[benchmarks] Add micro-benchmark for async/await with live variables
Issue: https://github.com/dart-lang/sdk/issues/48594
Issue: https://github.com/dart-lang/sdk/issues/48378
Change-Id: Ib5bd65c149342bb5d9bb2b5176a4a3b968a08a81
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/238980
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
diff --git a/benchmarks/AsyncLiveVars/dart/AsyncLiveVars.dart b/benchmarks/AsyncLiveVars/dart/AsyncLiveVars.dart
new file mode 100644
index 0000000..7969da6
--- /dev/null
+++ b/benchmarks/AsyncLiveVars/dart/AsyncLiveVars.dart
@@ -0,0 +1,305 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Micro-benchmark for testing async/await performance in presence of
+// different number of live values across await.
+
+import 'dart:async';
+
+import 'async_benchmark_base.dart' show AsyncBenchmarkBase;
+
+class MockClass {
+ static final String str = "${int.parse('42')}";
+ static final List<int> list =
+ List<int>.filled(int.parse('3'), int.parse('42'));
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ String get1() => str;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ List<int> get2() => list;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use1(String a0) => a0.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use2(String a0, List<int> a1) => a0.length + a1.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use4(String a0, List<int> a1, String a2, List<int> a3) =>
+ a0.length + a1.length + a2.length + a3.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use8(String a0, List<int> a1, String a2, List<int> a3, String a4,
+ List<int> a5, String a6, List<int> a7) =>
+ a0.length +
+ a1.length +
+ a2.length +
+ a3.length +
+ a4.length +
+ a5.length +
+ a6.length +
+ a7.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ Future<void> asyncMethod() async {}
+}
+
+class MockClass2 {
+ static int val1 = int.parse('42');
+ static int val2 = int.parse('43');
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ int get1() => val1;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ int get2() => val2;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use1(int a0) => a0;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use2(int a0, int a1) => a0 + a1;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use4(int a0, int a1, int a2, int a3) => a0 + a1 + a2 + a3;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ Future<void> asyncMethod() async {}
+}
+
+class LiveVarsBench extends AsyncBenchmarkBase {
+ LiveVarsBench(String name) : super(name);
+ @override
+ Future<void> exercise() async {
+ // These micro-benchmarks are too small, so
+ // make a larger number of iterations per measurement.
+ for (var i = 0; i < 10000; i++) {
+ await run();
+ }
+ }
+}
+
+class LiveObj1 extends LiveVarsBench {
+ LiveObj1() : super('AsyncLiveVars.LiveObj1');
+ final field1 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ }
+}
+
+class LiveObj2 extends LiveVarsBench {
+ LiveObj2() : super('AsyncLiveVars.LiveObj2');
+ final field1 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use2(obj1, obj2);
+ }
+}
+
+class LiveObj4 extends LiveVarsBench {
+ LiveObj4() : super('AsyncLiveVars.LiveObj4');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field2.use1(obj3);
+ await field2.asyncMethod();
+ field1.use4(obj1, obj2, obj3, obj4);
+ }
+}
+
+class LiveObj8 extends LiveVarsBench {
+ LiveObj8() : super('AsyncLiveVars.LiveObj8');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ final field3 = MockClass();
+ final field4 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ final obj5 = field3.get1();
+ final obj6 = field3.get2();
+ final obj7 = field4.get1();
+ final obj8 = field4.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field2.asyncMethod();
+ field3.use2(obj5, obj6);
+ await field4.asyncMethod();
+ field2.use8(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8);
+ }
+}
+
+class LiveObj16 extends LiveVarsBench {
+ LiveObj16() : super('AsyncLiveVars.LiveObj16');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ final field3 = MockClass();
+ final field4 = MockClass();
+ final field5 = MockClass();
+ final field6 = MockClass();
+ final field7 = MockClass();
+ final field8 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ final obj5 = field3.get1();
+ final obj6 = field3.get2();
+ final obj7 = field4.get1();
+ final obj8 = field4.get2();
+ final obj9 = field5.get1();
+ final obj10 = field5.get2();
+ final obj11 = field6.get1();
+ final obj12 = field6.get2();
