flutter code for 2 way isolate communication

To establish two-way isolate communication in Flutter, you can use Flutter's Isolate class along with the SendPort and ReceivePort classes. Here's an example code snippet:

 
import 'dart:isolate';

void main() async {
  ReceivePort mainReceivePort = ReceivePort();

  Isolate isolate = await Isolate.spawn(isolateFunction, mainReceivePort.sendPort);

  mainReceivePort.listen((message) {
    print('Received message from isolate: $message');
  });

  SendPort isolateSendPort = await mainReceivePort.first;

  isolateSendPort.send('Hello from main isolate!');
}

void isolateFunction(SendPort mainSendPort) {
  ReceivePort isolateReceivePort = ReceivePort();

  mainSendPort.send(isolateReceivePort.sendPort);

  isolateReceivePort.listen((message) {
    print('Received message in isolate: $message');
    mainSendPort.send('Hello from isolate!');
  });
}

In this example, the main isolate creates a ReceivePort (mainReceivePort) to receive messages from the spawned isolate. The main isolate spawns a new isolate by calling Isolate.spawn() and passes the SendPort of the mainReceivePort to the new isolate.

The spawned isolate receives the SendPort from the main isolate through the isolateFunction. It then creates a ReceivePort (isolateReceivePort) to receive messages from the main isolate. The spawned isolate sends its isolateReceivePort SendPort back to the main isolate.

Both isolates listen to their respective ReceivePort instances for incoming messages. When a message is received in either isolate, it can be processed accordingly. In this example, the main isolate sends a message to the spawned isolate, and the spawned isolate responds back to the main isolate.

Remember to import the necessary libraries:

 
import 'dart:isolate';

This example demonstrates a basic two-way communication setup between two isolates in Flutter. You can expand on this code to implement more complex communication patterns or handle different types of messages as per your specific requirements.

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In Flutter, you can use the flutter_isolate package to achieve two-way communication between isolates. Here's an example of how you can set up two isolates and communicate between them:

1. Add the flutter_isolate package to your pubspec.yaml file:

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dependencies:
  flutter_isolate: ^2.0.0

1. Import the necessary packages in your Dart file:

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import 'package:flutter_isolate/flutter_isolate.dart';
import 'package:flutter_isolate/isolate_runner.dart';

1. Create a function that will run in the first isolate:

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void firstIsolate(SendPort mainToIsolateStream) {
  // Create a receive port to listen for messages from the main isolate
  ReceivePort isolateToMainStream = ReceivePort();

  // Send the receive port back to the main isolate
  mainToIsolateStream.send(isolateToMainStream.sendPort);

  // Listen for messages from the main isolate
  isolateToMainStream.listen((message) {
    print('Message from main isolate: $message');

    // Send a response back to the main isolate
    mainToIsolateStream.send('Response from first isolate');
  });
}

1. Create a function that will run in the second isolate:

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void secondIsolate(SendPort mainToIsolateStream) {
  // Create a receive port to listen for messages from the main isolate
  ReceivePort isolateToMainStream = ReceivePort();

  // Send the receive port back to the main isolate
  mainToIsolateStream.send(isolateToMainStream.sendPort);

  // Listen for messages from the main isolate
  isolateToMainStream.listen((message) {
    print('Message from main isolate: $message');

    // Send a response back to the main isolate
    mainToIsolateStream.send('Response from second isolate');
  });
}

1. Set up the two isolates and communication in your Flutter widget:

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import 'package:flutter/material.dart';

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  SendPort firstIsolateToMainStream;
  SendPort secondIsolateToMainStream;

  @override
  void initState() {
    super.initState();

    // Set up the first isolate
    FlutterIsolate.spawn(firstIsolate).then((isolate) {
      // Receive the send port from the first isolate
      isolate.addOnExitListener().then((_) {
        print('First isolate exited');
      });
      isolate.listen((message) {
        if (message is SendPort) {
          firstIsolateToMainStream = message;
        } else {
          print('Response from first isolate: $message');
        }
      });
    });

    // Set up the second isolate
    FlutterIsolate.spawn(secondIsolate).then((isolate) {
      // Receive the send port from the second isolate
      isolate.addOnExitListener().then((_) {
        print('Second isolate exited');
      });
      isolate.listen((message) {
        if (message is SendPort) {
          secondIsolateToMainStream = message;
        } else {
          print('Response from second isolate: $message');
        }
      });
    });
  }

  void sendMessageToFirstIsolate(String message) {
    if (firstIsolateToMainStream != null) {
      firstIsolateToMainStream.send(message);
    }
  }

  void sendMessageToSecondIsolate(String message) {
    if (secondIsolateToMainStream != null) {
      secondIsolateToMainStream.send(message);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            RaisedButton(
              onPressed: () {
                sendMessageToFirstIsolate('Hello from main isolate');
              },
              child: Text('Send message to first isolate'),
            ),
            RaisedButton(
              onPressed: () {
                sendMessageToSecondIsolate('Hello from main isolate');
              },
              child: Text('Send message to second isolate'),
            ),
          ],
        ),
      ),
    );
  }
}

In this example, the firstIsolate and secondIsolate functions run in separate isolates and establish communication with the main isolate through SendPorts. The main isolate can send messages to the first and second isolates using the sendMessageToFirstIsolate and sendMessageToSecondIsolate functions, respectively. The isolates listen for messages and can send responses back to the main isolate.