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gstreamer/libs/gst/net/gstnetclientclock.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2005 Wim Taymans <wim@fluendo.com>
* 2005 Andy Wingo <wingo@pobox.com>
* Copyright (C) 2012 Collabora Ltd. <tim.muller@collabora.co.uk>
* Copyright (C) 2015 Sebastian Dröge <sebastian@centricular.com>
*
* gstnetclientclock.h: clock that synchronizes itself to a time provider over
* the network
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstnetclientclock
* @short_description: Special clock that synchronizes to a remote time
* provider.
* @see_also: #GstClock, #GstNetTimeProvider, #GstPipeline
*
* #GstNetClientClock implements a custom #GstClock that synchronizes its time
* to a remote time provider such as #GstNetTimeProvider. #GstNtpClock
* implements a #GstClock that synchronizes its time to a remote NTPv4 server.
*
* A new clock is created with gst_net_client_clock_new() or
* gst_ntp_clock_new(), which takes the address and port of the remote time
* provider along with a name and an initial time.
*
* This clock will poll the time provider and will update its calibration
* parameters based on the local and remote observations.
*
* The "round-trip" property limits the maximum round trip packets can take.
*
* Various parameters of the clock can be configured with the parent #GstClock
* "timeout", "window-size" and "window-threshold" object properties.
*
* A #GstNetClientClock and #GstNtpClock is typically set on a #GstPipeline with
* gst_pipeline_use_clock().
*
* If you set a #GstBus on the clock via the "bus" object property, it will
* send @GST_MESSAGE_ELEMENT messages with an attached #GstStructure containing
* statistics about clock accuracy and network traffic.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstnettimepacket.h"
#include "gstntppacket.h"
#include "gstnetclientclock.h"
#include <gio/gio.h>
#include <string.h>
GST_DEBUG_CATEGORY_STATIC (ncc_debug);
#define GST_CAT_DEFAULT (ncc_debug)
#define DEFAULT_ADDRESS "127.0.0.1"
#define DEFAULT_PORT 5637
#define DEFAULT_TIMEOUT GST_SECOND
#define DEFAULT_ROUNDTRIP_LIMIT GST_SECOND
/* Minimum timeout will be immediately (ie, as fast as one RTT), but no
* more often than 1/20th second (arbitrarily, to spread observations a little) */
#define DEFAULT_MINIMUM_UPDATE_INTERVAL (GST_SECOND / 20)
#define DEFAULT_BASE_TIME 0
/* Maximum number of clock updates we can skip before updating */
#define MAX_SKIPPED_UPDATES 5
#define MEDIAN_PRE_FILTERING_WINDOW 9
enum
{
PROP_0,
PROP_ADDRESS,
PROP_PORT,
PROP_ROUNDTRIP_LIMIT,
PROP_MINIMUM_UPDATE_INTERVAL,
PROP_BUS,
PROP_BASE_TIME,
PROP_INTERNAL_CLOCK
};
#define GST_NET_CLIENT_CLOCK_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_NET_CLIENT_CLOCK, GstNetClientClockPrivate))
struct _GstNetClientClockPrivate
{
GstClock *internal_clock;
GThread *thread;
GSocket *socket;
GSocketAddress *servaddr;
GCancellable *cancel;
gboolean made_cancel_fd;
GstClockTime timeout_expiration;
GstClockTime roundtrip_limit;
GstClockTime rtt_avg;
GstClockTime minimum_update_interval;
GstClockTime last_remote_poll_interval;
guint skipped_updates;
GstClockTime last_rtts[MEDIAN_PRE_FILTERING_WINDOW];
gint last_rtts_missing;
GstClockTime base_time;
gchar *address;
gint port;
GstBus *bus;
gboolean is_ntp;
};
#define _do_init \
GST_DEBUG_CATEGORY_INIT (ncc_debug, "netclock", 0, "Network client clock");
#define gst_net_client_clock_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstNetClientClock, gst_net_client_clock,
GST_TYPE_SYSTEM_CLOCK, _do_init);
static void gst_net_client_clock_finalize (GObject * object);
static void gst_net_client_clock_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_net_client_clock_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_net_client_clock_constructed (GObject * object);
static gboolean gst_net_client_clock_start (GstNetClientClock * self);
static void gst_net_client_clock_stop (GstNetClientClock * self);
static GstClockTime gst_net_client_clock_get_internal_time (GstClock * clock);
static void
gst_net_client_clock_class_init (GstNetClientClockClass * klass)
{
GObjectClass *gobject_class;
GstClockClass *clock_class;
gobject_class = G_OBJECT_CLASS (klass);
clock_class = GST_CLOCK_CLASS (klass);
g_type_class_add_private (klass, sizeof (GstNetClientClockPrivate));
gobject_class->finalize = gst_net_client_clock_finalize;
gobject_class->get_property = gst_net_client_clock_get_property;
gobject_class->set_property = gst_net_client_clock_set_property;
gobject_class->constructed = gst_net_client_clock_constructed;
g_object_class_install_property (gobject_class, PROP_ADDRESS,
g_param_spec_string ("address", "address",
"The IP address of the machine providing a time server",
DEFAULT_ADDRESS,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_PORT,
g_param_spec_int ("port", "port",
"The port on which the remote server is listening", 0, G_MAXUINT16,
DEFAULT_PORT,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_BUS,
g_param_spec_object ("bus", "bus",
"A GstBus on which to send clock status information", GST_TYPE_BUS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstNetClientClock::round-trip-limit:
*
* Maximum allowed round-trip for packets. If this property is set to a nonzero
* value, all packets with a round-trip interval larger than this limit will be
* ignored. This is useful for networks with severe and fluctuating transport
* delays. Filtering out these packets increases stability of the synchronization.
