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 <signal.h>
  14 #include <errno.h>
  15 #include <ctype.h>
  16 #include <fcntl.h>
  17 #include <vector>
  18 #include <string>
  19 #include <map>
  20 #include <set>
  21
  22 #include "acceptor.h"
  23 #include "config.h"
  24 #include "markpool.h"
  25 #include "metacube.h"
  26 #include "parse.h"
  27 #include "server.h"
  28 #include "serverpool.h"
  29 #include "input.h"
  30 #include "stats.h"
  31 #include "version.h"
  32 #include "state.pb.h"
  33
  34 using namespace std;
  35
  36 ServerPool *servers = NULL;
  37 volatile bool hupped = false;
  38
  39 void hup(int ignored)
  40 {
  41         hupped = true;
  42 }
  43
  44 // Serialize the given state to a file descriptor, and return the (still open)
  45 // descriptor.
  46 int make_tempfile(const CubemapStateProto &state)
  47 {
  48         char tmpl[] = "/tmp/cubemapstate.XXXXXX";
  49         int state_fd = mkstemp(tmpl);
  50         if (state_fd == -1) {
  51                 perror("mkstemp");
  52                 exit(1);
  53         }
  54
  55         string serialized;
  56         state.SerializeToString(&serialized);
  57
  58         const char *ptr = serialized.data();
  59         size_t to_write = serialized.size();
  60         while (to_write > 0) {
  61                 ssize_t ret = write(state_fd, ptr, to_write);
  62                 if (ret == -1) {
  63                         perror("write");
  64                         exit(1);
  65                 }
  66
  67                 ptr += ret;
  68                 to_write -= ret;
  69         }
  70
  71         return state_fd;
  72 }
  73
  74 CubemapStateProto collect_state(const timeval &serialize_start,
  75                                 const vector<Acceptor *> acceptors,
  76                                 const vector<Input *> inputs,
  77                                 ServerPool *servers)
  78 {
  79         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  80         state.set_serialize_start_sec(serialize_start.tv_sec);
  81         state.set_serialize_start_usec(serialize_start.tv_usec);
  82
  83         for (size_t i = 0; i < acceptors.size(); ++i) {
  84                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  85         }
  86
  87         for (size_t i = 0; i < inputs.size(); ++i) {
  88                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  89         }
  90
  91         return state;
  92 }
  93
  94 // Read the state back from the file descriptor made by make_tempfile,
  95 // and close it.
  96 CubemapStateProto read_tempfile(int state_fd)
  97 {
  98         if (lseek(state_fd, 0, SEEK_SET) == -1) {
  99                 perror("lseek");
 100                 exit(1);
 101         }
 102
 103         string serialized;
 104         char buf[4096];
 105         for ( ;; ) {
 106                 ssize_t ret = read(state_fd, buf, sizeof(buf));
 107                 if (ret == -1) {
 108                         perror("read");
 109                         exit(1);
 110                 }
 111                 if (ret == 0) {
 112                         // EOF.
 113                         break;
 114                 }
 115
 116                 serialized.append(string(buf, buf + ret));
 117         }
 118
 119         close(state_fd);  // Implicitly deletes the file.
 120
 121         CubemapStateProto state;
 122         if (!state.ParseFromString(serialized)) {
 123                 fprintf(stderr, "PANIC: Failed deserialization of state.\n");
 124                 exit(1);
 125         }
 126
 127         return state;
 128 }
 129
 130 // Find all port statements in the configuration file, and create acceptors for htem.
 131 vector<Acceptor *> create_acceptors(
 132         const Config &config,
 133         map<int, Acceptor *> *deserialized_acceptors)
 134 {
 135         vector<Acceptor *> acceptors;
 136         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
 137                 const AcceptorConfig &acceptor_config = config.acceptors[i];
 138                 Acceptor *acceptor = NULL;
 139                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
 140                         deserialized_acceptors->find(acceptor_config.port);
 141                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
 142                         acceptor = deserialized_acceptor_it->second;
 143                         deserialized_acceptors->erase(deserialized_acceptor_it);
 144                 } else {
 145                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
 146                         acceptor = new Acceptor(server_sock, acceptor_config.port);
 147                 }
 148                 acceptor->run();
 149                 acceptors.push_back(acceptor);
 150         }
 151
 152         // Close all acceptors that are no longer in the configuration file.
