Method detected

src/slave/slave.cpp:1441–1541

void Slave::detected(const Future<Option<MasterInfo>>& _master)
{
  CHECK(state == DISCONNECTED ||
        state == RUNNING ||
        state == TERMINATING) << state;

  if (state != TERMINATING) {
    state = DISCONNECTED;
  }

  // Pause the status updates.
  taskStatusUpdateManager->pause();
  operationStatusUpdateManager.pause();

  if (_master.isFailed()) {
    EXIT(EXIT_FAILURE) << "Failed to detect a master: " << _master.failure();
  }

  Option<MasterInfo> latest;

  if (_master.isDiscarded()) {
    LOG(INFO) << "Re-detecting master";
    latest = None();
    master = None();
  } else if (_master->isNone()) {
    LOG(INFO) << "Lost leading master";
    latest = None();
    master = None();
  } else {
    latest = _master.get();
    master = UPID(latest->pid());

    LOG(INFO) << "New master detected at " << master.get();

    // Cancel the pending registration timer to avoid spurious attempts
    // at reregistration. `Clock::cancel` is idempotent, so this call
    // is safe even if no timer is active or pending.
    Clock::cancel(agentRegistrationTimer);

    if (state == TERMINATING) {
      LOG(INFO) << "Skipping registration because agent is terminating";
      return;
    }

    if (requiredMasterCapabilities.agentUpdate) {
      protobuf::master::Capabilities masterCapabilities(
          latest->capabilities());

      if (!masterCapabilities.agentUpdate) {
        EXIT(EXIT_FAILURE) <<
          "Agent state changed on restart, but the detected master lacks the "
          "AGENT_UPDATE capability. Refusing to connect.";
        return;
      }

      if (dynamic_cast<mesos::master::detector::StandaloneMasterDetector*>(
          detector)) {
        LOG(WARNING) <<