[dart2js] Include memory usage in dart2js's output.

sigmundch · Commit Bot · commit 077a7907e6d3 · 2022-05-19T18:42:00.000Z
This adds a small text on the output of dart2js to indicate how much memory it consumed during compilation. It's implemented via a service protocol API that collects the total heap capacity at the time dart2js is practically done with compilation. Once this is in place, we could change our benchmarks to start using this metric. Change-Id: Iaf4425ef713ce0195474ef4e818149d46ab55e9b Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244802 Commit-Queue: Sigmund Cherem <sigmund@google.com> Reviewed-by: Ben Konyi <bkonyi@google.com> Reviewed-by: Joshua Litt <joshualitt@google.com>
diff --git a/pkg/compiler/lib/src/common/ram_usage.dart b/pkg/compiler/lib/src/common/ram_usage.dart
@@ -0,0 +1,39 @@
+// 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.
+
+/// This library contains logic to fetch RAM utilization information.
+/// It is implemented as an RPC that connects to the VM's vm_service isolate and
+/// all necessary details.
+///
+/// This is similar to the information that the VM prints when provided the
+/// `--print_metrics` flag. However, this API allows us to obtain the data
+/// directly while the process is running and embedded in the compiler output
+/// (and in the future in dump-info).
+///
+/// Note that one could alternatively use Process.maxRss instead, however that
+/// number may have a lot more variability depending on system conditions.
+/// Our goal with this number is not so much to be exact, but to have a good
+/// metric we can track overtime and use to detect improvements and regressions.
+import 'dart:developer';
+import 'package:vm_service/vm_service_io.dart' as vm_service_io;
+
+Future<int> _currentHeapCapacity() async {
+  final info =
+      await Service.controlWebServer(enable: true, silenceOutput: true);
+  final observatoryUri = info.serverUri!;
+  final wsUri = 'ws://${observatoryUri.authority}${observatoryUri.path}ws';
+  final vmService = await vm_service_io.vmServiceConnectUri(wsUri);
+  int sum = 0;
+  for (final group in (await vmService.getVM()).isolateGroups!) {
+    final usage = await vmService.getIsolateGroupMemoryUsage(group.id!);
+    sum += usage.heapCapacity!;
+  }
+  vmService.dispose();
+  return sum;
+}
+
+Future<String> currentHeapCapacityInMb() async {
+  final capacity = await _currentHeapCapacity();
+  return "${(capacity / (1024 * 1024)).toStringAsFixed(3)} MB";
+}
diff --git a/pkg/compiler/lib/src/dart2js.dart b/pkg/compiler/lib/src/dart2js.dart
@@ -16,6 +16,7 @@ import 'package:front_end/src/api_unstable/dart2js.dart' as fe;
 import '../compiler_api.dart' as api;
 import '../compiler_api_unmigrated.dart' as api_unmigrated;
 import 'commandline_options.dart';
+import 'common/ram_usage.dart';
 import 'options.dart' show CompilerOptions, FeatureOptions;
 import 'source_file_provider.dart';
 import 'util/command_line.dart';
@@ -933,7 +934,8 @@ Future<api.CompilationResult> compile(List<String> argv,
       RandomAccessFileOutputProvider(out, sourceMapOut,
           onInfo: diagnosticHandler.info, onFailure: fail);
 
-  api.CompilationResult compilationDone(api.CompilationResult result) {
+  Future<api.CompilationResult> compilationDone(
+      api.CompilationResult result) async {
     if (!result.isSuccess) {
       fail('Compilation failed.');
     }
@@ -1060,7 +1062,8 @@ Future<api.CompilationResult> compile(List<String> argv,
     print('$processName '
         '${_formatCharacterCount(inputSize)} $inputName to '
         '${_formatCharacterCount(outputSize)} $outputName in '
-        '${_formatDurationAsSeconds(wallclock.elapsed)} seconds');
+        '${_formatDurationAsSeconds(wallclock.elapsed)} seconds using '
+        '${await currentHeapCapacityInMb()} of memory');
     if (primaryOutputSize != null) {
       diagnosticHandler
           .info('${_formatCharacterCount(primaryOutputSize)} $outputName '
diff --git a/pkg/compiler/pubspec.yaml b/pkg/compiler/pubspec.yaml
@@ -19,6 +19,7 @@ dependencies:
   js_runtime: any
   js_shared: any
   kernel: any
+  vm_service: any
 
 dev_dependencies:
   args: any
