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 #if BOOST_VERSION >= 107400
  31 #include <boost/bind/placeholders.hpp>
  32 #else
  33 #include <boost/bind/bind.hpp>
  34 #endif
  35 #include <boost/lambda/lambda.hpp>
  36 #include <iostream>
  37
  38 #include "i18n.h"
  39
  40 using std::string;
  41 using std::list;
  42 using std::vector;
  43 using std::cout;
  44 using boost::shared_ptr;
  45 using boost::scoped_array;
  46 using boost::weak_ptr;
  47 using boost::optional;
  48 #if BOOST_VERSION >= 106100
  49 using namespace boost::placeholders;
  50 #endif
  51 using dcp::raw_convert;
  52
  53 EncodeServerFinder* EncodeServerFinder::_instance = 0;
  54
  55 EncodeServerFinder::EncodeServerFinder ()
  56         : _stop (false)
  57 {
  58         Config::instance()->Changed.connect (boost::bind (&EncodeServerFinder::config_changed, this, _1));
  59 }
  60
  61 void
  62 EncodeServerFinder::start ()
  63 {
  64         _search_thread = boost::thread (boost::bind(&EncodeServerFinder::search_thread, this));
  65         _listen_thread = boost::thread (boost::bind(&EncodeServerFinder::listen_thread, this));
  66 #ifdef DCPOMATIC_LINUX
  67         pthread_setname_np (_search_thread.native_handle(), "encode-server-search");
  68         pthread_setname_np (_listen_thread.native_handle(), "encode-server-listen");
  69 #endif
  70 }
  71
  72
  73 EncodeServerFinder::~EncodeServerFinder ()
  74 {
  75         stop ();
  76 }
  77
  78 void
  79 EncodeServerFinder::stop ()
  80 {
  81         boost::this_thread::disable_interruption dis;
  82
  83         _stop = true;
  84
  85         _search_condition.notify_all ();
  86         try {
  87                 _search_thread.join();
  88         } catch (...) {}
  89
  90         _listen_io_service.stop ();
  91         try {
  92                 _listen_thread.join ();
  93         } catch (...) {}
  94
  95         boost::mutex::scoped_lock lm (_servers_mutex);
  96         _servers.clear ();
  97 }
  98
  99 void
 100 EncodeServerFinder::search_thread ()
 101 try
 102 {
 103         boost::system::error_code error;
 104         boost::asio::io_service io_service;
 105         boost::asio::ip::udp::socket socket (io_service);
 106         socket.open (boost::asio::ip::udp::v4(), error);
 107         if (error) {
 108                 throw NetworkError ("failed to set up broadcast socket");
 109         }
 110
 111         socket.set_option (boost::asio::ip::udp::socket::reuse_address (true));
 112         socket.set_option (boost::asio::socket_base::broadcast (true));
 113
 114         string const data = DCPOMATIC_HELLO;
 115         int const interval = 10;
 116
 117         while (!_stop) {
 118                 if (Config::instance()->use_any_servers ()) {
 119                         /* Broadcast to look for servers */
 120                         try {
 121                                 boost::asio::ip::udp::endpoint end_point (boost::asio::ip::address_v4::broadcast(), HELLO_PORT);
 122                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 123                         } catch (...) {
 124
 125                         }
 126                 }
 127
 128                 /* Query our `definite' servers (if there are any) */
 129                 vector<string> servers = Config::instance()->servers ();
 130                 for (vector<string>::const_iterator i = servers.begin(); i != servers.end(); ++i) {
 131                         if (server_found (*i)) {
 132                                 /* Don't bother asking a server that we already know about */
 133                                 continue;
 134                         }
 135                         try {
 136                                 boost::asio::ip::udp::resolver resolver (io_service);
 137                                 boost::asio::ip::udp::resolver::query query (*i, raw_convert<string> (HELLO_PORT));
 138                                 boost::asio::ip::udp::endpoint end_point (*resolver.resolve (query));
 139                                 socket.send_to (boost::asio::buffer (data.c_str(), data.size() + 1), end_point);
 140                         } catch (...) {
 141
 142                         }
 143                 }
 144
 145                 /* Discard servers that we haven't seen for a while */
 146                 bool removed = false;
 147                 {
 148                         boost::mutex::scoped_lock lm (_servers_mutex);
 149
 150                         list<EncodeServerDescription>::iterator i = _servers.begin();
 151                         while (i != _servers.end()) {
 152                                 if (i->last_seen_seconds() > 2 * interval) {
 153                                         list<EncodeServerDescription>::iterator j = i;
 154                                         ++j;
 155                                         _servers.erase (i);
 156                                         i = j;
 157                                         removed = true;
 158                                 } else {
 159                                         ++i;
 160                                 }
 161                         }
 162                 }
 163
 164                 if (removed) {
 165                         emit (boost::bind (boost::ref (ServersListChanged)));
 166                 }
 167
 168                 boost::mutex::scoped_lock lm (_search_condition_mutex);
 169                 _search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (interval));
 170         }
 171 }
 172 catch (...)