* On the other hand, the lower the limit, the higher the amount of filtered
* packets. Empirical tests are typically necessary to estimate a good value
* for the limit.
* If the property is set to zero, the limit is disabled.
*
* Since: 1.4
*/
g_object_class_install_property (gobject_class, PROP_ROUNDTRIP_LIMIT,
g_param_spec_uint64 ("round-trip-limit", "round-trip limit",
"Maximum tolerable round-trip interval for packets, in nanoseconds "
"(0 = no limit)", 0, G_MAXUINT64, DEFAULT_ROUNDTRIP_LIMIT,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_MINIMUM_UPDATE_INTERVAL,
g_param_spec_uint64 ("minimum-update-interval", "minimum update interval",
"Minimum polling interval for packets, in nanoseconds"
"(0 = no limit)", 0, G_MAXUINT64, DEFAULT_MINIMUM_UPDATE_INTERVAL,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_BASE_TIME,
g_param_spec_uint64 ("base-time", "Base Time",
"Initial time that is reported before synchronization", 0,
G_MAXUINT64, DEFAULT_BASE_TIME,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_INTERNAL_CLOCK,
g_param_spec_object ("internal-clock", "Internal Clock",
"Internal clock that directly slaved to the remote clock",
GST_TYPE_CLOCK, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
clock_class->get_internal_time = gst_net_client_clock_get_internal_time;
}
static void
gst_net_client_clock_init (GstNetClientClock * self)
{
GstNetClientClockPrivate *priv;
self->priv = priv = GST_NET_CLIENT_CLOCK_GET_PRIVATE (self);
GST_OBJECT_FLAG_SET (self, GST_CLOCK_FLAG_CAN_SET_MASTER);
GST_OBJECT_FLAG_SET (self, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC);
priv->internal_clock = g_object_new (GST_TYPE_SYSTEM_CLOCK, NULL);
priv->port = DEFAULT_PORT;
priv->address = g_strdup (DEFAULT_ADDRESS);
gst_clock_set_timeout (priv->internal_clock, DEFAULT_TIMEOUT);
priv->thread = NULL;
priv->servaddr = NULL;
priv->rtt_avg = GST_CLOCK_TIME_NONE;
priv->roundtrip_limit = DEFAULT_ROUNDTRIP_LIMIT;
priv->minimum_update_interval = DEFAULT_MINIMUM_UPDATE_INTERVAL;
priv->last_remote_poll_interval = GST_CLOCK_TIME_NONE;
priv->skipped_updates = 0;
priv->last_rtts_missing = MEDIAN_PRE_FILTERING_WINDOW;
priv->base_time = DEFAULT_BASE_TIME;
}
static void
gst_net_client_clock_finalize (GObject * object)
{
GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
if (self->priv->thread) {
gst_net_client_clock_stop (self);
}
g_free (self->priv->address);
self->priv->address = NULL;
if (self->priv->servaddr != NULL) {
g_object_unref (self->priv->servaddr);
self->priv->servaddr = NULL;
}
if (self->priv->socket != NULL) {
g_socket_close (self->priv->socket, NULL);
g_object_unref (self->priv->socket);
self->priv->socket = NULL;
}
if (self->priv->bus != NULL) {
gst_object_unref (self->priv->bus);
self->priv->bus = NULL;
}
if (self->priv->internal_clock != NULL) {
gst_object_unref (self->priv->internal_clock);
self->priv->internal_clock = NULL;
}
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_net_client_clock_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
switch (prop_id) {
case PROP_ADDRESS:
GST_OBJECT_LOCK (self);
g_free (self->priv->address);
self->priv->address = g_value_dup_string (value);
if (self->priv->address == NULL)
self->priv->address = g_strdup (DEFAULT_ADDRESS);
GST_OBJECT_UNLOCK (self);
break;
case PROP_PORT:
GST_OBJECT_LOCK (self);
self->priv->port = g_value_get_int (value);
GST_OBJECT_UNLOCK (self);
break;
case PROP_ROUNDTRIP_LIMIT:
GST_OBJECT_LOCK (self);
self->priv->roundtrip_limit = g_value_get_uint64 (value);
GST_OBJECT_UNLOCK (self);
break;
case PROP_MINIMUM_UPDATE_INTERVAL:
GST_OBJECT_LOCK (self);
self->priv->minimum_update_interval = g_value_get_uint64 (value);
