src/lib/encode_server_finder.cc

   1 /*
   2     Copyright (C) 2013-2018 Carl Hetherington <cth@carlh.net>
   3
   4     This file is part of DCP-o-matic.
   5
   6     DCP-o-matic is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     DCP-o-matic is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 #include "encode_server_finder.h"
  22 #include "exceptions.h"
  23 #include "util.h"
  24 #include "config.h"
  25 #include "cross.h"
  26 #include "encode_server_description.h"
  27 #include "dcpomatic_log.h"
  28 #include "dcpomatic_socket.h"
  29 #include <dcp/raw_convert.h>
  30 #include <libcxml/cxml.h>
  31 #include <boost/bind/placeholders.hpp>
  32 #include <boost/lambda/lambda.hpp>
  33 #include <iostream>
  34
  35 #include "i18n.h"
  36
  37 using std::string;
  38 using std::list;
  39 using std::vector;
  40 using std::cout;
  41 using boost::shared_ptr;
  42 using boost::scoped_array;
  43 using boost::weak_ptr;
  44 using boost::optional;
  45 #if BOOST_VERSION >= 106100
  46 using namespace boost::placeholders;
  47 #endif
  48 using dcp::raw_convert;
  49
  50 EncodeServerFinder* EncodeServerFinder::_instance = 0;
  51
  52 EncodeServerFinder::EncodeServerFinder ()
  53         : _stop (false)
  54 {
  55         Config::instance()->Changed.connect (boost::bind (&EncodeServerFinder::config_changed, this, _1));
  56 }
  57
  58 void
  59 EncodeServerFinder::start ()
  60 {
  61         _search_thread = boost::thread (boost::bind(&EncodeServerFinder::search_thread, this));
  62         _listen_thread = boost::thread (boost::bind(&EncodeServerFinder::listen_thread, this));
  63 #ifdef DCPOMATIC_LINUX
  64         pthread_setname_np (_search_thread.native_handle(), "encode-server-search");
  65         pthread_setname_np (_listen_thread.native_handle(), "encode-server-listen");
  66 #endif
  67 }
  68
  69
  70 EncodeServerFinder::~EncodeServerFinder ()
  71 {
  72         stop ();
  73 }
  74
  75 void
  76 EncodeServerFinder::stop ()
  77 {
  78         boost::this_thread::disable_interruption dis;
  79
  80         _stop = true;
  81
  82         _search_condition.notify_all ();
  83         try {
  84                 _search_thread.join();
  85         } catch (...) {}
  86
  87         _listen_io_service.stop ();
  88         try {
  89                 _listen_thread.join ();
  90         } catch (...) {}
  91
  92         boost::mutex::scoped_lock lm (_servers_mutex);
  93         _servers.clear ();
  94 }
  95
  96 void
  97 EncodeServerFinder::search_thread ()
  98 try
  99 {
 100         boost::system::error_code error;
 101         boost::asio::io_service io_service;
 102         boost::asio::ip::udp::socket socket (io_service);
 103         socket.open (boost::asio::ip::udp::v4(), error);
 104         if (error) {
 105                 throw NetworkError ("failed to set up broadcast socket");
 106         }
 107
 108         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
 109         socket.set_option (boost::asio::socket_base::broadcast (true));
 110
 111         string const data = DCPOMATIC_HELLO;
 112         int const interval = 10;
 113
 114         while (!_stop) {
 115                 if (Config::instance()->use_any_servers ()) {
 116                         /* Broadcast to look for servers */
 117                         try {
 118                                 boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), HELLO_PORT);
 119                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 120                         } catch (...) {
 121
 122                         }
 123                 }
 124
 125                 /* Query our `definite' servers (if there are any) */
 126                 vector<string> servers = Config::instance()->servers ();
 127                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
 128                         if (server_found (*i)) {
 129                                 /* Don't bother asking a server that we already know about */
 130                                 continue;
 131                         }
 132                         try {
 133                                 LOG_DEBUG_ENCODE_SERVERS("Sending query to configured server %1", *i);
 134                                 boost::asio::ip::udp::resolver resolver (io_service);
 135                                 boost::asio::ip::udp::resolver::query query (*i, raw_convert<string> (HELLO_PORT));
 136                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
 137                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 138                         } catch (...) {
 139
 140                         }
 141                 }
 142
 143                 /* Discard servers that we haven't seen for a while */
 144                 bool removed = false;
 145                 {
 146                         boost::mutex::scoped_lock lm (_servers_mutex);
 147
 148                         list<EncodeServerDescription>::iterator i = _servers.begin();
 149                         while (i != _servers.end()) {
 150                                 if (i->last_seen_seconds() > 2 * interval) {
 151                                         list<EncodeServerDescription>::iterator j = i;
 152                                         ++j;
 153                                         _servers.erase (i);
 154                                         i = j;
 155                                         removed = true;
 156                                 } else {
 157                                         ++i;
 158                                 }
 159                         }
 160                 }
 161
 162                 if (removed) {
 163                         emit (boost::bind (boost::ref (ServersListChanged)));
 164                 }
 165
 166                 boost::mutex::scoped_lock lm (_search_condition_mutex);
 167                 _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (interval));
 168         }
 169 }
 170 catch (...)
