When I want to call a method channel from a spawned isolate using isolate_handler (because it doesn't work using dart's isolates), I get a MissingPluginException which doesn't happen when calling method channel from the main isolate.
class TestingIsolate {
static int _callCount = 0;
static int _lastNumber = 0;
final _isolates = IsolateHandler();
final resultStreamController = StreamController<double>();
static void _entryPoint(Map<String, dynamic> context) {
final messenger = HandledIsolate.initialize(context);
_startTesting(messenger);
}
Stream<double> init() {
_isolates.spawn<double>(_entryPoint,
onReceive: (result) => resultStreamController.add(result));
return resultStreamController.stream;
}
static const platform =
MethodChannel('com.mycompany.plugin_performance_test_poc');
static void _startTesting(HandledIsolateMessenger messenger) {
// Timer.periodic(const Duration(seconds: 1), (timer) {
// messenger.send(_callCount / timer.tick);
// });
final stopwatch = Stopwatch();
stopwatch.start();
while (stopwatch.elapsedMilliseconds < 3000) {
platform.invokeMethod('performanceTest', {'data': _lastNumber}).then(
(result) {
print("inside, $_lastNumber");
_lastNumber = result;
_callCount++;
});
}
stopwatch.stop();
messenger.send(_callCount * 3000 / stopwatch.elapsedMilliseconds);
}
}
I'm trying to test how many times can I run method channel per second.
Here's the UI part:
import 'package:async/async.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_performance_test_poc/testing_isolate.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
double _counter = 0;
Future<void> _executeTest() async {
TestingIsolate().init().listen((result) {
setState(() {
_counter = result;
});
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wireframe for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'The plugin has been called this many times per second:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _executeTest,
tooltip: 'Increment',
child: const Icon(Icons.play_arrow),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
And A native part of the code for android:
class MainActivity: FlutterActivity() {
private val CHANNEL = "com.mycompany.plugin_performance_test_poc"
override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
super.configureFlutterEngine(flutterEngine)
MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler {
call, result ->
if (call.method == "performanceTest") {
if (call.hasArgument("data")) {
result.success(call.argument<Int>("data") as Int + 1)
}
} else {
result.notImplemented()
}
}
}
}
