git.sesse.net Git - cubemap/blob - main.cpp

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <getopt.h>
   4 #include <limits.h>
   5 #include <signal.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/time.h>
  11 #include <sys/wait.h>
  12 #include <unistd.h>
  13 #include <map>
  14 #include <set>
  15 #include <string>
  16 #include <utility>
  17 #include <vector>
  18
  19 #include "acceptor.h"
  20 #include "accesslog.h"
  21 #include "config.h"
  22 #include "input.h"
  23 #include "log.h"
  24 #include "markpool.h"
  25 #include "serverpool.h"
  26 #include "state.pb.h"
  27 #include "stats.h"
  28 #include "stream.h"
  29 #include "util.h"
  30 #include "version.h"
  31
  32 using namespace std;
  33
  34 AccessLogThread *access_log = NULL;
  35 ServerPool *servers = NULL;
  36 vector<MarkPool *> mark_pools;
  37 volatile bool hupped = false;
  38 volatile bool stopped = false;
  39
  40 struct InputWithRefcount {
  41         Input *input;
  42         int refcount;
  43 };
  44
  45 void hup(int signum)
  46 {
  47         hupped = true;
  48         if (signum == SIGINT) {
  49                 stopped = true;
  50         }
  51 }
  52
  53 void do_nothing(int signum)
  54 {
  55 }
  56
  57 CubemapStateProto collect_state(const timeval &serialize_start,
  58                                 const vector<Acceptor *> acceptors,
  59                                 const multimap<string, InputWithRefcount> inputs,
  60                                 ServerPool *servers)
  61 {
  62         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  63         state.set_serialize_start_sec(serialize_start.tv_sec);
  64         state.set_serialize_start_usec(serialize_start.tv_usec);
  65
  66         for (size_t i = 0; i < acceptors.size(); ++i) {
  67                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  68         }
  69
  70         for (multimap<string, InputWithRefcount>::const_iterator input_it = inputs.begin();
  71              input_it != inputs.end();
  72              ++input_it) {
  73                 state.add_inputs()->MergeFrom(input_it->second.input->serialize());
  74         }
  75
  76         return state;
  77 }
  78
  79 // Find all port statements in the configuration file, and create acceptors for htem.
  80 vector<Acceptor *> create_acceptors(
  81         const Config &config,
  82         map<int, Acceptor *> *deserialized_acceptors)
  83 {
  84         vector<Acceptor *> acceptors;
  85         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
  86                 const AcceptorConfig &acceptor_config = config.acceptors[i];
  87                 Acceptor *acceptor = NULL;
  88                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
  89                         deserialized_acceptors->find(acceptor_config.port);
  90                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
  91                         acceptor = deserialized_acceptor_it->second;
  92                         deserialized_acceptors->erase(deserialized_acceptor_it);
  93                 } else {
  94                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
  95                         acceptor = new Acceptor(server_sock, acceptor_config.port);
  96                 }
  97                 acceptor->run();
  98                 acceptors.push_back(acceptor);
  99         }
 100
 101         // Close all acceptors that are no longer in the configuration file.
 102         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
 103              acceptor_it != deserialized_acceptors->end();
 104              ++acceptor_it) {
 105                 acceptor_it->second->close_socket();
 106                 delete acceptor_it->second;
 107         }
 108
 109         return acceptors;
 110 }
 111
 112 // Find all streams in the configuration file, and create inputs for them.
