1 /* GStreamer

     2  * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>

     3  *                    2005 Wim Taymans <wim@fluendo.com>

     4  *                    2005 Andy Wingo <wingo@pobox.com>

     5  *

     6  * gstnetclientclock.h: clock that synchronizes itself to a time provider over

     7  * the network

     8  *

     9  * This library is free software; you can redistribute it and/or

    10  * modify it under the terms of the GNU Library General Public

    11  * License as published by the Free Software Foundation; either

    12  * version 2 of the License, or (at your option) any later version.

    13  *

    14  * This library is distributed in the hope that it will be useful,

    15  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    17  * Library General Public License for more details.

    18  *

    19  * You should have received a copy of the GNU Library General Public

    20  * License along with this library; if not, write to the

    21  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

    22  * Boston, MA 02111-1307, USA.

    23  */

    24 /**

    25  * SECTION:gstnetclientclock

    26  * @short_description: Special clock that synchronizes to a remote time

    27  *                     provider.

    28  * @see_also: #GstClock, #GstNetTimeProvider, #GstPipeline

    29  *

    30  * This object implements a custom #GstClock that synchronizes its time

    31  * to a remote time provider such as #GstNetTimeProvider.

    32  *

    33  * A new clock is created with gst_net_client_clock_new() which takes the

    34  * address and port of the remote time provider along with a name and

    35  * an initial time.

    36  *

    37  * This clock will poll the time provider and will update its calibration

    38  * parameters based on the local and remote observations.

    39  *

    40  * Various parameters of the clock can be configured with the parent #GstClock

    41  * "timeout", "window-size" and "window-threshold" object properties.

    42  *

    43  * A #GstNetClientClock is typically set on a #GstPipeline with 

    44  * gst_pipeline_use_clock().

    45  *

    46  * Last reviewed on 2005-11-23 (0.9.5)

    47  */

    48 

    49 #ifdef HAVE_CONFIG_H

    50 #include "config.h"

    51 #endif

    52 

    53 #include "gstnettimepacket.h"

    54 #include "gstnetclientclock.h"

    55 

    56 #ifdef HAVE_UNISTD_H

    57 #include <unistd.h>

    58 #endif

    59 #ifdef __SYMBIAN32__

    60 #include <sys/select.h>

    61 #include <glib_global.h>

    62 #endif

    63 

    64 #if defined (_MSC_VER) && _MSC_VER >= 1400

    65 #include <io.h>

    66 #endif

    67 

    68 GST_DEBUG_CATEGORY_STATIC (ncc_debug);

    69 #define GST_CAT_DEFAULT (ncc_debug)

    70 

    71 #define DEFAULT_ADDRESS         "127.0.0.1"

    72 #define DEFAULT_PORT            5637

    73 #define DEFAULT_TIMEOUT         GST_SECOND

    74 

    75 #ifdef G_OS_WIN32

    76 #define getsockname(sock,addr,len) getsockname(sock,addr,(int *)len)

    77 #endif

    78 

    79 enum

    80 {

    81   PROP_0,

    82   PROP_ADDRESS,

    83   PROP_PORT,

    84 };

    85 

    86 #define GST_NET_CLIENT_CLOCK_GET_PRIVATE(obj)  \

    87   (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_NET_CLIENT_CLOCK, GstNetClientClockPrivate))

    88 

    89 struct _GstNetClientClockPrivate

    90 {

    91   GstPollFD sock;

    92   GstPoll *fdset;

    93 };

    94 

    95 #define _do_init(type) \

    96   GST_DEBUG_CATEGORY_INIT (ncc_debug, "netclock", 0, "Network client clock");

    97 

    98 GST_BOILERPLATE_FULL (GstNetClientClock, gst_net_client_clock,

    99     GstSystemClock, GST_TYPE_SYSTEM_CLOCK, _do_init);

   100 

   101 static void gst_net_client_clock_finalize (GObject * object);

   102 static void gst_net_client_clock_set_property (GObject * object, guint prop_id,

   103     const GValue * value, GParamSpec * pspec);

   104 static void gst_net_client_clock_get_property (GObject * object, guint prop_id,

   105     GValue * value, GParamSpec * pspec);

   106 

   107 static void gst_net_client_clock_stop (GstNetClientClock * self);

   108 

   109 #ifdef G_OS_WIN32

   110 static int

   111 inet_aton (const char *c, struct in_addr *paddr)