GST_OBJECT_UNLOCK (self);
break;
case PROP_BUS:
GST_OBJECT_LOCK (self);
if (self->priv->bus)
gst_object_unref (self->priv->bus);
self->priv->bus = g_value_dup_object (value);
GST_OBJECT_UNLOCK (self);
break;
case PROP_BASE_TIME:
self->priv->base_time = g_value_get_uint64 (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_net_client_clock_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
switch (prop_id) {
case PROP_ADDRESS:
GST_OBJECT_LOCK (self);
g_value_set_string (value, self->priv->address);
GST_OBJECT_UNLOCK (self);
break;
case PROP_PORT:
g_value_set_int (value, self->priv->port);
break;
case PROP_ROUNDTRIP_LIMIT:
GST_OBJECT_LOCK (self);
g_value_set_uint64 (value, self->priv->roundtrip_limit);
GST_OBJECT_UNLOCK (self);
break;
case PROP_MINIMUM_UPDATE_INTERVAL:
GST_OBJECT_LOCK (self);
g_value_set_uint64 (value, self->priv->minimum_update_interval);
GST_OBJECT_UNLOCK (self);
break;
case PROP_BUS:
GST_OBJECT_LOCK (self);
g_value_set_object (value, self->priv->bus);
GST_OBJECT_UNLOCK (self);
break;
case PROP_BASE_TIME:
g_value_set_uint64 (value, self->priv->base_time);
break;
case PROP_INTERNAL_CLOCK:
g_value_set_object (value, self->priv->internal_clock);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_net_client_clock_constructed (GObject * object)
{
GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
GstClock *internal_clock = self->priv->internal_clock;
GstClockTime internal;
G_OBJECT_CLASS (parent_class)->constructed (object);
/* gst_clock_get_time() values are guaranteed to be increasing. because no one
* has called get_time on this clock yet we are free to adjust to any value
* without worrying about worrying about MAX() issues with the clock's
* internal time.
*/
/* update our internal time so get_time() give something around base_time.
assume that the rate is 1 in the beginning. */
internal = gst_clock_get_internal_time (internal_clock);
gst_clock_set_calibration (internal_clock, internal,
self->priv->base_time, 1, 1);
{
GstClockTime now = gst_clock_get_time (internal_clock);
if (GST_CLOCK_DIFF (now, self->priv->base_time) > 0 ||
GST_CLOCK_DIFF (now, self->priv->base_time + GST_SECOND) < 0) {
g_warning ("unable to set the base time, expect sync problems!");
}
}
if (!gst_net_client_clock_start (self)) {
g_warning ("failed to start clock '%s'", GST_OBJECT_NAME (self));
}
/* all systems go, cap'n */
}
static GstClockTime
gst_net_client_clock_get_internal_time (GstClock * clock)
{
GstNetClientClock *self = GST_NET_CLIENT_CLOCK (clock);
return gst_clock_get_time (self->priv->internal_clock);
}
static gint
compare_clock_time (const GstClockTime * a, const GstClockTime * b)
{
if (*a < *b)
return -1;
else if (*a > *b)
return 1;
return 0;
}
static void
gst_net_client_clock_observe_times (GstNetClientClock * self,
GstClockTime local_1, GstClockTime remote_1, GstClockTime remote_2,
GstClockTime local_2)
{
GstNetClientClockPrivate *priv = self->priv;
GstClock *internal_clock = priv->internal_clock;
GstClockTime current_timeout = 0;
GstClockTime local_avg, remote_avg;
gdouble r_squared;
GstClock *clock;
GstClockTime rtt, rtt_limit, min_update_interval;
GstBus *bus = NULL;
/* Use for discont tracking */
GstClockTime time_before = 0;
GstClockTime min_guess = 0;
GstClockTimeDiff time_discont = 0;
gboolean synched, now_synched;
GstClockTime internal_time, external_time, rate_num, rate_den;
GstClockTime orig_internal_time, orig_external_time, orig_rate_num,
orig_rate_den;
GstClockTime max_discont;
GstClockTime last_rtts[MEDIAN_PRE_FILTERING_WINDOW];
GstClockTime median;
gint i;
GST_OBJECT_LOCK (self);
