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

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4 #include <unistd.h>
   5 #include <assert.h>
   6 #include <getopt.h>
   7 #include <arpa/inet.h>
   8 #include <sys/socket.h>
   9 #include <pthread.h>
  10 #include <sys/types.h>
  11 #include <sys/ioctl.h>
  12 #include <sys/poll.h>
  13 #include <sys/time.h>
  14 #include <sys/types.h>
  15 #include <sys/wait.h>
  16 #include <signal.h>
  17 #include <errno.h>
  18 #include <ctype.h>
  19 #include <fcntl.h>
  20 #include <vector>
  21 #include <string>
  22 #include <map>
  23 #include <set>
  24
  25 #include "acceptor.h"
  26 #include "config.h"
  27 #include "markpool.h"
  28 #include "metacube.h"
  29 #include "parse.h"
  30 #include "server.h"
  31 #include "serverpool.h"
  32 #include "input.h"
  33 #include "stats.h"
  34 #include "util.h"
  35 #include "version.h"
  36 #include "state.pb.h"
  37
  38 using namespace std;
  39
  40 ServerPool *servers = NULL;
  41 volatile bool hupped = false;
  42
  43 void hup(int ignored)
  44 {
  45         hupped = true;
  46 }
  47
  48 CubemapStateProto collect_state(const timeval &serialize_start,
  49                                 const vector<Acceptor *> acceptors,
  50                                 const vector<Input *> inputs,
  51                                 ServerPool *servers)
  52 {
  53         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  54         state.set_serialize_start_sec(serialize_start.tv_sec);
  55         state.set_serialize_start_usec(serialize_start.tv_usec);
  56
  57         for (size_t i = 0; i < acceptors.size(); ++i) {
  58                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  59         }
  60
  61         for (size_t i = 0; i < inputs.size(); ++i) {
  62                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  63         }
  64
  65         return state;
  66 }
  67
  68 // Find all port statements in the configuration file, and create acceptors for htem.
  69 vector<Acceptor *> create_acceptors(
  70         const Config &config,
  71         map<int, Acceptor *> *deserialized_acceptors)
  72 {
  73         vector<Acceptor *> acceptors;
  74         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
  75                 const AcceptorConfig &acceptor_config = config.acceptors[i];
  76                 Acceptor *acceptor = NULL;
  77                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
  78                         deserialized_acceptors->find(acceptor_config.port);
  79                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
  80                         acceptor = deserialized_acceptor_it->second;
  81                         deserialized_acceptors->erase(deserialized_acceptor_it);
  82                 } else {
  83                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
  84                         acceptor = new Acceptor(server_sock, acceptor_config.port);
  85                 }
  86                 acceptor->run();
  87                 acceptors.push_back(acceptor);
  88         }
  89
  90         // Close all acceptors that are no longer in the configuration file.
  91         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
  92              acceptor_it != deserialized_acceptors->end();
  93              ++acceptor_it) {
  94                 acceptor_it->second->close_socket();
  95                 delete acceptor_it->second;
  96         }
  97
  98         return acceptors;
  99 }
 100
 101 // Find all streams in the configuration file, and create inputs for them.
 102 vector<Input *> create_inputs(const Config &config,
 103                               map<string, Input *> *deserialized_inputs)
 104 {
 105         vector<Input *> inputs;
 106         for (unsigned i = 0; i < config.streams.size(); ++i) {
 107                 const StreamConfig &stream_config = config.streams[i];
 108                 if (stream_config.src.empty()) {
 109                         continue;
 110                 }
 111
 112                 string stream_id = stream_config.stream_id;
 113                 string src = stream_config.src;
 114
 115                 Input *input = NULL;
 116                 map<string, Input *>::iterator deserialized_input_it =
 117                         deserialized_inputs->find(stream_id);
 118                 if (deserialized_input_it != deserialized_inputs->end()) {
 119                         input = deserialized_input_it->second;
 120                         if (input->get_url() != src) {
 121                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 122                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 123                                 input->close_socket();
 124                                 delete input;
 125                                 input = NULL;
 126                         }
 127                         deserialized_inputs->erase(deserialized_input_it);
 128                 }
 129                 if (input == NULL) {
 130                         input = create_input(stream_id, src);
 131                         if (input == NULL) {
 132                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 133                                         src.c_str());
 134                                 continue;
 135                         }
 136                 }
 137                 input->run();
 138                 inputs.push_back(input);
 139         }
 140         return inputs;
 141 }
 142
 143 void create_streams(const Config &config,
 144                     const set<string> &deserialized_stream_ids,
 145                     map<string, Input *> *deserialized_inputs)
 146 {
 147         vector<MarkPool *> mark_pools;  // FIXME: leak
 148         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 149                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 150                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 151         }
 152
 153         set<string> expecting_stream_ids = deserialized_stream_ids;
 154         for (unsigned i = 0; i < config.streams.size(); ++i) {
 155                 const StreamConfig &stream_config = config.streams[i];
 156                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 157                         servers->add_stream(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                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 174                         stream_id.c_str());
 175                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 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 bool dry_run_config(const std::string &argv0, const std::string &config_filename)
 184 {
 185         char *argv0_copy = strdup(argv0.c_str());
 186         char *config_filename_copy = strdup(config_filename.c_str());
 187
 188         pid_t pid = fork();
 189         switch (pid) {
 190         case -1:
 191                 perror("fork()");
 192                 free(argv0_copy);
 193                 free(config_filename_copy);
 194                 return false;
 195         case 0:
 196                 // Child.