 113 void create_config_inputs(const Config &config, multimap<string, InputWithRefcount> *inputs)
 114 {
 115         for (unsigned i = 0; i < config.streams.size(); ++i) {
 116                 const StreamConfig &stream_config = config.streams[i];
 117                 if (stream_config.src.empty()) {
 118                         continue;
 119                 }
 120
 121                 string src = stream_config.src;
 122                 if (inputs->count(src) != 0) {
 123                         continue;
 124                 }
 125
 126                 InputWithRefcount iwr;
 127                 iwr.input = create_input(src);
 128                 if (iwr.input == NULL) {
 129                         log(ERROR, "did not understand URL '%s', clients will not get any data.",
 130                                 src.c_str());
 131                         continue;
 132                 }
 133                 iwr.refcount = 0;
 134                 inputs->insert(make_pair(src, iwr));
 135         }
 136 }
 137
 138 void create_streams(const Config &config,
 139                     const set<string> &deserialized_urls,
 140                     multimap<string, InputWithRefcount> *inputs)
 141 {
 142         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 143                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 144                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 145         }
 146
 147         set<string> expecting_urls = deserialized_urls;
 148         for (unsigned i = 0; i < config.streams.size(); ++i) {
 149                 const StreamConfig &stream_config = config.streams[i];
 150                 int stream_index;
 151                 if (deserialized_urls.count(stream_config.url) == 0) {
 152                         stream_index = servers->add_stream(stream_config.url,
 153                                                            stream_config.backlog_size,
 154                                                            Stream::Encoding(stream_config.encoding));
 155                 } else {
 156                         stream_index = servers->lookup_stream_by_url(stream_config.url);
 157                         assert(stream_index != -1);
 158                         servers->set_backlog_size(stream_index, stream_config.backlog_size);
 159                         servers->set_encoding(stream_index,
 160                                               Stream::Encoding(stream_config.encoding));
 161                 }
 162                 expecting_urls.erase(stream_config.url);
 163
 164                 if (stream_config.mark_pool != -1) {
 165                         servers->set_mark_pool(stream_index, mark_pools[stream_config.mark_pool]);
 166                 }
 167
 168                 string src = stream_config.src;
 169                 if (!src.empty()) {
 170                         multimap<string, InputWithRefcount>::iterator input_it = inputs->find(src);
 171                         assert(input_it != inputs->end());
 172                         input_it->second.input->add_destination(stream_index);
 173                         ++input_it->second.refcount;
 174                 }
 175         }
 176
 177         // Warn about any servers we've lost.
 178         // TODO: Make an option (delete=yes?) to actually shut down streams.
 179         for (set<string>::const_iterator stream_it = expecting_urls.begin();
 180              stream_it != expecting_urls.end();
 181              ++stream_it) {
 182                 string url = *stream_it;
 183                 log(WARNING, "stream '%s' disappeared from the configuration file. "
 184                              "It will not be deleted, but clients will not get any new inputs.",
 185                              url.c_str());
 186         }
 187 }
 188
 189 void open_logs(const vector<LogConfig> &log_destinations)
 190 {
 191         for (size_t i = 0; i < log_destinations.size(); ++i) {
 192                 if (log_destinations[i].type == LogConfig::LOG_TYPE_FILE) {
 193                         add_log_destination_file(log_destinations[i].filename);
 194                 } else if (log_destinations[i].type == LogConfig::LOG_TYPE_CONSOLE) {
 195                         add_log_destination_console();
 196                 } else if (log_destinations[i].type == LogConfig::LOG_TYPE_SYSLOG) {
 197                         add_log_destination_syslog();
 198                 } else {
 199                         assert(false);
 200                 }
 201         }
 202         start_logging();
 203 }
 204
 205 bool dry_run_config(const std::string &argv0, const std::string &config_filename)
 206 {
 207         char *argv0_copy = strdup(argv0.c_str());
 208         char *config_filename_copy = strdup(config_filename.c_str());
 209
 210         pid_t pid = fork();
 211         switch (pid) {
 212         case -1:
 213                 log_perror("fork()");
 214                 free(argv0_copy);
 215                 free(config_filename_copy);
 216                 return false;
 217         case 0:
 218                 // Child.
 219                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 220                 log_perror(argv0_copy);
 221                 _exit(1);
 222         default:
 223                 // Parent.
 224                 break;
 225         }
 226
 227         free(argv0_copy);
 228         free(config_filename_copy);
 229
 230         int status;
 231         pid_t err;
 232         do {
 233                 err = waitpid(pid, &status, 0);
 234         } while (err == -1 && errno == EINTR);
 235
 236         if (err == -1) {
 237                 log_perror("waitpid()");
 238                 return false;
 239         }
 240
 241         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 242 }
 243
 244 int main(int argc, char **argv)
 245 {
 246         signal(SIGHUP, hup);
 247         signal(SIGINT, hup);
 248         signal(SIGUSR1, do_nothing);  // Used in internal signalling.
 249         signal(SIGPIPE, SIG_IGN);
 250
 251         // Parse options.
