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 void hup(int signum)
  40 {
  41         hupped = true;
  42         if (signum == SIGINT) {
  43                 stopped = true;
  44         }
  45 }
  46
  47 CubemapStateProto collect_state(const timeval &serialize_start,
  48                                 const vector<Acceptor *> acceptors,
  49                                 const vector<Input *> inputs,
  50                                 ServerPool *servers)
  51 {
  52         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  53         state.set_serialize_start_sec(serialize_start.tv_sec);
  54         state.set_serialize_start_usec(serialize_start.tv_usec);
  55
  56         for (size_t i = 0; i < acceptors.size(); ++i) {
  57                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  58         }
  59
  60         for (size_t i = 0; i < inputs.size(); ++i) {
  61                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  62         }
  63
  64         return state;
  65 }
  66
  67 // Find all port statements in the configuration file, and create acceptors for htem.
  68 vector<Acceptor *> create_acceptors(
  69         const Config &config,
  70         map<int, Acceptor *> *deserialized_acceptors)
  71 {
  72         vector<Acceptor *> acceptors;
  73         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
  74                 const AcceptorConfig &acceptor_config = config.acceptors[i];
  75                 Acceptor *acceptor = NULL;
  76                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
  77                         deserialized_acceptors->find(acceptor_config.port);
  78                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
  79                         acceptor = deserialized_acceptor_it->second;
  80                         deserialized_acceptors->erase(deserialized_acceptor_it);
  81                 } else {
  82                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
  83                         acceptor = new Acceptor(server_sock, acceptor_config.port);
  84                 }
  85                 acceptor->run();
  86                 acceptors.push_back(acceptor);
  87         }
  88
  89         // Close all acceptors that are no longer in the configuration file.
  90         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
  91              acceptor_it != deserialized_acceptors->end();
  92              ++acceptor_it) {
  93                 acceptor_it->second->close_socket();
  94                 delete acceptor_it->second;
  95         }
  96
  97         return acceptors;
  98 }
  99
 100 // Find all streams in the configuration file, and create inputs for them.
 101 vector<Input *> create_inputs(const Config &config,
 102                               map<string, Input *> *deserialized_inputs)
 103 {
 104         vector<Input *> inputs;
 105         for (unsigned i = 0; i < config.streams.size(); ++i) {
 106                 const StreamConfig &stream_config = config.streams[i];
 107                 if (stream_config.src.empty()) {
 108                         continue;
 109                 }
 110
 111                 string stream_id = stream_config.stream_id;
 112                 string src = stream_config.src;
 113
 114                 Input *input = NULL;
 115                 map<string, Input *>::iterator deserialized_input_it =
 116                         deserialized_inputs->find(stream_id);
 117                 if (deserialized_input_it != deserialized_inputs->end()) {
 118                         input = deserialized_input_it->second;
 119                         if (input->get_url() != src) {
 120                                 log(INFO, "Stream '%s' has changed URL from '%s' to '%s', restarting input.",
 121                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 122                                 input->close_socket();
 123                                 delete input;
 124                                 input = NULL;
 125                         }
 126                         deserialized_inputs->erase(deserialized_input_it);
 127                 }
 128                 if (input == NULL) {
 129                         input = create_input(stream_id, src);
 130                         if (input == NULL) {
 131                                 log(ERROR, "did not understand URL '%s', clients will not get any data.",
 132                                         src.c_str());
 133                                 continue;
 134                         }
 135                 }
 136                 input->run();
 137                 inputs.push_back(input);
 138         }
 139         return inputs;
 140 }
 141
 142 void create_streams(const Config &config,
 143                     const set<string> &deserialized_stream_ids,
 144                     map<string, Input *> *deserialized_inputs)
 145 {
 146         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 147                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 148                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 149         }
 150
 151         set<string> expecting_stream_ids = deserialized_stream_ids;
 152         for (unsigned i = 0; i < config.streams.size(); ++i) {
 153                 const StreamConfig &stream_config = config.streams[i];
 154                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 155                         servers->add_stream(stream_config.stream_id, stream_config.backlog_size);
 156                 } else {
 157                         servers->set_backlog_size(stream_config.stream_id, stream_config.backlog_size);
 158                 }
 159                 expecting_stream_ids.erase(stream_config.stream_id);
 160
 161                 if (stream_config.mark_pool != -1) {
 162                         servers->set_mark_pool(stream_config.stream_id,
 163                                                mark_pools[stream_config.mark_pool]);
 164                 }
 165         }
 166
 167         // Warn about any servers we've lost.
 168         // TODO: Make an option (delete=yes?) to actually shut down streams.
