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 std::shared_ptr;
  41 using boost::scoped_array;
  42 using std::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                 BOOST_FOREACH (string const& i, Config::instance()->servers()) {
 126                         try {
 127                                 boost::asio::ip::udp::resolver resolver (io_service);
 128                                 boost::asio::ip::udp::resolver::query query (i, raw_convert<string> (HELLO_PORT));
 129                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
 130                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 131                         } catch (...) {
 132
 133                         }
 134                 }
 135
 136                 /* Discard servers that we haven't seen for a while */
 137                 bool removed = false;
 138                 {
 139                         boost::mutex::scoped_lock lm (_servers_mutex);
 140
 141                         list<EncodeServerDescription>::iterator i = _servers.begin();
 142                         while (i != _servers.end()) {
 143                                 if (i->last_seen_seconds() > 2 * interval) {
 144                                         list<EncodeServerDescription>::iterator j = i;
 145                                         ++j;
 146                                         _servers.erase (i);
 147                                         i = j;
 148                                         removed = true;
 149                                 } else {
 150                                         ++i;
 151                                 }
 152                         }
 153                 }
 154
 155                 if (removed) {
 156                         emit (boost::bind (boost::ref (ServersListChanged)));
 157                 }
 158
 159                 boost::mutex::scoped_lock lm (_search_condition_mutex);
 160                 _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (interval));
 161         }
 162 }
 163 catch (...)
 164 {
 165         store_current ();
 166 }
 167
 168 void
 169 EncodeServerFinder::listen_thread ()
 170 try {
 171         using namespace boost::asio::ip;
 172
 173         try {
 174                 _listen_acceptor.reset (
 175                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 176                         );
 177         } catch (...) {
 178                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 179         }
 180
 181         start_accept ();
 182         _listen_io_service.run ();
 183 }
 184 catch (...)
 185 {
 186         store_current ();
 187 }
 188
 189 void
 190 EncodeServerFinder::start_accept ()
 191 {
 192         shared_ptr<Socket> socket (new Socket ());
 193         _listen_acceptor->async_accept (
 194                 socket->socket(),
 195                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 196                 );
 197 }
 198
 199 void
 200 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 201 {
 202         if (ec) {
 203                 start_accept ();
 204                 return;
 205         }
 206
 207         uint32_t length;
 208         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 209         length = ntohl (length);
 210
 211         scoped_array<char> buffer (new char[length]);
 212         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 213
 214         string s (buffer.get());
 215         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 216         xml->read_string (s);
 217
 218         string const ip = socket->socket().remote_endpoint().address().to_string ();
 219         optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
 220         if (found) {
 221                 (*found)->set_seen ();
 222         } else {
 223                 EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
 224                 {
 225                         boost::mutex::scoped_lock lm (_servers_mutex);
 226                         _servers.push_back (sd);
 227                 }
 228                 emit (boost::bind (boost::ref (ServersListChanged)));
 229         }
 230
 231         start_accept ();
 232 }
 233
 234 optional<list<EncodeServerDescription>::iterator>
 235 EncodeServerFinder::server_found (string ip)
 236 {
 237         boost::mutex::scoped_lock lm (_servers_mutex);
 238         list<EncodeServerDescription>::iterator i = _servers.begin();
 239         while (i != _servers.end() && i->host_name() != ip) {
 240                 ++i;
 241         }
 242
 243         if (i != _servers.end()) {
 244                 return i;
 245         }
 246
 247         return optional<list<EncodeServerDescription>::iterator>();
 248 }
 249
 250 EncodeServerFinder*
 251 EncodeServerFinder::instance ()
 252 {
 253         if (!_instance) {
 254                 _instance = new EncodeServerFinder ();
 255                 _instance->start ();
 256         }
 257
 258         return _instance;
 259 }
 260
 261 void
 262 EncodeServerFinder::drop ()
 263 {
 264         delete _instance;
 265         _instance = 0;
 266 }
 267
 268 list<EncodeServerDescription>
 269 EncodeServerFinder::servers () const
 270 {
 271         boost::mutex::scoped_lock lm (_servers_mutex);
 272         return _servers;
 273 }
 274
 275 void
 276 EncodeServerFinder::config_changed (Config::Property what)
 277 {
 278         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 279                 {
 280                         boost::mutex::scoped_lock lm (_servers_mutex);
 281                         _servers.clear ();
 282                 }
 283                 ServersListChanged ();
 284                 _search_condition.notify_all ();
 285         }
 286 }