Tool to compute BMU plots from GC logs.

tests/standalone/verbose_gc_to_bmu_test.dart

+// Copyright (c) 2015, 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 test forks a second vm process that runs the BMU tool and verifies that
+// it produces some output. This test is mainly here to ensure that the BMU
+// tool compiles and runs.
+
+import "dart:async";
+import "dart:convert";
+import "dart:io";
+
+import "package:path/path.dart";
+
+// Tool script relative to the path of this test.
+var toolScript = "../../runtime/tools/verbose_gc_to_bmu.dart";
+
+// Target script relative to this test.
+var targetScript = "../language/gc_test.dart";
+const minOutputLines = 20;
+
+void checkExitCode(exitCode) {
+  if (exitCode != 0) {
+    print("Process terminated with exit code ${exitCode}.");
+    exit(-1);
+  }
+}
+
+void main() {
+  // Compute paths for tool and target relative to the path of this script.
+  var scriptDir = dirname(Platform.script.toFilePath());
+  var targPath = normalize(join(scriptDir, targetScript));
+  var targetResult =
+      Process.runSync(Platform.executable, ["--verbose_gc", targPath]);
+  checkExitCode(targetResult.exitCode);
+  var gcLog = targetResult.stderr;
+  var toolPath = normalize(join(scriptDir, toolScript));
+  Process.start(Platform.executable, [toolPath]).then((Process process) {
+    // Feed the GC log of the target to the BMU tool.
+    process.stdin.write(gcLog);
+    process.stdin.close();
+    var stdoutStringStream = process.stdout
+        .transform(UTF8.decoder)
+        .transform(new LineSplitter());
+    var stderrStringStream = process.stderr
+        .transform(UTF8.decoder)
+        .transform(new LineSplitter());
+    // Wait for 3 future events: stdout and stderr streams closed, and
+    // process terminated.
+    var futures = [];
+    var stdoutLines = [];
+    var stderrLines = [];
+    var subscription = stdoutStringStream.listen(stdoutLines.add);
+    futures.add(subscription.asFuture(true));
+    subscription = stderrStringStream.listen(stderrLines.add);
+    futures.add(subscription.asFuture(true));
+    futures.add(process.exitCode.then(checkExitCode));
+    Future.wait(futures).then((results) {
+      if (stderrLines.isNotEmpty) {
+        print("Unexpected output on stderr:");
+        print(stderrLines.join('\n'));
+        exit(-1);
+      }
+      if (stdoutLines.length < minOutputLines) {
+        print("Less than expected output on stdout:");
+        print(stdoutLines.join('\n'));
+        exit(-1);
+      }
+    });
+  });
+}