rtt_limit = self->priv->roundtrip_limit;
/* If the server told us a poll interval and it's bigger than the
* one configured via the property, use the server's */
if (self->priv->last_remote_poll_interval != GST_CLOCK_TIME_NONE &&
self->priv->last_remote_poll_interval >
self->priv->minimum_update_interval)
min_update_interval = self->priv->last_remote_poll_interval;
else
min_update_interval = self->priv->minimum_update_interval;
if (self->priv->bus)
bus = gst_object_ref (self->priv->bus);
GST_OBJECT_UNLOCK (self);
if (local_2 < local_1) {
GST_LOG_OBJECT (self, "Dropping observation: receive time %" GST_TIME_FORMAT
" < send time %" GST_TIME_FORMAT, GST_TIME_ARGS (local_1),
GST_TIME_ARGS (local_2));
goto bogus_observation;
}
if (remote_2 < remote_1) {
GST_LOG_OBJECT (self,
"Dropping observation: remote receive time %" GST_TIME_FORMAT
" < send time %" GST_TIME_FORMAT, GST_TIME_ARGS (remote_1),
GST_TIME_ARGS (remote_2));
goto bogus_observation;
}
/* The round trip time is (assuming symmetric path delays)
* delta = (local_2 - local_1) - (remote_2 - remote_1)
*/
rtt = GST_CLOCK_DIFF (local_1, local_2) - GST_CLOCK_DIFF (remote_1, remote_2);
if ((rtt_limit > 0) && (rtt > rtt_limit)) {
GST_LOG_OBJECT (self,
"Dropping observation: RTT %" GST_TIME_FORMAT " > limit %"
GST_TIME_FORMAT, GST_TIME_ARGS (rtt), GST_TIME_ARGS (rtt_limit));
goto bogus_observation;
}
for (i = 1; i < MEDIAN_PRE_FILTERING_WINDOW; i++)
self->priv->last_rtts[i - 1] = self->priv->last_rtts[i];
self->priv->last_rtts[i - 1] = rtt;
if (self->priv->last_rtts_missing) {
self->priv->last_rtts_missing--;
} else {
memcpy (&last_rtts, &self->priv->last_rtts, sizeof (last_rtts));
g_qsort_with_data (&last_rtts,
MEDIAN_PRE_FILTERING_WINDOW, sizeof (GstClockTime),
(GCompareDataFunc) compare_clock_time, NULL);
median = last_rtts[MEDIAN_PRE_FILTERING_WINDOW / 2];
/* FIXME: We might want to use something else here, like only allowing
* things in the interquartile range, or also filtering away delays that
* are too small compared to the median. This here worked well enough
* in tests so far.
*/
if (rtt > 2 * median) {
GST_LOG_OBJECT (self,
"Dropping observation, long RTT %" GST_TIME_FORMAT " > 2 * median %"
GST_TIME_FORMAT, GST_TIME_ARGS (rtt), GST_TIME_ARGS (median));
goto bogus_observation;
}
}
/* Track an average round trip time, for a bit of smoothing */
/* Always update before discarding a sample, so genuine changes in
* the network get picked up, eventually */
if (priv->rtt_avg == GST_CLOCK_TIME_NONE)
priv->rtt_avg = rtt;
else if (rtt < priv->rtt_avg) /* Shorter RTTs carry more weight than longer */
priv->rtt_avg = (3 * priv->rtt_avg + rtt) / 4;
else
priv->rtt_avg = (15 * priv->rtt_avg + rtt) / 16;
if (rtt > 2 * priv->rtt_avg) {
GST_LOG_OBJECT (self,
"Dropping observation, long RTT %" GST_TIME_FORMAT " > 2 * avg %"
GST_TIME_FORMAT, GST_TIME_ARGS (rtt), GST_TIME_ARGS (priv->rtt_avg));
goto bogus_observation;
}
/* The difference between the local and remote clock (again assuming
* symmetric path delays):
*
* local_1 + delta / 2 - remote_1 = theta
* or
* local_2 - delta / 2 - remote_2 = theta
*
* which gives after some simple algebraic transformations:
*
* (remote_1 - local_1) + (remote_2 - local_2)
* theta = -------------------------------------------
* 2
*
*
* Thus remote time at local_avg is equal to:
*
* local_avg + theta =
*
* local_1 + local_2 (remote_1 - local_1) + (remote_2 - local_2)
* ----------------- + -------------------------------------------
* 2 2
*
* =
*
* remote_1 + remote_2
* ------------------- = remote_avg
* 2
*
* We use this for our clock estimation, i.e. local_avg at remote clock
* being the same as remote_avg.
