benchmark memory usage for grid view of memory intensive widgets (flu…

…tter#61025)

dev/benchmarks/macrobenchmarks/lib/common.dart

@@ -15,5 +15,6 @@ const String kColorFilterAndFadeRouteName = '/color_filter_and_fade';
 const String kFadingChildAnimationRouteName = '/fading_child_animation';
 const String kImageFilteredTransformAnimationRouteName = '/imagefiltered_transform_animation';
 const String kMultiWidgetConstructionRouteName = '/multi_widget_construction';
+const String kHeavyGridViewRouteName = '/heavy_gridview';
 
 const String kScrollableName = '/macrobenchmark_listview';

dev/benchmarks/macrobenchmarks/lib/main.dart

@@ -4,6 +4,7 @@
 
 import 'package:flutter/material.dart';
 import 'package:macrobenchmarks/src/color_filter_and_fade.dart';
+import 'package:macrobenchmarks/src/heavy_grid_view.dart';
 import 'package:macrobenchmarks/src/large_images.dart';
 import 'package:macrobenchmarks/src/picture_cache.dart';
 
@@ -45,6 +46,7 @@ class MacrobenchmarksApp extends StatelessWidget {
         kFadingChildAnimationRouteName: (BuildContext context) => const FilteredChildAnimationPage(FilterType.opacity),
         kImageFilteredTransformAnimationRouteName: (BuildContext context) => const FilteredChildAnimationPage(FilterType.rotateFilter),
         kMultiWidgetConstructionRouteName: (BuildContext context) => const MultiWidgetConstructTable(10, 20),
+        kHeavyGridViewRouteName: (BuildContext context) => HeavyGridViewPage(),
       },
     );
   }
@@ -151,6 +153,13 @@ class HomePage extends StatelessWidget {
               Navigator.pushNamed(context, kMultiWidgetConstructionRouteName);
             },
           ),
+          RaisedButton(
+            key: const Key(kHeavyGridViewRouteName),
+            child: const Text('Heavy Grid View'),
+            onPressed: () {
+              Navigator.pushNamed(context, kHeavyGridViewRouteName);
+            },
+          ),
         ],
       ),
     );

dev/benchmarks/macrobenchmarks/lib/src/heavy_grid_view.dart

@@ -0,0 +1,32 @@
+// 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/material.dart';
+
+class HeavyGridViewPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return GridView.builder(
+      itemCount: 1000,
+      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 3),
+      itemBuilder: (BuildContext context, int index) => HeavyWidget(index),
+    ).build(context);
+  }
+}
+
+class HeavyWidget extends StatelessWidget {
+  HeavyWidget(this.index) : super(key: ValueKey<int>(index));
+
+  final int index;
+  final List<int> _weight = List<int>(1000000);
+
+  @override
+  Widget build(BuildContext context) {
+    return SizedBox(
+      width: 200,
+      height: 200,
+      child: Text('$index: ${_weight.length}'),
+    );
+  }
+}

dev/benchmarks/macrobenchmarks/test_memory/heavy_gridview.dart

@@ -0,0 +1,24 @@
+// 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 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:macrobenchmarks/common.dart';
+import 'package:macrobenchmarks/main.dart';
+
+Future<void> endOfAnimation() async {
+  do {
+    await SchedulerBinding.instance.endOfFrame;
+  } while (SchedulerBinding.instance.hasScheduledFrame);
+}
+
+Future<void> main() async {
+  runApp(const MacrobenchmarksApp(initialRoute: kHeavyGridViewRouteName));
+  await endOfAnimation();
+  await Future<void>.delayed(const Duration(milliseconds: 50));
+  debugPrint('==== MEMORY BENCHMARK ==== READY ====');
+}

dev/devicelab/bin/tasks/fast_scroll_heavy_gridview__memory.dart

@@ -0,0 +1,45 @@
+// 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 'package:flutter_devicelab/framework/adb.dart';
+import 'package:flutter_devicelab/framework/framework.dart';
+import 'package:flutter_devicelab/framework/utils.dart';
+import 'package:flutter_devicelab/tasks/perf_tests.dart';
+
+const String kPackageName = 'com.example.macrobenchmarks';
+const String kActivityName = 'com.example.macrobenchmarks.MainActivity';
+
+class FastScrollHeavyGridViewMemoryTest extends MemoryTest {
+  FastScrollHeavyGridViewMemoryTest()
+      : super(
+          '${flutterDirectory.path}/dev/benchmarks/macrobenchmarks',
+          'test_memory/heavy_gridview.dart', kPackageName,
+        );
+
+  @override
+  AndroidDevice get device => super.device as AndroidDevice;
+
+  @override
+  int get iterationCount => 5;
+
+  @override
+  Future<void> useMemory() async {
+    await launchApp();
+    await recordStart();
+    await device.shellExec('input', <String>['swipe', '50 1500 50 50 50']);
+    await Future<void>.delayed(const Duration(milliseconds: 1500));
+    await device.shellExec('input', <String>['swipe', '50 1500 50 50 50']);
+    await Future<void>.delayed(const Duration(milliseconds: 1500));
+    await device.shellExec('input', <String>['swipe', '50 1500 50 50 50']);
+    await Future<void>.delayed(const Duration(milliseconds: 1500));
+    await recordEnd();
+  }
+}
+
+Future<void> main() async {
+  deviceOperatingSystem = DeviceOperatingSystem.android;
+  await task(FastScrollHeavyGridViewMemoryTest().run);
+}

dev/devicelab/manifest.yaml

@@ -803,6 +803,14 @@ tasks:
     stage: devicelab
     required_agent_capabilities: ["mac/android"]
 
+  fast_scroll_heavy_gridview__memory:
+    description: >
+      Measures memory usage for scrolling through a grid view of heavy memory
+      usage widgets.
+    stage: devicelab
+    required_agent_capabilities: ["linux/android"]
+    flaky: true
+
   animated_placeholder_perf:
     description: >
       Measures frame build and rasterizer times, as well as frame build counts