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 "version.h"
  35 #include "state.pb.h"
  36
  37 using namespace std;
  38
  39 ServerPool *servers = NULL;
  40 volatile bool hupped = false;
  41
  42 void hup(int ignored)
  43 {
  44         hupped = true;
  45 }
  46
  47 // Serialize the given state to a file descriptor, and return the (still open)
  48 // descriptor.
  49 int make_tempfile(const CubemapStateProto &state)
  50 {
  51         char tmpl[] = "/tmp/cubemapstate.XXXXXX";
  52         int state_fd = mkstemp(tmpl);
  53         if (state_fd == -1) {
  54                 perror("mkstemp");
  55                 exit(1);
  56         }
  57
  58         string serialized;
  59         state.SerializeToString(&serialized);
  60
  61         const char *ptr = serialized.data();
  62         size_t to_write = serialized.size();
  63         while (to_write > 0) {
  64                 ssize_t ret = write(state_fd, ptr, to_write);
  65                 if (ret == -1) {
  66                         perror("write");
  67                         exit(1);
  68                 }
  69
  70                 ptr += ret;
  71                 to_write -= ret;
  72         }
  73
  74         return state_fd;
  75 }
  76
  77 CubemapStateProto collect_state(const timeval &serialize_start,
  78                                 const vector<Acceptor *> acceptors,
  79                                 const vector<Input *> inputs,
  80                                 ServerPool *servers)
  81 {
  82         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  83         state.set_serialize_start_sec(serialize_start.tv_sec);
  84         state.set_serialize_start_usec(serialize_start.tv_usec);
  85
  86         for (size_t i = 0; i < acceptors.size(); ++i) {
  87                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  88         }
  89
  90         for (size_t i = 0; i < inputs.size(); ++i) {
  91                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  92         }
  93
  94         return state;
  95 }
  96
  97 // Read the state back from the file descriptor made by make_tempfile,
  98 // and close it.
  99 CubemapStateProto read_tempfile(int state_fd)
 100 {
 101         if (lseek(state_fd, 0, SEEK_SET) == -1) {
 102                 perror("lseek");
 103                 exit(1);
 104         }
 105
 106         string serialized;
 107         char buf[4096];
 108         for ( ;; ) {
 109                 ssize_t ret = read(state_fd, buf, sizeof(buf));
 110                 if (ret == -1) {
 111                         perror("read");
 112                         exit(1);
 113                 }
 114                 if (ret == 0) {
 115                         // EOF.
 116                         break;
 117                 }
 118
 119                 serialized.append(string(buf, buf + ret));
 120         }
 121
 122         close(state_fd);  // Implicitly deletes the file.
 123
 124         CubemapStateProto state;
 125         if (!state.ParseFromString(serialized)) {
 126                 fprintf(stderr, "PANIC: Failed deserialization of state.\n");
 127                 exit(1);
 128         }
 129
 130         return state;
 131 }
 132
 133 // Find all port statements in the configuration file, and create acceptors for htem.
 134 vector<Acceptor *> create_acceptors(
 135         const Config &config,
 136         map<int, Acceptor *> *deserialized_acceptors)
 137 {
 138         vector<Acceptor *> acceptors;
 139         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
 140                 const AcceptorConfig &acceptor_config = config.acceptors[i];
 141                 Acceptor *acceptor = NULL;
 142                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
 143                         deserialized_acceptors->find(acceptor_config.port);
 144                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
 145                         acceptor = deserialized_acceptor_it->second;
 146                         deserialized_acceptors->erase(deserialized_acceptor_it);
 147                 } else {
 148                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
 149                         acceptor = new Acceptor(server_sock, acceptor_config.port);
 150                 }
 151                 acceptor->run();
 152                 acceptors.push_back(acceptor);
 153         }
 154
 155         // Close all acceptors that are no longer in the configuration file.
 156         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
 157              acceptor_it != deserialized_acceptors->end();
 158              ++acceptor_it) {
 159                 acceptor_it->second->close_socket();
 160                 delete acceptor_it->second;
 161         }
 162
 163         return acceptors;
 164 }
 165
 166 // Find all streams in the configuration file, and create inputs for them.
