medium_01_isolates_spawn.dart

import 'dart:async';
import 'dart:io';

import 'dart:isolate';

main(List<String> args) async {
  Isolate timerIsolate;
  final mainControlPort = ReceivePort();

  // Creates a new isolate
  // Once it's start, it will run the "timerTick" function and
  // the param will be the "mainControlPort.sendPort".
  // This away it can send messages back to the "parent" main Isolate when needed
  timerIsolate = await Isolate.spawn(
    timerTick,
    mainControlPort.sendPort,
    debugName: "TimerIsolate",
  );
}

void timerTick(SendPort mainPort) async {
  stdout.writeln(Isolate.current.debugName + " started");

  Timer.periodic(Duration(seconds: 1), (timer) {
    final ts = DateTime.now().toIso8601String();
    stdout.writeln("sending back to MainIsolate: " + ts);
    mainPort.send(ts);
  });
}