   112 {

   113   /* note that inet_addr is deprecated on unix because

   114    * inet_addr returns -1 (INADDR_NONE) for the valid 255.255.255.255

   115    * address. */

   116   paddr->s_addr = inet_addr (c);

   117   if (paddr->s_addr == INADDR_NONE)

   118     return 0;

   119 

   120   return 1;

   121 }

   122 #endif

   123 

   124 static void

   125 gst_net_client_clock_base_init (gpointer g_class)

   126 {

   127   /* nop */

   128 }

   129 

   130 static void

   131 gst_net_client_clock_class_init (GstNetClientClockClass * klass)

   132 {

   133   GObjectClass *gobject_class;

   134 

   135   gobject_class = G_OBJECT_CLASS (klass);

   136 

   137   g_type_class_add_private (klass, sizeof (GstNetClientClockPrivate));

   138 

   139   gobject_class->finalize = gst_net_client_clock_finalize;

   140   gobject_class->get_property = gst_net_client_clock_get_property;

   141   gobject_class->set_property = gst_net_client_clock_set_property;

   142 

   143   g_object_class_install_property (gobject_class, PROP_ADDRESS,

   144       g_param_spec_string ("address", "address",

   145           "The address of the machine providing a time server, "

   146           "as a dotted quad (x.x.x.x)", DEFAULT_ADDRESS, G_PARAM_READWRITE));

   147   g_object_class_install_property (gobject_class, PROP_PORT,

   148       g_param_spec_int ("port", "port",

   149           "The port on which the remote server is listening", 0, G_MAXUINT16,

   150           DEFAULT_PORT, G_PARAM_READWRITE));

   151 }

   152 

   153 static void

   154 gst_net_client_clock_init (GstNetClientClock * self,

   155     GstNetClientClockClass * g_class)

   156 {

   157   GstClock *clock = GST_CLOCK_CAST (self);

   158 

   159 #ifdef G_OS_WIN32

   160   WSADATA w;

   161   int error = WSAStartup (0x0202, &w);

   162 

   163   if (error) {

   164     GST_DEBUG_OBJECT (self, "Error on WSAStartup");

   165   }

   166   if (w.wVersion != 0x0202) {

   167     WSACleanup ();

   168   }

   169 #endif

   170   self->priv = GST_NET_CLIENT_CLOCK_GET_PRIVATE (self);

   171 

   172   self->port = DEFAULT_PORT;

   173   self->address = g_strdup (DEFAULT_ADDRESS);

   174 

   175   clock->timeout = DEFAULT_TIMEOUT;

   176 

   177   self->priv->sock.fd = -1;

   178   self->thread = NULL;

   179 

   180   self->servaddr = NULL;

   181 }

   182 

   183 static void

   184 gst_net_client_clock_finalize (GObject * object)

   185 {

   186   GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);

   187 

   188   if (self->thread) {

   189     gst_net_client_clock_stop (self);

   190     g_assert (self->thread == NULL);

   191   }

   192 

   193   if (self->priv->fdset) {

   194     gst_poll_free (self->priv->fdset);

   195     self->priv->fdset = NULL;

   196   }

   197 

   198   g_free (self->address);

   199   self->address = NULL;

   200 

   201   g_free (self->servaddr);

   202   self->servaddr = NULL;

   203 

   204 #ifdef G_OS_WIN32

   205   WSACleanup ();

   206 #endif

   207 

   208   G_OBJECT_CLASS (parent_class)->finalize (object);

   209 }

   210 

   211 static void

   212 gst_net_client_clock_set_property (GObject * object, guint prop_id,

   213     const GValue * value, GParamSpec * pspec)

   214 {

   215   GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);

   216 

   217   switch (prop_id) {

   218     case PROP_ADDRESS:

   219       g_free (self->address);

   220       if (g_value_get_string (value) == NULL)

   221         self->address = g_strdup (DEFAULT_ADDRESS);

   222       else

   223         self->address = g_strdup (g_value_get_string (value));

   224       break;

   225     case PROP_PORT:

   226       self->port = g_value_get_int (value);

   227       break;

   228     default:

   229       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

   230       break;

   231   }

   232 }

   233 

   234 static void

   235 gst_net_client_clock_get_property (GObject * object, guint prop_id,

   236     GValue * value, GParamSpec * pspec)

   237 {

   238   GstNetClientClock *self = GST_NET_CLIENT_CLOCK (object);

   239 

   240   switch (prop_id) {

   241     case PROP_ADDRESS:

   242       g_value_set_string (value, self->address);

   243       break;

   244     case PROP_PORT:

   245       g_value_set_int (value, self->port);

   246       break;

   247     default:

   248       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

   249       break;

   250   }

   251 }

   252 

   253 static void

   254 gst_net_client_clock_observe_times (GstNetClientClock * self,

   255     GstClockTime local_1, GstClockTime remote, GstClockTime local_2)

   256 {

   257   GstClockTime local_avg;

   258   gdouble r_squared;

   259   GstClock *clock;

   260 

   261   if (local_2 < local_1)

   262     goto bogus_observation;

   263 

   264   local_avg = (local_2 + local_1) / 2;

   265 

   266   clock = GST_CLOCK_CAST (self);

   267 

   268   gst_clock_add_observation (GST_CLOCK (self), local_avg, remote, &r_squared);

   269 

   270   GST_CLOCK_SLAVE_LOCK (self);

   271   if (clock->filling) {

   272     self->current_timeout = 0;

   273   } else {

   274     /* geto formula */

   275     self->current_timeout =

   276         (1e-3 / (1 - MIN (r_squared, 0.99999))) * GST_SECOND;

   277     self->current_timeout = MIN (self->current_timeout, clock->timeout);

   278   }

   279   GST_CLOCK_SLAVE_UNLOCK (clock);

   280 

   281   return;

   282 

   283 bogus_observation:

   284   {

   285     GST_WARNING_OBJECT (self, "time packet receive time < send time (%"

   286         GST_TIME_FORMAT " < %" GST_TIME_FORMAT ")", GST_TIME_ARGS (local_1),

   287         GST_TIME_ARGS (local_2));

   288     return;

   289   }

   290 }

   291 

   292 static gint

   293 gst_net_client_clock_do_select (GstNetClientClock * self)

   294 {

   295   while (TRUE) {

   296     GstClockTime diff;

   297     gint ret;

   298 

   299     GST_LOG_OBJECT (self, "doing select");

   300 

   301     diff = gst_clock_get_internal_time (GST_CLOCK (self));

   302     ret = gst_poll_wait (self->priv->fdset, self->current_timeout);

   303     diff = gst_clock_get_internal_time (GST_CLOCK (self)) - diff;

   304 

   305     if (diff > self->current_timeout)

   306       self->current_timeout = 0;

   307     else

   308       self->current_timeout -= diff;

   309 

   310     GST_LOG_OBJECT (self, "select returned %d", ret);

   311 

   312     if (ret < 0 && errno != EBUSY) {

   313       if (errno != EAGAIN && errno != EINTR)

   314         goto select_error;

   315       else

   316         continue;

   317     } else {

   318       return ret;

   319     }

   320 

   321     g_assert_not_reached ();

   322 

   323     /* log errors and keep going */

   324   select_error:

   325     {

   326       GST_WARNING_OBJECT (self, "select error %d: %s (%d)", ret,

   327           g_strerror (errno), errno);

   328       continue;

   329     }

   330   }

   331 

   332   g_assert_not_reached ();

   333   return -1;

   334 }

   335 

   336 static gpointer

   337 gst_net_client_clock_thread (gpointer data)

   338 {

   339   GstNetClientClock *self = data;

   340   struct sockaddr_in tmpaddr;

   341   socklen_t len;

   342   GstNetTimePacket *packet;

   343   gint ret;

   344   GstClock *clock = data;

   345 

   346   while (TRUE) {

   347     ret = gst_net_client_clock_do_select (self);

   348 

   349     if (ret < 0 && errno == EBUSY) {

   350       GST_LOG_OBJECT (self, "stop");

   351       goto stopped;

   352     } else if (ret == 0) {

   353       /* timed out, let's send another packet */

   354       GST_DEBUG_OBJECT (self, "timed out");

   355 

   356       packet = gst_net_time_packet_new (NULL);

   357 

   358       packet->local_time = gst_clock_get_internal_time (GST_CLOCK (self));

   359 

   360       GST_DEBUG_OBJECT (self, "sending packet, local time = %" GST_TIME_FORMAT,

   361           GST_TIME_ARGS (packet->local_time));

   362       gst_net_time_packet_send (packet, self->priv->sock.fd,

   363           (struct sockaddr *) self->servaddr, sizeof (struct sockaddr_in));

   364 

   365       g_free (packet);

   366 

   367       /* reset timeout */

   368       self->current_timeout = clock->timeout;

   369       continue;

