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         start_of_thread ("EncodeServerFinder-search");
 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                 for (auto const& i: Config::instance()->servers()) {
 128                         try {
 129                                 boost::asio::ip::udp::resolver resolver (io_service);
 130                                 boost::asio::ip::udp::resolver::query query (i, raw_convert<string> (HELLO_PORT));
 131                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
 132                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 133                         } catch (...) {
 134
 135                         }
 136                 }
 137
 138                 /* Discard servers that we haven't seen for a while */
 139                 bool removed = false;
 140                 {
 141                         boost::mutex::scoped_lock lm (_servers_mutex);
 142
 143                         list<EncodeServerDescription>::iterator i = _servers.begin();
 144                         while (i != _servers.end()) {
 145                                 if (i->last_seen_seconds() > 2 * interval) {
 146                                         list<EncodeServerDescription>::iterator j = i;
 147                                         ++j;
 148                                         _servers.erase (i);
 149                                         i = j;
 150                                         removed = true;
 151                                 } else {
 152                                         ++i;
 153                                 }
 154                         }
 155                 }
 156
 157                 if (removed) {
 158                         emit (boost::bind (boost::ref (ServersListChanged)));
 159                 }
 160
 161                 boost::mutex::scoped_lock lm (_search_condition_mutex);
 162                 _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (interval));
 163         }
 164 }
 165 catch (...)
 166 {
 167         store_current ();
 168 }
 169
 170 void
 171 EncodeServerFinder::listen_thread ()
 172 try {
 173         start_of_thread ("EncodeServerFinder-listen");
 174
 175         using namespace boost::asio::ip;
 176
 177         try {
 178                 _listen_acceptor.reset (
 179                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 180                         );
 181         } catch (...) {
 182                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 183         }
 184
 185         start_accept ();
 186         _listen_io_service.run ();
 187 }
 188 catch (...)
 189 {
 190         store_current ();
 191 }
 192
 193 void
 194 EncodeServerFinder::start_accept ()
 195 {
 196         shared_ptr<Socket> socket (new Socket ());
 197         _listen_acceptor->async_accept (
 198                 socket->socket(),
 199                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 200                 );
 201 }
 202
 203 void
 204 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 205 {
 206         if (ec) {
 207                 start_accept ();
 208                 return;
 209         }
 210
 211         uint32_t length;
 212         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 213         length = ntohl (length);
 214
 215         scoped_array<char> buffer (new char[length]);
 216         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 217
 218         string s (buffer.get());
 219         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 220         xml->read_string (s);
 221
 222         string const ip = socket->socket().remote_endpoint().address().to_string ();
 223         optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
 224         if (found) {
 225                 (*found)->set_seen ();
 226         } else {
 227                 EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
 228                 {
 229                         boost::mutex::scoped_lock lm (_servers_mutex);
 230                         _servers.push_back (sd);
 231                 }
 232                 emit (boost::bind (boost::ref (ServersListChanged)));
 233         }
 234
 235         start_accept ();
 236 }
 237
 238 optional<list<EncodeServerDescription>::iterator>
 239 EncodeServerFinder::server_found (string ip)
 240 {
 241         boost::mutex::scoped_lock lm (_servers_mutex);
 242         list<EncodeServerDescription>::iterator i = _servers.begin();
 243         while (i != _servers.end() && i->host_name() != ip) {
 244                 ++i;
 245         }
 246
 247         if (i != _servers.end()) {
 248                 return i;
 249         }
 250
 251         return optional<list<EncodeServerDescription>::iterator>();
 252 }
 253
 254 EncodeServerFinder*
 255 EncodeServerFinder::instance ()
 256 {
 257         if (!_instance) {
 258                 _instance = new EncodeServerFinder ();
 259                 _instance->start ();
 260         }
 261
 262         return _instance;
 263 }
 264
 265 void
 266 EncodeServerFinder::drop ()
 267 {
 268         delete _instance;
 269         _instance = 0;
 270 }
 271
 272 list<EncodeServerDescription>
 273 EncodeServerFinder::servers () const
 274 {
 275         boost::mutex::scoped_lock lm (_servers_mutex);
 276         return _servers;
 277 }
 278
 279 void
 280 EncodeServerFinder::config_changed (Config::Property what)
 281 {
 282         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 283                 {
 284                         boost::mutex::scoped_lock lm (_servers_mutex);
 285                         _servers.clear ();
 286                 }
 287                 ServersListChanged ();
 288                 _search_condition.notify_all ();
 289         }
 290 }