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

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <getopt.h>
   4 #include <google/protobuf/stubs/common.h>
   5 #include <signal.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/time.h>
  11 #include <sys/wait.h>
  12 #include <unistd.h>
  13 #include <map>
  14 #include <set>
  15 #include <string>
  16 #include <utility>
  17 #include <vector>
  18
  19 #include "acceptor.h"
  20 #include "config.h"
  21 #include "input.h"
  22 #include "markpool.h"
  23 #include "serverpool.h"
  24 #include "state.pb.h"
  25 #include "stats.h"
  26 #include "util.h"
  27 #include "version.h"
  28
  29 using namespace std;
  30
  31 ServerPool *servers = NULL;
  32 volatile bool hupped = false;
  33
  34 void hup(int ignored)
  35 {
  36         hupped = true;
  37 }
  38
  39 CubemapStateProto collect_state(const timeval &serialize_start,
  40                                 const vector<Acceptor *> acceptors,
  41                                 const vector<Input *> inputs,
  42                                 ServerPool *servers)
  43 {
  44         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  45         state.set_serialize_start_sec(serialize_start.tv_sec);
  46         state.set_serialize_start_usec(serialize_start.tv_usec);
  47
  48         for (size_t i = 0; i < acceptors.size(); ++i) {
  49                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  50         }
  51
  52         for (size_t i = 0; i < inputs.size(); ++i) {
  53                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  54         }
  55
  56         return state;
  57 }
  58
  59 // Find all port statements in the configuration file, and create acceptors for htem.
  60 vector<Acceptor *> create_acceptors(
  61         const Config &config,
  62         map<int, Acceptor *> *deserialized_acceptors)
  63 {
  64         vector<Acceptor *> acceptors;
  65         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
  66                 const AcceptorConfig &acceptor_config = config.acceptors[i];
  67                 Acceptor *acceptor = NULL;
  68                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
  69                         deserialized_acceptors->find(acceptor_config.port);
  70                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
  71                         acceptor = deserialized_acceptor_it->second;
  72                         deserialized_acceptors->erase(deserialized_acceptor_it);
  73                 } else {
  74                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
  75                         acceptor = new Acceptor(server_sock, acceptor_config.port);
  76                 }
  77                 acceptor->run();
  78                 acceptors.push_back(acceptor);
  79         }
  80
  81         // Close all acceptors that are no longer in the configuration file.
  82         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
  83              acceptor_it != deserialized_acceptors->end();
  84              ++acceptor_it) {
  85                 acceptor_it->second->close_socket();
  86                 delete acceptor_it->second;
  87         }
  88
  89         return acceptors;
  90 }
  91
  92 // Find all streams in the configuration file, and create inputs for them.
  93 vector<Input *> create_inputs(const Config &config,
  94                               map<string, Input *> *deserialized_inputs)
  95 {
  96         vector<Input *> inputs;
  97         for (unsigned i = 0; i < config.streams.size(); ++i) {
  98                 const StreamConfig &stream_config = config.streams[i];
  99                 if (stream_config.src.empty()) {
 100                         continue;
 101                 }
 102
 103                 string stream_id = stream_config.stream_id;
 104                 string src = stream_config.src;
 105
 106                 Input *input = NULL;
 107                 map<string, Input *>::iterator deserialized_input_it =
 108                         deserialized_inputs->find(stream_id);
 109                 if (deserialized_input_it != deserialized_inputs->end()) {
 110                         input = deserialized_input_it->second;
 111                         if (input->get_url() != src) {
 112                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 113                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 114                                 input->close_socket();
 115                                 delete input;
 116                                 input = NULL;
 117                         }
 118                         deserialized_inputs->erase(deserialized_input_it);
 119                 }
 120                 if (input == NULL) {
 121                         input = create_input(stream_id, src);
 122                         if (input == NULL) {
 123                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 124                                         src.c_str());
 125                                 continue;
 126                         }
 127                 }
 128                 input->run();
 129                 inputs.push_back(input);
 130         }
 131         return inputs;
 132 }
 133
 134 void create_streams(const Config &config,
 135                     const set<string> &deserialized_stream_ids,
 136                     map<string, Input *> *deserialized_inputs)
 137 {
 138         vector<MarkPool *> mark_pools;  // FIXME: leak
 139         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 140                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 141                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 142         }
 143
 144         set<string> expecting_stream_ids = deserialized_stream_ids;
 145         for (unsigned i = 0; i < config.streams.size(); ++i) {
 146                 const StreamConfig &stream_config = config.streams[i];
 147                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 148                         servers->add_stream(stream_config.stream_id, stream_config.backlog_size);
 149                 }
 150                 expecting_stream_ids.erase(stream_config.stream_id);
 151
 152                 if (stream_config.mark_pool != -1) {
 153                         servers->set_mark_pool(stream_config.stream_id,
 154                                                mark_pools[stream_config.mark_pool]);
 155                 }
 156         }
 157
 158         // Warn about any servers we've lost.
