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_socket.h"
  28 #include <dcp/raw_convert.h>
  29 #include <libcxml/cxml.h>
  30 #include <boost/lambda/lambda.hpp>
  31 #include <iostream>
  32
  33 #include "i18n.h"
  34
  35 using std::string;
  36 using std::list;
  37 using std::vector;
  38 using std::cout;
  39 using boost::shared_ptr;
  40 using boost::scoped_array;
  41 using boost::weak_ptr;
  42 using dcp::raw_convert;
  43
  44 EncodeServerFinder* EncodeServerFinder::_instance = 0;
  45
  46 EncodeServerFinder::EncodeServerFinder ()
  47         : _search_thread (0)
  48         , _listen_thread (0)
  49         , _stop (false)
  50 {
  51         Config::instance()->Changed.connect (boost::bind (&EncodeServerFinder::config_changed, this, _1));
  52 }
  53
  54 void
  55 EncodeServerFinder::start ()
  56 {
  57         _search_thread = new boost::thread (boost::bind (&EncodeServerFinder::search_thread, this));
  58         _listen_thread = new boost::thread (boost::bind (&EncodeServerFinder::listen_thread, this));
  59 }
  60
  61
  62 EncodeServerFinder::~EncodeServerFinder ()
  63 {
  64         stop ();
  65 }
  66
  67 void
  68 EncodeServerFinder::stop ()
  69 {
  70         _stop = true;
  71
  72         _search_condition.notify_all ();
  73         if (_search_thread) {
  74                 /* Ideally this would be a DCPOMATIC_ASSERT(_search_thread->joinable()) but we
  75                    can't throw exceptions from a destructor.
  76                 */
  77                 if (_search_thread->joinable ()) {
  78                         _search_thread->join ();
  79                 }
  80         }
  81         delete _search_thread;
  82         _search_thread = 0;
  83
  84         _listen_io_service.stop ();
  85         if (_listen_thread) {
  86                 /* Ideally this would be a DCPOMATIC_ASSERT(_listen_thread->joinable()) but we
  87                    can't throw exceptions from a destructor.
  88                 */
  89                 if (_listen_thread->joinable ()) {
  90                         _listen_thread->join ();
  91                 }
  92         }
  93         delete _listen_thread;
  94         _listen_thread = 0;
  95
  96         boost::mutex::scoped_lock lm (_servers_mutex);
  97         _servers.clear ();
  98 }
  99
 100 void
 101 EncodeServerFinder::search_thread ()
 102 try
 103 {
 104         boost::system::error_code error;
 105         boost::asio::io_service io_service;
 106         boost::asio::ip::udp::socket socket (io_service);
 107         socket.open (boost::asio::ip::udp::v4(), error);
 108         if (error) {
 109                 throw NetworkError ("failed to set up broadcast socket");
 110         }
 111
 112         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
 113         socket.set_option (boost::asio::socket_base::broadcast (true));
 114
 115         string const data = DCPOMATIC_HELLO;
 116
 117         while (!_stop) {
 118                 if (Config::instance()->use_any_servers ()) {
 119                         /* Broadcast to look for servers */
 120                         try {
 121                                 boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), HELLO_PORT);
 122                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 123                         } catch (...) {
 124
 125                         }
 126                 }
 127
 128                 /* Query our `definite' servers (if there are any) */
 129                 vector<string> servers = Config::instance()->servers ();
 130                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
 131                         if (server_found (*i)) {
 132                                 /* Don't bother asking a server that we already know about */
 133                                 continue;
 134                         }
 135                         try {
 136                                 boost::asio::ip::udp::resolver resolver (io_service);
 137                                 boost::asio::ip::udp::resolver::query query (*i, raw_convert<string> (HELLO_PORT));
 138                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
 139                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 140                         } catch (...) {
 141
 142                         }
 143                 }
 144
 145                 boost::mutex::scoped_lock lm (_search_condition_mutex);
 146                 _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (10));
 147         }
 148 }
 149 catch (...)
 150 {
 151         store_current ();
 152 }
 153
 154 void
 155 EncodeServerFinder::listen_thread ()
 156 try {
 157         using namespace boost::asio::ip;
 158
 159         try {
 160                 _listen_acceptor.reset (
 161                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 162                         );
 163         } catch (...) {
 164                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 165         }
 166
 167         start_accept ();
 168         _listen_io_service.run ();
 169 }
 170 catch (...)
 171 {
 172         store_current ();
 173 }
 174
 175 void
 176 EncodeServerFinder::start_accept ()
 177 {
 178         shared_ptr<Socket> socket (new Socket ());
 179         _listen_acceptor->async_accept (
 180                 socket->socket(),
 181                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 182                 );
 183 }
 184
 185 void
 186 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 187 {
 188         if (ec) {
 189                 start_accept ();
 190                 return;
 191         }
 192
 193         uint32_t length;
 194         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 195         length = ntohl (length);
 196
 197         scoped_array<char> buffer (new char[length]);
 198         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 199
 200         string s (buffer.get());
 201         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 202         xml->read_string (s);
 203
 204         string const ip = socket->socket().remote_endpoint().address().to_string ();
 205         if (!server_found (ip) && xml->optional_number_child<int>("Version").get_value_or (0) == SERVER_LINK_VERSION) {
 206                 EncodeServerDescription sd (ip, xml->number_child<int> ("Threads"));
 207                 {
 208                         boost::mutex::scoped_lock lm (_servers_mutex);
 209                         _servers.push_back (sd);
 210                 }
 211                 emit (boost::bind (boost::ref (ServersListChanged)));
 212         }
 213
 214         start_accept ();
 215 }
 216
 217 bool
 218 EncodeServerFinder::server_found (string ip) const
 219 {
 220         boost::mutex::scoped_lock lm (_servers_mutex);
 221         list<EncodeServerDescription>::const_iterator i = _servers.begin();
 222         while (i != _servers.end() && i->host_name() != ip) {
 223                 ++i;
 224         }
 225
 226         return i != _servers.end ();
 227 }
 228
 229 EncodeServerFinder*
 230 EncodeServerFinder::instance ()
 231 {
 232         if (!_instance) {
 233                 _instance = new EncodeServerFinder ();
 234                 _instance->start ();
 235         }
 236
 237         return _instance;
 238 }
 239
 240 void
 241 EncodeServerFinder::drop ()
 242 {
 243         delete _instance;
 244         _instance = 0;
 245 }
 246
 247 list<EncodeServerDescription>
 248 EncodeServerFinder::servers () const
 249 {
 250         boost::mutex::scoped_lock lm (_servers_mutex);
 251         return _servers;
 252 }
 253
 254 void
 255 EncodeServerFinder::config_changed (Config::Property what)
 256 {
 257         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 258                 {
 259                         boost::mutex::scoped_lock lm (_servers_mutex);
 260                         _servers.clear ();
 261                 }
 262                 ServersListChanged ();
 263                 _search_condition.notify_all ();
 264         }
 265 }