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 volatile bool hupped = false;
  36 volatile bool stopped = false;
  37
  38 void hup(int signum)
  39 {
  40         hupped = true;
  41         if (signum == SIGINT) {
  42                 stopped = true;
  43         }
  44 }
  45
  46 CubemapStateProto collect_state(const timeval &serialize_start,
  47                                 const vector<Acceptor *> acceptors,
  48                                 const vector<Input *> inputs,
  49                                 ServerPool *servers)
  50 {
  51         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  52         state.set_serialize_start_sec(serialize_start.tv_sec);
  53         state.set_serialize_start_usec(serialize_start.tv_usec);
  54
  55         for (size_t i = 0; i < acceptors.size(); ++i) {
  56                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  57         }
  58
  59         for (size_t i = 0; i < inputs.size(); ++i) {
  60                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  61         }
  62
  63         return state;
  64 }
  65
  66 // Find all port statements in the configuration file, and create acceptors for htem.
  67 vector<Acceptor *> create_acceptors(
  68         const Config &config,
  69         map<int, Acceptor *> *deserialized_acceptors)
  70 {
  71         vector<Acceptor *> acceptors;
  72         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
  73                 const AcceptorConfig &acceptor_config = config.acceptors[i];
  74                 Acceptor *acceptor = NULL;
  75                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
  76                         deserialized_acceptors->find(acceptor_config.port);
  77                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
  78                         acceptor = deserialized_acceptor_it->second;
  79                         deserialized_acceptors->erase(deserialized_acceptor_it);
  80                 } else {
  81                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
  82                         acceptor = new Acceptor(server_sock, acceptor_config.port);
  83                 }
  84                 acceptor->run();
  85                 acceptors.push_back(acceptor);
  86         }
  87
  88         // Close all acceptors that are no longer in the configuration file.
  89         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
  90              acceptor_it != deserialized_acceptors->end();
  91              ++acceptor_it) {
  92                 acceptor_it->second->close_socket();
  93                 delete acceptor_it->second;
  94         }
  95
  96         return acceptors;
  97 }
  98
  99 // Find all streams in the configuration file, and create inputs for them.
 100 vector<Input *> create_inputs(const Config &config,
 101                               map<string, Input *> *deserialized_inputs)
 102 {
 103         vector<Input *> inputs;
 104         for (unsigned i = 0; i < config.streams.size(); ++i) {
 105                 const StreamConfig &stream_config = config.streams[i];
 106                 if (stream_config.src.empty()) {
 107                         continue;
 108                 }
 109
 110                 string stream_id = stream_config.stream_id;
 111                 string src = stream_config.src;
 112
 113                 Input *input = NULL;
 114                 map<string, Input *>::iterator deserialized_input_it =
 115                         deserialized_inputs->find(stream_id);
 116                 if (deserialized_input_it != deserialized_inputs->end()) {
 117                         input = deserialized_input_it->second;
 118                         if (input->get_url() != src) {
 119                                 log(INFO, "Stream '%s' has changed URL from '%s' to '%s', restarting input.",
 120                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 121                                 input->close_socket();
 122                                 delete input;
 123                                 input = NULL;
 124                         }
 125                         deserialized_inputs->erase(deserialized_input_it);
 126                 }
 127                 if (input == NULL) {
 128                         input = create_input(stream_id, src);
 129                         if (input == NULL) {
 130                                 log(ERROR, "did not understand URL '%s', clients will not get any data.",
 131                                         src.c_str());
 132                                 continue;
 133                         }
 134                 }
 135                 input->run();
 136                 inputs.push_back(input);
 137         }
 138         return inputs;
 139 }
 140
 141 void create_streams(const Config &config,
 142                     const set<string> &deserialized_stream_ids,
 143                     map<string, Input *> *deserialized_inputs)
 144 {
 145         vector<MarkPool *> mark_pools;  // FIXME: leak
 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                 };
 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                         assert(false);
 267                 }
 268         }
 269
 270         string config_filename = "cubemap.config";
 271         if (optind < argc) {
 272                 config_filename = argv[optind++];
 273         }
 274
 275         // Canonicalize argv[0] and config_filename.
 276         char argv0_canon[PATH_MAX];
 277         char config_filename_canon[PATH_MAX];
 278
 279         if (realpath(argv[0], argv0_canon) == NULL) {
 280                 log_perror(argv[0]);
 281                 exit(1);
 282         }
 283         if (realpath(config_filename.c_str(), config_filename_canon) == NULL) {
 284                 log_perror(config_filename.c_str());
 285                 exit(1);
 286         }
 287
 288         // Now parse the configuration file.
 289         Config config;
 290         if (!parse_config(config_filename_canon, &config)) {
 291                 exit(1);
 292         }
 293         if (test_config) {
 294                 exit(0);
 295         }
 296
 297         // Ideally we'd like to daemonize only when we've started up all threads etc.,
 298         // but daemon() forks, which is not good in multithreaded software, so we'll
 299         // have to do it here.
 300         if (config.daemonize) {
 301                 if (daemon(0, 0) == -1) {
 302                         log_perror("daemon");
 303                         exit(1);
 304                 }
 305         }
 306
 307 start:
 308         // Open logs as soon as possible.
