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