*/
local_avg = (local_2 + local_1) / 2;
remote_avg = (remote_2 + remote_1) / 2;
GST_LOG_OBJECT (self,
"local1 %" G_GUINT64_FORMAT " remote1 %" G_GUINT64_FORMAT " remote2 %"
G_GUINT64_FORMAT " remoteavg %" G_GUINT64_FORMAT " localavg %"
G_GUINT64_FORMAT " local2 %" G_GUINT64_FORMAT, local_1, remote_1,
remote_2, remote_avg, local_avg, local_2);
clock = GST_CLOCK_CAST (self);
/* Store what the clock produced as 'now' before this update */
gst_clock_get_calibration (internal_clock, &orig_internal_time,
&orig_external_time, &orig_rate_num, &orig_rate_den);
internal_time = orig_internal_time;
external_time = orig_external_time;
rate_num = orig_rate_num;
rate_den = orig_rate_den;
min_guess =
gst_clock_adjust_with_calibration (internal_clock, local_1,
internal_time, external_time, rate_num, rate_den);
time_before =
gst_clock_adjust_with_calibration (internal_clock, local_2,
internal_time, external_time, rate_num, rate_den);
/* Maximum discontinuity, when we're synched with the master. Could make this a property,
* but this value seems to work fine */
max_discont = priv->rtt_avg / 4;
/* If the remote observation was within a max_discont window around our min/max estimates, we're synched */
synched =
(GST_CLOCK_DIFF (remote_avg, min_guess) < (GstClockTimeDiff) (max_discont)
&& GST_CLOCK_DIFF (time_before,
remote_avg) < (GstClockTimeDiff) (max_discont));
if (gst_clock_add_observation_unapplied (internal_clock,
local_avg, remote_avg, &r_squared, &internal_time, &external_time,
&rate_num, &rate_den)) {
/* Now compare the difference (discont) in the clock
* after this observation */
time_discont = GST_CLOCK_DIFF (time_before,
gst_clock_adjust_with_calibration (internal_clock, local_2,
internal_time, external_time, rate_num, rate_den));
/* If we were in sync with the remote clock, clamp the allowed
* discontinuity to within quarter of one RTT. In sync means our send/receive estimates
* of remote time correctly windowed the actual remote time observation */
if (synched && ABS (time_discont) > max_discont) {
GstClockTimeDiff offset;
GST_DEBUG_OBJECT (clock,
"Too large a discont, clamping to 1/4 average RTT = %"
GST_TIME_FORMAT, GST_TIME_ARGS (max_discont));
if (time_discont > 0) { /* Too large a forward step - add a -ve offset */
offset = max_discont - time_discont;
if (-offset > external_time)
external_time = 0;
else
external_time += offset;
} else { /* Too large a backward step - add a +ve offset */
offset = -(max_discont + time_discont);
external_time += offset;
}
time_discont += offset;
}
/* Check if the new clock params would have made our observation within range */
now_synched =
(GST_CLOCK_DIFF (remote_avg,
gst_clock_adjust_with_calibration (internal_clock,
local_1, internal_time, external_time, rate_num,
rate_den)) < (GstClockTimeDiff) (max_discont))
&&
(GST_CLOCK_DIFF (gst_clock_adjust_with_calibration
(internal_clock, local_2, internal_time, external_time,
rate_num, rate_den),
remote_avg) < (GstClockTimeDiff) (max_discont));
/* Only update the clock if we had synch or just gained it */
if (synched || now_synched || priv->skipped_updates > MAX_SKIPPED_UPDATES) {
gst_clock_set_calibration (internal_clock, internal_time,
external_time, rate_num, rate_den);
/* ghetto formula - shorter timeout for bad correlations */
current_timeout = (1e-3 / (1 - MIN (r_squared, 0.99999))) * GST_SECOND;
current_timeout =
MIN (current_timeout, gst_clock_get_timeout (internal_clock));
priv->skipped_updates = 0;
/* FIXME: When do we consider the clock absolutely not synced anymore? */
gst_clock_set_synced (GST_CLOCK (self), TRUE);
} else {
/* Restore original calibration vars for the report, we're not changing the clock */
internal_time = orig_internal_time;
external_time = orig_external_time;
rate_num = orig_rate_num;
rate_den = orig_rate_den;
time_discont = 0;
priv->skipped_updates++;
}
}
/* Limit the polling to at most one per minimum_update_interval */
if (rtt < min_update_interval)
current_timeout = MAX (min_update_interval - rtt, current_timeout);
if (bus) {
GstStructure *s;