 169         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 170              stream_it != expecting_stream_ids.end();
 171              ++stream_it) {
 172                 string stream_id = *stream_it;
 173                 log(WARNING, "stream '%s' disappeared from the configuration file. "
 174                              "It will not be deleted, but clients will not get any new inputs.",
 175                              stream_id.c_str());
 176                 if (deserialized_inputs->count(stream_id) != 0) {
 177                         delete (*deserialized_inputs)[stream_id];
 178                         deserialized_inputs->erase(stream_id);
 179                 }
 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<string, Input *> deserialized_inputs;
 328         map<int, Acceptor *> deserialized_acceptors;
 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                         servers->add_stream_from_serialized(loaded_state.streams(i));
 346                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 347                 }
 348
 349                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 350                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 351                         deserialized_inputs.insert(make_pair(
 352                                 loaded_state.inputs(i).stream_id(),
 353                                 create_input(loaded_state.inputs(i))));
 354                 }
 355
 356                 // Deserialize the acceptors.
 357                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 358                         deserialized_acceptors.insert(make_pair(
 359                                 loaded_state.acceptors(i).port(),
 360                                 new Acceptor(loaded_state.acceptors(i))));
 361                 }
 362
 363                 log(INFO, "Deserialization done.");
 364         }
 365
 366         // Find all streams in the configuration file, and create them.
 367         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 368
 369         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 370         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 371
 372         // All deserialized inputs should now have been taken care of, one way or the other.
 373         assert(deserialized_inputs.empty());
 374
 375         // Put back the existing clients. It doesn't matter which server we
 376         // allocate them to, so just do round-robin. However, we need to add
 377         // them after the mark pools have been set up.
 378         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 379                 servers->add_client_from_serialized(loaded_state.clients(i));
 380         }
 381
 382         servers->run();
 383
 384         // Start writing statistics.
 385         StatsThread *stats_thread = NULL;
 386         if (!config.stats_file.empty()) {
 387                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 388                 stats_thread->run();
 389         }
 390
 391         struct timeval server_start;
 392         gettimeofday(&server_start, NULL);
 393         if (state_fd != -1) {
 394                 // Measure time from we started deserializing (below) to now, when basically everything
 395                 // is up and running. This is, in other words, a conservative estimate of how long our
 396                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 397                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 398                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 399                 log(INFO, "Re-exec happened in approx. %.0f ms.", glitch_time * 1000.0);
 400         }
 401
 402         while (!hupped) {
 403                 usleep(100000);
 404         }
 405
 406         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 407         gettimeofday(&serialize_start, NULL);
 408
 409         if (stats_thread != NULL) {
 410                 stats_thread->stop();
 411                 delete stats_thread;
 412         }
 413         for (size_t i = 0; i < acceptors.size(); ++i) {
 414                 acceptors[i]->stop();
 415         }
 416         for (size_t i = 0; i < inputs.size(); ++i) {
 417                 inputs[i]->stop();
 418         }
 419         servers->stop();
 420
 421         CubemapStateProto state;
 422         if (stopped) {
 423                 log(INFO, "Shutting down.");
 424         } else {
 425                 log(INFO, "Serializing state and re-execing...");
 426                 state = collect_state(
 427                         serialize_start, acceptors, inputs, servers);
 428                 string serialized;
 429                 state.SerializeToString(&serialized);
 430                 state_fd = make_tempfile(serialized);
 431                 if (state_fd == -1) {
 432                         exit(1);
 433                 }
 434         }
 435         delete servers;
 436
 437         for (unsigned i = 0; i < mark_pools.size(); ++i) {
 438                 delete mark_pools[i];
 439         }
 440         mark_pools.clear();
 441
 442         access_log->stop();
 443         delete access_log;
 444         shut_down_logging();
 445
 446         if (stopped) {
 447                 exit(0);
 448         }
 449
 450         // OK, so the signal was SIGHUP. Check that the new config is okay, then exec the new binary.
 451         if (!dry_run_config(argv0_canon, config_filename_canon)) {
 452                 open_logs(config.log_destinations);
 453                 log(ERROR, "%s --test-config failed. Restarting old version instead of new.", argv[0]);
 454                 hupped = false;
 455                 shut_down_logging();
 456                 goto start;
 457         }
 458
 459         char buf[16];
 460         sprintf(buf, "%d", state_fd);
 461
 462         for ( ;; ) {
 463                 execlp(argv0_canon, argv0_canon, config_filename_canon, "--state", buf, NULL);
 464                 open_logs(config.log_destinations);
 465                 log_perror("execlp");
 466                 log(ERROR, "re-exec of %s failed. Waiting 0.2 seconds and trying again...", argv0_canon);
 467                 shut_down_logging();
 468                 usleep(200000);
 469         }
 470 }