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 {
  78         CubemapStateProto state = servers->serialize();  // Fills streams() and clients().
  79         state.set_serialize_start_sec(serialize_start.tv_sec);
  80         state.set_serialize_start_usec(serialize_start.tv_usec);
  81
  82         for (size_t i = 0; i < acceptors.size(); ++i) {
  83                 state.add_acceptors()->MergeFrom(acceptors[i]->serialize());
  84         }
  85
  86         for (size_t i = 0; i < inputs.size(); ++i) {
  87                 state.add_inputs()->MergeFrom(inputs[i]->serialize());
  88         }
  89
  90         return state;
  91 }
  92
  93 // Read the state back from the file descriptor made by make_tempfile,
  94 // and close it.
  95 CubemapStateProto read_tempfile(int state_fd)
  96 {
  97         if (lseek(state_fd, 0, SEEK_SET) == -1) {
  98                 perror("lseek");
  99                 exit(1);
 100         }
 101
 102         string serialized;
 103         char buf[4096];
 104         for ( ;; ) {
 105                 ssize_t ret = read(state_fd, buf, sizeof(buf));
 106                 if (ret == -1) {
 107                         perror("read");
 108                         exit(1);
 109                 }
 110                 if (ret == 0) {
 111                         // EOF.
 112                         break;
 113                 }
 114
 115                 serialized.append(string(buf, buf + ret));
 116         }
 117
 118         close(state_fd);  // Implicitly deletes the file.
 119
 120         CubemapStateProto state;
 121         if (!state.ParseFromString(serialized)) {
 122                 fprintf(stderr, "PANIC: Failed deserialization of state.\n");
 123                 exit(1);
 124         }
 125
 126         return state;
 127 }
 128
 129 // Find all port statements in the configuration file, and create acceptors for htem.
 130 vector<Acceptor *> create_acceptors(
 131         const Config &config,
 132         map<int, Acceptor *> *deserialized_acceptors)
 133 {
 134         vector<Acceptor *> acceptors;
 135         for (unsigned i = 0; i < config.acceptors.size(); ++i) {
 136                 const AcceptorConfig &acceptor_config = config.acceptors[i];
 137                 Acceptor *acceptor = NULL;
 138                 map<int, Acceptor *>::iterator deserialized_acceptor_it =
 139                         deserialized_acceptors->find(acceptor_config.port);
 140                 if (deserialized_acceptor_it != deserialized_acceptors->end()) {
 141                         acceptor = deserialized_acceptor_it->second;
 142                         deserialized_acceptors->erase(deserialized_acceptor_it);
 143                 } else {
 144                         int server_sock = create_server_socket(acceptor_config.port, TCP_SOCKET);
 145                         acceptor = new Acceptor(server_sock, acceptor_config.port);
 146                 }
 147                 acceptor->run();
 148                 acceptors.push_back(acceptor);
 149         }
 150
 151         // Close all acceptors that are no longer in the configuration file.
 152         for (map<int, Acceptor *>::iterator acceptor_it = deserialized_acceptors->begin();
 153              acceptor_it != deserialized_acceptors->end();
 154              ++acceptor_it) {
 155                 acceptor_it->second->close_socket();
 156                 delete acceptor_it->second;
 157         }
 158
 159         return acceptors;
 160 }
 161
 162 // Find all streams in the configuration file, and create inputs for them.
