How is interaction with isolators implemented in the system?

In Flutter, interaction with isolates is carried out through message passing, as isolates do not share memory and run in separate threads.

The main steps for interacting with isolates:

1. Creating an isolate — a new isolate is launched using the Isolate.spawn() function, which is passed a function and initial data.

2. Sending messages — objects SendPort and ReceivePort are used for data exchange between the main thread and the isolate.

3. Processing messages — the isolate listens for incoming messages via ReceivePort and sends responses through SendPort.

Example of interaction:

import 'dart:isolate';

void isolateEntry(SendPort mainSendPort) {
  final port = ReceivePort();
  mainSendPort.send(port.sendPort);

  port.listen((message) {
    final data = message[0] as int;
    final replyPort = message[1] as SendPort;
    // Perform some work
    final result = data * 2;
    replyPort.send(result);
  });
}

void main() async {
  final receivePort = ReceivePort();
  await Isolate.spawn(isolateEntry, receivePort.sendPort);

  final sendPort = await receivePort.first as SendPort;
  final response = ReceivePort();

  sendPort.send([10, response.sendPort]);
  final result = await response.first;
  print('Result from isolate: $result'); // Result from isolate: 20
}

Thus, interaction with isolates is built on message exchange through ports, which ensures safety and parallelism without shared memory.