Esempi in C++ (Cpp) per FileDescriptor::setNonBlock

Esempio n. 1

File: listener.cpp Progetto: facebook/watchman

bool w_start_listener(const char *path)
{
#ifndef _WIN32
  struct sigaction sa;
  sigset_t sigset;
#endif

#ifdef HAVE_LIBGIMLI_H
  hb = gimli_heartbeat_attach();
#endif

#if defined(HAVE_KQUEUE) || defined(HAVE_FSEVENTS)
  {
    struct rlimit limit;
# ifndef __OpenBSD__
    int mib[2] = { CTL_KERN,
#  ifdef KERN_MAXFILESPERPROC
      KERN_MAXFILESPERPROC
#  else
      KERN_MAXFILES
#  endif
    };
# endif
    int maxperproc;

    getrlimit(RLIMIT_NOFILE, &limit);

# ifndef __OpenBSD__
    {
      size_t len;

      len = sizeof(maxperproc);
      sysctl(mib, 2, &maxperproc, &len, NULL, 0);
      w_log(W_LOG_ERR, "file limit is %" PRIu64
          " kern.maxfilesperproc=%i\n",
          limit.rlim_cur, maxperproc);
    }
# else
    maxperproc = limit.rlim_max;
    w_log(W_LOG_ERR, "openfiles-cur is %" PRIu64
        " openfiles-max=%i\n",
        limit.rlim_cur, maxperproc);
# endif

    if (limit.rlim_cur != RLIM_INFINITY &&
        maxperproc > 0 &&
        limit.rlim_cur < (rlim_t)maxperproc) {
      limit.rlim_cur = maxperproc;

      if (setrlimit(RLIMIT_NOFILE, &limit)) {
        w_log(W_LOG_ERR,
          "failed to raise limit to %" PRIu64 " (%s).\n",
          limit.rlim_cur,
          strerror(errno));
      } else {
        w_log(W_LOG_ERR,
            "raised file limit to %" PRIu64 "\n",
            limit.rlim_cur);
      }
    }

    getrlimit(RLIMIT_NOFILE, &limit);
#ifndef HAVE_FSEVENTS
    if (limit.rlim_cur < 10240) {
      w_log(W_LOG_ERR,
          "Your file descriptor limit is very low (%" PRIu64 "), "
          "please consult the watchman docs on raising the limits\n",
          limit.rlim_cur);
    }
#endif
  }
#endif

#ifndef _WIN32
  signal(SIGPIPE, SIG_IGN);

  /* allow SIGUSR1 and SIGCHLD to wake up a blocked thread, without restarting
   * syscalls */
  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = wakeme;
  sa.sa_flags = 0;
  sigaction(SIGUSR1, &sa, NULL);
  sigaction(SIGCHLD, &sa, NULL);

  // Block SIGCHLD everywhere
  sigemptyset(&sigset);
  sigaddset(&sigset, SIGCHLD);
  sigprocmask(SIG_BLOCK, &sigset, NULL);

  if (listener_fd) {
    // Assume that it was prepped by w_listener_prep_inetd()
    w_log(W_LOG_ERR, "Using socket from inetd as listening socket\n");
  } else {
    listener_fd = get_listener_socket(path);
    if (!listener_fd) {
      return false;
    }
  }
  listener_fd.setCloExec();
#endif

#ifdef HAVE_LIBGIMLI_H
  if (hb) {
    gimli_heartbeat_set(hb, GIMLI_HB_RUNNING);
  } else {
    w_setup_signal_handlers();
  }
#else
  w_setup_signal_handlers();
#endif
  listener_fd.setNonBlock();

  startSanityCheckThread();

  // Now run the dispatch
#ifndef _WIN32
  listener_thread_event = w_event_make();
  accept_loop(std::move(listener_fd));
#else
  named_pipe_accept_loop(path);
#endif

  // Wait for clients, waking any sleeping clients up in the process
  {
    auto interval = std::chrono::microseconds(2000);
    const auto max_interval = std::chrono::seconds(1);
    const auto deadline =
        std::chrono::steady_clock::now() + std::chrono::seconds(10);

    int last_count = 0, n_clients = 0;

    while (true) {
      {
        auto clientsLock = clients.rlock();
        n_clients = clientsLock->size();

        for (auto client : *clientsLock) {
          client->ping->notify();
        }
      }

      if (n_clients == 0) {
        break;
      }

      if (std::chrono::steady_clock::now() >= deadline) {
        log(ERR, "Abandoning wait for ", n_clients, " outstanding clients\n");
        break;
      }

      if (n_clients != last_count) {
        log(ERR, "waiting for ", n_clients, " clients to terminate\n");
      }

      /* sleep override */
      std::this_thread::sleep_for(interval);
      interval *= 2;
      if (interval > max_interval) {
        interval = max_interval;
      }
    }
  }

  w_state_shutdown();

  return true;
}