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

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdint.h>
   4 #include <assert.h>
   5 #include <getopt.h>
   6 #include <arpa/inet.h>
   7 #include <sys/socket.h>
   8 #include <pthread.h>
   9 #include <sys/types.h>
  10 #include <sys/ioctl.h>
  11 #include <sys/poll.h>
  12 #include <sys/time.h>
  13 #include <sys/types.h>
  14 #include <sys/wait.h>
  15 #include <signal.h>
  16 #include <errno.h>
  17 #include <ctype.h>
  18 #include <fcntl.h>
  19 #include <vector>
  20 #include <string>
  21 #include <map>
  22 #include <set>
  23
  24 #include "acceptor.h"
  25 #include "config.h"
  26 #include "markpool.h"
  27 #include "metacube.h"
  28 #include "parse.h"
  29 #include "server.h"
  30 #include "serverpool.h"
  31 #include "input.h"
  32 #include "stats.h"
  33 #include "version.h"
  34 #include "state.pb.h"
  35
  36 using namespace std;
  37
  38 ServerPool *servers = NULL;
  39 volatile bool hupped = false;
  40
  41 void hup(int ignored)
  42 {
  43         hupped = true;
  44 }
  45
  46 // Serialize the given state to a file descriptor, and return the (still open)
  47 // descriptor.
  48 int make_tempfile(const CubemapStateProto &state)
  49 {
  50         char tmpl[] = "/tmp/cubemapstate.XXXXXX";
  51         int state_fd = mkstemp(tmpl);
  52         if (state_fd == -1) {
  53                 perror("mkstemp");
  54                 exit(1);
  55         }
  56
  57         string serialized;
  58         state.SerializeToString(&serialized);
  59
  60         const char *ptr = serialized.data();
  61         size_t to_write = serialized.size();
  62         while (to_write > 0) {
  63                 ssize_t ret = write(state_fd, ptr, to_write);
  64                 if (ret == -1) {
  65                         perror("write");
  66                         exit(1);
  67                 }
  68
  69                 ptr += ret;
  70                 to_write -= ret;
  71         }
  72
  73         return state_fd;
  74 }
  75
  76 CubemapStateProto collect_state(const timeval &serialize_start,
  77                                 const vector<Acceptor *> acceptors,
  78                                 const vector<Input *> inputs,
  79                                 ServerPool *servers)
  80 {
  81         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  82         state.set_serialize_start_sec(serialize_start.tv_sec);
  83         state.set_serialize_start_usec(serialize_start.tv_usec);
  84
  85         for (size_t i = 0; i < acceptors.size(); ++i) {
  86                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  87         }
  88
  89         for (size_t i = 0; i < inputs.size(); ++i) {
  90                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  91         }
  92
  93         return state;
  94 }
  95
  96 // Read the state back from the file descriptor made by make_tempfile,
  97 // and close it.
  98 CubemapStateProto read_tempfile(int state_fd)
  99 {
 100         if (lseek(state_fd, 0, SEEK_SET) == -1) {
 101                 perror("lseek");
 102                 exit(1);
 103         }
 104
 105         string serialized;
 106         char buf[4096];
 107         for ( ;; ) {
 108                 ssize_t ret = read(state_fd, buf, sizeof(buf));
 109                 if (ret == -1) {
 110                         perror("read");
 111                         exit(1);
 112                 }
 113                 if (ret == 0) {
 114                         // EOF.
 115                         break;
 116                 }
 117
 118                 serialized.append(string(buf, buf + ret));
 119         }
 120
 121         close(state_fd);  // Implicitly deletes the file.
 122
 123         CubemapStateProto state;
 124         if (!state.ParseFromString(serialized)) {
 125                 fprintf(stderr, "PANIC: Failed deserialization of state.\n");
 126                 exit(1);
 127         }
 128
 129         return state;
 130 }
 131
 132 // Find all port statements in the configuration file, and create acceptors for htem.
