VM restart + shutdown fixes

runtime/observatory/tests/service/vm_restart_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.
+// VMOptions=--compile-all --error_on_bad_type --error_on_bad_override
+
+import 'dart:async';
+import 'dart:developer';
+import 'dart:io';
+import 'package:observatory/service_io.dart';
+import 'package:unittest/unittest.dart';
+import 'test_helper.dart';
+
+int count = 0;
+
+void test() {
+  while (true) {
+    count++;
+    debugger();
+  }
+}
+
+var tests = [
+  hasStoppedAtBreakpoint,
+
+  (Isolate isolate) async {
+    // The loop has run one time.
+    var result = await isolate.rootLibrary.evaluate('count');
+    expect(result.type, equals('Instance'));
+    expect(result.valueAsString, equals('1'));
+
+    Completer completer = new Completer();
+    var stream = await isolate.vm.getEventStream(VM.kDebugStream);
+    var subscription;
+    subscription = stream.listen((ServiceEvent event) {
+      if (event.kind == ServiceEvent.kResume) {
+        subscription.cancel();
+        completer.complete();
+      }
+    });
+    isolate.resume();
+    await completer.future;
+
+    // The loop has run twice.
+    result = await isolate.rootLibrary.evaluate('count');
+    expect(result.type, equals('Instance'));
+    expect(result.valueAsString, equals('2'));
+  },
+
+  hasStoppedAtBreakpoint,
+
+  (Isolate isolate) async {
+    Isolate newIsolate = null;
+
+    Completer testCompleter = new Completer();
+    var debugStream = await isolate.vm.getEventStream(VM.kDebugStream);
+    var debugSub;
+    debugSub = debugStream.listen((ServiceEvent event) {
+      if (event.kind == ServiceEvent.kPauseBreakpoint) {
+        if (event.isolate == newIsolate) {
+          // The old isolate has died and the new isolate is at
+          // the breakpoint.
+          newIsolate.reload().then((_) {
+            newIsolate.rootLibrary.evaluate('count').then((result) {
+              expect(result.type, equals('Instance'));
+              expect(result.valueAsString, equals('1'));
+              debugSub.cancel();
+              testCompleter.complete();
+            });
+          });
+        }
+      }
+    });
+    
+    Completer restartCompleter = new Completer();
+    var isolateStream = await isolate.vm.getEventStream(VM.kIsolateStream);
+    var isolateSub;
+    bool exit = false;
+    bool start = false;
+    isolateSub = isolateStream.listen((ServiceEvent event) {
+      if (event.kind == ServiceEvent.kIsolateExit) {
+        print('Old isolate exited');
+        expect(event.isolate, equals(isolate));

[Cutch, 2015/10/05 18:10:46]

nit: flip order of print and expect

[turnidge, 2015/10/05 22:18:24]

Done.

+        exit = true;
+      }
+      if (event.kind == ServiceEvent.kIsolateStart) {
+        print('New isolate started');
+        newIsolate = event.isolate;
+        start = true;
+      }
+      if (exit && start) {
+        isolateSub.cancel();
+        restartCompleter.complete();
+      }
+    });
+
+    // Restart the vm.
+    print("restarting");
+    await isolate.vm.restart();
+    await restartCompleter.future;
+    print("restarted");
+    await testCompleter.future;
+  },
+];
+
+  
+main(args) => runIsolateTests(args, tests, testeeConcurrent: test);