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

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <getopt.h>
   4 #include <signal.h>
   5 #include <stddef.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <sys/time.h>
  10 #include <sys/wait.h>
  11 #include <unistd.h>
  12 #include <map>
  13 #include <set>
  14 #include <string>
  15 #include <utility>
  16 #include <vector>
  17
  18 #include "acceptor.h"
  19 #include "config.h"
  20 #include "input.h"
  21 #include "markpool.h"
  22 #include "serverpool.h"
  23 #include "state.pb.h"
  24 #include "stats.h"
  25 #include "util.h"
  26 #include "version.h"
  27
  28 using namespace std;
  29
  30 ServerPool *servers = NULL;
  31 volatile bool hupped = false;
  32
  33 void hup(int ignored)
  34 {
  35         hupped = true;
  36 }
  37
  38 CubemapStateProto collect_state(const timeval &serialize_start,
  39                                 const vector<Acceptor *> acceptors,
  40                                 const vector<Input *> inputs,
  41                                 ServerPool *servers)
  42 {
  43         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  44         state.set_serialize_start_sec(serialize_start.tv_sec);
  45         state.set_serialize_start_usec(serialize_start.tv_usec);
  46
  47         for (size_t i = 0; i < acceptors.size(); ++i) {
  48                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  49         }
  50
  51         for (size_t i = 0; i < inputs.size(); ++i) {
  52                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  53         }
  54
  55         return state;
  56 }
  57
  58 // Find all port statements in the configuration file, and create acceptors for htem.
  59 vector<Acceptor *> create_acceptors(
  60         const Config &config,
  61         map<int, Acceptor *> *deserialized_acceptors)
  62 {
  63         vector<Acceptor *> acceptors;
  64         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
  65                 const AcceptorConfig &acceptor_config = config.acceptors[i];
  66                 Acceptor *acceptor = NULL;
  67                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
  68                         deserialized_acceptors->find(acceptor_config.port);
  69                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
  70                         acceptor = deserialized_acceptor_it->second;
  71                         deserialized_acceptors->erase(deserialized_acceptor_it);
  72                 } else {
  73                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
  74                         acceptor = new Acceptor(server_sock, acceptor_config.port);
  75                 }
  76                 acceptor->run();
  77                 acceptors.push_back(acceptor);
  78         }
  79
  80         // Close all acceptors that are no longer in the configuration file.
  81         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
  82              acceptor_it != deserialized_acceptors->end();
  83              ++acceptor_it) {
  84                 acceptor_it->second->close_socket();
  85                 delete acceptor_it->second;
  86         }
  87
  88         return acceptors;
  89 }
  90
  91 // Find all streams in the configuration file, and create inputs for them.
  92 vector<Input *> create_inputs(const Config &config,
  93                               map<string, Input *> *deserialized_inputs)
  94 {
  95         vector<Input *> inputs;
  96         for (unsigned i = 0; i < config.streams.size(); ++i) {
  97                 const StreamConfig &stream_config = config.streams[i];
  98                 if (stream_config.src.empty()) {
  99                         continue;
 100                 }
 101
 102                 string stream_id = stream_config.stream_id;
 103                 string src = stream_config.src;
 104
 105                 Input *input = NULL;
 106                 map<string, Input *>::iterator deserialized_input_it =
 107                         deserialized_inputs->find(stream_id);
 108                 if (deserialized_input_it != deserialized_inputs->end()) {
 109                         input = deserialized_input_it->second;
 110                         if (input->get_url() != src) {
 111                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 112                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 113                                 input->close_socket();
 114                                 delete input;
 115                                 input = NULL;
 116                         }
 117                         deserialized_inputs->erase(deserialized_input_it);
 118                 }
 119                 if (input == NULL) {
 120                         input = create_input(stream_id, src);
 121                         if (input == NULL) {
 122                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 123                                         src.c_str());
 124                                 continue;
 125                         }
 126                 }
 127                 input->run();
 128                 inputs.push_back(input);
 129         }
 130         return inputs;
 131 }
 132
 133 void create_streams(const Config &config,
 134                     const set<string> &deserialized_stream_ids,
 135                     map<string, Input *> *deserialized_inputs)
 136 {
 137         vector<MarkPool *> mark_pools;  // FIXME: leak
 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, stream_config.backlog_size);
 148                 } else {
 149                         servers->set_backlog_size(stream_config.stream_id, stream_config.backlog_size);
 150                 }
 151                 expecting_stream_ids.erase(stream_config.stream_id);
 152
 153                 if (stream_config.mark_pool != -1) {
 154                         servers->set_mark_pool(stream_config.stream_id,
 155                                                mark_pools[stream_config.mark_pool]);
 156                 }
 157         }
 158
 159         // Warn about any servers we've lost.
 160         // TODO: Make an option (delete=yes?) to actually shut down streams.
 161         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 162              stream_it != expecting_stream_ids.end();
 163              ++stream_it) {
 164                 string stream_id = *stream_it;
 165                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 166                         stream_id.c_str());
 167                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 168                 if (deserialized_inputs->count(stream_id) != 0) {
 169                         delete (*deserialized_inputs)[stream_id];
 170                         deserialized_inputs->erase(stream_id);
 171                 }
 172         }
 173 }
 174
 175 bool dry_run_config(const std::string &argv0, const std::string &config_filename)
 176 {
 177         char *argv0_copy = strdup(argv0.c_str());
 178         char *config_filename_copy = strdup(config_filename.c_str());
 179
 180         pid_t pid = fork();
 181         switch (pid) {
 182         case -1:
 183                 perror("fork()");
 184                 free(argv0_copy);
 185                 free(config_filename_copy);
 186                 return false;
 187         case 0:
 188                 // Child.