 163 vector<Input *> create_inputs(const Config &config,
 164                               map<string, Input *> *deserialized_inputs)
 165 {
 166         vector<Input *> inputs;
 167         for (unsigned i = 0; i < config.streams.size(); ++i) {
 168                 const StreamConfig &stream_config = config.streams[i];
 169                 if (stream_config.src.empty()) {
 170                         continue;
 171                 }
 172
 173                 string stream_id = stream_config.stream_id;
 174                 string src = stream_config.src;
 175
 176                 Input *input = NULL;
 177                 map<string, Input *>::iterator deserialized_input_it =
 178                         deserialized_inputs->find(stream_id);
 179                 if (deserialized_input_it != deserialized_inputs->end()) {
 180                         input = deserialized_input_it->second;
 181                         if (input->get_url() != src) {
 182                                 fprintf(stderr, "INFO: Stream '%s' has changed URL from '%s' to '%s', restarting input.\n",
 183                                         stream_id.c_str(), input->get_url().c_str(), src.c_str());
 184                                 input->close_socket();
 185                                 delete input;
 186                                 input = NULL;
 187                         }
 188                         deserialized_inputs->erase(deserialized_input_it);
 189                 }
 190                 if (input == NULL) {
 191                         input = create_input(stream_id, src);
 192                         if (input == NULL) {
 193                                 fprintf(stderr, "ERROR: did not understand URL '%s', clients will not get any data.\n",
 194                                         src.c_str());
 195                                 continue;
 196                         }
 197                 }
 198                 input->run();
 199                 inputs.push_back(input);
 200         }
 201         return inputs;
 202 }
 203
 204 void create_streams(const Config &config,
 205                     const set<string> &deserialized_stream_ids,
 206                     map<string, Input *> *deserialized_inputs)
 207 {
 208         vector<MarkPool *> mark_pools;  // FIXME: leak
 209         for (unsigned i = 0; i < config.mark_pools.size(); ++i) {
 210                 const MarkPoolConfig &mp_config = config.mark_pools[i];
 211                 mark_pools.push_back(new MarkPool(mp_config.from, mp_config.to));
 212         }
 213
 214         set<string> expecting_stream_ids = deserialized_stream_ids;
 215         for (unsigned i = 0; i < config.streams.size(); ++i) {
 216                 const StreamConfig &stream_config = config.streams[i];
 217                 if (deserialized_stream_ids.count(stream_config.stream_id) == 0) {
 218                         servers->add_stream(stream_config.stream_id);
 219                 }
 220                 expecting_stream_ids.erase(stream_config.stream_id);
 221
 222                 if (stream_config.mark_pool != -1) {
 223                         servers->set_mark_pool(stream_config.stream_id,
 224                                                mark_pools[stream_config.mark_pool]);
 225                 }
 226         }
 227
 228         // Warn about any servers we've lost.
 229         // TODO: Make an option (delete=yes?) to actually shut down streams.
 230         for (set<string>::const_iterator stream_it = expecting_stream_ids.begin();
 231              stream_it != expecting_stream_ids.end();
 232              ++stream_it) {
 233                 string stream_id = *stream_it;
 234                 fprintf(stderr, "WARNING: stream '%s' disappeared from the configuration file.\n",
 235                         stream_id.c_str());
 236                 fprintf(stderr, "         It will not be deleted, but clients will not get any new inputs.\n");
 237                 if (deserialized_inputs->count(stream_id) != 0) {
 238                         delete (*deserialized_inputs)[stream_id];
 239                         deserialized_inputs->erase(stream_id);
 240                 }
 241         }
 242 }
 243
 244 int main(int argc, char **argv)
 245 {
 246         fprintf(stderr, "\nCubemap " SERVER_VERSION " starting.\n");
 247
 248         struct timeval serialize_start;
 249         bool is_reexec = false;
 250
 251         string config_filename = (argc == 1) ? "cubemap.config" : argv[1];
 252         Config config;
 253         if (!parse_config(config_filename, &config)) {
 254                 exit(1);
 255         }
 256
 257         servers = new ServerPool(config.num_servers);
 258
 259         CubemapStateProto loaded_state;
 260         set<string> deserialized_stream_ids;
 261         map<string, Input *> deserialized_inputs;
 262         map<int, Acceptor *> deserialized_acceptors;
 263         if (argc == 4 && strcmp(argv[2], "-state") == 0) {
 264                 is_reexec = true;
 265
 266                 fprintf(stderr, "Deserializing state from previous process... ");
 267                 int state_fd = atoi(argv[3]);
 268                 loaded_state = read_tempfile(state_fd);
 269
 270                 serialize_start.tv_sec = loaded_state.serialize_start_sec();
 271                 serialize_start.tv_usec = loaded_state.serialize_start_usec();
 272
 273                 // Deserialize the streams.
 274                 for (int i = 0; i < loaded_state.streams_size(); ++i) {
 275                         servers->add_stream_from_serialized(loaded_state.streams(i));
 276                         deserialized_stream_ids.insert(loaded_state.streams(i).stream_id());
 277                 }
 278
 279                 // Deserialize the inputs. Note that we don't actually add them to any state yet.