GstMessage *msg;
/* Output a stats message, whether we updated the clock or not */
s = gst_structure_new ("gst-netclock-statistics",
"synchronised", G_TYPE_BOOLEAN, synched,
"rtt", G_TYPE_UINT64, rtt,
"rtt-average", G_TYPE_UINT64, priv->rtt_avg,
"local", G_TYPE_UINT64, local_avg,
"remote", G_TYPE_UINT64, remote_avg,
"discontinuity", G_TYPE_INT64, time_discont,
"remote-min-estimate", G_TYPE_UINT64, min_guess,
"remote-max-estimate", G_TYPE_UINT64, time_before,
"remote-min-error", G_TYPE_INT64, GST_CLOCK_DIFF (remote_avg,
min_guess), "remote-max-error", G_TYPE_INT64,
GST_CLOCK_DIFF (remote_avg, time_before), "request-send", G_TYPE_UINT64,
local_1, "request-receive", G_TYPE_UINT64, local_2, "r-squared",
G_TYPE_DOUBLE, r_squared, "timeout", G_TYPE_UINT64, current_timeout,
"internal-time", G_TYPE_UINT64, internal_time, "external-time",
G_TYPE_UINT64, external_time, "rate-num", G_TYPE_UINT64, rate_num,
"rate-den", G_TYPE_UINT64, rate_den, "rate", G_TYPE_DOUBLE,
(gdouble) (rate_num) / rate_den, "local-clock-offset", G_TYPE_INT64,
GST_CLOCK_DIFF (internal_time, external_time), NULL);
msg = gst_message_new_element (GST_OBJECT (self), s);
gst_bus_post (bus, msg);
}
GST_INFO ("next timeout: %" GST_TIME_FORMAT, GST_TIME_ARGS (current_timeout));
self->priv->timeout_expiration = gst_util_get_timestamp () + current_timeout;
if (bus)
gst_object_unref (bus);
return;
bogus_observation:
if (bus)
gst_object_unref (bus);
/* Schedule a new packet again soon */
self->priv->timeout_expiration = gst_util_get_timestamp () + (GST_SECOND / 4);
return;
}
static gpointer
gst_net_client_clock_thread (gpointer data)
{
GstNetClientClock *self = data;
GstClock *internal_clock = self->priv->internal_clock;
GSocket *socket = self->priv->socket;
GError *err = NULL;
GST_INFO_OBJECT (self, "net client clock thread running, socket=%p", socket);
g_socket_set_blocking (socket, TRUE);
g_socket_set_timeout (socket, 0);
while (!g_cancellable_is_cancelled (self->priv->cancel)) {
GstClockTime expiration_time = self->priv->timeout_expiration;
GstClockTime now = gst_util_get_timestamp ();
gint64 socket_timeout;
if (now >= expiration_time || (expiration_time - now) <= GST_MSECOND) {
socket_timeout = 0;
} else {
socket_timeout = (expiration_time - now) / GST_USECOND;
}
GST_TRACE_OBJECT (self, "timeout: %" G_GINT64_FORMAT "us", socket_timeout);
if (!g_socket_condition_timed_wait (socket, G_IO_IN, socket_timeout,
self->priv->cancel, &err)) {
/* cancelled, timeout or error */
if (err->code == G_IO_ERROR_CANCELLED) {
GST_INFO_OBJECT (self, "cancelled");
g_clear_error (&err);
break;
} else if (err->code == G_IO_ERROR_TIMED_OUT) {
/* timed out, let's send another packet */
GST_DEBUG_OBJECT (self, "timed out");
if (self->priv->is_ntp) {
GstNtpPacket *packet;
packet = gst_ntp_packet_new (NULL, NULL);
packet->transmit_time = gst_clock_get_internal_time (internal_clock);
GST_DEBUG_OBJECT (self,
"sending packet, local time = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->transmit_time));
gst_ntp_packet_send (packet, self->priv->socket,
self->priv->servaddr, NULL);
g_free (packet);
} else {
GstNetTimePacket *packet;
packet = gst_net_time_packet_new (NULL);
packet->local_time = gst_clock_get_internal_time (internal_clock);
GST_DEBUG_OBJECT (self,
"sending packet, local time = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->local_time));
gst_net_time_packet_send (packet, self->priv->socket,
self->priv->servaddr, NULL);
g_free (packet);
}
/* reset timeout (but are expecting a response sooner anyway) */
self->priv->timeout_expiration =
gst_util_get_timestamp () + gst_clock_get_timeout (internal_clock);
} else {
GST_DEBUG_OBJECT (self, "socket error: %s", err->message);
g_usleep (G_USEC_PER_SEC / 10); /* throttle */
}
g_clear_error (&err);
} else {
GstClockTime new_local;
/* got packet */
new_local = gst_clock_get_internal_time (internal_clock);
if (self->priv->is_ntp) {
GstNtpPacket *packet;
packet = gst_ntp_packet_receive (socket, NULL, &err);
if (packet != NULL) {
GST_LOG_OBJECT (self, "got packet back");
