Method Open

be/src/exec/hdfs-scan-node.cc:164–173

This function registers the ThreadTokenAvailableCb to start up the initial scanner threads. Scan ranges are not issued until the first GetNext() call; scanner threads will block on ranges_issued_barrier_ until ranges are issued.

// threads. Scan ranges are not issued until the first GetNext() call; scanner threads
// will block on ranges_issued_barrier_ until ranges are issued.
Status HdfsScanNode::Open(RuntimeState* state) {
  SCOPED_TIMER(runtime_profile_->total_time_counter());
  ScopedOpenEventAdder ea(this);
  RETURN_IF_ERROR(HdfsScanNodeBase::Open(state));
  thread_state_.Open(this, FLAGS_max_row_batches);

  thread_avail_cb_id_ = runtime_state_->resource_pool()->AddThreadAvailableCb(
      bind<void>(mem_fn(&HdfsScanNode::ThreadTokenAvailableCb), this, _1));
  return Status::OK();
}

void HdfsScanNode::Close(RuntimeState* state) {
  if (is_closed()) return;