[vm/benchmark] Introduce benchmarks that measures event loop latency for regexp processing.

This captures performance issues reported on https://github.com/flutter/flutter/issues/88063

Change-Id: Ie216808a02231be7915c60268718f3e0a0dc3c99
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210282
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>

benchmarks/EventLoopLatencyRegexp/dart/EventLoopLatencyRegexp.dart

@@ -0,0 +1,33 @@
+// Copyright (c) 2021, 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 'dart:isolate';
+
+import 'regexp_benchmark.dart';
+import '../../EventLoopLatencyJson/dart/latency.dart';
+
+main() async {
+  final exitPort = ReceivePort();
+  final exitFuture = exitPort.first;
+  final isolate = await Isolate.spawn(run, null, onExit: exitPort.sendPort);
+
+  // Measure event loop latency.
+  const tickDuration = const Duration(milliseconds: 1);
+  const numberOfTicks = 8 * 1000; // min 8 seconds.
+  final EventLoopLatencyStats stats =
+      await measureEventLoopLatency(tickDuration, numberOfTicks);
+
+  // Kill isolate & wait until it's dead.
+  isolate.kill(priority: Isolate.immediate);
+  await exitFuture;
+
+  // Report event loop latency statistics.
+  stats.report('EventLoopLatencyRegexp');
+}
+
+void run(dynamic msg) {
+  while (true) {
+    RegexpBenchmark().run();
+  }
+}

benchmarks/EventLoopLatencyRegexp/dart/regexp_benchmark.dart

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+// Copyright (c) 2021, 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 'dart:math';
+import 'dart:convert';
+
+class RegexpBenchmark {
+  void run() {
+    final re = RegExp(r'(x+)*y');
+    final s = 'x' * 26 + '';
+    re.allMatches(s).iterator.moveNext();
+  }
+}

benchmarks/EventLoopLatencyRegexp/dart2/EventLoopLatencyRegexp.dart

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+// Copyright (c) 2020, 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.
+
+// @dart=2.9
+
+import 'dart:isolate';
+
+import 'json_benchmark.dart';
+import '../../EventLoopLatencyJson/dart2/latency.dart';
+
+main() async {
+  final exitPort = ReceivePort();
+  final exitFuture = exitPort.first;
+  final isolate = await Isolate.spawn(run, null, onExit: exitPort.sendPort);
+
+  // Measure event loop latency.
+  const tickDuration = const Duration(milliseconds: 1);
+  const numberOfTicks = 8 * 1000; // min 8 seconds.
+  final EventLoopLatencyStats stats =
+      await measureEventLoopLatency(tickDuration, numberOfTicks);
+
+  // Kill isolate & wait until it's dead.
+  isolate.kill(priority: Isolate.immediate);
+  await exitFuture;
+
+  // Report event loop latency statistics.
+  stats.report('EventLoopLatencyRegexp');
+}
+
+void run(dynamic msg) {
+  while (true) {
+    RegexpBenchmark().run();
+  }
+}

benchmarks/EventLoopLatencyRegexp/dart2/regexp_benchmark.dart

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+// Copyright (c) 2021, 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.
+
+// @dart=2.9
+
+import 'dart:math';
+import 'dart:convert';
+
+class RegexpBenchmark {
+  void run() {
+    final re = RegExp(r'(x+)*y');
+    final s = 'x' * 26 + '';
+    re.allMatches(s).iterator.moveNext();
+  }
+}