 171 {
 172         store_current ();
 173 }
 174
 175 void
 176 EncodeServerFinder::listen_thread ()
 177 try {
 178         using namespace boost::asio::ip;
 179         LOG_DEBUG_ENCODE_SERVERS_NC("Listen thread starting");
 180
 181         try {
 182                 _listen_acceptor.reset (
 183                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 184                         );
 185         } catch (...) {
 186                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 187         }
 188
 189         start_accept ();
 190         _listen_io_service.run ();
 191 }
 192 catch (std::exception& e)
 193 {
 194         LOG_DEBUG_ENCODE_SERVERS("Listen thread terminating (%1)", e.what());
 195         store_current ();
 196 }
 197 catch (...)
 198 {
 199         LOG_DEBUG_ENCODE_SERVERS_NC("Listen thread terminating (unknown)");
 200         store_current ();
 201 }
 202
 203 void
 204 EncodeServerFinder::start_accept ()
 205 {
 206         shared_ptr<Socket> socket (new Socket ());
 207         _listen_acceptor->async_accept (
 208                 socket->socket(),
 209                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 210                 );
 211 }
 212
 213 void
 214 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 215 {
 216         if (ec) {
 217                 LOG_DEBUG_ENCODE_SERVERS_NC("Error arrived at handle_accept");
 218                 start_accept ();
 219                 return;
 220         }
 221
 222         string const ip = socket->socket().remote_endpoint().address().to_string ();
 223         LOG_DEBUG_ENCODE_SERVERS("Received reply from remote server %1", ip);
 224
 225         uint32_t length;
 226         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 227         length = ntohl (length);
 228
 229         scoped_array<char> buffer (new char[length]);
 230         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 231
 232         string s (buffer.get());
 233         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 234         xml->read_string (s);
 235
 236         optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
 237         if (found) {
 238                 LOG_DEBUG_ENCODE_SERVERS("%1 already seen", ip);
 239                 (*found)->set_seen ();
 240         } else {
 241                 EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
 242                 {
 243                         boost::mutex::scoped_lock lm (_servers_mutex);
 244                         _servers.push_back (sd);
 245                 }
 246                 LOG_DEBUG_ENCODE_SERVERS("%1 is new; offers %2 threads, version %3", sd.threads(), sd.link_version());
 247                 emit (boost::bind (boost::ref (ServersListChanged)));
 248         }
 249
 250         start_accept ();
 251 }
 252
 253 optional<list<EncodeServerDescription>::iterator>
 254 EncodeServerFinder::server_found (string ip)
 255 {
 256         boost::mutex::scoped_lock lm (_servers_mutex);
 257         list<EncodeServerDescription>::iterator i = _servers.begin();
 258         while (i != _servers.end() && i->host_name() != ip) {
 259                 ++i;
 260         }
 261
 262         if (i != _servers.end()) {
 263                 return i;
 264         }
 265
 266         return optional<list<EncodeServerDescription>::iterator>();
 267 }
 268
 269 EncodeServerFinder*
 270 EncodeServerFinder::instance ()
 271 {
 272         if (!_instance) {
 273                 _instance = new EncodeServerFinder ();
 274                 _instance->start ();
 275         }
 276
 277         return _instance;
 278 }
 279
 280 void
 281 EncodeServerFinder::drop ()
 282 {
 283         delete _instance;
 284         _instance = 0;
 285 }
 286
 287 list<EncodeServerDescription>
 288 EncodeServerFinder::servers () const
 289 {
 290         boost::mutex::scoped_lock lm (_servers_mutex);
 291         return _servers;
 292 }
 293
 294 void
 295 EncodeServerFinder::config_changed (Config::Property what)
 296 {
 297         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 298                 {
 299                         boost::mutex::scoped_lock lm (_servers_mutex);
 300                         _servers.clear ();
 301                 }
 302                 ServersListChanged ();
 303                 _search_condition.notify_all ();
 304         }
 305 }