Add fine grained command line and service protocol control over timeline streams recording

runtime/observatory/tests/service/vm_timeline_flags_test.dart

+// Copyright (c) 2016, 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.
+// VMOptions=--error_on_bad_type --error_on_bad_override
+
+import 'dart:developer';
+import 'package:observatory/service_io.dart';
+import 'package:unittest/unittest.dart';
+
+import 'test_helper.dart';
+
+primeDartTimeline() {
+  while (true) {
+    Timeline.startSync('apple');
+    Timeline.finishSync();
+    debugger();
+  }
+}
+
+bool isDart(Map event) => event['cat'] == 'Dart';
+bool isMetaData(Map event) => event['ph'] == 'M';
+bool isNotMetaData(Map event) => !isMetaData(event);
+bool isNotDartAndMetaData(Map event) => !isDart(event) && !isMetaData(event);
+
+List<Map> filterEvents(List<Map> events, filter) {
+  return events.where(filter).toList();
+}
+
+int dartEventCount;
+
+var tests = [
+  hasStoppedAtBreakpoint,
+  (Isolate isolate) async {
+    // Get the flags.
+    Map flags = await isolate.vm.invokeRpcNoUpgrade('_getVMTimelineFlags', {});
+    expect(flags['type'], 'TimelineFlags');
+    // Confirm that 'Dart' is available.
+    expect(flags['availableStreams'].contains('Dart'), isTrue);
+    // Confirm that nothing is being recorded.
+    expect(flags['recordedStreams'].length, equals(0));
+  },
+  (Isolate isolate) async {
+    // Get the timeline.
+    Map result = await isolate.vm.invokeRpcNoUpgrade('_getVMTimeline', {});
+    expect(result['type'], equals('_Timeline'));
+    expect(result['traceEvents'], new isInstanceOf<List>());
+    // Confirm that it as no non-meta data events.
+    expect(filterEvents(result['traceEvents'], isNotMetaData).length, 0);
+  },
+  (Isolate isolate) async {
+    // Enable the Dart category.
+    await isolate.vm.invokeRpcNoUpgrade('_setVMTimelineFlags', {
+      "recordedStreams": ["Dart"]
+    });
+  },
+  (Isolate isolate) async {
+    // Get the flags.
+    Map flags = await isolate.vm.invokeRpcNoUpgrade('_getVMTimelineFlags', {});
+    expect(flags['type'], 'TimelineFlags');
+    // Confirm that only Dart is being recorded.
+    expect(flags['recordedStreams'].length, equals(1));
+    expect(flags['recordedStreams'].contains('Dart'), isTrue);
+  },
+  resumeIsolate,
+  (Isolate isolate) async {
+    // Get the timeline.
+    Map result = await isolate.vm.invokeRpcNoUpgrade('_getVMTimeline', {});
+    expect(result['type'], equals('_Timeline'));
+    expect(result['traceEvents'], new isInstanceOf<List>());
+    // Confirm that Dart events are added.
+    expect(filterEvents(result['traceEvents'], isDart).length, greaterThan(0));
+    // Confirm that zero non-Dart events are added.
+    expect(
+        filterEvents(result['traceEvents'], isNotDartAndMetaData).length,
+        equals(0));
+  },
+  hasStoppedAtBreakpoint,
+  (Isolate isolate) async {
+    // Disable the Dart category.
+    await isolate.vm.invokeRpcNoUpgrade('_setVMTimelineFlags', {
+      "recordedStreams": []
+    });
+    // Grab the timeline and remember the number of Dart events.
+    Map result = await isolate.vm.invokeRpcNoUpgrade('_getVMTimeline', {});
+    expect(result['type'], equals('_Timeline'));
+    expect(result['traceEvents'], new isInstanceOf<List>());
+    dartEventCount = filterEvents(result['traceEvents'], isDart).length;
+  },
+  (Isolate isolate) async {
+    // Get the flags.
+    Map flags = await isolate.vm.invokeRpcNoUpgrade('_getVMTimelineFlags', {});
+    expect(flags['type'], 'TimelineFlags');
+    // Confirm that 'Dart' is not being recorded.
+    expect(flags['recordedStreams'].length, equals(0));
+  },
+  resumeIsolate,
+  (Isolate isolate) async {
+    // Grab the timeline and verify that we haven't added any new Dart events.
+    Map result = await isolate.vm.invokeRpcNoUpgrade('_getVMTimeline', {});
+    expect(result['type'], equals('_Timeline'));
+    expect(result['traceEvents'], new isInstanceOf<List>());
+    expect(filterEvents(result['traceEvents'], isDart).length, dartEventCount);
+    // Confirm that zero non-Dart events are added.
+    expect(
+        filterEvents(result['traceEvents'], isNotDartAndMetaData).length,
+        equals(0));
+  },
+];
+
+main(args) async => runIsolateTests(args,
+                                    tests,
+                                    testeeConcurrent: primeDartTimeline);