Added performance benchmarks for platform channels (#81414)

dev/benchmarks/platform_channels_benchmarks/.metadata

+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: ce18d702e90d3dff9fee53d61a770c94f14f2811
+  channel: master
+
+project_type: app

dev/benchmarks/platform_channels_benchmarks/README.md

+# platform_channels_benchmarks
+
+The harness for running performance benchmark tests for Platform Channels.
+
+If you want to run these benchmarks outside of devicelab you need to first run:
+`flutter create --platforms="ios,android" --no-overwrite .`

dev/benchmarks/platform_channels_benchmarks/android/app/src/main/kotlin/com/example/platform_channels_benchmarks/MainActivity.kt

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package com.example.platform_channels_benchmarks
+
+import io.flutter.embedding.android.FlutterActivity
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.plugin.common.BasicMessageChannel
+import io.flutter.plugin.common.StandardMessageCodec
+
+class MainActivity: FlutterActivity() {
+
+    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
+        val basicStandard = BasicMessageChannel(flutterEngine.dartExecutor, "dev.flutter.echo.basic.standard", StandardMessageCodec.INSTANCE)
+        basicStandard.setMessageHandler { message, reply -> reply.reply(message) }
+        super.configureFlutterEngine(flutterEngine)
+    }
+}

dev/benchmarks/platform_channels_benchmarks/ios/Runner/AppDelegate.swift

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import Flutter
+import UIKit
+
+@UIApplicationMain
+@objc class AppDelegate: FlutterAppDelegate {
+  override func application(
+    _ application: UIApplication,
+    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
+  ) -> Bool {
+    GeneratedPluginRegistrant.register(with: self)
+
+    let registrar = self.registrar(forPlugin: "Echo")!
+    let basicStandard = FlutterBasicMessageChannel(
+      name: "dev.flutter.echo.basic.standard", binaryMessenger: registrar.messenger(),
+      codec: FlutterStandardMessageCodec.sharedInstance())
+    basicStandard.setMessageHandler { (input, reply) in
+      reply(input)
+    }
+
+    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
+  }
+}

dev/benchmarks/platform_channels_benchmarks/lib/main.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:math' as math;
+import 'dart:typed_data';
+
+import 'package:flutter/foundation.dart' show kDebugMode;
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:microbenchmarks/common.dart';
+
+List<Object> _makeTestBuffer(int size) {
+  final List<Object> answer = <Object>[];
+  for (int i = 0; i < size; ++i) {
+    switch (i % 9) {
+      case 0:
+        answer.add(1);
+        break;
+      case 1:
+        answer.add(math.pow(2, 65));
+        break;
+      case 2:
+        answer.add(1234.0);
+        break;
+      case 3:
+        answer.add(null);
+        break;
+      case 4:
+        answer.add(<int>[1234]);
+        break;
+      case 5:
+        answer.add(<String, int>{'hello': 1234});
+        break;
+      case 6:
+        answer.add('this is a test');
+        break;
+      case 7:
+        answer.add(true);
+        break;
+      case 8:
+        answer.add(Uint8List(64));
+        break;
+    }
+  }
+  return answer;
+}
+
+Future<void> _runTests() async {
+  if (kDebugMode) {
+    throw Exception(
+        "Must be run in profile mode! Use 'flutter run --profile'.");
+  }
+  const int numMessages = 2500;
+
+  const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+    'dev.flutter.echo.basic.standard',
+    StandardMessageCodec(),
+  );
+  final Stopwatch watch = Stopwatch();
+
+  watch.start();
+  for (int i = 0; i < numMessages; ++i) {
+    await channel.send(1234);
+  }
+  watch.stop();
+  final double smallPayloadTime = watch.elapsedMicroseconds / numMessages;
+
+  watch.reset();
+  /// WARNING: Don't change the following line of code, it will invalidate
+  /// `Large` tests.  Instead make a different test.  The size of largeBuffer
+  /// serialized is 14214 bytes.
+  final List<Object> largeBuffer = _makeTestBuffer(1000);
+
+  int size = 0;
+  watch.start();
+  for (int i = 0; i < numMessages; ++i) {
+    final List<Object> result = await channel.send(largeBuffer) as List<Object>;
+    // This check should be tiny compared to the actual channel send/receive.
+    size += (result == null) ? 0 : result.length;
+  }
+  watch.stop();
+  final double largePayloadTime = watch.elapsedMicroseconds / numMessages;
+
+  if (size != largeBuffer.length * numMessages) {
+    throw Exception(
+        'There is an error with the echo channel, the results don\'t add up: $size');
+  }
+
+  final BenchmarkResultPrinter printer = BenchmarkResultPrinter();
+  printer.addResult(
+    description: 'BasicMessageChannel/StandardMessageCodec/Flutter->Host/Small',
+    value: smallPayloadTime,
+    unit: 'µs',
+    name: 'platform_channel_basic_standard_2host_small',
+  );
+  printer.addResult(
+    description: 'BasicMessageChannel/StandardMessageCodec/Flutter->Host/Large',
+    value: largePayloadTime,
+    unit: 'µs',
+    name: 'platform_channel_basic_standard_2host_large',
+  );
+  printer.printToStdout();
+}
+
+class _BenchmarkWidget extends StatefulWidget {
+  const _BenchmarkWidget(this.tests, {Key key}) : super(key: key);
+
+  final Future<void> Function() tests;
+
+  @override
+  _BenchmarkWidgetState createState() => _BenchmarkWidgetState();
+}
+
+class _BenchmarkWidgetState extends State<_BenchmarkWidget> {
+  @override
+  void initState() {
+    widget.tests();
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) => Container();
+}
+
+void main() {
+  runApp(const _BenchmarkWidget(_runTests));
+}