 173 {
 174         store_current ();
 175 }
 176
 177 void
 178 EncodeServerFinder::listen_thread ()
 179 try {
 180         using namespace boost::asio::ip;
 181
 182         try {
 183                 _listen_acceptor.reset (
 184                         new tcp::acceptor (_listen_io_service, tcp::endpoint (tcp::v4(), is_batch_converter ? BATCH_SERVER_PRESENCE_PORT : MAIN_SERVER_PRESENCE_PORT))
 185                         );
 186         } catch (...) {
 187                 boost::throw_exception (NetworkError (_("Could not listen for remote encode servers.  Perhaps another instance of DCP-o-matic is running.")));
 188         }
 189
 190         start_accept ();
 191         _listen_io_service.run ();
 192 }
 193 catch (...)
 194 {
 195         store_current ();
 196 }
 197
 198 void
 199 EncodeServerFinder::start_accept ()
 200 {
 201         shared_ptr<Socket> socket (new Socket ());
 202         _listen_acceptor->async_accept (
 203                 socket->socket(),
 204                 boost::bind (&EncodeServerFinder::handle_accept, this, boost::asio::placeholders::error, socket)
 205                 );
 206 }
 207
 208 void
 209 EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Socket> socket)
 210 {
 211         if (ec) {
 212                 start_accept ();
 213                 return;
 214         }
 215
 216         uint32_t length;
 217         socket->read (reinterpret_cast<uint8_t*> (&length), sizeof (uint32_t));
 218         length = ntohl (length);
 219
 220         scoped_array<char> buffer (new char[length]);
 221         socket->read (reinterpret_cast<uint8_t*> (buffer.get()), length);
 222
 223         string s (buffer.get());
 224         shared_ptr<cxml::Document> xml (new cxml::Document ("ServerAvailable"));
 225         xml->read_string (s);
 226
 227         string const ip = socket->socket().remote_endpoint().address().to_string ();
 228         optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
 229         if (found) {
 230                 (*found)->set_seen ();
 231         } else {
 232                 EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
 233                 {
 234                         boost::mutex::scoped_lock lm (_servers_mutex);
 235                         _servers.push_back (sd);
 236                 }
 237                 emit (boost::bind (boost::ref (ServersListChanged)));
 238         }
 239
 240         start_accept ();
 241 }
 242
 243 optional<list<EncodeServerDescription>::iterator>
 244 EncodeServerFinder::server_found (string ip)
 245 {
 246         boost::mutex::scoped_lock lm (_servers_mutex);
 247         list<EncodeServerDescription>::iterator i = _servers.begin();
 248         while (i != _servers.end() && i->host_name() != ip) {
 249                 ++i;
 250         }
 251
 252         if (i != _servers.end()) {
 253                 return i;
 254         }
 255
 256         return optional<list<EncodeServerDescription>::iterator>();
 257 }
 258
 259 EncodeServerFinder*
 260 EncodeServerFinder::instance ()
 261 {
 262         if (!_instance) {
 263                 _instance = new EncodeServerFinder ();
 264                 _instance->start ();
 265         }
 266
 267         return _instance;
 268 }
 269
 270 void
 271 EncodeServerFinder::drop ()
 272 {
 273         delete _instance;
 274         _instance = 0;
 275 }
 276
 277 list<EncodeServerDescription>
 278 EncodeServerFinder::servers () const
 279 {
 280         boost::mutex::scoped_lock lm (_servers_mutex);
 281         return _servers;
 282 }
 283
 284 void
 285 EncodeServerFinder::config_changed (Config::Property what)
 286 {
 287         if (what == Config::USE_ANY_SERVERS || what == Config::SERVERS) {
 288                 {
 289                         boost::mutex::scoped_lock lm (_servers_mutex);
 290                         _servers.clear ();
 291                 }
 292                 ServersListChanged ();
 293                 _search_condition.notify_all ();
 294         }
 295 }