 167 vector<Input *> create_inputs(const Config &config,
 168                               map<string, Input *> *deserialized_inputs)
 169 {
 170         vector<Input *> inputs;
 171         for (unsigned i = 0; i < config.streams.size(); ++i) {
 172                 const StreamConfig &stream_config = config.streams[i];
 173                 if (stream_config.src.empty()) {
 174                         continue;
 175                 }
 176
 177                 string stream_id = stream_config.stream_id;
 178                 string src = stream_config.src;
 179
 180                 Input *input = NULL;
 181                 map<string, Input *>::iterator deserialized_input_it =
 182                         deserialized_inputs->find(stream_id);
 183                 if (deserialized_input_it != deserialized_inputs->end()) {
 184                         input = deserialized_input_it->second;
 185                         if (input->get_url() != src) {
 186                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 187                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 188                                 input->close_socket();
 189                                 delete input;
 190                                 input = NULL;
 191                         }
 192                         deserialized_inputs->erase(deserialized_input_it);
 193                 }
 194                 if (input == NULL) {
 195                         input = create_input(stream_id, src);
 196                         if (input == NULL) {
 197                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 198                                         src.c_str());
 199                                 continue;
 200                         }
 201                 }
 202                 input->run();
 203                 inputs.push_back(input);
 204         }
 205         return inputs;
 206 }
 207
 208 void create_streams(const Config &config,
 209                     const set<string> &deserialized_stream_ids,
 210                     map<string, Input *> *deserialized_inputs)
 211 {
 212         vector<MarkPool *> mark_pools;  // FIXME: leak
 213         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 214                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 215                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 216         }
 217
 218         set<string> expecting_stream_ids = deserialized_stream_ids;
 219         for (unsigned i = 0; i < config.streams.size(); ++i) {
 220                 const StreamConfig &stream_config = config.streams[i];
 221                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 222                         servers->add_stream(stream_config.stream_id);
 223                 }
 224                 expecting_stream_ids.erase(stream_config.stream_id);
 225
 226                 if (stream_config.mark_pool != -1) {
 227                         servers->set_mark_pool(stream_config.stream_id,
 228                                                mark_pools[stream_config.mark_pool]);
 229                 }
 230         }
 231
 232         // Warn about any servers we've lost.
 233         // TODO: Make an option (delete=yes?) to actually shut down streams.
 234         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 235              stream_it != expecting_stream_ids.end();
 236              ++stream_it) {
 237                 string stream_id = *stream_it;
 238                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 239                         stream_id.c_str());
 240                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 241                 if (deserialized_inputs->count(stream_id) != 0) {
 242                         delete (*deserialized_inputs)[stream_id];
 243                         deserialized_inputs->erase(stream_id);
 244                 }
 245         }
 246 }
 247
 248 bool dry_run_config(const std::string &argv0, const std::string &config_filename)
 249 {
 250         char *argv0_copy = strdup(argv0.c_str());
 251         char *config_filename_copy = strdup(config_filename.c_str());
 252
 253         pid_t pid = fork();
 254         switch (pid) {
 255         case -1:
 256                 perror("fork()");
 257                 free(argv0_copy);
 258                 free(config_filename_copy);
 259                 return false;
 260         case 0:
 261                 // Child.
 262                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 263                 perror(argv0_copy);
 264                 _exit(1);
 265         default:
 266                 // Parent.
 267                 break;
 268         }
 269
 270         free(argv0_copy);
 271         free(config_filename_copy);
 272
 273         int status;
 274         pid_t err;
 275         do {
 276                 err = waitpid(pid, &status, 0);
 277         } while (err == -1 && errno == EINTR);
 278
 279         if (err == -1) {
 280                 perror("waitpid()");
 281                 return false;
 282         }
 283
 284         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 285 }
 286
 287 int main(int argc, char **argv)
 288 {
 289         // Parse options.
