gstreamer/gst/net/gstnetclientclock.c
Wim Taymans a9f7f7b7b6 Doc fixes.
Original commit message from CVS:
Doc fixes.
2005-11-24 09:44:07 +00:00

597 lines
16 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2005 Wim Taymans <wim@fluendo.com>
* 2005 Andy Wingo <wingo@pobox.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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstnetclientclock
* @short_description: Special clock that synchronizes to a remote time
* provider.
* @see_also: #GstClock, #GstNetTimeProvider, #GstPipeline
*
* This object implements a custom #GstClock that synchronizes its time
* to a remote time provider such as #GstNetTimeProvider.
*
* A new clock is created with gst_net_client_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.
*
* Various parameters of the clock can be configured with the parent #GstClock
* "timeout", "window-size" and "window-threshold" object properties.
*
* A #GstNetClientClock is typically set on a #GstPipeline with
* gst_pipeline_use_clock().
*
* Last reviewed on 2005-11-23 (0.9.5)
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <unistd.h>
#include "gstnettimepacket.h"
#include "gstnetclientclock.h"
GST_DEBUG_CATEGORY (ncc_debug);
#define GST_CAT_DEFAULT (ncc_debug)
/* #define DEBUGGING_ENABLED */
#ifdef DEBUGGING_ENABLED
#define DEBUG(x, args...) g_print (x "\n", ##args)
#else
#define DEBUG(x, args...) /* nop */
#endif
/* the select call is also performed on the control sockets, that way
* we can send special commands to unblock or restart the select call */
#define CONTROL_RESTART 'R' /* restart the select call */
#define CONTROL_STOP 'S' /* stop the select call */
#define CONTROL_SOCKETS(self) self->control_sock
#define WRITE_SOCKET(self) self->control_sock[1]
#define READ_SOCKET(self) self->control_sock[0]
#define SEND_COMMAND(self, command) \
G_STMT_START { \
unsigned char c; c = command; \
write (WRITE_SOCKET(self), &c, 1); \
} G_STMT_END
#define READ_COMMAND(self, command, res) \
G_STMT_START { \
res = read(READ_SOCKET(self), &command, 1); \
} G_STMT_END
#define DEFAULT_ADDRESS "127.0.0.1"
#define DEFAULT_PORT 5637
#define DEFAULT_TIMEOUT GST_SECOND
enum
{
PROP_0,
PROP_ADDRESS,
PROP_PORT,
};
#define _do_init(type) \
GST_DEBUG_CATEGORY_INIT (ncc_debug, "netclock", 0, "Network client clock");
GST_BOILERPLATE_FULL (GstNetClientClock, gst_net_client_clock,
GstSystemClock, 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_stop (GstNetClientClock * self);
static void
gst_net_client_clock_base_init (gpointer g_class)
{
/* nop */
}
static void
gst_net_client_clock_class_init (GstNetClientClockClass * klass)
{
GObjectClass *gobject_class;
gobject_class = (GObjectClass *) klass;
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;
g_object_class_install_property (gobject_class, PROP_ADDRESS,
g_param_spec_string ("address", "address",
"The address of the machine providing a time server, "
"as a dotted quad (x.x.x.x)", DEFAULT_ADDRESS, G_PARAM_READWRITE));
g_object_class_install_property (G_OBJECT_CLASS (klass), 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));
}
static void
gst_net_client_clock_init (GstNetClientClock * self,
GstNetClientClockClass * g_class)
{
GstClock *clock = GST_CLOCK_CAST (self);
self->port = DEFAULT_PORT;
self->address = g_strdup (DEFAULT_ADDRESS);
clock->timeout = DEFAULT_TIMEOUT;
self->sock = -1;
self->thread = NULL;
self->servaddr = NULL;
READ_SOCKET (self) = -1;
WRITE_SOCKET (self) = -1;
}
static void
gst_net_client_clock_finalize (GObject * object)
{
GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);
if (self->thread) {
gst_net_client_clock_stop (self);
g_assert (self->thread == NULL);
}
if (READ_SOCKET (self) != -1) {
close (READ_SOCKET (self));
close (WRITE_SOCKET (self));
READ_SOCKET (self) = -1;
WRITE_SOCKET (self) = -1;
}
g_free (self->address);
self->address = NULL;
g_free (self->servaddr);
self->servaddr = 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:
g_free (self->address);
