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 <arpa/inet.h>
   6 #include <sys/socket.h>
   7 #include <pthread.h>
   8 #include <sys/types.h>
   9 #include <sys/ioctl.h>
  10 #include <sys/poll.h>
  11 #include <sys/time.h>
  12 #include <signal.h>
  13 #include <errno.h>
  14 #include <ctype.h>
  15 #include <fcntl.h>
  16 #include <vector>
  17 #include <string>
  18 #include <map>
  19 #include <set>
  20
  21 #include "acceptor.h"
  22 #include "config.h"
  23 #include "markpool.h"
  24 #include "metacube.h"
  25 #include "parse.h"
  26 #include "server.h"
  27 #include "serverpool.h"
  28 #include "input.h"
  29 #include "stats.h"
  30 #include "version.h"
  31 #include "state.pb.h"
  32
  33 using namespace std;
  34
  35 ServerPool *servers = NULL;
  36 volatile bool hupped = false;
  37
  38 void hup(int ignored)
  39 {
  40         hupped = true;
  41 }
  42
  43 // Serialize the given state to a file descriptor, and return the (still open)
  44 // descriptor.
  45 int make_tempfile(const CubemapStateProto &state)
  46 {
  47         char tmpl[] = "/tmp/cubemapstate.XXXXXX";
  48         int state_fd = mkstemp(tmpl);
  49         if (state_fd == -1) {
  50                 perror("mkstemp");
  51                 exit(1);
  52         }
  53
  54         string serialized;
  55         state.SerializeToString(&serialized);
  56
  57         const char *ptr = serialized.data();
  58         size_t to_write = serialized.size();
  59         while (to_write > 0) {
  60                 ssize_t ret = write(state_fd, ptr, to_write);
  61                 if (ret == -1) {
  62                         perror("write");
  63                         exit(1);
  64                 }
  65
  66                 ptr += ret;
  67                 to_write -= ret;
  68         }
  69
  70         return state_fd;
  71 }
  72
  73 CubemapStateProto collect_state(const timeval &serialize_start,
  74                                 const vector<Acceptor *> acceptors,
  75                                 const vector<Input *> inputs,
  76                                 ServerPool *servers,
  77                                 int num_servers)
  78 {
  79         CubemapStateProto state;
  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         for (int i = 0; i < num_servers; ++i) {
  92                 CubemapStateProto local_state = servers->get_server(i)->serialize();
  93
  94                 // The stream state should be identical between the servers, so we only store it once.
  95                 if (i == 0) {
  96                         state.mutable_streams()->MergeFrom(local_state.streams());
  97                 }
  98                 for (int j = 0; j < local_state.clients_size(); ++j) {
  99                         state.add_clients()->MergeFrom(local_state.clients(j));
 100                 }
 101         }
 102
 103         return state;
 104 }
 105
 106 // Read the state back from the file descriptor made by make_tempfile,
 107 // and close it.
 108 CubemapStateProto read_tempfile(int state_fd)
 109 {
 110         if (lseek(state_fd, 0, SEEK_SET) == -1) {
 111                 perror("lseek");
 112                 exit(1);
 113         }
 114
 115         string serialized;
 116         char buf[4096];
 117         for ( ;; ) {
 118                 ssize_t ret = read(state_fd, buf, sizeof(buf));
 119                 if (ret == -1) {
 120                         perror("read");
 121                         exit(1);
 122                 }
 123                 if (ret == 0) {
 124                         // EOF.
 125                         break;
 126                 }
 127
 128                 serialized.append(string(buf, buf + ret));
 129         }
 130
 131         close(state_fd);  // Implicitly deletes the file.
 132
 133         CubemapStateProto state;
 134         if (!state.ParseFromString(serialized)) {
 135                 fprintf(stderr, "PANIC: Failed deserialization of state.\n");
 136                 exit(1);
 137         }
 138
 139         return state;
 140 }
 141
 142 // Find all port statements in the configuration file, and create acceptors for htem.