 252         int state_fd = -1;
 253         bool test_config = false;
 254         for ( ;; ) {
 255                 static const option long_options[] = {
 256                         { "state", required_argument, 0, 's' },
 257                         { "test-config", no_argument, 0, 't' },
 258                         { 0, 0, 0, 0 }
 259                 };
 260                 int option_index = 0;
 261                 int c = getopt_long(argc, argv, "s:t", long_options, &option_index);
 262
 263                 if (c == -1) {
 264                         break;
 265                 }
 266                 switch (c) {
 267                 case 's':
 268                         state_fd = atoi(optarg);
 269                         break;
 270                 case 't':
 271                         test_config = true;
 272                         break;
 273                 default:
 274                         fprintf(stderr, "Unknown option '%s'\n", argv[option_index]);
 275                         exit(1);
 276                 }
 277         }
 278
 279         string config_filename = "cubemap.config";
 280         if (optind < argc) {
 281                 config_filename = argv[optind++];
 282         }
 283
 284         // Canonicalize argv[0] and config_filename.
 285         char argv0_canon[PATH_MAX];
 286         char config_filename_canon[PATH_MAX];
 287
 288         if (realpath(argv[0], argv0_canon) == NULL) {
 289                 log_perror(argv[0]);
 290                 exit(1);
 291         }
 292         if (realpath(config_filename.c_str(), config_filename_canon) == NULL) {
 293                 log_perror(config_filename.c_str());
 294                 exit(1);
 295         }
 296
 297         // Now parse the configuration file.
 298         Config config;
 299         if (!parse_config(config_filename_canon, &config)) {
 300                 exit(1);
 301         }
 302         if (test_config) {
 303                 exit(0);
 304         }
 305
 306         // Ideally we'd like to daemonize only when we've started up all threads etc.,
 307         // but daemon() forks, which is not good in multithreaded software, so we'll
 308         // have to do it here.
 309         if (config.daemonize) {
 310                 if (daemon(0, 0) == -1) {
 311                         log_perror("daemon");
 312                         exit(1);
 313                 }
 314         }
 315
 316 start:
 317         // Open logs as soon as possible.
 318         open_logs(config.log_destinations);
 319
 320         log(INFO, "Cubemap " SERVER_VERSION " starting.");
 321         if (config.access_log_file.empty()) {
 322                 // Create a dummy logger.
 323                 access_log = new AccessLogThread();
 324         } else {
 325                 access_log = new AccessLogThread(config.access_log_file);
 326         }
 327         access_log->run();
 328
 329         servers = new ServerPool(config.num_servers);
 330
 331         CubemapStateProto loaded_state;
 332         struct timeval serialize_start;
 333         set<string> deserialized_urls;
 334         map<int, Acceptor *> deserialized_acceptors;
 335         multimap<string, InputWithRefcount> inputs;  // multimap due to older versions without deduplication.
 336         if (state_fd != -1) {
 337                 log(INFO, "Deserializing state from previous process...");
 338                 string serialized;
 339                 if (!read_tempfile(state_fd, &serialized)) {
 340                         exit(1);
 341                 }
 342                 if (!loaded_state.ParseFromString(serialized)) {
 343                         log(ERROR, "Failed deserialization of state.");
 344                         exit(1);
 345                 }
 346
 347                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 348                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 349
 350                 // Deserialize the streams.
 351                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 352                         const StreamProto &stream = loaded_state.streams(i);
 353
 354                         vector<int> data_fds;
 355                         for (int j = 0; j < stream.data_fds_size(); ++j) {
 356                                 data_fds.push_back(stream.data_fds(j));
 357                         }
 358
 359                         // Older versions stored the data once in the protobuf instead of
 360                         // sending around file descriptors.
 361                         if (data_fds.empty() && stream.has_data()) {
 362                                 data_fds.push_back(make_tempfile(stream.data()));
 363                         }
 364
 365                         servers->add_stream_from_serialized(stream, data_fds);
 366                         deserialized_urls.insert(stream.url());
 367                 }
 368
 369                 // Deserialize the inputs. Note that we don't actually add them to any stream yet.
 370                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 371                         InputWithRefcount iwr;
 372                         iwr.input = create_input(loaded_state.inputs(i));
 373                         iwr.refcount = 0;
 374                         inputs.insert(make_pair(loaded_state.inputs(i).url(), iwr));
 375                 }
 376
 377                 // Deserialize the acceptors.