 189                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 190                 perror(argv0_copy);
 191                 _exit(1);
 192         default:
 193                 // Parent.
 194                 break;
 195         }
 196
 197         free(argv0_copy);
 198         free(config_filename_copy);
 199
 200         int status;
 201         pid_t err;
 202         do {
 203                 err = waitpid(pid, &status, 0);
 204         } while (err == -1 && errno == EINTR);
 205
 206         if (err == -1) {
 207                 perror("waitpid()");
 208                 return false;
 209         }
 210
 211         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 212 }
 213
 214 int main(int argc, char **argv)
 215 {
 216         signal(SIGHUP, hup);
 217         signal(SIGPIPE, SIG_IGN);
 218
 219         // Parse options.
 220         int state_fd = -1;
 221         bool test_config = false;
 222         for ( ;; ) {
 223                 static const option long_options[] = {
 224                         { "state", required_argument, 0, 's' },
 225                         { "test-config", no_argument, 0, 't' },
 226                 };
 227                 int option_index = 0;
 228                 int c = getopt_long (argc, argv, "s:t", long_options, &option_index);
 229
 230                 if (c == -1) {
 231                         break;
 232                 }
 233                 switch (c) {
 234                 case 's':
 235                         state_fd = atoi(optarg);
 236                         break;
 237                 case 't':
 238                         test_config = true;
 239                         break;
 240                 default:
 241                         assert(false);
 242                 }
 243         }
 244
 245         string config_filename = "cubemap.config";
 246         if (optind < argc) {
 247                 config_filename = argv[optind++];
 248         }
 249
 250         Config config;
 251         if (!parse_config(config_filename, &config)) {
 252                 exit(1);
 253         }
 254         if (test_config) {
 255                 exit(0);
 256         }
 257
 258 start:
 259         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 260         servers = new ServerPool(config.num_servers);
 261
 262         CubemapStateProto loaded_state;
 263         struct timeval serialize_start;
 264         set<string> deserialized_stream_ids;
 265         map<string, Input *> deserialized_inputs;
 266         map<int, Acceptor *> deserialized_acceptors;
 267         if (state_fd != -1) {
 268                 fprintf(stderr, "Deserializing state from previous process... ");
 269                 string serialized;
 270                 if (!read_tempfile(state_fd, &serialized)) {
 271                         exit(1);
 272                 }
 273                 if (!loaded_state.ParseFromString(serialized)) {
 274                         fprintf(stderr, "ERROR: Failed deserialization of state.\n");
 275                         exit(1);
 276                 }
 277
 278                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 279                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 280
 281                 // Deserialize the streams.
 282                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 283                         servers->add_stream_from_serialized(loaded_state.streams(i));
 284                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 285                 }
 286
 287                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 288                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 289                         deserialized_inputs.insert(make_pair(
 290                                 loaded_state.inputs(i).stream_id(),
 291                                 create_input(loaded_state.inputs(i))));
 292                 }
 293
 294                 // Deserialize the acceptors.
 295                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 296                         deserialized_acceptors.insert(make_pair(
 297                                 loaded_state.acceptors(i).port(),
 298                                 new Acceptor(loaded_state.acceptors(i))));
 299                 }
 300
 301                 fprintf(stderr, "done.\n");
 302         }
 303
 304         // Find all streams in the configuration file, and create them.
 305         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 306
 307         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 308         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 309
 310         // All deserialized inputs should now have been taken care of, one way or the other.
 311         assert(deserialized_inputs.empty());
 312
 313         // Put back the existing clients. It doesn't matter which server we
 314         // allocate them to, so just do round-robin. However, we need to add
 315         // them after the mark pools have been set up.
 316         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 317                 servers->add_client_from_serialized(loaded_state.clients(i));
 318         }
 319
 320         servers->run();
 321
 322         // Start writing statistics.
 323         StatsThread *stats_thread = NULL;
 324         if (!config.stats_file.empty()) {
 325                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 326                 stats_thread->run();
 327         }
 328
 329         struct timeval server_start;
 330         gettimeofday(&server_start, NULL);
 331         if (state_fd != -1) {
 332                 // Measure time from we started deserializing (below) to now, when basically everything
 333                 // is up and running. This is, in other words, a conservative estimate of how long our
 334                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 335                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 336                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 337                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 338         }
 339
 340         while (!hupped) {
 341                 usleep(100000);
 342         }
 343
 344         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 345         gettimeofday(&serialize_start, NULL);
 346
 347         if (stats_thread != NULL) {
 348                 stats_thread->stop();
 349         }
 350         for (size_t i = 0; i < acceptors.size(); ++i) {
 351                 acceptors[i]->stop();
 352         }
 353         for (size_t i = 0; i < inputs.size(); ++i) {
 354                 inputs[i]->stop();
 355         }
 356         servers->stop();
 357
 358         fprintf(stderr, "Serializing state and re-execing...\n");
 359         CubemapStateProto state = collect_state(
 360                 serialize_start, acceptors, inputs, servers);
 361         string serialized;
 362         state.SerializeToString(&serialized);
 363         state_fd = make_tempfile(serialized);
 364         if (state_fd == -1) {
 365                 exit(1);
 366         }
 367         delete servers;
 368
 369         if (!dry_run_config(argv[0], config_filename)) {
 370                 fprintf(stderr, "ERROR: %s --test-config failed. Restarting old version instead of new.\n", argv[0]);
 371                 hupped = false;
 372                 goto start;
 373         }
 374
 375         char buf[16];
 376         sprintf(buf, "%d", state_fd);
 377
 378         for ( ;; ) {
 379                 execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
 380                 perror("execlp");
 381                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 382                 usleep(200000);
 383         }
 384 }