 143 vector<Acceptor *> create_acceptors(
 144         const Config &config,
 145         map<int, Acceptor *> *deserialized_acceptors)
 146 {
 147         vector<Acceptor *> acceptors;
 148         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
 149                 const AcceptorConfig &acceptor_config = config.acceptors[i];
 150                 Acceptor *acceptor = NULL;
 151                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
 152                         deserialized_acceptors->find(acceptor_config.port);
 153                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
 154                         acceptor = deserialized_acceptor_it->second;
 155                         deserialized_acceptors->erase(deserialized_acceptor_it);
 156                 } else {
 157                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
 158                         acceptor = new Acceptor(server_sock, acceptor_config.port);
 159                 }
 160                 acceptor->run();
 161                 acceptors.push_back(acceptor);
 162         }
 163
 164         // Close all acceptors that are no longer in the configuration file.
 165         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
 166              acceptor_it != deserialized_acceptors->end();
 167              ++acceptor_it) {
 168                 acceptor_it->second->close_socket();
 169                 delete acceptor_it->second;
 170         }
 171
 172         return acceptors;
 173 }
 174
 175 // Find all streams in the configuration file, and create inputs for them.
 176 vector<Input *> create_inputs(const Config &config,
 177                               map<string, Input *> *deserialized_inputs)
 178 {
 179         vector<Input *> inputs;
 180         for (unsigned i = 0; i < config.streams.size(); ++i) {
 181                 const StreamConfig &stream_config = config.streams[i];
 182                 if (stream_config.src.empty()) {
 183                         continue;
 184                 }
 185
 186                 string stream_id = stream_config.stream_id;
 187                 string src = stream_config.src;
 188
 189                 Input *input = NULL;
 190                 map<string, Input *>::iterator deserialized_input_it =
 191                         deserialized_inputs->find(stream_id);
 192                 if (deserialized_input_it != deserialized_inputs->end()) {
 193                         input = deserialized_input_it->second;
 194                         if (input->get_url() != src) {
 195                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 196                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 197                                 input->close_socket();
 198                                 delete input;
 199                                 input = NULL;
 200                         }
 201                         deserialized_inputs->erase(deserialized_input_it);
 202                 }
 203                 if (input == NULL) {
 204                         input = create_input(stream_id, src);
 205                         if (input == NULL) {
 206                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 207                                         src.c_str());
 208                                 continue;
 209                         }
 210                 }
 211                 input->run();
 212                 inputs.push_back(input);
 213         }
 214         return inputs;
 215 }
 216
 217 void create_streams(const Config &config,
 218                     const set<string> &deserialized_stream_ids,
 219                     map<string, Input *> *deserialized_inputs)
 220 {
 221         vector<MarkPool *> mark_pools;  // FIXME: leak
 222         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 223                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 224                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 225         }
 226
 227         set<string> expecting_stream_ids = deserialized_stream_ids;
 228         for (unsigned i = 0; i < config.streams.size(); ++i) {
 229                 const StreamConfig &stream_config = config.streams[i];
 230                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 231                         servers->add_stream(stream_config.stream_id);
 232                 }
 233                 expecting_stream_ids.erase(stream_config.stream_id);
 234
 235                 if (stream_config.mark_pool != -1) {
 236                         servers->set_mark_pool(stream_config.stream_id,
 237                                                mark_pools[stream_config.mark_pool]);
 238                 }
 239         }
 240
 241         // Warn about any servers we've lost.
 242         // TODO: Make an option (delete=yes?) to actually shut down streams.
 243         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 244              stream_it != expecting_stream_ids.end();
 245              ++stream_it) {
 246                 string stream_id = *stream_it;
 247                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 248                         stream_id.c_str());
 249                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 250                 if (deserialized_inputs->count(stream_id) != 0) {
 251                         delete (*deserialized_inputs)[stream_id];
 252                         deserialized_inputs->erase(stream_id);
 253                 }
 254         }
 255 }
 256
 257 int main(int argc, char **argv)
 258 {
 259         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 260
 261         struct timeval serialize_start;
 262         bool is_reexec = false;
 263
 264         string config_filename = (argc == 1) ? "cubemap.config" : argv[1];
 265         Config config;
 266         if (!parse_config(config_filename, &config)) {
 267                 exit(1);
 268         }
 269
 270         servers = new ServerPool(config.num_servers);
 271
 272         CubemapStateProto loaded_state;
 273         set<string> deserialized_stream_ids;
 274         map<string, Input *> deserialized_inputs;
 275         map<int, Acceptor *> deserialized_acceptors;
 276         if (argc == 4 && strcmp(argv[2], "-state") == 0) {
 277                 is_reexec = true;
 278
 279                 fprintf(stderr, "Deserializing state from previous process... ");
 280                 int state_fd = atoi(argv[3]);
 281                 loaded_state = read_tempfile(state_fd);
 282
 283                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 284                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 285
 286                 // Deserialize the streams.