GST_LOG_OBJECT (self, "local_1 = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->origin_time));
GST_LOG_OBJECT (self, "remote_1 = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->receive_time));
GST_LOG_OBJECT (self, "remote_2 = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->transmit_time));
GST_LOG_OBJECT (self, "local_2 = %" GST_TIME_FORMAT,
GST_TIME_ARGS (new_local));
GST_LOG_OBJECT (self, "poll_interval = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->poll_interval));
/* Remember the last poll interval we ever got from the server */
if (packet->poll_interval != GST_CLOCK_TIME_NONE)
self->priv->last_remote_poll_interval = packet->poll_interval;
/* observe_times will reset the timeout */
gst_net_client_clock_observe_times (self, packet->origin_time,
packet->receive_time, packet->transmit_time, new_local);
g_free (packet);
} else if (err != NULL) {
if (g_error_matches (err, GST_NTP_ERROR, GST_NTP_ERROR_WRONG_VERSION)
|| g_error_matches (err, GST_NTP_ERROR, GST_NTP_ERROR_KOD_DENY)) {
GST_ERROR_OBJECT (self, "fatal receive error: %s", err->message);
break;
} else if (g_error_matches (err, GST_NTP_ERROR,
GST_NTP_ERROR_KOD_RATE)) {
GST_WARNING_OBJECT (self, "need to limit rate");
/* If the server did not tell us a poll interval before, double
* our minimum poll interval. Otherwise we assume that the server
* already told us something sensible and that this error here
* was just a spurious error */
if (self->priv->last_remote_poll_interval == GST_CLOCK_TIME_NONE)
self->priv->minimum_update_interval *= 2;
/* And wait a bit before we send the next packet instead of
* sending it immediately */
self->priv->timeout_expiration =
gst_util_get_timestamp () +
gst_clock_get_timeout (internal_clock);
} else {
GST_WARNING_OBJECT (self, "receive error: %s", err->message);
}
g_clear_error (&err);
}
} else {
GstNetTimePacket *packet;
packet = gst_net_time_packet_receive (socket, NULL, &err);
if (packet != NULL) {
GST_LOG_OBJECT (self, "got packet back");
GST_LOG_OBJECT (self, "local_1 = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->local_time));
GST_LOG_OBJECT (self, "remote = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->remote_time));
GST_LOG_OBJECT (self, "local_2 = %" GST_TIME_FORMAT,
GST_TIME_ARGS (new_local));
/* observe_times will reset the timeout */
gst_net_client_clock_observe_times (self, packet->local_time,
packet->remote_time, packet->remote_time, new_local);
g_free (packet);
} else if (err != NULL) {
GST_WARNING_OBJECT (self, "receive error: %s", err->message);
g_clear_error (&err);
}
}
}
}
GST_INFO_OBJECT (self, "shutting down net client clock thread");
return NULL;
}
static gboolean
gst_net_client_clock_start (GstNetClientClock * self)
{
GSocketAddress *servaddr;
GSocketAddress *myaddr;
GSocketAddress *anyaddr;
GInetAddress *inetaddr;
GSocket *socket;
GError *error = NULL;
GSocketFamily family;
GPollFD dummy_pollfd;
g_return_val_if_fail (self->priv->address != NULL, FALSE);
g_return_val_if_fail (self->priv->servaddr == NULL, FALSE);
/* create target address */
inetaddr = g_inet_address_new_from_string (self->priv->address);
if (inetaddr == NULL)
goto bad_address;
family = g_inet_address_get_family (inetaddr);
servaddr = g_inet_socket_address_new (inetaddr, self->priv->port);
g_object_unref (inetaddr);
g_assert (servaddr != NULL);
GST_DEBUG_OBJECT (self, "will communicate with %s:%d", self->priv->address,
self->priv->port);
socket = g_socket_new (family, G_SOCKET_TYPE_DATAGRAM,
G_SOCKET_PROTOCOL_UDP, &error);
if (socket == NULL)
goto no_socket;
GST_DEBUG_OBJECT (self, "binding socket");
inetaddr = g_inet_address_new_any (family);
anyaddr = g_inet_socket_address_new (inetaddr, 0);
g_socket_bind (socket, anyaddr, TRUE, &error);
g_object_unref (anyaddr);
g_object_unref (inetaddr);
if (error != NULL)
goto bind_error;
/* check address we're bound to, mostly for debugging purposes */
myaddr = g_socket_get_local_address (socket, &error);
if (myaddr == NULL)
goto getsockname_error;
GST_DEBUG_OBJECT (self, "socket opened on UDP port %d",
