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