 290         int state_fd = -1;
 291         bool test_config = false;
 292         for ( ;; ) {
 293                 static const option long_options[] = {
 294                         { "state", required_argument, 0, 's' },
 295                         { "test-config", no_argument, 0, 't' },
 296                 };
 297                 int option_index = 0;
 298                 int c = getopt_long (argc, argv, "s:t", long_options, &option_index);
 299
 300                 if (c == -1) {
 301                         break;
 302                 }
 303                 switch (c) {
 304                 case 's':
 305                         state_fd = atoi(optarg);
 306                         break;
 307                 case 't':
 308                         test_config = true;
 309                         break;
 310                 default:
 311                         assert(false);
 312                 }
 313         }
 314
 315         string config_filename = "cubemap.config";
 316         if (optind < argc) {
 317                 config_filename = argv[optind++];
 318         }
 319
 320         Config config;
 321         if (!parse_config(config_filename, &config)) {
 322                 exit(1);
 323         }
 324         if (test_config) {
 325                 exit(0);
 326         }
 327
 328 start:
 329         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 330         servers = new ServerPool(config.num_servers);
 331
 332         CubemapStateProto loaded_state;
 333         struct timeval serialize_start;
 334         set<string> deserialized_stream_ids;
 335         map<string, Input *> deserialized_inputs;
 336         map<int, Acceptor *> deserialized_acceptors;
 337         if (state_fd != -1) {
 338                 fprintf(stderr, "Deserializing state from previous process... ");
 339                 loaded_state = read_tempfile(state_fd);
 340
 341                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 342                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 343
 344                 // Deserialize the streams.
 345                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 346                         servers->add_stream_from_serialized(loaded_state.streams(i));
 347                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 348                 }
 349
 350                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 351                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 352                         deserialized_inputs.insert(make_pair(
 353                                 loaded_state.inputs(i).stream_id(),
 354                                 create_input(loaded_state.inputs(i))));
 355                 }
 356
 357                 // Deserialize the acceptors.
 358                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 359                         deserialized_acceptors.insert(make_pair(
 360                                 loaded_state.acceptors(i).port(),
 361                                 new Acceptor(loaded_state.acceptors(i))));
 362                 }
 363
 364                 fprintf(stderr, "done.\n");
 365         }
 366
 367         // Find all streams in the configuration file, and create them.
 368         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 369
 370         servers->run();
 371
 372         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 373         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 374
 375         // All deserialized inputs should now have been taken care of, one way or the other.
 376         assert(deserialized_inputs.empty());
 377
 378         // Put back the existing clients. It doesn't matter which server we
 379         // allocate them to, so just do round-robin. However, we need to add
 380         // them after the mark pools have been set up.
 381         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 382                 servers->add_client_from_serialized(loaded_state.clients(i));
 383         }
 384
 385         // Start writing statistics.
 386         StatsThread *stats_thread = NULL;
 387         if (!config.stats_file.empty()) {
 388                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 389                 stats_thread->run();
 390         } else if (config.stats_interval != -1) {
 391                 fprintf(stderr, "WARNING: 'stats_interval' given, but no 'stats_file'. No statistics will be written.\n");
 392         }
 393
 394         signal(SIGHUP, hup);
 395
 396         struct timeval server_start;
 397         gettimeofday(&server_start, NULL);
 398         if (state_fd != -1) {
 399                 // Measure time from we started deserializing (below) to now, when basically everything
 400                 // is up and running. This is, in other words, a conservative estimate of how long our
 401                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 402                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 403                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 404                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 405         }
 406
 407         while (!hupped) {
 408                 usleep(100000);
 409         }
 410
 411         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 412         gettimeofday(&serialize_start, NULL);
 413
 414         if (stats_thread != NULL) {
 415                 stats_thread->stop();
 416         }
 417         for (size_t i = 0; i < acceptors.size(); ++i) {
 418                 acceptors[i]->stop();
 419         }
 420         for (size_t i = 0; i < inputs.size(); ++i) {
 421                 inputs[i]->stop();
 422         }
 423         servers->stop();
 424
 425         fprintf(stderr, "Serializing state and re-execing...\n");
 426         state_fd = make_tempfile(collect_state(
 427                 serialize_start, acceptors, inputs, servers));
 428         delete servers;
 429
 430         if (!dry_run_config(argv[0], config_filename)) {
 431                 fprintf(stderr, "ERROR: %s --test-config failed. Restarting old version instead of new.\n", argv[0]);
 432                 hupped = false;
 433                 goto start;
 434         }
 435
 436         char buf[16];
 437         sprintf(buf, "%d", state_fd);
 438
 439         for ( ;; ) {
 440                 execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
 441                 perror("execlp");
 442                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 443                 usleep(200000);
 444         }
 445 }