dev/benchmarks/platform_channels_benchmarks/pubspec.yaml

+name: platform_channels_benchmarks
+description: Test harness for Platform Channel performance tests.
+publish_to: 'none' # Remove this line if you wish to publish to pub.dev
+
+version: 1.0.0+1
+
+environment:
+  sdk: ">=2.9.0 <3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  microbenchmarks:
+    path: ../microbenchmarks
+  cupertino_icons: 1.0.2
+
+  _fe_analyzer_shared: 21.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  analyzer: 1.5.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  args: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  async: 2.6.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  boolean_selector: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  characters: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  charcode: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  cli_util: 0.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  collection: 1.15.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  convert: 3.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  coverage: 1.0.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  crypto: 3.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  file: 6.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  glob: 2.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http_multi_server: 3.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  http_parser: 4.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  io: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  js: 0.6.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  logging: 1.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  matcher: 0.12.10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  meta: 1.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  mime: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  node_preamble: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  package_config: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  path: 1.8.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pedantic: 1.11.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pool: 1.5.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  pub_semver: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf: 1.1.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_packages_handler: 3.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_static: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  shelf_web_socket: 1.0.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_map_stack_trace: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_maps: 0.10.10 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  source_span: 1.8.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  stack_trace: 1.10.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  stream_channel: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  string_scanner: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  term_glyph: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test: 1.16.8 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_api: 0.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  test_core: 0.3.19 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  typed_data: 1.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vector_math: 2.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  vm_service: 6.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  watcher: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  web_socket_channel: 2.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  webkit_inspection_protocol: 1.0.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  yaml: 3.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+
+  clock: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+  fake_async: 1.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
+
+flutter:
+  uses-material-design: true
+
+# PUBSPEC CHECKSUM: 77ad

dev/devicelab/bin/tasks/platform_channels_benchmarks.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_devicelab/framework/adb.dart'
+    show DeviceOperatingSystem;
+import 'package:flutter_devicelab/framework/framework.dart' show task;
+import 'package:flutter_devicelab/tasks/platform_channels_benchmarks.dart'
+    as platform_channels_benchmarks;
+
+Future<void> main() async {
+  await task(
+      platform_channels_benchmarks.runTask(DeviceOperatingSystem.android));
+}