 133 vector<Acceptor *> create_acceptors(
 134         const Config &config,
 135         map<int, Acceptor *> *deserialized_acceptors)
 136 {
 137         vector<Acceptor *> acceptors;
 138         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
 139                 const AcceptorConfig &acceptor_config = config.acceptors[i];
 140                 Acceptor *acceptor = NULL;
 141                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
 142                         deserialized_acceptors->find(acceptor_config.port);
 143                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
 144                         acceptor = deserialized_acceptor_it->second;
 145                         deserialized_acceptors->erase(deserialized_acceptor_it);
 146                 } else {
 147                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
 148                         acceptor = new Acceptor(server_sock, acceptor_config.port);
 149                 }
 150                 acceptor->run();
 151                 acceptors.push_back(acceptor);
 152         }
 153
 154         // Close all acceptors that are no longer in the configuration file.
 155         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
 156              acceptor_it != deserialized_acceptors->end();
 157              ++acceptor_it) {
 158                 acceptor_it->second->close_socket();
 159                 delete acceptor_it->second;
 160         }
 161
 162         return acceptors;
 163 }
 164
 165 // Find all streams in the configuration file, and create inputs for them.
 166 vector<Input *> create_inputs(const Config &config,
 167                               map<string, Input *> *deserialized_inputs)
 168 {
 169         vector<Input *> inputs;
 170         for (unsigned i = 0; i < config.streams.size(); ++i) {
 171                 const StreamConfig &stream_config = config.streams[i];
 172                 if (stream_config.src.empty()) {
 173                         continue;
 174                 }
 175
 176                 string stream_id = stream_config.stream_id;
 177                 string src = stream_config.src;
 178
 179                 Input *input = NULL;
 180                 map<string, Input *>::iterator deserialized_input_it =
 181                         deserialized_inputs->find(stream_id);
 182                 if (deserialized_input_it != deserialized_inputs->end()) {
 183                         input = deserialized_input_it->second;
 184                         if (input->get_url() != src) {
 185                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 186                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 187                                 input->close_socket();
 188                                 delete input;
 189                                 input = NULL;
 190                         }
 191                         deserialized_inputs->erase(deserialized_input_it);
 192                 }
 193                 if (input == NULL) {
 194                         input = create_input(stream_id, src);
 195                         if (input == NULL) {
 196                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 197                                         src.c_str());
 198                                 continue;
 199                         }
 200                 }
 201                 input->run();
 202                 inputs.push_back(input);
 203         }
 204         return inputs;
 205 }
 206
 207 void create_streams(const Config &config,
 208                     const set<string> &deserialized_stream_ids,
 209                     map<string, Input *> *deserialized_inputs)
 210 {
 211         vector<MarkPool *> mark_pools;  // FIXME: leak
 212         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 213                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 214                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 215         }
 216
 217         set<string> expecting_stream_ids = deserialized_stream_ids;
 218         for (unsigned i = 0; i < config.streams.size(); ++i) {
 219                 const StreamConfig &stream_config = config.streams[i];
 220                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 221                         servers->add_stream(stream_config.stream_id);
 222                 }
 223                 expecting_stream_ids.erase(stream_config.stream_id);
 224
 225                 if (stream_config.mark_pool != -1) {
 226                         servers->set_mark_pool(stream_config.stream_id,
 227                                                mark_pools[stream_config.mark_pool]);
 228                 }
 229         }
 230
 231         // Warn about any servers we've lost.
 232         // TODO: Make an option (delete=yes?) to actually shut down streams.
 233         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 234              stream_it != expecting_stream_ids.end();
 235              ++stream_it) {
 236                 string stream_id = *stream_it;
 237                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 238                         stream_id.c_str());
 239                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 240                 if (deserialized_inputs->count(stream_id) != 0) {
 241                         delete (*deserialized_inputs)[stream_id];
 242                         deserialized_inputs->erase(stream_id);
 243                 }
 244         }
 245 }
 246
 247 bool dry_run_config(const std::string &argv0, const std::string &config_filename)
 248 {
 249         char *argv0_copy = strdup(argv0.c_str());
 250         char *config_filename_copy = strdup(config_filename.c_str());
 251
 252         pid_t pid = fork();
 253         switch (pid) {
 254         case -1:
 255                 perror("fork()");
 256                 free(argv0_copy);
 257                 free(config_filename_copy);
 258                 return false;
 259         case 0:
 260                 // Child.
 261                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 262                 perror(argv0_copy);
 263                 _exit(1);
 264         default:
 265                 // Parent.
