/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2005 Wim Taymans * 2005 Andy Wingo * * 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 #include "gstnettimepacket.h" #include "gstnetclientclock.h" GST_DEBUG_CATEGORY_STATIC (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 #ifdef G_OS_WIN32 #define getsockname(sock,addr,len) getsockname(sock,addr,(int *)len) #endif 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); #ifdef G_OS_WIN32 static int inet_aton (const char *c, struct in_addr *paddr) { /* note that inet_addr is deprecated on unix because * inet_addr returns -1 (INADDR_NONE) for the valid 255.255.255.255 * address. */ paddr->s_addr = inet_addr (c); if (paddr->s_addr == INADDR_NONE) return 0; return 1; } #endif 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 = G_OBJECT_CLASS (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 (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)); } static void gst_net_client_clock_init (GstNetClientClock * self, GstNetClientClockClass * g_class) { GstClock *clock = GST_CLOCK_CAST (self); #ifdef G_OS_WIN32 WSADATA w; int error = WSAStartup (0x0202, &w); if (error) { GST_DEBUG_OBJECT (self, "Error on WSAStartup"); } if (w.wVersion != 0x0202) { WSACleanup (); } #endif 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; #ifdef G_OS_WIN32 WSACleanup (); #endif 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); #ifdef G_OS_WIN32 if (((max_sock + 1) != READ_SOCKET (self)) || ((max_sock + 1) != WRITE_SOCKET (self))) { ret = select (max_sock + 1, readfds, NULL, NULL, (struct timeval *) ptv); } else { ret = 1; } #else ret = select (max_sock + 1, readfds, NULL, NULL, (struct timeval *) ptv); #endif 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; memset (&servaddr, 0, sizeof (servaddr)); servaddr.sin_family = AF_INET; /* host byte order */ servaddr.sin_port = htons (self->port); /* short, network byte order */ GST_DEBUG_OBJECT (self, "socket opened on UDP port %hd", ntohs (servaddr.sin_port)); 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!"); } #ifdef G_OS_WIN32 GST_DEBUG_OBJECT (ret, "creating pipe"); if ((iret = pipe (CONTROL_SOCKETS (ret))) < 0) goto no_socket_pair; #else 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); #endif 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; } }