dev/devicelab/bin/tasks/platform_channels_benchmarks_ios.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_devicelab/framework/adb.dart'
+    show DeviceOperatingSystem;
+import 'package:flutter_devicelab/framework/framework.dart' show task;
+import 'package:flutter_devicelab/tasks/platform_channels_benchmarks.dart'
+    as platform_channels_benchmarks;
+
+Future<void> main() async {
+  await task(platform_channels_benchmarks.runTask(DeviceOperatingSystem.ios));
+}

dev/devicelab/lib/microbenchmarks.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:flutter_devicelab/framework/utils.dart';
+import 'package:path/path.dart' as path;
+
+/// Launches a new Flutter process.
+Future<Process> startFlutter({
+  List<String> options = const <String>[],
+  bool canFail = false,
+  Map<String, String> environment,
+}) {
+  final List<String> args = flutterCommandArgs('run', options);
+  return startProcess(path.join(flutterDirectory.path, 'bin', 'flutter'), args, environment: environment);
+}
+
+/// Reades through the print commands from [process] waiting for the magic phase
+/// that contains microbenchmarks results as defined in
+/// `dev/benchmarks/microbenchmarks/lib/common.dart`.
+Future<Map<String, double>> readJsonResults(Process process) {
+  // IMPORTANT: keep these values in sync with dev/benchmarks/microbenchmarks/lib/common.dart
+  const String jsonStart = '================ RESULTS ================';
+  const String jsonEnd = '================ FORMATTED ==============';
+  const String jsonPrefix = ':::JSON:::';
+  bool jsonStarted = false;
+  final StringBuffer jsonBuf = StringBuffer();
+  final Completer<Map<String, double>> completer = Completer<Map<String, double>>();
+
+  final StreamSubscription<String> stderrSub = process.stderr
+      .transform<String>(const Utf8Decoder())
+      .transform<String>(const LineSplitter())
+      .listen((String line) {
+        stderr.writeln('[STDERR] $line');
+      });
+
+  bool processWasKilledIntentionally = false;
+  bool resultsHaveBeenParsed = false;
+  final StreamSubscription<String> stdoutSub = process.stdout
+      .transform<String>(const Utf8Decoder())
+      .transform<String>(const LineSplitter())
+      .listen((String line) async {
+    print(line);
+
+    if (line.contains(jsonStart)) {
+      jsonStarted = true;
+      return;
+    }
+
+    if (line.contains(jsonEnd)) {
+      final String jsonOutput = jsonBuf.toString();
+
+      // If we end up here and have already parsed the results, it suggests that
+      // we have received output from another test because our `flutter run`
+      // process did not terminate correctly.
+      // https://github.com/flutter/flutter/issues/19096#issuecomment-402756549
+      if (resultsHaveBeenParsed) {
+        throw 'Additional JSON was received after results has already been '
+              'processed. This suggests the `flutter run` process may have lived '
+              'past the end of our test and collected additional output from the '
+              'next test.\n\n'
+              'The JSON below contains all collected output, including both from '
+              'the original test and what followed.\n\n'
+              '$jsonOutput';
+      }
+
+      jsonStarted = false;
+      processWasKilledIntentionally = true;
+      resultsHaveBeenParsed = true;
+      // Sending a SIGINT/SIGTERM to the process here isn't reliable because [process] is
+      // the shell (flutter is a shell script) and doesn't pass the signal on.
+      // Sending a `q` is an instruction to quit using the console runner.
+      // See https://github.com/flutter/flutter/issues/19208
+      process.stdin.write('q');
+      await process.stdin.flush();
+      // Also send a kill signal in case the `q` above didn't work.
+      process.kill(ProcessSignal.sigint);
+      try {
+        completer.complete(Map<String, double>.from(json.decode(jsonOutput) as Map<String, dynamic>));
+      } catch (ex) {
+        completer.completeError('Decoding JSON failed ($ex). JSON string was: $jsonOutput');
+      }
+      return;
+    }
+
+    if (jsonStarted && line.contains(jsonPrefix))
+      jsonBuf.writeln(line.substring(line.indexOf(jsonPrefix) + jsonPrefix.length));
+  });
+
+  process.exitCode.then<void>((int code) async {
+    await Future.wait<void>(<Future<void>>[
+      stdoutSub.cancel(),
+      stderrSub.cancel(),
+    ]);
+    if (!processWasKilledIntentionally && code != 0) {
+      completer.completeError('flutter run failed: exit code=$code');
+    }
+  });
+
+  return completer.future;
+}