if (g_value_get_string (value) == NULL)
self->address = g_strdup (DEFAULT_ADDRESS);
else
self->address = g_strdup (g_value_get_string (value));
break;
case PROP_PORT:
self->port = g_value_get_int (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:
g_value_set_string (value, self->address);
break;
case PROP_PORT:
g_value_set_int (value, self->port);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_net_client_clock_observe_times (GstNetClientClock * self,
GstClockTime local_1, GstClockTime remote, GstClockTime local_2)
{
GstClockTime local_avg;
gdouble r_squared;
GstClock *clock;
if (local_2 < local_1)
goto bogus_observation;
local_avg = (local_2 + local_1) / 2;
clock = GST_CLOCK_CAST (self);
gst_clock_add_observation (GST_CLOCK (self), local_avg, remote, &r_squared);
GST_CLOCK_SLAVE_LOCK (self);
if (clock->filling) {
self->current_timeout = 0;
} else {
/* geto formula */
self->current_timeout =
(1e-3 / (1 - MIN (r_squared, 0.99999))) * GST_SECOND;
self->current_timeout = MIN (self->current_timeout, clock->timeout);
}
GST_CLOCK_SLAVE_UNLOCK (clock);
return;
bogus_observation:
{
GST_WARNING_OBJECT (self, "time packet receive time < send time (%",
GST_TIME_FORMAT, " < %" GST_TIME_FORMAT ")", GST_TIME_ARGS (local_1),
GST_TIME_ARGS (local_2));
return;
}
}
static gint
gst_net_client_clock_do_select (GstNetClientClock * self, fd_set * readfds)
{
gint max_sock;
gint ret;
while (TRUE) {
FD_ZERO (readfds);
FD_SET (self->sock, readfds);
FD_SET (READ_SOCKET (self), readfds);
max_sock = MAX (self->sock, READ_SOCKET (self));
GST_LOG_OBJECT (self, "doing select");
{
GstClockTime diff;
GTimeVal tv, *ptv = &tv;
diff = gst_clock_get_internal_time (GST_CLOCK (self));
GST_TIME_TO_TIMEVAL (self->current_timeout, tv);
ret = select (max_sock + 1, readfds, NULL, NULL, (struct timeval *) ptv);
diff = gst_clock_get_internal_time (GST_CLOCK (self)) - diff;
if (diff > self->current_timeout)
self->current_timeout = 0;
else
self->current_timeout -= diff;
}
GST_LOG_OBJECT (self, "select returned %d", ret);
if (ret < 0) {
if (errno != EAGAIN && errno != EINTR)
goto select_error;
else
continue;
} else {
return ret;
}
g_assert_not_reached ();
/* log errors and keep going */
select_error:
{
GST_WARNING_OBJECT (self, "select error %d: %s (%d)", ret,
g_strerror (errno), errno);
continue;
}
}
g_assert_not_reached ();
return -1;
}
static gpointer
gst_net_client_clock_thread (gpointer data)
{
GstNetClientClock *self = data;
struct sockaddr_in tmpaddr;
socklen_t len;
fd_set read_fds;
GstNetTimePacket *packet;
gint ret;
GstClock *clock = data;
while (TRUE) {
ret = gst_net_client_clock_do_select (self, &read_fds);
if (FD_ISSET (READ_SOCKET (self), &read_fds)) {
/* got control message */
while (TRUE) {
gchar command;
int res;
READ_COMMAND (self, command, res);
if (res < 0) {
GST_LOG_OBJECT (self, "no more commands");
break;
}
DEBUG ("control message: '%c'", command);
switch (command) {
case CONTROL_STOP:
/* break out of the select loop */
GST_LOG_OBJECT (self, "stop");
goto stopped;
default:
GST_WARNING_OBJECT (self, "unknown message: '%c'", command);
g_warning ("netclientclock: unknown control message received");
continue;
}
g_assert_not_reached ();
}
continue;
} else if (ret == 0) {
/* timed out, let's send another packet */
DEBUG ("timed out");
packet = gst_net_time_packet_new (NULL);
packet->local_time = gst_clock_get_internal_time (GST_CLOCK (self));
DEBUG ("sending packet, local time = %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet->local_time));
gst_net_time_packet_send (packet, self->sock,
(struct sockaddr *) self->servaddr, sizeof (struct sockaddr_in));
g_free (packet);
/* reset timeout */
self->current_timeout = clock->timeout;
continue;
} else if (FD_ISSET (self->sock, &read_fds)) {
/* got data in */
GstClockTime new_local = gst_clock_get_internal_time (GST_CLOCK (self));
len = sizeof (struct sockaddr);
packet = gst_net_time_packet_receive (self->sock,
(struct sockaddr *) &tmpaddr, &len);
if (!packet)
goto receive_error;
DEBUG ("got packet back");