 159         // TODO: Make an option (delete=yes?) to actually shut down streams.
 160         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 161              stream_it != expecting_stream_ids.end();
 162              ++stream_it) {
 163                 string stream_id = *stream_it;
 164                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 165                         stream_id.c_str());
 166                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 167                 if (deserialized_inputs->count(stream_id) != 0) {
 168                         delete (*deserialized_inputs)[stream_id];
 169                         deserialized_inputs->erase(stream_id);
 170                 }
 171         }
 172 }
 173
 174 bool dry_run_config(const std::string &argv0, const std::string &config_filename)
 175 {
 176         char *argv0_copy = strdup(argv0.c_str());
 177         char *config_filename_copy = strdup(config_filename.c_str());
 178
 179         pid_t pid = fork();
 180         switch (pid) {
 181         case -1:
 182                 perror("fork()");
 183                 free(argv0_copy);
 184                 free(config_filename_copy);
 185                 return false;
 186         case 0:
 187                 // Child.
 188                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 189                 perror(argv0_copy);
 190                 _exit(1);
 191         default:
 192                 // Parent.
 193                 break;
 194         }
 195
 196         free(argv0_copy);
 197         free(config_filename_copy);
 198
 199         int status;
 200         pid_t err;
 201         do {
 202                 err = waitpid(pid, &status, 0);
 203         } while (err == -1 && errno == EINTR);
 204
 205         if (err == -1) {
 206                 perror("waitpid()");
 207                 return false;
 208         }
 209
 210         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 211 }
 212
 213 int main(int argc, char **argv)
 214 {
 215         // Parse options.
 216         int state_fd = -1;
 217         bool test_config = false;
 218         for ( ;; ) {
 219                 static const option long_options[] = {
 220                         { "state", required_argument, 0, 's' },
 221                         { "test-config", no_argument, 0, 't' },
 222                 };
 223                 int option_index = 0;
 224                 int c = getopt_long (argc, argv, "s:t", long_options, &option_index);
 225
 226                 if (c == -1) {
 227                         break;
 228                 }
 229                 switch (c) {
 230                 case 's':
 231                         state_fd = atoi(optarg);
 232                         break;
 233                 case 't':
 234                         test_config = true;
 235                         break;
 236                 default:
 237                         assert(false);
 238                 }
 239         }
 240
 241         string config_filename = "cubemap.config";
 242         if (optind < argc) {
 243                 config_filename = argv[optind++];
 244         }
 245
 246         Config config;
 247         if (!parse_config(config_filename, &config)) {
 248                 exit(1);
 249         }
 250         if (test_config) {
 251                 exit(0);
 252         }
 253
 254 start:
 255         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 256         servers = new ServerPool(config.num_servers);
 257
 258         CubemapStateProto loaded_state;
 259         struct timeval serialize_start;
 260         set<string> deserialized_stream_ids;
 261         map<string, Input *> deserialized_inputs;
 262         map<int, Acceptor *> deserialized_acceptors;
 263         if (state_fd != -1) {
 264                 fprintf(stderr, "Deserializing state from previous process... ");
 265                 string serialized;
 266                 if (!read_tempfile(state_fd, &serialized)) {
 267                         exit(1);
 268                 }
 269                 if (!loaded_state.ParseFromString(serialized)) {
 270                         fprintf(stderr, "ERROR: Failed deserialization of state.\n");
 271                         exit(1);
 272                 }
 273
 274                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 275                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 276
 277                 // Deserialize the streams.
