail (GST_IS_CLOCK (clock));
if (CLASS (clock)->set_resolution)
CLASS (clock)->set_resolution (clock, resolution);
}
/**
* gst_clock_get_resolution
* @clock: The clock get the resolution of
*
* Get the accuracy of the clock.
*
* Returns: the resolution of the clock in microseconds.
*/
guint64
gst_clock_get_resolution (GstClock *clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), 0LL);
if (CLASS (clock)->get_resolution)
return CLASS (clock)->get_resolution (clock);
return 1LL;
}