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/bind/placeholders.hpp>
  31 #include <boost/lambda/lambda.hpp>
  32 #include <iostream>
  33
  34 #include "i18n.h"
  35
  36 using std::string;
  37 using std::list;
  38 using std::vector;
  39 using std::cout;
  40 using boost::shared_ptr;
  41 using boost::scoped_array;
  42 using boost::weak_ptr;
  43 using boost::optional;
  44 #if BOOST_VERSION >= 106100
  45 using namespace boost::placeholders;
  46 #endif
  47 using dcp::raw_convert;
  48
  49 EncodeServerFinder* EncodeServerFinder::_instance = 0;
  50
  51 EncodeServerFinder::EncodeServerFinder ()
  52         : _stop (false)
  53 {
  54         Config::instance()->Changed.connect (boost::bind (&EncodeServerFinder::config_changed, this, _1));
  55 }
  56
  57 void
  58 EncodeServerFinder::start ()
  59 {
  60         _search_thread = boost::thread (boost::bind(&EncodeServerFinder::search_thread, this));
  61         _listen_thread = boost::thread (boost::bind(&EncodeServerFinder::listen_thread, this));
  62 #ifdef DCPOMATIC_LINUX
  63         pthread_setname_np (_search_thread.native_handle(), "encode-server-search");
  64         pthread_setname_np (_listen_thread.native_handle(), "encode-server-listen");
  65 #endif
  66 }
  67
  68
  69 EncodeServerFinder::~EncodeServerFinder ()
  70 {
  71         stop ();
  72 }
  73
  74 void
  75 EncodeServerFinder::stop ()
  76 {
  77         boost::this_thread::disable_interruption dis;
  78
  79         _stop = true;
  80
  81         _search_condition.notify_all ();
  82         try {
  83                 _search_thread.join();
  84         } catch (...) {}
  85
  86         _listen_io_service.stop ();
  87         try {
  88                 _listen_thread.join ();
  89         } catch (...) {}
  90
  91         boost::mutex::scoped_lock lm (_servers_mutex);
  92         _servers.clear ();
  93 }
  94
  95 void
  96 EncodeServerFinder::search_thread ()
  97 try
  98 {
  99         boost::system::error_code error;
 100         boost::asio::io_service io_service;
 101         boost::asio::ip::udp::socket socket (io_service);
 102         socket.open (boost::asio::ip::udp::v4(), error);
 103         if (error) {
 104                 throw NetworkError ("failed to set up broadcast socket");
 105         }
 106
 107         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
 108         socket.set_option (boost::asio::socket_base::broadcast (true));
 109
 110         string const data = DCPOMATIC_HELLO;
 111         int const interval = 10;
 112
 113         while (!_stop) {
 114                 if (Config::instance()->use_any_servers ()) {
 115                         /* Broadcast to look for servers */
 116                         try {
 117                                 boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), HELLO_PORT);
 118                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 119                         } catch (...) {
 120
 121                         }
 122                 }
 123
 124                 /* Query our `definite' servers (if there are any) */
 125                 vector<string> servers = Config::instance()->servers ();
 126                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
 127                         if (server_found (*i)) {
 128                                 /* Don't bother asking a server that we already know about */
 129                                 continue;
 130                         }
 131                         try {
 132                                 boost::asio::ip::udp::resolver resolver (io_service);
 133                                 boost::asio::ip::udp::resolver::query query (*i, raw_convert<string> (HELLO_PORT));
 134                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
 135                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 136                         } catch (...) {
 137
 138                         }
 139                 }
 140
 141                 /* Discard servers that we haven't seen for a while */
 142                 bool removed = false;
 143                 {
 144                         boost::mutex::scoped_lock lm (_servers_mutex);
 145
 146                         list<EncodeServerDescription>::iterator i = _servers.begin();
 147                         while (i != _servers.end()) {
 148                                 if (i->last_seen_seconds() > 2 * interval) {
 149                                         list<EncodeServerDescription>::iterator j = i;
 150                                         ++j;
 151                                         _servers.erase (i);
 152                                         i = j;
 153                                         removed = true;
 154                                 } else {
 155                                         ++i;
 156                                 }
 157                         }
 158                 }
 159
 160                 if (removed) {
 161                         emit (boost::bind (boost::ref (ServersListChanged)));
 162                 }
 163
 164                 boost::mutex::scoped_lock lm (_search_condition_mutex);
 165                 _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (interval));
 166         }
 167 }
 168 catch (...)
 169 {
 170         store_current ();
 171 }
 172
 173 void
 174 EncodeServerFinder::listen_thread ()
 175 try {
 176         using namespace boost::asio::ip;
 177
 178         try {
 179                 _listen_acceptor.reset (
 180                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 181                         );
 182         } catch (...) {
 183                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 184         }
 185
 186         start_accept ();
 187         _listen_io_service.run ();
 188 }
 189 catch (...)
 190 {
 191         store_current ();
 192 }
 193
 194 void
 195 EncodeServerFinder::start_accept ()
 196 {
 197         shared_ptr<Socket> socket (new Socket ());
 198         _listen_acceptor->async_accept (
 199                 socket->socket(),
 200                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 201                 );
 202 }
 203
 204 void
 205 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 206 {
 207         if (ec) {
 208                 start_accept ();
 209                 return;
 210         }
 211
 212         uint32_t length;
 213         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 214         length = ntohl (length);
 215
 216         scoped_array<char> buffer (new char[length]);
 217         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 218
 219         string s (buffer.get());
 220         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 221         xml->read_string (s);
 222
 223         string const ip = socket->socket().remote_endpoint().address().to_string ();
 224         optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
 225         if (found) {
 226                 (*found)->set_seen ();
 227         } else {
 228                 EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
 229                 {
 230                         boost::mutex::scoped_lock lm (_servers_mutex);
 231                         _servers.push_back (sd);
 232                 }
 233                 emit (boost::bind (boost::ref (ServersListChanged)));
 234         }
 235
 236         start_accept ();
 237 }
 238
 239 optional<list<EncodeServerDescription>::iterator>
 240 EncodeServerFinder::server_found (string ip)
 241 {
 242         boost::mutex::scoped_lock lm (_servers_mutex);
 243         list<EncodeServerDescription>::iterator i = _servers.begin();
 244         while (i != _servers.end() && i->host_name() != ip) {
 245                 ++i;
 246         }
 247
 248         if (i != _servers.end()) {
 249                 return i;
 250         }
 251
 252         return optional<list<EncodeServerDescription>::iterator>();
 253 }
 254
 255 EncodeServerFinder*
 256 EncodeServerFinder::instance ()
 257 {
 258         if (!_instance) {
 259                 _instance = new EncodeServerFinder ();
 260                 _instance->start ();
 261         }
 262
 263         return _instance;
 264 }
 265
 266 void
 267 EncodeServerFinder::drop ()
 268 {
 269         delete _instance;
 270         _instance = 0;
 271 }
 272
 273 list<EncodeServerDescription>
 274 EncodeServerFinder::servers () const
 275 {
 276         boost::mutex::scoped_lock lm (_servers_mutex);
 277         return _servers;
 278 }
 279
 280 void
 281 EncodeServerFinder::config_changed (Config::Property what)
 282 {
 283         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 284                 {
 285                         boost::mutex::scoped_lock lm (_servers_mutex);
 286                         _servers.clear ();
 287                 }
 288                 ServersListChanged ();
 289                 _search_condition.notify_all ();
 290         }
 291 }