   370     } else if (gst_poll_fd_can_read (self->priv->fdset, &self->priv->sock)) {

   371       /* got data in */

   372       GstClockTime new_local = gst_clock_get_internal_time (GST_CLOCK (self));

   373 

   374       len = sizeof (struct sockaddr);

   375       packet = gst_net_time_packet_receive (self->priv->sock.fd,

   376           (struct sockaddr *) &tmpaddr, &len);

   377 

   378       if (!packet)

   379         goto receive_error;

   380 

   381       GST_LOG_OBJECT (self, "got packet back");

   382       GST_LOG_OBJECT (self, "local_1 = %" GST_TIME_FORMAT,

   383           GST_TIME_ARGS (packet->local_time));

   384       GST_LOG_OBJECT (self, "remote = %" GST_TIME_FORMAT,

   385           GST_TIME_ARGS (packet->remote_time));

   386       GST_LOG_OBJECT (self, "local_2 = %" GST_TIME_FORMAT,

   387           GST_TIME_ARGS (new_local));

   388 

   389       /* observe_times will reset the timeout */

   390       gst_net_client_clock_observe_times (self, packet->local_time,

   391           packet->remote_time, new_local);

   392 

   393       g_free (packet);

   394       continue;

   395     } else {

   396       GST_WARNING_OBJECT (self, "unhandled select return state?");

   397       continue;

   398     }

   399 

   400     g_assert_not_reached ();

   401 

   402   stopped:

   403     {

   404       GST_DEBUG_OBJECT (self, "shutting down");

   405       /* socket gets closed in _stop() */

   406       return NULL;

   407     }

   408   receive_error:

   409     {

   410       GST_WARNING_OBJECT (self, "receive error");

   411       continue;

   412     }

   413 

   414     g_assert_not_reached ();

   415 

   416   }

   417 

   418   g_assert_not_reached ();

   419 

   420   return NULL;

   421 }

   422 

   423 static gboolean

   424 gst_net_client_clock_start (GstNetClientClock * self)

   425 {

   426   struct sockaddr_in servaddr, myaddr;

   427   socklen_t len;

   428   gint ret;

   429   GError *error;

   430 

   431   g_return_val_if_fail (self->address != NULL, FALSE);

   432   g_return_val_if_fail (self->servaddr == NULL, FALSE);

   433 

   434   if ((ret = socket (AF_INET, SOCK_DGRAM, 0)) < 0)

   435     goto no_socket;

   436 

   437   self->priv->sock.fd = ret;

   438 

   439   len = sizeof (myaddr);

   440 #ifndef __SYMBIAN32__

   441   ret = getsockname (self->priv->sock.fd, (struct sockaddr *) &myaddr, &len);

   442   if (ret < 0)

   443     goto getsockname_error;

   444 #endif

   445   memset (&servaddr, 0, sizeof (servaddr));

   446   servaddr.sin_family = AF_INET;        /* host byte order */

   447   servaddr.sin_port = htons (self->port);       /* short, network byte order */

   448 

   449   GST_DEBUG_OBJECT (self, "socket opened on UDP port %hd",

   450       ntohs (servaddr.sin_port));

   451 

   452    #ifndef __SYMBIAN32__

   453    if (!inet_aton (self->address, &servaddr.sin_addr))

   454       goto bad_address;

   455    #else

   456    if ((servaddr.sin_addr.s_addr=inet_addr(self->address))==-1)

   457    goto bad_address; 

   458   #endif//__SYMBIAN32__

   459   self->servaddr = g_malloc (sizeof (struct sockaddr_in));

   460   memcpy (self->servaddr, &servaddr, sizeof (servaddr));

   461 

   462   GST_DEBUG_OBJECT (self, "will communicate with %s:%d", self->address,

   463       self->port);

   464 

   465   gst_poll_add_fd (self->priv->fdset, &self->priv->sock);

   466   gst_poll_fd_ctl_read (self->priv->fdset, &self->priv->sock, TRUE);

   467 

   468   self->thread = g_thread_create (gst_net_client_clock_thread, self, TRUE,

   469       &error);

   470   if (!self->thread)

   471     goto no_thread;

   472 

   473   return TRUE;

   474 

   475   /* ERRORS */

   476 no_socket:

   477   {

   478     GST_ERROR_OBJECT (self, "socket failed %d: %s (%d)", ret,

   479         g_strerror (errno), errno);

   480     return FALSE;

   481   }

   482 getsockname_error:

   483   {

   484     GST_ERROR_OBJECT (self, "getsockname failed %d: %s (%d)", ret,

   485         g_strerror (errno), errno);

   486     close (self->priv->sock.fd);

   487     self->priv->sock.fd = -1;

   488     return FALSE;

   489   }

   490 bad_address:

   491   {

   492     GST_ERROR_OBJECT (self, "inet_aton failed %d: %s (%d)", ret,

   493         g_strerror (errno), errno);

   494     close (self->priv->sock.fd);

   495     self->priv->sock.fd = -1;

   496     return FALSE;

   497   }

   498 no_thread:

   499   {

   500     GST_ERROR_OBJECT (self, "could not create thread: %s", error->message);

   501     gst_poll_remove_fd (self->priv->fdset, &self->priv->sock);

   502     close (self->priv->sock.fd);

   503     self->priv->sock.fd = -1;

   504     g_free (self->servaddr);

   505     self->servaddr = NULL;

   506     g_error_free (error);

   507     return FALSE;

   508   }

   509 }

   510 

   511 static void

   512 gst_net_client_clock_stop (GstNetClientClock * self)

   513 {

   514   gst_poll_set_flushing (self->priv->fdset, TRUE);

   515   g_thread_join (self->thread);

   516   self->thread = NULL;

   517 

   518   if (self->priv->sock.fd != -1) {

   519     gst_poll_remove_fd (self->priv->fdset, &self->priv->sock);

   520     close (self->priv->sock.fd);

   521     self->priv->sock.fd = -1;

   522   }

   523 }

   524 

   525 /**

   526  * gst_net_client_clock_new:

   527  * @name: a name for the clock

   528  * @remote_address: the address of the remote clock provider

   529  * @remote_port: the port of the remote clock provider

   530  * @base_time: initial time of the clock

   531  *

   532  * Create a new #GstNetClientClock that will report the time

   533  * provided by the #GstNetClockProvider on @remote_address and 

   534  * @remote_port.

   535  *

   536  * Returns: a new #GstClock that receives a time from the remote

   537  * clock.

   538  */

   539 #ifdef __SYMBIAN32__

   540 EXPORT_C

   541 #endif

   542 

   543 GstClock *

   544 gst_net_client_clock_new (gchar * name, const gchar * remote_address,

   545     gint remote_port, GstClockTime base_time)

   546 {

   547   GstNetClientClock *ret;

   548   GstClockTime internal;

   549 

   550   g_return_val_if_fail (remote_address != NULL, NULL);

   551   g_return_val_if_fail (remote_port > 0, NULL);

   552   g_return_val_if_fail (remote_port <= G_MAXUINT16, NULL);

   553   g_return_val_if_fail (base_time != GST_CLOCK_TIME_NONE, NULL);

   554 

   555   ret = g_object_new (GST_TYPE_NET_CLIENT_CLOCK, "address", remote_address,

   556       "port", remote_port, NULL);

   557 

   558   /* gst_clock_get_time() values are guaranteed to be increasing. because no one

   559    * has called get_time on this clock yet we are free to adjust to any value

   560    * without worrying about worrying about MAX() issues with the clock's

   561    * internal time.

   562    */

   563 

   564   /* update our internal time so get_time() give something around base_time.

   565      assume that the rate is 1 in the beginning. */

   566   internal = gst_clock_get_internal_time (GST_CLOCK (ret));

   567   gst_clock_set_calibration (GST_CLOCK (ret), internal, base_time, 1, 1);

   568 

   569   {

   570     GstClockTime now = gst_clock_get_time (GST_CLOCK (ret));

   571 

   572     if (now < base_time || now > base_time + GST_SECOND)

   573       g_warning ("unable to set the base time, expect sync problems!");

   574   }

   575 

   576   if ((ret->priv->fdset = gst_poll_new (TRUE)) == NULL)

   577     goto no_fdset;

   578 

   579   if (!gst_net_client_clock_start (ret))

   580     goto failed_start;

   581 

   582   /* all systems go, cap'n */

   583   return (GstClock *) ret;

   584 

   585 no_fdset:

   586   {

   587     GST_ERROR_OBJECT (ret, "could not create an fdset: %s (%d)",

   588         g_strerror (errno), errno);

   589     gst_object_unref (ret);

   590     return NULL;

   591   }

   592 failed_start:

   593   {

   594     /* already printed a nice error */

   595     gst_object_unref (ret);

   596     return NULL;

   597   }

   598 }