dev/devicelab/lib/tasks/microbenchmarks.dart

@@ -3,13 +3,13 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:convert';
 import 'dart:io';
 
 import 'package:flutter_devicelab/framework/adb.dart';
 import 'package:flutter_devicelab/framework/framework.dart';
 import 'package:flutter_devicelab/framework/task_result.dart';
 import 'package:flutter_devicelab/framework/utils.dart';
+import 'package:flutter_devicelab/microbenchmarks.dart';
 import 'package:path/path.dart' as path;
 
 /// Creates a device lab task that runs benchmarks in
@@ -34,14 +34,15 @@ TaskFunction createMicrobenchmarkTask() {
             device.deviceId,
           ];
           options.add(benchmarkPath);
-          return _startFlutter(
+          return startFlutter(
             options: options,
             canFail: false,
           );
         });
 
-        return _readJsonResults(flutterProcess);
+        return readJsonResults(flutterProcess);
       }
+
       return _run();
     }
 
@@ -57,99 +58,9 @@ TaskFunction createMicrobenchmarkTask() {
       ...await _runMicrobench('lib/language/sync_star_semantics_bench.dart'),
       ...await _runMicrobench('lib/foundation/all_elements_bench.dart'),
       ...await _runMicrobench('lib/foundation/change_notifier_bench.dart'),
- };
+    };
 
-    return TaskResult.success(allResults, benchmarkScoreKeys: allResults.keys.toList());
+    return TaskResult.success(allResults,
+        benchmarkScoreKeys: allResults.keys.toList());
   };
 }
-
-Future<Process> _startFlutter({
-  List<String> options = const <String>[],
-  bool canFail = false,
-  Map<String, String> environment,
-}) {
-  final List<String> args = flutterCommandArgs('run', options);
-  return startProcess(path.join(flutterDirectory.path, 'bin', 'flutter'), args, environment: environment);
-}
-
-Future<Map<String, double>> _readJsonResults(Process process) {
-  // IMPORTANT: keep these values in sync with dev/benchmarks/microbenchmarks/lib/common.dart
-  const String jsonStart = '================ RESULTS ================';
-  const String jsonEnd = '================ FORMATTED ==============';
-  const String jsonPrefix = ':::JSON:::';
-  bool jsonStarted = false;
-  final StringBuffer jsonBuf = StringBuffer();
-  final Completer<Map<String, double>> completer = Completer<Map<String, double>>();
-
-  final StreamSubscription<String> stderrSub = process.stderr
-      .transform<String>(const Utf8Decoder())
-      .transform<String>(const LineSplitter())
-      .listen((String line) {
-        stderr.writeln('[STDERR] $line');
-      });
-
-  bool processWasKilledIntentionally = false;
-  bool resultsHaveBeenParsed = false;
-  final StreamSubscription<String> stdoutSub = process.stdout
-      .transform<String>(const Utf8Decoder())
-      .transform<String>(const LineSplitter())
-      .listen((String line) async {
-    print(line);
-
-    if (line.contains(jsonStart)) {
-      jsonStarted = true;
-      return;
-    }
-
-    if (line.contains(jsonEnd)) {
-      final String jsonOutput = jsonBuf.toString();
-
-      // If we end up here and have already parsed the results, it suggests that
-      // we have received output from another test because our `flutter run`
-      // process did not terminate correctly.
-      // https://github.com/flutter/flutter/issues/19096#issuecomment-402756549
-      if (resultsHaveBeenParsed) {
-        throw 'Additional JSON was received after results has already been '
-              'processed. This suggests the `flutter run` process may have lived '
-              'past the end of our test and collected additional output from the '
-              'next test.\n\n'
-              'The JSON below contains all collected output, including both from '
-              'the original test and what followed.\n\n'
-              '$jsonOutput';
-      }
-
-      jsonStarted = false;
-      processWasKilledIntentionally = true;
-      resultsHaveBeenParsed = true;
-      // Sending a SIGINT/SIGTERM to the process here isn't reliable because [process] is
-      // the shell (flutter is a shell script) and doesn't pass the signal on.
-      // Sending a `q` is an instruction to quit using the console runner.
-      // See https://github.com/flutter/flutter/issues/19208
-      process.stdin.write('q');
-      await process.stdin.flush();
-      // Also send a kill signal in case the `q` above didn't work.
-      process.kill(ProcessSignal.sigint);
-      try {
-        completer.complete(Map<String, double>.from(json.decode(jsonOutput) as Map<String, dynamic>));
-      } catch (ex) {
-        completer.completeError('Decoding JSON failed ($ex). JSON string was: $jsonOutput');
-      }
-      return;
-    }
-
-    if (jsonStarted && line.contains(jsonPrefix))
-      jsonBuf.writeln(line.substring(line.indexOf(jsonPrefix) + jsonPrefix.length));
-  });
-
-  process.exitCode.then<void>((int code) async {
-    await Future.wait<void>(<Future<void>>[
-      stdoutSub.cancel(),
-      stderrSub.cancel(),
-    ]);
-    if (!processWasKilledIntentionally && code != 0) {
-      completer.completeError('flutter run failed: exit code=$code');
-    }
-  });
-
-  return completer.future;
-}