 266                 break;
 267         }
 268
 269         free(argv0_copy);
 270         free(config_filename_copy);
 271
 272         int status;
 273         pid_t err;
 274         do {
 275                 err = waitpid(pid, &status, 0);
 276         } while (err == -1 && errno == EINTR);
 277
 278         if (err == -1) {
 279                 perror("waitpid()");
 280                 return false;
 281         }
 282
 283         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 284 }
 285
 286 int main(int argc, char **argv)
 287 {
 288         // Parse options.
 289         int state_fd = -1;
 290         bool test_config = false;
 291         for ( ;; ) {
 292                 static const option long_options[] = {
 293                         { "state", required_argument, 0, 's' },
 294                         { "test-config", no_argument, 0, 't' },
 295                 };
 296                 int option_index = 0;
 297                 int c = getopt_long (argc, argv, "s:t", long_options, &option_index);
 298
 299                 if (c == -1) {
 300                         break;
 301                 }
 302                 switch (c) {
 303                 case 's':
 304                         state_fd = atoi(optarg);
 305                         break;
 306                 case 't':
 307                         test_config = true;
 308                         break;
 309                 default:
 310                         assert(false);
 311                 }
 312         }
 313
 314         string config_filename = "cubemap.config";
 315         if (optind < argc) {
 316                 config_filename = argv[optind++];
 317         }
 318
 319         Config config;
 320         if (!parse_config(config_filename, &config)) {
 321                 exit(1);
 322         }
 323         if (test_config) {
 324                 exit(0);
 325         }
 326
 327 start:
 328         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 329         servers = new ServerPool(config.num_servers);
 330
 331         CubemapStateProto loaded_state;
 332         struct timeval serialize_start;
 333         set<string> deserialized_stream_ids;
 334         map<string, Input *> deserialized_inputs;
 335         map<int, Acceptor *> deserialized_acceptors;
 336         if (state_fd != -1) {
 337                 fprintf(stderr, "Deserializing state from previous process... ");
 338                 loaded_state = read_tempfile(state_fd);
 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                 fprintf(stderr, "done.\n");
 364         }
 365
 366         // Find all streams in the configuration file, and create them.
 367         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 368
 369         servers->run();
 370
 371         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 372         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 373
 374         // All deserialized inputs should now have been taken care of, one way or the other.
 375         assert(deserialized_inputs.empty());
 376
 377         // Put back the existing clients. It doesn't matter which server we
 378         // allocate them to, so just do round-robin. However, we need to add
 379         // them after the mark pools have been set up.
 380         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 381                 servers->add_client_from_serialized(loaded_state.clients(i));
 382         }
 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         } else if (config.stats_interval != -1) {
 390                 fprintf(stderr, "WARNING: 'stats_interval' given, but no 'stats_file'. No statistics will be written.\n");
 391         }
 392
 393         signal(SIGHUP, hup);
 394
 395         struct timeval server_start;
 396         gettimeofday(&server_start, NULL);
 397         if (state_fd != -1) {
 398                 // Measure time from we started deserializing (below) to now, when basically everything
 399                 // is up and running. This is, in other words, a conservative estimate of how long our
 400                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 401                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 402                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 403                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 404         }
 405
 406         while (!hupped) {
 407                 usleep(100000);
 408         }
 409
 410         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 411         gettimeofday(&serialize_start, NULL);
 412
 413         if (stats_thread != NULL) {
 414                 stats_thread->stop();
 415         }
 416         for (size_t i = 0; i < acceptors.size(); ++i) {
 417                 acceptors[i]->stop();
 418         }
 419         for (size_t i = 0; i < inputs.size(); ++i) {
 420                 inputs[i]->stop();
 421         }
 422         servers->stop();
 423
 424         fprintf(stderr, "Serializing state and re-execing...\n");
 425         state_fd = make_tempfile(collect_state(
 426                 serialize_start, acceptors, inputs, servers));
 427         delete servers;
 428
 429         if (!dry_run_config(argv[0], config_filename)) {
 430                 fprintf(stderr, "ERROR: %s --test-config failed. Restarting old version instead of new.\n", argv[0]);
 431                 hupped = false;
 432                 goto start;
 433         }
 434
 435         char buf[16];
 436         sprintf(buf, "%d", state_fd);
 437
 438         for ( ;; ) {
 439                 execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
 440                 perror("execlp");
 441                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 442                 usleep(200000);
 443         }
 444 }