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                 } else {
 150                         servers->set_backlog_size(stream_config.stream_id, stream_config.backlog_size);
 151                 }
 152                 expecting_stream_ids.erase(stream_config.stream_id);
 153
 154                 if (stream_config.mark_pool != -1) {
 155                         servers->set_mark_pool(stream_config.stream_id,
 156                                                mark_pools[stream_config.mark_pool]);
 157                 }
 158         }
 159
 160         // Warn about any servers we've lost.
 161         // TODO: Make an option (delete=yes?) to actually shut down streams.
 162         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 163              stream_it != expecting_stream_ids.end();
 164              ++stream_it) {
 165                 string stream_id = *stream_it;
 166                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 167                         stream_id.c_str());
 168                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 169                 if (deserialized_inputs->count(stream_id) != 0) {
 170                         delete (*deserialized_inputs)[stream_id];
 171                         deserialized_inputs->erase(stream_id);
 172                 }
 173         }
 174 }
 175
 176 bool dry_run_config(const std::string &argv0, const std::string &config_filename)
 177 {
 178         char *argv0_copy = strdup(argv0.c_str());
 179         char *config_filename_copy = strdup(config_filename.c_str());
 180
 181         pid_t pid = fork();
 182         switch (pid) {
 183         case -1:
 184                 perror("fork()");
 185                 free(argv0_copy);
 186                 free(config_filename_copy);
 187                 return false;
 188         case 0:
 189                 // Child.
 190                 execlp(argv0_copy, argv0_copy, "--test-config", config_filename_copy, NULL);
 191                 perror(argv0_copy);
 192                 _exit(1);
 193         default:
 194                 // Parent.
 195                 break;
 196         }
 197
 198         free(argv0_copy);
 199         free(config_filename_copy);
 200
 201         int status;
 202         pid_t err;
 203         do {
 204                 err = waitpid(pid, &status, 0);
 205         } while (err == -1 && errno == EINTR);
 206
 207         if (err == -1) {
 208                 perror("waitpid()");
 209                 return false;
 210         }
 211
 212         return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
 213 }
 214
 215 int main(int argc, char **argv)
 216 {
 217         // Parse options.
 218         int state_fd = -1;
 219         bool test_config = false;
 220         for ( ;; ) {
 221                 static const option long_options[] = {
 222                         { "state", required_argument, 0, 's' },
 223                         { "test-config", no_argument, 0, 't' },
 224                 };
 225                 int option_index = 0;
 226                 int c = getopt_long (argc, argv, "s:t", long_options, &option_index);
 227
 228                 if (c == -1) {
 229                         break;
 230                 }
 231                 switch (c) {
 232                 case 's':
 233                         state_fd = atoi(optarg);
 234                         break;
 235                 case 't':
 236                         test_config = true;
 237                         break;
 238                 default:
 239                         assert(false);
 240                 }
 241         }
 242
 243         string config_filename = "cubemap.config";
 244         if (optind < argc) {
 245                 config_filename = argv[optind++];
 246         }
 247
 248         Config config;
 249         if (!parse_config(config_filename, &config)) {
 250                 exit(1);
 251         }
 252         if (test_config) {
 253                 exit(0);
 254         }
 255
 256 start:
 257         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 258         servers = new ServerPool(config.num_servers);
 259
 260         CubemapStateProto loaded_state;
 261         struct timeval serialize_start;
 262         set<string> deserialized_stream_ids;
 263         map<string, Input *> deserialized_inputs;
 264         map<int, Acceptor *> deserialized_acceptors;
 265         if (state_fd != -1) {
 266                 fprintf(stderr, "Deserializing state from previous process... ");
 267                 string serialized;
 268                 if (!read_tempfile(state_fd, &serialized)) {
 269                         exit(1);
 270                 }
 271                 if (!loaded_state.ParseFromString(serialized)) {
 272                         fprintf(stderr, "ERROR: Failed deserialization of state.\n");
 273                         exit(1);
 274                 }
 275
 276                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 277                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 278
 279                 // Deserialize the streams.
 280                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 281                         servers->add_stream_from_serialized(loaded_state.streams(i));
 282                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 283                 }
 284
 285                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 286                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 287                         deserialized_inputs.insert(make_pair(
 288                                 loaded_state.inputs(i).stream_id(),
 289                                 create_input(loaded_state.inputs(i))));
 290                 }
 291
 292                 // Deserialize the acceptors.
 293                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 294                         deserialized_acceptors.insert(make_pair(
 295                                 loaded_state.acceptors(i).port(),
 296                                 new Acceptor(loaded_state.acceptors(i))));
 297                 }
 298
 299                 fprintf(stderr, "done.\n");
 300         }
 301
 302         // Find all streams in the configuration file, and create them.
 303         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 304
 305         servers->run();
 306
 307         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 308         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 309
 310         // All deserialized inputs should now have been taken care of, one way or the other.
 311         assert(deserialized_inputs.empty());
 312
 313         // Put back the existing clients. It doesn't matter which server we
 314         // allocate them to, so just do round-robin. However, we need to add
 315         // them after the mark pools have been set up.
 316         for (int i = 0; i < loaded_state.clients_size(); ++i) {
 317                 servers->add_client_from_serialized(loaded_state.clients(i));
 318         }
 319
 320         // Start writing statistics.
 321         StatsThread *stats_thread = NULL;
 322         if (!config.stats_file.empty()) {
 323                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 324                 stats_thread->run();
 325         }
 326
 327         signal(SIGHUP, hup);
 328
 329         struct timeval server_start;
 330         gettimeofday(&server_start, NULL);
 331         if (state_fd != -1) {
 332                 // Measure time from we started deserializing (below) to now, when basically everything
 333                 // is up and running. This is, in other words, a conservative estimate of how long our
 334                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 335                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 336                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 337                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 338         }
 339
 340         while (!hupped) {
 341                 usleep(100000);
 342         }
 343
 344         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 345         gettimeofday(&serialize_start, NULL);
 346
 347         if (stats_thread != NULL) {
 348                 stats_thread->stop();
 349         }
 350         for (size_t i = 0; i < acceptors.size(); ++i) {
 351                 acceptors[i]->stop();
 352         }
 353         for (size_t i = 0; i < inputs.size(); ++i) {
 354                 inputs[i]->stop();
 355         }
 356         servers->stop();
 357
 358         fprintf(stderr, "Serializing state and re-execing...\n");
 359         CubemapStateProto state = collect_state(
 360                 serialize_start, acceptors, inputs, servers);
 361         string serialized;
 362         state.SerializeToString(&serialized);
 363         state_fd = make_tempfile(serialized);
 364         if (state_fd == -1) {
 365                 exit(1);
 366         }
 367         delete servers;
 368
 369         if (!dry_run_config(argv[0], config_filename)) {
 370                 fprintf(stderr, "ERROR: %s --test-config failed. Restarting old version instead of new.\n", argv[0]);
 371                 hupped = false;
 372                 goto start;
 373         }
 374
 375         char buf[16];
 376         sprintf(buf, "%d", state_fd);
 377
 378         for ( ;; ) {
 379                 execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
 380                 perror("execlp");
 381                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 382                 usleep(200000);
 383         }
 384 }