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 #ifdef DCPOMATIC_LINUX
  60         pthread_setname_np (_search_thread->native_handle(), "encode-server-search");
  61         pthread_setname_np (_listen_thread->native_handle(), "encode-server-listen");
  62 #endif
  63 }
  64
  65
  66 EncodeServerFinder::~EncodeServerFinder ()
  67 {
  68         stop ();
  69 }
  70
  71 void
  72 EncodeServerFinder::stop ()
  73 {
  74         _stop = true;
  75
  76         _search_condition.notify_all ();
  77         if (_search_thread) {
  78                 /* Ideally this would be a DCPOMATIC_ASSERT(_search_thread->joinable()) but we
  79                    can't throw exceptions from a destructor.
  80                 */
  81                 if (_search_thread->joinable ()) {
  82                         _search_thread->join ();
  83                 }
  84         }
  85         delete _search_thread;
  86         _search_thread = 0;
  87
  88         _listen_io_service.stop ();
  89         if (_listen_thread) {
  90                 /* Ideally this would be a DCPOMATIC_ASSERT(_listen_thread->joinable()) but we
  91                    can't throw exceptions from a destructor.
  92                 */
  93                 if (_listen_thread->joinable ()) {
  94                         _listen_thread->join ();
  95                 }
  96         }
  97         delete _listen_thread;
  98         _listen_thread = 0;
  99
 100         boost::mutex::scoped_lock lm (_servers_mutex);
 101         _servers.clear ();
 102 }
 103
 104 void
 105 EncodeServerFinder::search_thread ()
 106 try
 107 {
 108         boost::system::error_code error;
 109         boost::asio::io_service io_service;
 110         boost::asio::ip::udp::socket socket (io_service);
 111         socket.open (boost::asio::ip::udp::v4(), error);
 112         if (error) {
 113                 throw NetworkError ("failed to set up broadcast socket");
 114         }
 115
 116         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
 117         socket.set_option (boost::asio::socket_base::broadcast (true));
 118
 119         string const data = DCPOMATIC_HELLO;
 120
 121         while (!_stop) {
 122                 if (Config::instance()->use_any_servers ()) {
 123                         /* Broadcast to look for servers */
 124                         try {
 125                                 boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), HELLO_PORT);
 126                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 127                         } catch (...) {
 128
 129                         }
 130                 }
 131
 132                 /* Query our `definite' servers (if there are any) */
 133                 vector<string> servers = Config::instance()->servers ();
 134                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
 135                         if (server_found (*i)) {
 136                                 /* Don't bother asking a server that we already know about */
 137                                 continue;
 138                         }
 139                         try {
 140                                 boost::asio::ip::udp::resolver resolver (io_service);
 141                                 boost::asio::ip::udp::resolver::query query (*i, raw_convert<string> (HELLO_PORT));
 142                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
 143                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 144                         } catch (...) {
 145
 146                         }
 147                 }
 148
 149                 boost::mutex::scoped_lock lm (_search_condition_mutex);
 150                 _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (10));
 151         }
 152 }
 153 catch (...)
 154 {
 155         store_current ();
 156 }
 157
 158 void
 159 EncodeServerFinder::listen_thread ()
 160 try {
 161         using namespace boost::asio::ip;
 162
 163         try {
 164                 _listen_acceptor.reset (
 165                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 166                         );
 167         } catch (...) {
 168                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 169         }
 170
 171         start_accept ();
 172         _listen_io_service.run ();
 173 }
 174 catch (...)
 175 {
 176         store_current ();
 177 }
 178
 179 void
 180 EncodeServerFinder::start_accept ()
 181 {
 182         shared_ptr<Socket> socket (new Socket ());
 183         _listen_acceptor->async_accept (
 184                 socket->socket(),
 185                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 186                 );
 187 }
 188
 189 void
 190 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 191 {
 192         if (ec) {
 193                 start_accept ();
 194                 return;
 195         }
 196
 197         uint32_t length;
 198         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 199         length = ntohl (length);
 200
 201         scoped_array<char> buffer (new char[length]);
 202         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 203
 204         string s (buffer.get());
 205         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 206         xml->read_string (s);
 207
 208         string const ip = socket->socket().remote_endpoint().address().to_string ();
 209         if (!server_found (ip) && xml->optional_number_child<int>("Version").get_value_or (0) == SERVER_LINK_VERSION) {
 210                 EncodeServerDescription sd (ip, xml->number_child<int> ("Threads"));
 211                 {
 212                         boost::mutex::scoped_lock lm (_servers_mutex);
 213                         _servers.push_back (sd);
 214                 }
 215                 emit (boost::bind (boost::ref (ServersListChanged)));
 216         }
 217
 218         start_accept ();
 219 }
 220
 221 bool
 222 EncodeServerFinder::server_found (string ip) const
 223 {
 224         boost::mutex::scoped_lock lm (_servers_mutex);
 225         list<EncodeServerDescription>::const_iterator i = _servers.begin();
 226         while (i != _servers.end() && i->host_name() != ip) {
 227                 ++i;
 228         }
 229
 230         return i != _servers.end ();
 231 }
 232
 233 EncodeServerFinder*
 234 EncodeServerFinder::instance ()
 235 {
 236         if (!_instance) {
 237                 _instance = new EncodeServerFinder ();
 238                 _instance->start ();
 239         }
 240
 241         return _instance;
 242 }
 243
 244 void
 245 EncodeServerFinder::drop ()
 246 {
 247         delete _instance;
 248         _instance = 0;
 249 }
 250
 251 list<EncodeServerDescription>
 252 EncodeServerFinder::servers () const
 253 {
 254         boost::mutex::scoped_lock lm (_servers_mutex);
 255         return _servers;
 256 }
 257
 258 void
 259 EncodeServerFinder::config_changed (Config::Property what)
 260 {
 261         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 262                 {
 263                         boost::mutex::scoped_lock lm (_servers_mutex);
 264                         _servers.clear ();
 265                 }
 266                 ServersListChanged ();
 267                 _search_condition.notify_all ();
 268         }
 269 }