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