+ final obj13 = field7.get1();
+ final obj14 = field7.get2();
+ final obj15 = field8.get1();
+ final obj16 = field8.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field2.asyncMethod();
+ field5.use2(obj11, obj12);
+ await field4.asyncMethod();
+ field2.use8(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8);
+ field3.use8(obj9, obj10, obj11, obj12, obj13, obj14, obj15, obj16);
+ }
+}
+
+class LiveInt1 extends LiveVarsBench {
+ LiveInt1() : super('AsyncLiveVars.LiveInt1');
+ final field1 = MockClass2();
+ @override
+ Future<void> run() async {
+ final int1 = field1.get1();
+ await field1.asyncMethod();
+ field1.use1(int1);
+ await field1.asyncMethod();
+ field1.use1(int1);
+ await field1.asyncMethod();
+ field1.use1(int1);
+ }
+}
+
+class LiveInt4 extends LiveVarsBench {
+ LiveInt4() : super('AsyncLiveVars.LiveInt4');
+ final field1 = MockClass2();
+ final field2 = MockClass2();
+ @override
+ Future<void> run() async {
+ final int1 = field1.get1();
+ final int2 = field1.get2();
+ final int3 = field2.get1();
+ final int4 = field2.get2();
+ await field1.asyncMethod();
+ field1.use1(int1);
+ await field1.asyncMethod();
+ field2.use1(int3);
+ await field2.asyncMethod();
+ field1.use4(int1, int2, int3, int4);
+ }
+}
+
+class LiveObj2Int2 extends LiveVarsBench {
+ LiveObj2Int2() : super('AsyncLiveVars.LiveObj2Int2');
+ final field1 = MockClass();
+ final field2 = MockClass2();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final int1 = field2.get1();
+ final int2 = field2.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field2.use1(int1);
+ await field2.asyncMethod();
+ field1.use2(obj1, obj2);
+ field2.use2(int1, int2);
+ }
+}
+
+class LiveObj4Int4 extends LiveVarsBench {
+ LiveObj4Int4() : super('AsyncLiveVars.LiveObj4Int4');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ final field3 = MockClass2();
+ final field4 = MockClass2();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ final int1 = field3.get1();
+ final int2 = field3.get2();
+ final int3 = field4.get1();
+ final int4 = field4.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field2.asyncMethod();
+ field3.use2(int2, int4);
+ await field4.asyncMethod();
+ field2.use4(obj1, obj2, obj3, obj4);
+ field4.use4(int1, int2, int3, int4);
+ }
+}
+
+Future<void> main() async {
+ final benchmarks = [
+ LiveObj1(),
+ LiveObj2(),
+ LiveObj4(),
+ LiveObj8(),
+ LiveObj16(),
+ LiveInt1(),
+ LiveInt4(),
+ LiveObj2Int2(),
+ LiveObj4Int4()
+ ];
+ for (final bench in benchmarks) {
+ await bench.report();
+ }
+}
diff --git a/benchmarks/AsyncLiveVars/dart/async_benchmark_base.dart b/benchmarks/AsyncLiveVars/dart/async_benchmark_base.dart
new file mode 100644
index 0000000..9a415b9
--- /dev/null
+++ b/benchmarks/AsyncLiveVars/dart/async_benchmark_base.dart
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. 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:benchmark_harness/benchmark_harness.dart'
+ show PrintEmitter, ScoreEmitter;
+
+// Similar to BenchmarkBase from package:benchmark_harness.
+class AsyncBenchmarkBase {
+ final String name;
+ final ScoreEmitter emitter;
+
+ // Empty constructor.
+ const AsyncBenchmarkBase(this.name, {this.emitter = const PrintEmitter()});
+
+ // The benchmark code.
+ // This function is not used, if both [warmup] and [exercise] are overwritten.
+ Future<void> run() async {}
+
+ // Runs a short version of the benchmark. By default invokes [run] once.
+ Future<void> warmup() async {
+ await run();
+ }
+
+ // Exercises the benchmark. By default invokes [run] 10 times.
+ Future<void> exercise() async {
+ for (var i = 0; i < 10; i++) {
+ await run();
+ }
+ }
+
+ // Not measured setup code executed prior to the benchmark runs.
+ Future<void> setup() async {}
+
+ // Not measures teardown code executed after the benchark runs.
+ Future<void> teardown() async {}
+
+ // Measures the score for this benchmark by executing it repeatedly until
+ // time minimum has been reached.
+ static Future<double> measureFor(Function f, int minimumMillis) async {
+ final int minimumMicros = minimumMillis * 1000;
+ int iter = 0;
+ final watch = Stopwatch();
+ watch.start();
+ int elapsed = 0;
+ while (elapsed < minimumMicros) {
+ await f();
+ elapsed = watch.elapsedMicroseconds;
+ iter++;
+ }
+ return elapsed / iter;
+ }
+
+ // Measures the score for the benchmark and returns it.
+ Future<double> measure() async {
+ await setup();
+ // Warmup for at least 100ms. Discard result.
+ await measureFor(warmup, 100);
+ // Run the benchmark for at least 2000ms.