g_inet_socket_address_get_port (G_INET_SOCKET_ADDRESS (myaddr)));
g_object_unref (myaddr);
self->priv->cancel = g_cancellable_new ();
self->priv->made_cancel_fd =
g_cancellable_make_pollfd (self->priv->cancel, &dummy_pollfd);
self->priv->socket = socket;
self->priv->servaddr = G_SOCKET_ADDRESS (servaddr);
self->priv->thread = g_thread_try_new ("GstNetClientClock",
gst_net_client_clock_thread, self, &error);
if (error != NULL)
goto no_thread;
return TRUE;
/* ERRORS */
no_socket:
{
GST_ERROR_OBJECT (self, "socket_new() failed: %s", error->message);
g_error_free (error);
return FALSE;
}
bind_error:
{
GST_ERROR_OBJECT (self, "bind failed: %s", error->message);
g_error_free (error);
g_object_unref (socket);
return FALSE;
}
getsockname_error:
{
GST_ERROR_OBJECT (self, "get_local_address() failed: %s", error->message);
g_error_free (error);
g_object_unref (socket);
return FALSE;
}
bad_address:
{
GST_ERROR_OBJECT (self, "inet_address_new_from_string('%s') failed",
self->priv->address);
return FALSE;
}
no_thread:
{
GST_ERROR_OBJECT (self, "could not create thread: %s", error->message);
g_object_unref (self->priv->servaddr);
self->priv->servaddr = NULL;
g_object_unref (self->priv->socket);
self->priv->socket = NULL;
g_error_free (error);
return FALSE;
}
}
static void
gst_net_client_clock_stop (GstNetClientClock * self)
{
if (self->priv->thread == NULL)
return;
GST_INFO_OBJECT (self, "stopping...");
g_cancellable_cancel (self->priv->cancel);
g_thread_join (self->priv->thread);
self->priv->thread = NULL;
if (self->priv->made_cancel_fd)
g_cancellable_release_fd (self->priv->cancel);
g_object_unref (self->priv->cancel);
self->priv->cancel = NULL;
g_object_unref (self->priv->servaddr);
self->priv->servaddr = NULL;
g_object_unref (self->priv->socket);
self->priv->socket = NULL;
GST_INFO_OBJECT (self, "stopped");
}
/**
* gst_net_client_clock_new:
* @name: a name for the clock
* @remote_address: the address of the remote clock provider
* @remote_port: the port of the remote clock provider
* @base_time: initial time of the clock
*
* Create a new #GstNetClientClock that will report the time
* provided by the #GstNetTimeProvider on @remote_address and
* @remote_port.
*
* Returns: a new #GstClock that receives a time from the remote
* clock.
*/
GstClock *
gst_net_client_clock_new (const gchar * name, const gchar * remote_address,
gint remote_port, GstClockTime base_time)
{
GstNetClientClock *ret;
g_return_val_if_fail (remote_address != NULL, NULL);
g_return_val_if_fail (remote_port > 0, NULL);
g_return_val_if_fail (remote_port <= G_MAXUINT16, NULL);
g_return_val_if_fail (base_time != GST_CLOCK_TIME_NONE, NULL);
ret = g_object_new (GST_TYPE_NET_CLIENT_CLOCK, "address", remote_address,
"port", remote_port, "base-time", base_time, NULL);
return (GstClock *) ret;
}
G_DEFINE_TYPE (GstNtpClock, gst_ntp_clock, GST_TYPE_NET_CLIENT_CLOCK);
static void
gst_ntp_clock_class_init (GstNtpClockClass * klass)
{
}
static void
gst_ntp_clock_init (GstNtpClock * self)
{
GST_NET_CLIENT_CLOCK (self)->priv->is_ntp = TRUE;
}
/**
* gst_ntp_clock_new:
* @name: a name for the clock
* @remote_address: the address of the remote clock provider
* @remote_port: the port of the remote clock provider
* @base_time: initial time of the clock
*
* Create a new #GstNtpClock that will report the time provided by
* the NTPv4 server on @remote_address and @remote_port.
*
* Returns: a new #GstClock that receives a time from the remote
* clock.
*
* Since: 1.6
*/
GstClock *
gst_ntp_clock_new (const gchar * name, const gchar * remote_address,
gint remote_port, GstClockTime base_time)
{
GstNetClientClock *ret;
g_return_val_if_fail (remote_address != NULL, NULL);
g_return_val_if_fail (remote_port > 0, NULL);
g_return_val_if_fail (remote_port <= G_MAXUINT16, NULL);
g_return_val_if_fail (base_time != GST_CLOCK_TIME_NONE, NULL);
ret = g_object_new (GST_TYPE_NTP_CLOCK, "address", remote_address,
"port", remote_port, "base-time", base_time, NULL);
return (GstClock *) ret;
}
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