 378                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 379                         deserialized_acceptors.insert(make_pair(
 380                                 loaded_state.acceptors(i).port(),
 381                                 new Acceptor(loaded_state.acceptors(i))));
 382                 }
 383
 384                 log(INFO, "Deserialization done.");
 385         }
 386
 387         // Add any new inputs coming from the config.
 388         create_config_inputs(config, &inputs);
 389
 390         // Find all streams in the configuration file, create them, and connect to the inputs.
 391         create_streams(config, deserialized_urls, &inputs);
 392         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 393
 394         // Put back the existing clients. It doesn't matter which server we
 395         // allocate them to, so just do round-robin. However, we need to add
 396         // them after the mark pools have been set up.
 397         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 398                 servers->add_client_from_serialized(loaded_state.clients(i));
 399         }
 400
 401         servers->run();
 402
 403         // Now delete all inputs that are longer in use, and start the others.
 404         for (multimap<string, InputWithRefcount>::iterator input_it = inputs.begin();
 405              input_it != inputs.end(); ) {
 406                 if (input_it->second.refcount == 0) {
 407                         log(WARNING, "Input '%s' no longer in use, closing.",
 408                             input_it->first.c_str());
 409                         input_it->second.input->close_socket();
 410                         delete input_it->second.input;
 411                         inputs.erase(input_it++);
 412                 } else {
 413                         input_it->second.input->run();
 414                         ++input_it;
 415                 }
 416         }
 417
 418         // Start writing statistics.
 419         StatsThread *stats_thread = NULL;
 420         if (!config.stats_file.empty()) {
 421                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 422                 stats_thread->run();
 423         }
 424
 425         struct timeval server_start;
 426         gettimeofday(&server_start, NULL);
 427         if (state_fd != -1) {
 428                 // Measure time from we started deserializing (below) to now, when basically everything
 429                 // is up and running. This is, in other words, a conservative estimate of how long our
 430                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 431                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 432                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 433                 log(INFO, "Re-exec happened in approx. %.0f ms.", glitch_time * 1000.0);
 434         }
 435
 436         while (!hupped) {
 437                 usleep(100000);
 438         }
 439
 440         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 441         gettimeofday(&serialize_start, NULL);
 442
 443         if (stats_thread != NULL) {
 444                 stats_thread->stop();
 445                 delete stats_thread;
 446         }
 447         for (size_t i = 0; i < acceptors.size(); ++i) {
 448                 acceptors[i]->stop();
 449         }
 450         for (multimap<string, InputWithRefcount>::iterator input_it = inputs.begin();
 451              input_it != inputs.end();
 452              ++input_it) {
 453                 input_it->second.input->stop();
 454         }
 455         servers->stop();
 456
 457         CubemapStateProto state;
 458         if (stopped) {
 459                 log(INFO, "Shutting down.");
 460         } else {
 461                 log(INFO, "Serializing state and re-execing...");
 462                 state = collect_state(
 463                         serialize_start, acceptors, inputs, servers);
 464                 string serialized;
 465                 state.SerializeToString(&serialized);
 466                 state_fd = make_tempfile(serialized);
 467                 if (state_fd == -1) {
 468                         exit(1);
 469                 }
 470         }
 471         delete servers;
 472
 473         for (unsigned i = 0; i < mark_pools.size(); ++i) {
 474                 delete mark_pools[i];
 475         }
 476         mark_pools.clear();
 477
 478         access_log->stop();
 479         delete access_log;
 480         shut_down_logging();
 481
 482         if (stopped) {
 483                 exit(0);
 484         }
 485
 486         // OK, so the signal was SIGHUP. Check that the new config is okay, then exec the new binary.
 487         if (!dry_run_config(argv0_canon, config_filename_canon)) {
 488                 open_logs(config.log_destinations);
 489                 log(ERROR, "%s --test-config failed. Restarting old version instead of new.", argv[0]);
 490                 hupped = false;
 491                 shut_down_logging();
 492                 goto start;
 493         }
 494
 495         char buf[16];
 496         sprintf(buf, "%d", state_fd);
 497
 498         for ( ;; ) {
 499                 execlp(argv0_canon, argv0_canon, config_filename_canon, "--state", buf, NULL);
 500                 open_logs(config.log_destinations);
 501                 log_perror("execlp");
 502                 log(ERROR, "re-exec of %s failed. Waiting 0.2 seconds and trying again...", argv0_canon);
 503                 shut_down_logging();
 504                 usleep(200000);
 505         }
 506 }