+ final result = await measureFor(exercise, 2000);
+ await teardown();
+ return result;
+ }
+
+ Future<void> report() async {
+ emitter.emit(name, await measure());
+ }
+}
diff --git a/benchmarks/AsyncLiveVars/dart2/AsyncLiveVars.dart b/benchmarks/AsyncLiveVars/dart2/AsyncLiveVars.dart
new file mode 100644
index 0000000..9176274
--- /dev/null
+++ b/benchmarks/AsyncLiveVars/dart2/AsyncLiveVars.dart
@@ -0,0 +1,307 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Micro-benchmark for testing async/await performance in presence of
+// different number of live values across await.
+
+// @dart=2.9
+
+import 'dart:async';
+
+import 'async_benchmark_base.dart' show AsyncBenchmarkBase;
+
+class MockClass {
+ static final String str = "${int.parse('42')}";
+ static final List<int> list =
+ List<int>.filled(int.parse('3'), int.parse('42'));
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ String get1() => str;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ List<int> get2() => list;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use1(String a0) => a0.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use2(String a0, List<int> a1) => a0.length + a1.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use4(String a0, List<int> a1, String a2, List<int> a3) =>
+ a0.length + a1.length + a2.length + a3.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use8(String a0, List<int> a1, String a2, List<int> a3, String a4,
+ List<int> a5, String a6, List<int> a7) =>
+ a0.length +
+ a1.length +
+ a2.length +
+ a3.length +
+ a4.length +
+ a5.length +
+ a6.length +
+ a7.length;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ Future<void> asyncMethod() async {}
+}
+
+class MockClass2 {
+ static int val1 = int.parse('42');
+ static int val2 = int.parse('43');
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ int get1() => val1;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ int get2() => val2;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use1(int a0) => a0;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use2(int a0, int a1) => a0 + a1;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ void use4(int a0, int a1, int a2, int a3) => a0 + a1 + a2 + a3;
+
+ @pragma('vm:never-inline')
+ @pragma('dart2js:noInline')
+ Future<void> asyncMethod() async {}
+}
+
+class LiveVarsBench extends AsyncBenchmarkBase {
+ LiveVarsBench(String name) : super(name);
+ @override
+ Future<void> exercise() async {
+ // These micro-benchmarks are too small, so
+ // make a larger number of iterations per measurement.
+ for (var i = 0; i < 10000; i++) {
+ await run();
+ }
+ }
+}
+
+class LiveObj1 extends LiveVarsBench {
+ LiveObj1() : super('AsyncLiveVars.LiveObj1');
+ final field1 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ }
+}
+
+class LiveObj2 extends LiveVarsBench {
+ LiveObj2() : super('AsyncLiveVars.LiveObj2');
+ final field1 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field1.use2(obj1, obj2);
+ }
+}
+
+class LiveObj4 extends LiveVarsBench {
+ LiveObj4() : super('AsyncLiveVars.LiveObj4');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field2.use1(obj3);
+ await field2.asyncMethod();
+ field1.use4(obj1, obj2, obj3, obj4);
+ }
+}
+
+class LiveObj8 extends LiveVarsBench {
+ LiveObj8() : super('AsyncLiveVars.LiveObj8');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ final field3 = MockClass();
+ final field4 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ final obj5 = field3.get1();
+ final obj6 = field3.get2();
+ final obj7 = field4.get1();
+ final obj8 = field4.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field2.asyncMethod();
+ field3.use2(obj5, obj6);
+ await field4.asyncMethod();
+ field2.use8(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8);
+ }
+}
+
+class LiveObj16 extends LiveVarsBench {
+ LiveObj16() : super('AsyncLiveVars.LiveObj16');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ final field3 = MockClass();
+ final field4 = MockClass();
+ final field5 = MockClass();
+ final field6 = MockClass();
+ final field7 = MockClass();
+ final field8 = MockClass();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ final obj5 = field3.get1();
+ final obj6 = field3.get2();
+ final obj7 = field4.get1();
+ final obj8 = field4.get2();
+ final obj9 = field5.get1();
+ final obj10 = field5.get2();
+ final obj11 = field6.get1();
+ final obj12 = field6.get2();
+ final obj13 = field7.get1();
+ final obj14 = field7.get2();
+ final obj15 = field8.get1();
+ final obj16 = field8.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field2.asyncMethod();
+ field5.use2(obj11, obj12);
