Function synchronized

src/sched/sched.cpp:2080–2167

Status MesosSchedulerDriver::start()
{
  synchronized (mutex) {
    if (status != DRIVER_NOT_STARTED) {
      return status;
    }

    if (detector == nullptr) {
      Try<shared_ptr<MasterDetector>> detector_ = DetectorPool::get(url);

      if (detector_.isError()) {
        status = DRIVER_ABORTED;
        string message = "Failed to create a master detector for '" +
        master + "': " + detector_.error();
        scheduler->error(this, message);
        return status;
      }

      // Save the detector so we can delete it later.
      detector = detector_.get();
    }

    // Load scheduler flags.
    internal::scheduler::Flags flags;
    Try<flags::Warnings> load = flags.load("MESOS_");

    if (load.isError()) {
      status = DRIVER_ABORTED;
      scheduler->error(this, load.error());
      return status;
    }

    // Log any flag warnings.
    foreach (const flags::Warning& warning, load->warnings) {
      LOG(WARNING) << warning.message;
    }

    // Initialize modules. Note that since other subsystems may depend
    // upon modules, we should initialize modules before anything else.
    if (flags.modules.isSome() && flags.modulesDir.isSome()) {
      status = DRIVER_ABORTED;
      scheduler->error(
          this,
          "Only one of MESOS_MODULES or MESOS_MODULES_DIR should be specified");
      return status;
    }

    if (flags.modulesDir.isSome()) {
      Try<Nothing> result =
        modules::ModuleManager::load(flags.modulesDir.get());
      if (result.isError()) {
        status = DRIVER_ABORTED;
        scheduler->error(this, "Error loading modules: " + result.error());
        return status;
      }
    }

    if (flags.modules.isSome()) {
      Try<Nothing> result = modules::ModuleManager::load(flags.modules.get());
      if (result.isError()) {