shutdownOnCompletion method

@override Future<void> shutdownOnCompletion()

Kill the spawned process after processing current items in queue.

Implementation

@override
Future<void> shutdownOnCompletion() async {
  _isActive = false;

  // Start winding down.
  _toProcessPort.send(shutdownCode);

  // To ensure that the Future completes only when the _isolate has been shutdown.
  return processingIsComplete;
}