+ await field4.asyncMethod();
+ field2.use8(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8);
+ field3.use8(obj9, obj10, obj11, obj12, obj13, obj14, obj15, obj16);
+ }
+}
+
+class LiveInt1 extends LiveVarsBench {
+ LiveInt1() : super('AsyncLiveVars.LiveInt1');
+ final field1 = MockClass2();
+ @override
+ Future<void> run() async {
+ final int1 = field1.get1();
+ await field1.asyncMethod();
+ field1.use1(int1);
+ await field1.asyncMethod();
+ field1.use1(int1);
+ await field1.asyncMethod();
+ field1.use1(int1);
+ }
+}
+
+class LiveInt4 extends LiveVarsBench {
+ LiveInt4() : super('AsyncLiveVars.LiveInt4');
+ final field1 = MockClass2();
+ final field2 = MockClass2();
+ @override
+ Future<void> run() async {
+ final int1 = field1.get1();
+ final int2 = field1.get2();
+ final int3 = field2.get1();
+ final int4 = field2.get2();
+ await field1.asyncMethod();
+ field1.use1(int1);
+ await field1.asyncMethod();
+ field2.use1(int3);
+ await field2.asyncMethod();
+ field1.use4(int1, int2, int3, int4);
+ }
+}
+
+class LiveObj2Int2 extends LiveVarsBench {
+ LiveObj2Int2() : super('AsyncLiveVars.LiveObj2Int2');
+ final field1 = MockClass();
+ final field2 = MockClass2();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final int1 = field2.get1();
+ final int2 = field2.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field1.asyncMethod();
+ field2.use1(int1);
+ await field2.asyncMethod();
+ field1.use2(obj1, obj2);
+ field2.use2(int1, int2);
+ }
+}
+
+class LiveObj4Int4 extends LiveVarsBench {
+ LiveObj4Int4() : super('AsyncLiveVars.LiveObj4Int4');
+ final field1 = MockClass();
+ final field2 = MockClass();
+ final field3 = MockClass2();
+ final field4 = MockClass2();
+ @override
+ Future<void> run() async {
+ final obj1 = field1.get1();
+ final obj2 = field1.get2();
+ final obj3 = field2.get1();
+ final obj4 = field2.get2();
+ final int1 = field3.get1();
+ final int2 = field3.get2();
+ final int3 = field4.get1();
+ final int4 = field4.get2();
+ await field1.asyncMethod();
+ field1.use1(obj1);
+ await field2.asyncMethod();
+ field3.use2(int2, int4);
+ await field4.asyncMethod();
+ field2.use4(obj1, obj2, obj3, obj4);
+ field4.use4(int1, int2, int3, int4);
+ }
+}
+
+Future<void> main() async {
+ final benchmarks = [
+ LiveObj1(),
+ LiveObj2(),
+ LiveObj4(),
+ LiveObj8(),
+ LiveObj16(),
+ LiveInt1(),
+ LiveInt4(),
+ LiveObj2Int2(),
+ LiveObj4Int4()
+ ];
+ for (final bench in benchmarks) {
+ await bench.report();
+ }
+}
diff --git a/benchmarks/AsyncLiveVars/dart2/async_benchmark_base.dart b/benchmarks/AsyncLiveVars/dart2/async_benchmark_base.dart
new file mode 100644
index 0000000..9a415b9
--- /dev/null
+++ b/benchmarks/AsyncLiveVars/dart2/async_benchmark_base.dart
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. 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:benchmark_harness/benchmark_harness.dart'
+ show PrintEmitter, ScoreEmitter;
+
+// Similar to BenchmarkBase from package:benchmark_harness.
+class AsyncBenchmarkBase {
+ final String name;
+ final ScoreEmitter emitter;
+
+ // Empty constructor.
+ const AsyncBenchmarkBase(this.name, {this.emitter = const PrintEmitter()});
+
+ // The benchmark code.
+ // This function is not used, if both [warmup] and [exercise] are overwritten.
+ Future<void> run() async {}
+
+ // Runs a short version of the benchmark. By default invokes [run] once.
+ Future<void> warmup() async {
+ await run();
+ }
+
+ // Exercises the benchmark. By default invokes [run] 10 times.
+ Future<void> exercise() async {
+ for (var i = 0; i < 10; i++) {
+ await run();
+ }
+ }
+
+ // Not measured setup code executed prior to the benchmark runs.
+ Future<void> setup() async {}
+
+ // Not measures teardown code executed after the benchark runs.
+ Future<void> teardown() async {}
+
+ // Measures the score for this benchmark by executing it repeatedly until
+ // time minimum has been reached.
+ static Future<double> measureFor(Function f, int minimumMillis) async {
+ final int minimumMicros = minimumMillis * 1000;
+ int iter = 0;
+ final watch = Stopwatch();
+ watch.start();
+ int elapsed = 0;
+ while (elapsed < minimumMicros) {
+ await f();
+ elapsed = watch.elapsedMicroseconds;
+ iter++;
+ }
+ return elapsed / iter;
+ }
+
+ // Measures the score for the benchmark and returns it.
+ Future<double> measure() async {
+ await setup();
+ // Warmup for at least 100ms. Discard result.
+ await measureFor(warmup, 100);
+ // Run the benchmark for at least 2000ms.
+ final result = await measureFor(exercise, 2000);
+ await teardown();
+ return result;
+ }
+
+ Future<void> report() async {
+ emitter.emit(name, await measure());
+ }
+}