dev/devicelab/lib/tasks/platform_channels_benchmarks.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:io' show Process, Directory;
+
+import 'package:flutter_devicelab/framework/adb.dart' as adb;
+import 'package:flutter_devicelab/framework/framework.dart' show TaskFunction;
+import 'package:flutter_devicelab/framework/task_result.dart' show TaskResult;
+import 'package:flutter_devicelab/framework/utils.dart' as utils;
+import 'package:flutter_devicelab/microbenchmarks.dart' as microbenchmarks;
+import 'package:path/path.dart' as path;
+
+TaskFunction runTask(adb.DeviceOperatingSystem operatingSystem) {
+  return () async {
+    adb.deviceOperatingSystem = operatingSystem;
+    final adb.Device device = await adb.devices.workingDevice;
+    await device.unlock();
+
+    final Directory appDir = utils.dir(path.join(utils.flutterDirectory.path,
+        'dev/benchmarks/platform_channels_benchmarks'));
+    final Process flutterProcess = await utils.inDirectory(appDir, () async {
+      final String flutterExe =
+          path.join(utils.flutterDirectory.path, 'bin', 'flutter');
+      final List<String> createArgs = <String>[
+        'create',
+        '--platforms',
+        'ios,android',
+        '--no-overwrite',
+        '-v',
+        '.'
+      ];
+      print('\nExecuting: $flutterExe $createArgs $appDir');
+      utils.eval(flutterExe, createArgs);
+
+      final List<String> options = <String>[
+        '-v',
+        // --release doesn't work on iOS due to code signing issues
+        '--profile',
+        '--no-publish-port',
+        '-d',
+        device.deviceId,
+      ];
+      return microbenchmarks.startFlutter(
+        options: options,
+        canFail: false,
+      );
+    });
+
+    final Map<String, double> results =
+        await microbenchmarks.readJsonResults(flutterProcess);
+    return TaskResult.success(results,
+        benchmarkScoreKeys: results.keys.toList());
+  };
+}

dev/prod_builders.json

@@ -372,6 +372,12 @@
       "task_name": "linux_picture_cache_perf__e2e_summary",
       "flaky": false
     },
+    {
+      "name": "Linux platform channels benchmarks",
+      "repo": "flutter",
+      "task_name": "linux_platform_channels_benchmarks",
+      "flaky": true
+    },
     {
       "name": "Linux platform_views_scroll_perf__timeline_summary",
       "repo": "flutter",
@@ -1152,6 +1158,12 @@
       "task_name": "mac_ios_platform_channel_sample_test_swift",
       "flaky": false
     },
+    {
+      "name": "Mac_ios platform channels benchmarks",
+      "repo": "flutter",
+      "task_name": "mac_ios_platform_channels_benchmarks",
+      "flaky": true
+    },
     {
       "name": "Mac_ios platform_interaction_test_ios",
       "repo": "flutter",