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 boost::optional;
  43 using dcp::raw_convert;
  44
  45 EncodeServerFinder* EncodeServerFinder::_instance = 0;
  46
  47 EncodeServerFinder::EncodeServerFinder ()
  48         : _stop (false)
  49 {
  50         Config::instance()->Changed.connect (boost::bind (&EncodeServerFinder::config_changed, this, _1));
  51 }
  52
  53 void
  54 EncodeServerFinder::start ()
  55 {
  56         _search_thread = boost::thread (boost::bind(&EncodeServerFinder::search_thread, this));
  57         _listen_thread = boost::thread (boost::bind(&EncodeServerFinder::listen_thread, this));
  58 #ifdef DCPOMATIC_LINUX
  59         pthread_setname_np (_search_thread.native_handle(), "encode-server-search");
  60         pthread_setname_np (_listen_thread.native_handle(), "encode-server-listen");
  61 #endif
  62 }
  63
  64
  65 EncodeServerFinder::~EncodeServerFinder ()
  66 {
  67         stop ();
  68 }
  69
  70 void
  71 EncodeServerFinder::stop ()
  72 {
  73         _stop = true;
  74
  75         _search_condition.notify_all ();
  76         if (_search_thread.joinable()) {
  77                 try {
  78                         _search_thread.join();
  79                 } catch (...) {
  80
  81                 }
  82         }
  83
  84         _listen_io_service.stop ();
  85         if (_listen_thread.joinable()) {
  86                 try {
  87                         _listen_thread.join ();
  88                 } catch (...) {
  89
  90                 }
  91         }
  92
  93         boost::mutex::scoped_lock lm (_servers_mutex);
  94         _servers.clear ();
  95 }
  96
  97 void
  98 EncodeServerFinder::search_thread ()
  99 try
 100 {
 101         boost::system::error_code error;
 102         boost::asio::io_service io_service;
 103         boost::asio::ip::udp::socket socket (io_service);
 104         socket.open (boost::asio::ip::udp::v4(), error);
 105         if (error) {
 106                 throw NetworkError ("failed to set up broadcast socket");
 107         }
 108
 109         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
 110         socket.set_option (boost::asio::socket_base::broadcast (true));
 111
 112         string const data = DCPOMATIC_HELLO;
 113         int const interval = 10;
 114
 115         while (!_stop) {
 116                 if (Config::instance()->use_any_servers ()) {
 117                         /* Broadcast to look for servers */
 118                         try {
 119                                 boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), HELLO_PORT);
 120                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 121                         } catch (...) {
 122
 123                         }
 124                 }
 125
 126                 /* Query our `definite' servers (if there are any) */
 127                 vector<string> servers = Config::instance()->servers ();
 128                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
 129                         if (server_found (*i)) {
 130                                 /* Don't bother asking a server that we already know about */
 131                                 continue;
 132                         }
 133                         try {
 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
 180         try {
 181                 _listen_acceptor.reset (
 182                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 183                         );
 184         } catch (...) {
 185                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 186         }
 187
 188         start_accept ();
 189         _listen_io_service.run ();
 190 }
 191 catch (...)
 192 {
 193         store_current ();
 194 }
 195
 196 void
 197 EncodeServerFinder::start_accept ()
 198 {
 199         shared_ptr<Socket> socket (new Socket ());
 200         _listen_acceptor->async_accept (
 201                 socket->socket(),
 202                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 203                 );
 204 }
 205
 206 void
 207 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 208 {
 209         if (ec) {
 210                 start_accept ();
 211                 return;
 212         }
 213
 214         uint32_t length;
 215         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 216         length = ntohl (length);
 217
 218         scoped_array<char> buffer (new char[length]);
 219         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 220
 221         string s (buffer.get());
 222         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 223         xml->read_string (s);
 224
 225         string const ip = socket->socket().remote_endpoint().address().to_string ();
 226         optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
 227         if (found) {
 228                 (*found)->set_seen ();
 229         } else {
 230                 EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
 231                 {
 232                         boost::mutex::scoped_lock lm (_servers_mutex);
 233                         _servers.push_back (sd);
 234                 }
 235                 emit (boost::bind (boost::ref (ServersListChanged)));
 236         }
 237
 238         start_accept ();
 239 }
 240
 241 optional<list<EncodeServerDescription>::iterator>
 242 EncodeServerFinder::server_found (string ip)
 243 {
 244         boost::mutex::scoped_lock lm (_servers_mutex);
 245         list<EncodeServerDescription>::iterator i = _servers.begin();
 246         while (i != _servers.end() && i->host_name() != ip) {
 247                 ++i;
 248         }
 249
 250         if (i != _servers.end()) {
 251                 return i;
 252         }
 253
 254         return optional<list<EncodeServerDescription>::iterator>();
 255 }
 256
 257 EncodeServerFinder*
 258 EncodeServerFinder::instance ()
 259 {
 260         if (!_instance) {
 261                 _instance = new EncodeServerFinder ();
 262                 _instance->start ();
 263         }
 264
 265         return _instance;
 266 }
 267
 268 void
 269 EncodeServerFinder::drop ()
 270 {
 271         delete _instance;
 272         _instance = 0;
 273 }
 274
 275 list<EncodeServerDescription>
 276 EncodeServerFinder::servers () const
 277 {
 278         boost::mutex::scoped_lock lm (_servers_mutex);
 279         return _servers;
 280 }
 281
 282 void
 283 EncodeServerFinder::config_changed (Config::Property what)
 284 {
 285         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 286                 {
 287                         boost::mutex::scoped_lock lm (_servers_mutex);
 288                         _servers.clear ();
 289                 }
 290                 ServersListChanged ();
 291                 _search_condition.notify_all ();
 292         }
 293 }