 280                 for (int i = 0; i < loaded_state.inputs_size(); ++i) {
 281                         deserialized_inputs.insert(make_pair(
 282                                 loaded_state.inputs(i).stream_id(),
 283                                 create_input(loaded_state.inputs(i))));
 284                 }
 285
 286                 // Convert the acceptor from older serialized formats.
 287                 if (loaded_state.has_server_sock() && loaded_state.has_port()) {
 288                         AcceptorProto *acceptor = loaded_state.add_acceptors();
 289                         acceptor->set_server_sock(loaded_state.server_sock());
 290                         acceptor->set_port(loaded_state.port());
 291                 }
 292
 293                 // Deserialize the acceptors.
 294                 for (int i = 0; i < loaded_state.acceptors_size(); ++i) {
 295                         deserialized_acceptors.insert(make_pair(
 296                                 loaded_state.acceptors(i).port(),
 297                                 new Acceptor(loaded_state.acceptors(i))));
 298                 }
 299
 300                 fprintf(stderr, "done.\n");
 301         }
 302
 303         // Find all streams in the configuration file, and create them.
 304         create_streams(config, deserialized_stream_ids, &deserialized_inputs);
 305
 306         servers->run();
 307
 308         vector<Acceptor *> acceptors = create_acceptors(config, &deserialized_acceptors);
 309         vector<Input *> inputs = create_inputs(config, &deserialized_inputs);
 310
 311         // All deserialized inputs should now have been taken care of, one way or the other.
 312         assert(deserialized_inputs.empty());
 313
 314         if (is_reexec) {
 315                 // Put back the existing clients. It doesn't matter which server we
 316                 // allocate them to, so just do round-robin. However, we need to add
 317                 // them after the mark pools have been set up.
 318                 for (int i = 0; i < loaded_state.clients_size(); ++i) {
 319                         servers->add_client_from_serialized(loaded_state.clients(i));
 320                 }
 321         }
 322
 323         // Start writing statistics.
 324         StatsThread *stats_thread = NULL;
 325         if (!config.stats_file.empty()) {
 326                 stats_thread = new StatsThread(config.stats_file, config.stats_interval);
 327                 stats_thread->run();
 328         } else if (config.stats_interval != -1) {
 329                 fprintf(stderr, "WARNING: 'stats_interval' given, but no 'stats_file'. No statistics will be written.\n");
 330         }
 331
 332         signal(SIGHUP, hup);
 333
 334         struct timeval server_start;
 335         gettimeofday(&server_start, NULL);
 336         if (is_reexec) {
 337                 // Measure time from we started deserializing (below) to now, when basically everything
 338                 // is up and running. This is, in other words, a conservative estimate of how long our
 339                 // “glitch” period was, not counting of course reconnects if the configuration changed.
 340                 double glitch_time = server_start.tv_sec - serialize_start.tv_sec +
 341                         1e-6 * (server_start.tv_usec - serialize_start.tv_usec);
 342                 fprintf(stderr, "Re-exec happened in approx. %.0f ms.\n", glitch_time * 1000.0);
 343         }
 344
 345         while (!hupped) {
 346                 usleep(100000);
 347         }
 348
 349         // OK, we've been HUPed. Time to shut down everything, serialize, and re-exec.
 350         gettimeofday(&serialize_start, NULL);
 351
 352         if (stats_thread != NULL) {
 353                 stats_thread->stop();
 354         }
 355         for (size_t i = 0; i < acceptors.size(); ++i) {
 356                 acceptors[i]->stop();
 357         }
 358         for (size_t i = 0; i < inputs.size(); ++i) {
 359                 inputs[i]->stop();
 360         }
 361         servers->stop();
 362
 363         fprintf(stderr, "Serializing state and re-execing...\n");
 364         int state_fd = make_tempfile(collect_state(
 365                 serialize_start, acceptors, inputs, servers));
 366         delete servers;
 367
 368         char buf[16];
 369         sprintf(buf, "%d", state_fd);
 370
 371         for ( ;; ) {
 372                 execlp(argv[0], argv[0], config_filename.c_str(), "-state", buf, NULL);
 373                 perror("execlp");
 374                 fprintf(stderr, "PANIC: re-exec of %s failed. Waiting 0.2 seconds and trying again...\n", argv[0]);
 375                 usleep(200000);
 376         }
 377 }