 197                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 198                 perror(argv0_copy);
 199                 _exit(1);
 200         default:
 201                 // Parent.
 202                 break;
 203         }
 204
 205         free(argv0_copy);
 206         free(config_filename_copy);
 207
 208         int status;
 209         pid_t err;
 210         do {
 211                 err = waitpid(pid, &status, 0);
 212         } while (err == -1 && errno == EINTR);
 213
 214         if (err == -1) {
 215                 perror("waitpid()");
 216                 return false;
 217         }
 218
 219         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 220 }
 221
 222 int main(int argc, char **argv)
 223 {
 224         // Parse options.
 225         int state_fd = -1;
 226         bool test_config = false;
 227         for ( ;; ) {
 228                 static const option long_options[] = {
 229                         { "state", required_argument, 0, 's' },
 230                         { "test-config", no_argument, 0, 't' },
 231                 };
 232                 int option_index = 0;
 233                 int c = getopt_long (argc, argv, "s:t", long_options, &option_index);
 234
 235                 if (c == -1) {
 236                         break;
 237                 }
 238                 switch (c) {
 239                 case 's':
 240                         state_fd = atoi(optarg);
 241                         break;
 242                 case 't':
 243                         test_config = true;
 244                         break;
 245                 default:
 246                         assert(false);
 247                 }
 248         }
 249
 250         string config_filename = "cubemap.config";
 251         if (optind < argc) {
 252                 config_filename = argv[optind++];
 253         }
 254
 255         Config config;
 256         if (!parse_config(config_filename, &config)) {
 257                 exit(1);
 258         }
 259         if (test_config) {
 260                 exit(0);
 261         }
 262
 263 start:
 264         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 265         servers = new ServerPool(config.num_servers);
 266
 267         CubemapStateProto loaded_state;
 268         struct timeval serialize_start;
 269         set<string> deserialized_stream_ids;
 270         map<string, Input *> deserialized_inputs;
 271         map<int, Acceptor *> deserialized_acceptors;
 272         if (state_fd != -1) {
 273                 fprintf(stderr, "Deserializing state from previous process... ");
 274                 string serialized;
 275                 if (!read_tempfile(state_fd, &serialized)) {
 276                         exit(1);
 277                 }
 278                 if (!loaded_state.ParseFromString(serialized)) {
 279                         fprintf(stderr, "ERROR: Failed deserialization of state.\n");
 280                         exit(1);
 281                 }
 282
 283                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 284                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 285
 286                 // Deserialize the streams.
 287                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 288                         servers->add_stream_from_serialized(loaded_state.streams(i));
 289                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 290                 }
 291
 292                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 293                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 294                         deserialized_inputs.insert(make_pair(
 295                                 loaded_state.inputs(i).stream_id(),
 296                                 create_input(loaded_state.inputs(i))));
 297                 }
 298
 299                 // Deserialize the acceptors.
 300                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 301                         deserialized_acceptors.insert(make_pair(
 302                                 loaded_state.acceptors(i).port(),
 303                                 new Acceptor(loaded_state.acceptors(i))));
 304                 }
 305
 306                 fprintf(stderr, "done.\n");
 307         }
 308
 309         // Find all streams in the configuration file, and create them.
 310         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 311
 312         servers->run();
 313
 314         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 315         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 316
 317         // All deserialized inputs should now have been taken care of, one way or the other.
 318         assert(deserialized_inputs.empty());
 319
 320         // Put back the existing clients. It doesn't matter which server we
 321         // allocate them to, so just do round-robin. However, we need to add
 322         // them after the mark pools have been set up.
 323         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 324                 servers->add_client_from_serialized(loaded_state.clients(i));
 325         }
 326
 327         // Start writing statistics.
 328         StatsThread *stats_thread = NULL;
 329         if (!config.stats_file.empty()) {
 330                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 331                 stats_thread->run();
 332         }
 333
 334         signal(SIGHUP, hup);
 335
 336         struct timeval server_start;
 337         gettimeofday(&server_start, NULL);
 338         if (state_fd != -1) {
 339                 // Measure time from we started deserializing (below) to now, when basically everything
 340                 // is up and running. This is, in other words, a conservative estimate of how long our
 341                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 342                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 343                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 344                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 345         }
 346
 347         while (!hupped) {
 348                 usleep(100000);
 349         }
 350
 351         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 352         gettimeofday(&serialize_start, NULL);
 353
 354         if (stats_thread != NULL) {
 355                 stats_thread->stop();
 356         }
 357         for (size_t i = 0; i < acceptors.size(); ++i) {
 358                 acceptors[i]->stop();
 359         }
 360         for (size_t i = 0; i < inputs.size(); ++i) {
 361                 inputs[i]->stop();
 362         }
 363         servers->stop();
 364
 365         fprintf(stderr, "Serializing state and re-execing...\n");
 366         CubemapStateProto state = collect_state(
 367                 serialize_start, acceptors, inputs, servers);
 368         string serialized;
 369         state.SerializeToString(&serialized);
 370         state_fd = make_tempfile(serialized);
 371         if (state_fd == -1) {
 372                 exit(1);
 373         }
 374         delete servers;
 375
 376         if (!dry_run_config(argv[0], config_filename)) {
 377                 fprintf(stderr, "ERROR: %s --test-config failed. Restarting old version instead of new.\n", argv[0]);
 378                 hupped = false;
 379                 goto start;
 380         }
 381
 382         char buf[16];
 383         sprintf(buf, "%d", state_fd);
 384
 385         for ( ;; ) {
 386                 execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
 387                 perror("execlp");
 388                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 389                 usleep(200000);
 390         }
 391 }