DEBUG ("local_1 = %" GST_TIME_FORMAT, GST_TIME_ARGS (packet->local_time));
DEBUG ("remote = %" GST_TIME_FORMAT, GST_TIME_ARGS (packet->remote_time));
DEBUG ("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, new_local);
g_free (packet);
continue;
} else {
GST_WARNING_OBJECT (self, "unhandled select return state?");
continue;
}
g_assert_not_reached ();
stopped:
{
GST_DEBUG_OBJECT (self, "shutting down");
/* socket gets closed in _stop() */
return NULL;
}
receive_error:
{
GST_WARNING_OBJECT (self, "receive error");
continue;
}
g_assert_not_reached ();
}
g_assert_not_reached ();
return NULL;
}
static gboolean
gst_net_client_clock_start (GstNetClientClock * self)
{
struct sockaddr_in servaddr, myaddr;
socklen_t len;
gint ret;
GError *error;
g_return_val_if_fail (self->address != NULL, FALSE);
g_return_val_if_fail (self->servaddr == NULL, FALSE);
if ((ret = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
goto no_socket;
self->sock = ret;
len = sizeof (myaddr);
ret = getsockname (self->sock, (struct sockaddr *) &myaddr, &len);
if (ret < 0)
goto getsockname_error;
GST_DEBUG_OBJECT (self, "socket opened on UDP port %hd",
ntohs (servaddr.sin_port));
memset (&servaddr, 0, sizeof (servaddr));
servaddr.sin_family = AF_INET; /* host byte order */
servaddr.sin_port = htons (self->port); /* short, network byte order */
if (!inet_aton (self->address, &servaddr.sin_addr))
goto bad_address;
self->servaddr = g_malloc (sizeof (struct sockaddr_in));
memcpy (self->servaddr, &servaddr, sizeof (servaddr));
GST_DEBUG_OBJECT (self, "will communicate with %s:%d", self->address,
self->port);
self->thread = g_thread_create (gst_net_client_clock_thread, self, TRUE,
&error);
if (!self->thread)
goto no_thread;
return TRUE;
/* ERRORS */
no_socket:
{
GST_ERROR_OBJECT (self, "socket failed %d: %s (%d)", ret,
g_strerror (errno), errno);
return FALSE;
}
getsockname_error:
{
GST_ERROR_OBJECT (self, "getsockname failed %d: %s (%d)", ret,
g_strerror (errno), errno);
close (self->sock);
self->sock = -1;
return FALSE;
}
bad_address:
{
GST_ERROR_OBJECT (self, "inet_aton failed %d: %s (%d)", ret,
g_strerror (errno), errno);
close (self->sock);
self->sock = -1;
return FALSE;
}
no_thread:
{
GST_ERROR_OBJECT (self, "could not create thread: %s", error->message);
close (self->sock);
self->sock = -1;
g_free (self->servaddr);
self->servaddr = NULL;
g_error_free (error);
return FALSE;
}
}
static void
gst_net_client_clock_stop (GstNetClientClock * self)
{
SEND_COMMAND (self, CONTROL_STOP);
g_thread_join (self->thread);
self->thread = NULL;
if (self->sock != -1) {
close (self->sock);
self->sock = -1;
}
}
/**
* 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 #GstNetClockProvider on @remote_address and
* @remote_port.
*
* Returns: a new #GstClock that receives a time from the remote
* clock.
*/
GstClock *
gst_net_client_clock_new (gchar * name, const gchar * remote_address,
gint remote_port, GstClockTime base_time)
{
GstNetClientClock *ret;
GstClockTime internal;
gint iret;
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, NULL);
/* 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 (GST_CLOCK (ret));
gst_clock_set_calibration (GST_CLOCK (ret), internal, base_time, 1, 1);
{
GstClockTime now = gst_clock_get_time (GST_CLOCK (ret));
if (now < base_time || now > base_time + GST_SECOND)
g_warning ("unable to set the base time, expect sync problems!");
}
GST_DEBUG_OBJECT (ret, "creating socket pair");
if ((iret = socketpair (PF_UNIX, SOCK_STREAM, 0, CONTROL_SOCKETS (ret))) < 0)
goto no_socket_pair;
fcntl (READ_SOCKET (ret), F_SETFL, O_NONBLOCK);
fcntl (WRITE_SOCKET (ret), F_SETFL, O_NONBLOCK);
if (!gst_net_client_clock_start (ret))
goto failed_start;
/* all systems go, cap'n */
return (GstClock *) ret;
no_socket_pair:
{
GST_ERROR_OBJECT (ret, "no socket pair %d: %s (%d)", iret,
g_strerror (errno), errno);
gst_object_unref (ret);
return NULL;
}
failed_start:
{
/* already printed a nice error */
gst_object_unref (ret);
return NULL;
}
}