 153         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
 154              acceptor_it != deserialized_acceptors->end();
 155              ++acceptor_it) {
 156                 acceptor_it->second->close_socket();
 157                 delete acceptor_it->second;
 158         }
 159
 160         return acceptors;
 161 }
 162
 163 // Find all streams in the configuration file, and create inputs for them.
 164 vector<Input *> create_inputs(const Config &config,
 165                               map<string, Input *> *deserialized_inputs)
 166 {
 167         vector<Input *> inputs;
 168         for (unsigned i = 0; i < config.streams.size(); ++i) {
 169                 const StreamConfig &stream_config = config.streams[i];
 170                 if (stream_config.src.empty()) {
 171                         continue;
 172                 }
 173
 174                 string stream_id = stream_config.stream_id;
 175                 string src = stream_config.src;
 176
 177                 Input *input = NULL;
 178                 map<string, Input *>::iterator deserialized_input_it =
 179                         deserialized_inputs->find(stream_id);
 180                 if (deserialized_input_it != deserialized_inputs->end()) {
 181                         input = deserialized_input_it->second;
 182                         if (input->get_url() != src) {
 183                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 184                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 185                                 input->close_socket();
 186                                 delete input;
 187                                 input = NULL;
 188                         }
 189                         deserialized_inputs->erase(deserialized_input_it);
 190                 }
 191                 if (input == NULL) {
 192                         input = create_input(stream_id, src);
 193                         if (input == NULL) {
 194                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 195                                         src.c_str());
 196                                 continue;
 197                         }
 198                 }
 199                 input->run();
 200                 inputs.push_back(input);
 201         }
 202         return inputs;
 203 }
 204
 205 void create_streams(const Config &config,
 206                     const set<string> &deserialized_stream_ids,
 207                     map<string, Input *> *deserialized_inputs)
 208 {
 209         vector<MarkPool *> mark_pools;  // FIXME: leak
 210         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 211                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 212                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 213         }
 214
 215         set<string> expecting_stream_ids = deserialized_stream_ids;
 216         for (unsigned i = 0; i < config.streams.size(); ++i) {
 217                 const StreamConfig &stream_config = config.streams[i];
 218                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 219                         servers->add_stream(stream_config.stream_id);
 220                 }
 221                 expecting_stream_ids.erase(stream_config.stream_id);
 222
 223                 if (stream_config.mark_pool != -1) {
 224                         servers->set_mark_pool(stream_config.stream_id,
 225                                                mark_pools[stream_config.mark_pool]);
 226                 }
 227         }
 228
 229         // Warn about any servers we've lost.
 230         // TODO: Make an option (delete=yes?) to actually shut down streams.
 231         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 232              stream_it != expecting_stream_ids.end();
 233              ++stream_it) {
 234                 string stream_id = *stream_it;
 235                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 236                         stream_id.c_str());
 237                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 238                 if (deserialized_inputs->count(stream_id) != 0) {
 239                         delete (*deserialized_inputs)[stream_id];
 240                         deserialized_inputs->erase(stream_id);
 241                 }
 242         }
 243 }
 244
 245 int main(int argc, char **argv)
 246 {
 247         // Parse options.
