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Revert "const vs. non-const widget build benchmark" (#148970)

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Reverts flutter/flutter#148261

For some reason, the benchmark is flaky only on iOS. Android runs are fine. See https://github.com/flutter/flutter/issues/148845.

Closes https://github.com/flutter/flutter/issues/148845.
This commit is contained in:
Michael Goderbauer
2024-05-23 11:20:53 -07:00
committed by GitHub
parent 2025ebe767
commit 6cdb632970
2 changed files with 0 additions and 230 deletions
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229
dev/benchmarks/microbenchmarks/lib/building/const_vs_non_const_bench.dart
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@@ -1,229 +0,0 @@
// 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';
import 'package:flutter_test/flutter_test.dart';
import '../common.dart';
const Duration kBenchmarkTime = Duration(seconds: 15);
Future<List<double>> runBuildBenchmark(ValueGetter<Widget> buildApp) async {
assert(false, "Don't run benchmarks in debug mode! Use 'flutter run --release'.");
// We control the framePolicy below to prevent us from scheduling frames in
// the engine, so that the engine does not interfere with our timings.
final LiveTestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized() as LiveTestWidgetsFlutterBinding;
final Stopwatch watch = Stopwatch();
int iterations = 0;
final List<double> values = <double>[];
await benchmarkWidgets((WidgetTester tester) async {
await tester.pumpWidget(buildApp());
await tester.pump();
await tester.pumpAndSettle(const Duration(seconds: 1));
// Cannot use expects/asserts here since this is running outside of a test
// in release mode.
final int numberOfSizedBoxes = find.byType(SizedBox).evaluate().length;
if (numberOfSizedBoxes != 30) {
throw StateError('Expected 30 SizedBox widgets, but only found $numberOfSizedBoxes.');
}
if (find.text('testToken').evaluate().length != 1) {
throw StateError('Did not find expected leaf widget.');
}
final Element rootWidget = tester.element(find.byKey(rootKey));
Duration elapsed = Duration.zero;
final LiveTestWidgetsFlutterBindingFramePolicy defaultPolicy = binding.framePolicy;
binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.benchmark;
while (elapsed < kBenchmarkTime) {
watch.reset();
watch.start();
rootWidget.markNeedsBuild();
await tester.pumpBenchmark(Duration(milliseconds: iterations * 16));
watch.stop();
iterations += 1;
elapsed += Duration(microseconds: watch.elapsedMicroseconds);
values.add(watch.elapsedMicroseconds.toDouble());
}
binding.framePolicy = defaultPolicy;
});
return values;
}
double calculateMean(List<double> values) {
return values.reduce((double x, double y) => x + y) / values.length;
}
Future<void> main() async {
final BenchmarkResultPrinter printer = BenchmarkResultPrinter();
final double constMean = calculateMean(await runBuildBenchmark(() => ConstApp(key: rootKey)));
final double nonConstMean = calculateMean(await runBuildBenchmark(() => NonConstApp(key: rootKey)));
printer.addResult(
description: 'const app build',
value: constMean,
unit: 'µs per iteration',
name: 'const_app_build_iteration',
);
printer.addResult(
description: 'non-const app build',
value: nonConstMean,
unit: 'µs per iteration',
name: 'non_const_app_build_iteration',
);
printer.addResult(
description: 'const speed-up (vs. non-const)',
value: ((nonConstMean - constMean) / constMean) * 100,
unit: '%',
name: 'const_speed_up',
);
printer.printToStdout();
}
final Key rootKey = UniqueKey();
class ConstApp extends StatelessWidget {
const ConstApp({super.key});
@override
Widget build(BuildContext context) {
return const SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: SizedBox(
child: Text('testToken', textDirection: TextDirection.ltr),
),
),
),
),
),
),
),
),
),
),
),
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),
),
),
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),
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);
}
}
class NonConstApp extends StatelessWidget {
const NonConstApp({super.key});
@override
Widget build(BuildContext context) {
// The explicit goal is to test the performance of non-const widgets,
// hence all these ignores.
return SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: SizedBox( // ignore: prefer_const_constructors
child: Text('testToken', textDirection: TextDirection.ltr), // ignore: prefer_const_constructors
),
),
),
),
),
),
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),
),
),
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),
),
),
);
}
}

1
dev/devicelab/lib/tasks/microbenchmarks.dart
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@@ -75,7 +75,6 @@ TaskFunction createMicrobenchmarkTask({
...await runMicrobench('lib/stocks/layout_bench.dart'),
...await runMicrobench('lib/ui/image_bench.dart'),
...await runMicrobench('lib/layout/text_intrinsic_bench.dart'),
...await runMicrobench('lib/building/const_vs_non_const_bench.dart'),
};
return TaskResult.success(allResults,