Method Cancel

be/src/runtime/coordinator.cc:1105–1119

}

void Coordinator::Cancel(bool wait_until_finalized) {
  // Illegal to call Cancel() before Exec() returns, so there's no danger of the cancel
  // RPC passing the exec RPC.
  DCHECK(exec_rpcs_complete_.Load()) << "Exec() must be called first";
  discard_result(SetNonErrorTerminalState(ExecState::CANCELLED));
  // CancelBackends() is called for all transitions into a terminal state.
  // RETURNED_RESULTS, however, calls it with fire_and_forget=false and may be blocked
  // waiting for cancellation. In that case, we want explicit cancellation to unblock
  // backend_exec_complete_barrier_, which we do by forcing cancellation.
  if (ReturnedAllResults()) CancelBackends(/*fire_and_forget=*/ true);

  // IMPALA-5756: Wait until finalized, in case a different thread was handling the
  // transition to the terminal state.
  if (wait_until_finalized) finalized_.Get();
}

void Coordinator::CancelBackends(bool fire_and_forget) {
  int num_cancelled = 0;