 278                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 279                         servers->add_stream_from_serialized(loaded_state.streams(i));
 280                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 281                 }
 282
 283                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 284                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 285                         deserialized_inputs.insert(make_pair(
 286                                 loaded_state.inputs(i).stream_id(),
 287                                 create_input(loaded_state.inputs(i))));
 288                 }
 289
 290                 // Deserialize the acceptors.
 291                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 292                         deserialized_acceptors.insert(make_pair(
 293                                 loaded_state.acceptors(i).port(),
 294                                 new Acceptor(loaded_state.acceptors(i))));
 295                 }
 296
 297                 fprintf(stderr, "done.\n");
 298         }
 299
 300         // Find all streams in the configuration file, and create them.
 301         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 302
 303         servers->run();
 304
 305         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 306         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 307
 308         // All deserialized inputs should now have been taken care of, one way or the other.
 309         assert(deserialized_inputs.empty());
 310
 311         // Put back the existing clients. It doesn't matter which server we
 312         // allocate them to, so just do round-robin. However, we need to add
 313         // them after the mark pools have been set up.
 314         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 315                 servers->add_client_from_serialized(loaded_state.clients(i));
 316         }
 317
 318         // Start writing statistics.
 319         StatsThread *stats_thread = NULL;
 320         if (!config.stats_file.empty()) {
 321                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 322                 stats_thread->run();
 323         }
 324
 325         signal(SIGHUP, hup);
 326
 327         struct timeval server_start;
 328         gettimeofday(&server_start, NULL);
 329         if (state_fd != -1) {
 330                 // Measure time from we started deserializing (below) to now, when basically everything
 331                 // is up and running. This is, in other words, a conservative estimate of how long our
 332                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 333                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 334                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 335                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 336         }
 337
 338         while (!hupped) {
 339                 usleep(100000);
 340         }
 341
 342         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 343         gettimeofday(&serialize_start, NULL);
 344
 345         if (stats_thread != NULL) {
 346                 stats_thread->stop();
 347         }
 348         for (size_t i = 0; i < acceptors.size(); ++i) {
 349                 acceptors[i]->stop();
 350         }
 351         for (size_t i = 0; i < inputs.size(); ++i) {
 352                 inputs[i]->stop();
 353         }
 354         servers->stop();
 355
 356         fprintf(stderr, "Serializing state and re-execing...\n");
 357         CubemapStateProto state = collect_state(
 358                 serialize_start, acceptors, inputs, servers);
 359         string serialized;
 360         state.SerializeToString(&serialized);
 361         state_fd = make_tempfile(serialized);
 362         if (state_fd == -1) {
 363                 exit(1);
 364         }
 365         delete servers;
 366
 367         if (!dry_run_config(argv[0], config_filename)) {
 368                 fprintf(stderr, "ERROR: %s --test-config failed. Restarting old version instead of new.\n", argv[0]);
 369                 hupped = false;
 370                 goto start;
 371         }
 372
 373         char buf[16];
 374         sprintf(buf, "%d", state_fd);
 375
 376         for ( ;; ) {
 377                 execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
 378                 perror("execlp");
 379                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 380                 usleep(200000);
 381         }
 382 }