 287                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 288                         servers->add_stream_from_serialized(loaded_state.streams(i));
 289                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 290                 }
 291
 292                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 293                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 294                         deserialized_inputs.insert(make_pair(
 295                                 loaded_state.inputs(i).stream_id(),
 296                                 create_input(loaded_state.inputs(i))));
 297                 }
 298
 299                 // Convert the acceptor from older serialized formats.
 300                 if (loaded_state.has_server_sock() && loaded_state.has_port()) {
 301                         AcceptorProto *acceptor = loaded_state.add_acceptors();
 302                         acceptor->set_server_sock(loaded_state.server_sock());
 303                         acceptor->set_port(loaded_state.port());
 304                 }
 305
 306                 // Deserialize the acceptors.
 307                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 308                         deserialized_acceptors.insert(make_pair(
 309                                 loaded_state.acceptors(i).port(),
 310                                 new Acceptor(loaded_state.acceptors(i))));
 311                 }
 312
 313                 fprintf(stderr, "done.\n");
 314         }
 315
 316         // Find all streams in the configuration file, and create them.
 317         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 318
 319         servers->run();
 320
 321         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 322         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 323
 324         // All deserialized inputs should now have been taken care of, one way or the other.
 325         assert(deserialized_inputs.empty());
 326
 327         if (is_reexec) {
 328                 // Put back the existing clients. It doesn't matter which server we
 329                 // allocate them to, so just do round-robin. However, we need to add
 330                 // them after the mark pools have been set up.
 331                 for (int i = 0; i < loaded_state.clients_size(); ++i) {
 332                         servers->add_client_from_serialized(loaded_state.clients(i));
 333                 }
 334         }
 335
 336         // Start writing statistics.
 337         StatsThread *stats_thread = NULL;
 338         if (!config.stats_file.empty()) {
 339                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 340                 stats_thread->run();
 341         } else if (config.stats_interval != -1) {
 342                 fprintf(stderr, "WARNING: 'stats_interval' given, but no 'stats_file'. No statistics will be written.\n");
 343         }
 344
 345         signal(SIGHUP, hup);
 346
 347         struct timeval server_start;
 348         gettimeofday(&server_start, NULL);
 349         if (is_reexec) {
 350                 // Measure time from we started deserializing (below) to now, when basically everything
 351                 // is up and running. This is, in other words, a conservative estimate of how long our
 352                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 353                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 354                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 355                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 356         }
 357
 358         while (!hupped) {
 359                 usleep(100000);
 360         }
 361
 362         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 363         gettimeofday(&serialize_start, NULL);
 364
 365         if (stats_thread != NULL) {
 366                 stats_thread->stop();
 367         }
 368         for (size_t i = 0; i < acceptors.size(); ++i) {
 369                 acceptors[i]->stop();
 370         }
 371         for (size_t i = 0; i < inputs.size(); ++i) {
 372                 inputs[i]->stop();
 373         }
 374         servers->stop();
 375
 376         fprintf(stderr, "Serializing state and re-execing...\n");
 377         int state_fd = make_tempfile(collect_state(
 378                 serialize_start, acceptors, inputs, servers, config.num_servers));
 379         delete servers;
 380
 381         char buf[16];
 382         sprintf(buf, "%d", state_fd);
 383
 384         for ( ;; ) {
 385                 execlp(argv[0], argv[0], config_filename.c_str(), "-state", buf, NULL);
 386                 perror("execlp");
 387                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 388                 usleep(200000);
 389         }
 390 }