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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wim.taymans@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>
#include "gst_private.h"
#include "gstlog.h"
#include "gstsystemclock.h"
static GstClock *_the_system_clock = NULL;
static void gst_system_clock_class_init (GstSystemClockClass *klass);
static void gst_system_clock_init (GstSystemClock *clock);
static void gst_system_clock_dispose (GObject *object);
static GstClockTime gst_system_clock_get_internal_time (GstClock *clock);
static guint64 gst_system_clock_get_resolution (GstClock *clock);
static GstClockEntryStatus gst_system_clock_wait (GstClock *clock, GstClockEntry *entry);
static void gst_system_clock_unlock (GstClock *clock, GstClockEntry *entry);
static GStaticMutex _gst_sysclock_mutex = G_STATIC_MUTEX_INIT;
static GstClockClass *parent_class = NULL;
/* static guint gst_system_clock_signals[LAST_SIGNAL] = { 0 }; */
GType
gst_system_clock_get_type (void)
{
static GType clock_type = 0;
if (!clock_type) {
static const GTypeInfo clock_info = {
sizeof (GstSystemClockClass),
NULL,
NULL,
(GClassInitFunc) gst_system_clock_class_init,
NULL,
NULL,
sizeof (GstSystemClock),
4,
(GInstanceInitFunc) gst_system_clock_init,
NULL
};
clock_type = g_type_register_static (GST_TYPE_CLOCK, "GstSystemClock",
&clock_info, 0);
}
return clock_type;
}
static void
gst_system_clock_class_init (GstSystemClockClass *klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
GstClockClass *gstclock_class;
gobject_class = (GObjectClass*) klass;
gstobject_class = (GstObjectClass*) klass;
gstclock_class = (GstClockClass*) klass;
parent_class = g_type_class_ref (GST_TYPE_CLOCK);
gobject_class->dispose = gst_system_clock_dispose;
gstclock_class->get_internal_time = gst_system_clock_get_internal_time;
gstclock_class->get_resolution = gst_system_clock_get_resolution;
gstclock_class->wait = gst_system_clock_wait;
gstclock_class->unlock = gst_system_clock_unlock;
}
static void
gst_system_clock_init (GstSystemClock *clock)
{
clock->mutex = g_mutex_new();
clock->cond = g_cond_new ();
}
static void
gst_system_clock_dispose (GObject *object)
{
GstClock *clock = (GstClock *) object;
GstSystemClock *sysclock = (GstSystemClock *) object;
/* there are subclasses of GstSystemClock running around... */
if (_the_system_clock == clock) {
g_warning ("disposing systemclock!");
/* no parent dispose here, this is bad enough already */
} else {
G_OBJECT_CLASS (parent_class)->dispose (object);
/* FIXME: Notifying before freeing? */
g_cond_free (sysclock->cond);
g_mutex_free (sysclock->mutex);
}
}
/**
* gst_system_clock_obtain
*
* Get a handle to the default system clock.
*
* Returns: the default clock.
*/
GstClock*
gst_system_clock_obtain (void)
{
GstClock *clock = _the_system_clock;
if (clock == NULL) {
g_static_mutex_lock (&_gst_sysclock_mutex);
if (_the_system_clock != NULL) {
clock = _the_system_clock;
g_static_mutex_unlock (&_gst_sysclock_mutex);
goto have_clock;
}
clock = GST_CLOCK (g_object_new (GST_TYPE_SYSTEM_CLOCK, NULL));
gst_object_set_name (GST_OBJECT (clock), "GstSystemClock");
gst_object_ref (GST_OBJECT (clock));
gst_object_sink (GST_OBJECT (clock));
_the_system_clock = clock;
g_static_mutex_unlock (&_gst_sysclock_mutex);
}
have_clock:
gst_object_ref (GST_OBJECT (clock));
return clock;
}
static GstClockTime
gst_system_clock_get_internal_time (GstClock *clock)
{
GTimeVal timeval;
g_get_current_time (&timeval);
return GST_TIMEVAL_TO_TIME (timeval);
}
static guint64
gst_system_clock_get_resolution (GstClock *clock)
{
return 1 * GST_USECOND;
}
static GstClockEntryStatus
gst_system_clock_wait (GstClock *clock, GstClockEntry *entry)
{
GstClockEntryStatus res;
GstClockTime current, target;
gint64 diff;
GstSystemClock *sysclock = GST_SYSTEM_CLOCK (clock);
current = gst_clock_get_time (clock);
diff = GST_CLOCK_ENTRY_TIME (entry) - current;
if (ABS (diff) > clock->max_diff) {
g_warning ("abnormal clock request diff: ABS(%" G_GINT64_FORMAT
") > %" G_GINT64_FORMAT, diff, clock->max_diff);
return GST_CLOCK_ENTRY_EARLY;
}
target = gst_system_clock_get_internal_time (clock) + diff;
GST_DEBUG (GST_CAT_CLOCK, "real_target %" G_GUINT64_FORMAT
" target %" G_GUINT64_FORMAT
" now %" G_GUINT64_FORMAT,
target, GST_CLOCK_ENTRY_TIME (entry), current);
if (((gint64)target) > 0) {
GTimeVal tv;
GST_TIME_TO_TIMEVAL (target, tv);
g_mutex_lock (sysclock->mutex);
g_cond_timed_wait (sysclock->cond, sysclock->mutex, &tv);
g_mutex_unlock (sysclock->mutex);
res = entry->status;
}
else {
res = GST_CLOCK_ENTRY_EARLY;
}
return res;
}
static void
gst_system_clock_unlock (GstClock *clock, GstClockEntry *entry)
{
GstSystemClock *sysclock = GST_SYSTEM_CLOCK (clock);
g_mutex_lock (sysclock->mutex);
g_cond_broadcast (sysclock->cond);
g_mutex_unlock (sysclock->mutex);
}
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