 309         open_logs(config.log_destinations);
 310
 311         log(INFO, "Cubemap " SERVER_VERSION " starting.");
 312         if (config.access_log_file.empty()) {
 313                 // Create a dummy logger.
 314                 access_log = new AccessLogThread();
 315         } else {
 316                 access_log = new AccessLogThread(config.access_log_file);
 317         }
 318         access_log->run();
 319
 320         servers = new ServerPool(config.num_servers);
 321
 322         CubemapStateProto loaded_state;
 323         struct timeval serialize_start;
 324         set<string> deserialized_stream_ids;
 325         map<string, Input *> deserialized_inputs;
 326         map<int, Acceptor *> deserialized_acceptors;
 327         if (state_fd != -1) {
 328                 log(INFO, "Deserializing state from previous process...");
 329                 string serialized;
 330                 if (!read_tempfile(state_fd, &serialized)) {
 331                         exit(1);
 332                 }
 333                 if (!loaded_state.ParseFromString(serialized)) {
 334                         log(ERROR, "Failed deserialization of state.");
 335                         exit(1);
 336                 }
 337
 338                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 339                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 340
 341                 // Deserialize the streams.
 342                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 343                         servers->add_stream_from_serialized(loaded_state.streams(i));
 344                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 345                 }
 346
 347                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 348                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 349                         deserialized_inputs.insert(make_pair(
 350                                 loaded_state.inputs(i).stream_id(),
 351                                 create_input(loaded_state.inputs(i))));
 352                 }
 353
 354                 // Deserialize the acceptors.
 355                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 356                         deserialized_acceptors.insert(make_pair(
 357                                 loaded_state.acceptors(i).port(),
 358                                 new Acceptor(loaded_state.acceptors(i))));
 359                 }
 360
 361                 log(INFO, "Deserialization done.");
 362         }
 363
 364         // Find all streams in the configuration file, and create them.
 365         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 366
 367         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 368         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 369
 370         // All deserialized inputs should now have been taken care of, one way or the other.
 371         assert(deserialized_inputs.empty());
 372
 373         // Put back the existing clients. It doesn't matter which server we
 374         // allocate them to, so just do round-robin. However, we need to add
 375         // them after the mark pools have been set up.
 376         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 377                 servers->add_client_from_serialized(loaded_state.clients(i));
 378         }
 379
 380         servers->run();
 381
 382         // Start writing statistics.
 383         StatsThread *stats_thread = NULL;
 384         if (!config.stats_file.empty()) {
 385                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 386                 stats_thread->run();
 387         }
 388
 389         struct timeval server_start;
 390         gettimeofday(&server_start, NULL);
 391         if (state_fd != -1) {
 392                 // Measure time from we started deserializing (below) to now, when basically everything
 393                 // is up and running. This is, in other words, a conservative estimate of how long our
 394                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 395                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 396                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 397                 log(INFO, "Re-exec happened in approx. %.0f ms.", glitch_time * 1000.0);
 398         }
 399
 400         while (!hupped) {
 401                 usleep(100000);
 402         }
 403
 404         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 405         gettimeofday(&serialize_start, NULL);
 406
 407         if (stats_thread != NULL) {
 408                 stats_thread->stop();
 409         }
 410         for (size_t i = 0; i < acceptors.size(); ++i) {
 411                 acceptors[i]->stop();
 412         }
 413         for (size_t i = 0; i < inputs.size(); ++i) {
 414                 inputs[i]->stop();
 415         }
 416         servers->stop();
 417
 418         CubemapStateProto state;
 419         if (stopped) {
 420                 log(INFO, "Shutting down.");
 421         } else {
 422                 log(INFO, "Serializing state and re-execing...");
 423                 state = collect_state(
 424                         serialize_start, acceptors, inputs, servers);
 425                 string serialized;
 426                 state.SerializeToString(&serialized);
 427                 state_fd = make_tempfile(serialized);
 428                 if (state_fd == -1) {
 429                         exit(1);
 430                 }
 431         }
 432         delete servers;
 433         access_log->stop();
 434         delete access_log;
 435         shut_down_logging();
 436
 437         if (stopped) {
 438                 exit(0);
 439         }
 440
 441         // OK, so the signal was SIGHUP. Check that the new config is okay, then exec the new binary.
 442         if (!dry_run_config(argv0_canon, config_filename_canon)) {
 443                 open_logs(config.log_destinations);
 444                 log(ERROR, "%s --test-config failed. Restarting old version instead of new.", argv[0]);
 445                 hupped = false;
 446                 shut_down_logging();
 447                 goto start;
 448         }
 449
 450         char buf[16];
 451         sprintf(buf, "%d", state_fd);
 452
 453         for ( ;; ) {
 454                 execlp(argv0_canon, argv0_canon, config_filename_canon, "--state", buf, NULL);
 455                 open_logs(config.log_destinations);
 456                 log_perror("execlp");
 457                 log(ERROR, "re-exec of %s failed. Waiting 0.2 seconds and trying again...", argv0_canon);
 458                 shut_down_logging();
 459                 usleep(200000);
 460         }
 461 }