 248         int state_fd = -1;
 249         bool test_config = false;
 250         for ( ;; ) {
 251                 static const option long_options[] = {
 252                         { "state", required_argument, 0, 's' },
 253                         { "test-config", no_argument, 0, 't' },
 254                 };
 255                 int option_index = 0;
 256                 int c = getopt_long (argc, argv, "s:t", long_options, &option_index);
 257
 258                 if (c == -1) {
 259                         break;
 260                 }
 261                 switch (c) {
 262                 case 's':
 263                         state_fd = atoi(optarg);
 264                         break;
 265                 case 't':
 266                         test_config = true;
 267                         break;
 268                 default:
 269                         assert(false);
 270                 }
 271         }
 272
 273         string config_filename = "cubemap.config";
 274         if (optind < argc) {
 275                 config_filename = argv[optind++];
 276         }
 277
 278         struct timeval serialize_start;
 279
 280         Config config;
 281         if (!parse_config(config_filename, &config)) {
 282                 exit(1);
 283         }
 284         if (test_config) {
 285                 exit(0);
 286         }
 287
 288         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 289         servers = new ServerPool(config.num_servers);
 290
 291         CubemapStateProto loaded_state;
 292         set<string> deserialized_stream_ids;
 293         map<string, Input *> deserialized_inputs;
 294         map<int, Acceptor *> deserialized_acceptors;
 295         if (state_fd != -1) {
 296                 fprintf(stderr, "Deserializing state from previous process... ");
 297                 loaded_state = read_tempfile(state_fd);
 298
 299                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 300                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 301
 302                 // Deserialize the streams.
 303                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 304                         servers->add_stream_from_serialized(loaded_state.streams(i));
 305                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 306                 }
 307
 308                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 309                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 310                         deserialized_inputs.insert(make_pair(
 311                                 loaded_state.inputs(i).stream_id(),
 312                                 create_input(loaded_state.inputs(i))));
 313                 }
 314
 315                 // Deserialize the acceptors.
 316                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 317                         deserialized_acceptors.insert(make_pair(
 318                                 loaded_state.acceptors(i).port(),
 319                                 new Acceptor(loaded_state.acceptors(i))));
 320                 }
 321
 322                 fprintf(stderr, "done.\n");
 323         }
 324
 325         // Find all streams in the configuration file, and create them.
 326         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 327
 328         servers->run();
 329
 330         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 331         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 332
 333         // All deserialized inputs should now have been taken care of, one way or the other.
 334         assert(deserialized_inputs.empty());
 335
 336         // Put back the existing clients. It doesn't matter which server we
 337         // allocate them to, so just do round-robin. However, we need to add
 338         // them after the mark pools have been set up.
 339         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 340                 servers->add_client_from_serialized(loaded_state.clients(i));
 341         }
 342
 343         // Start writing statistics.
 344         StatsThread *stats_thread = NULL;
 345         if (!config.stats_file.empty()) {
 346                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 347                 stats_thread->run();
 348         } else if (config.stats_interval != -1) {
 349                 fprintf(stderr, "WARNING: 'stats_interval' given, but no 'stats_file'. No statistics will be written.\n");
 350         }
 351
 352         signal(SIGHUP, hup);
 353
 354         struct timeval server_start;
 355         gettimeofday(&server_start, NULL);
 356         if (state_fd != -1) {
 357                 // Measure time from we started deserializing (below) to now, when basically everything
 358                 // is up and running. This is, in other words, a conservative estimate of how long our
 359                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 360                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 361                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 362                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 363         }
 364
 365         while (!hupped) {
 366                 usleep(100000);
 367         }
 368
 369         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 370         gettimeofday(&serialize_start, NULL);
 371
 372         if (stats_thread != NULL) {
 373                 stats_thread->stop();
 374         }
 375         for (size_t i = 0; i < acceptors.size(); ++i) {
 376                 acceptors[i]->stop();
 377         }
 378         for (size_t i = 0; i < inputs.size(); ++i) {
 379                 inputs[i]->stop();
 380         }
 381         servers->stop();
 382
 383         fprintf(stderr, "Serializing state and re-execing...\n");
 384         state_fd = make_tempfile(collect_state(
 385                 serialize_start, acceptors, inputs, servers));
 386         delete servers;
 387
 388         char buf[16];
 389         sprintf(buf, "%d", state_fd);
 390
 391         for ( ;; ) {
 392                 execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
 393                 perror("execlp");
 394                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 395                 usleep(200000);
 396         }
 397 }