Rework error handling in the service protocol and in Observatory.

runtime/observatory/lib/src/elements/cpu_profile.dart

 // Copyright (c) 2013, 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.
 
 library cpu_profile_element;
 
 import 'dart:async';
 import 'dart:html';
 import 'observatory_element.dart';
 import 'package:observatory/service.dart';
@@ skipping 447 matching lines @@
   final CpuProfile profile = new CpuProfile();
 
   CpuProfileElement.created() : super.created();
 
   @override
   void attached() {
     super.attached();
   }
 
   void isolateChanged(oldValue) {
-    _getCpuProfile();
+    _getCpuProfile().catchError(app.handleException);
   }
 
   void tagSelectorChanged(oldValue) {
-    _getCpuProfile();
+    _getCpuProfile().catchError(app.handleException);
   }
 
   void modeSelectorChanged(oldValue) {
     _updateView();
   }
 
   void directionSelectorChanged(oldValue) {
     _updateView();
   }
 
-  void clear(var done) {
-    _clearCpuProfile().whenComplete(done);
-  }
-
-  Future _clearCpuProfile() {
+  Future clearCpuProfile() {
     profile.clear();
     if (isolate == null) {
       return new Future.value(null);
     }
     return isolate.invokeRpc('clearCpuProfile', { })
         .then((ServiceMap response) {
           _updateView();
         });
   }
 
-  void refresh(var done) {
-    _getCpuProfile().whenComplete(done);
+  Future refresh() {
+    return _getCpuProfile();
   }
 
   _onFetchStarted() {
     _sw.reset();
     _sw.start();
     state = 'Requested';
   }
 
   _onFetchFinished() {
     _sw.stop();
     fetchTime = formatTimeMilliseconds(_sw.elapsedMilliseconds);
   }
 
   Future _onLoadStarted() {
     _sw.reset();
     _sw.start();
     state = 'Loading';
     return window.animationFrame;
   }
 
   _onLoadFinished() {
     _sw.stop();
     loadTime = formatTimeMilliseconds(_sw.elapsedMilliseconds);
     state = 'Loaded';
   }
 
-  Future _getCpuProfile() {
+  Future _getCpuProfile() async {
     profile.clear();
     if (functionTree != null) {
       functionTree.clear();
       functionTree = null;
     }
     if (codeTree != null) {
       codeTree.clear();
       codeTree = null;
     }
     if (isolate == null) {
       return new Future.value(null);
     }
     _onFetchStarted();
-    return isolate.invokeRpc('getCpuProfile', { 'tags': tagSelector })
-        .then((response) async {
+    try {
+      var params = { 'tags': tagSelector };
+      var response = await isolate.invokeRpc('getCpuProfile', params);
       _onFetchFinished();
       await _onLoadStarted();
-      try {
-        profile.load(isolate, response);
-        _onLoadFinished();
-        _updateView();
-      } catch (e, st) {
+      profile.load(isolate, response);
+      _onLoadFinished();
+      _updateView();
+    } catch (e, st) {
+      bool handled = false;
+      if (e is ServerRpcException) {
+        ServerRpcException se = e;
+        if (se.code == ServerRpcException.kProfilingDisabled) {
+          state = 'Disabled';
+          handled = true;
+        }
+      }
+      if (!handled) {
         state = 'Exception';
         exception = e;
         stackTrace = st;
+        rethrow;
       }
-    }).catchError((e, st) {
-      state = 'Exception';
-      exception = e;
-      stackTrace = st;
-    });
+    }
   }
 
   void _updateView() {
     sampleCount = profile.sampleCount.toString();
     refreshTime = new DateTime.now().toString();
     stackDepth = profile.stackDepth.toString();
     sampleRate = profile.sampleRate.toStringAsFixed(0);
     timeSpan = formatTime(profile.timeSpan);
     bool exclusive = directionSelector == 'Up';
     if (functionTree != null) {
@@ skipping 219 matching lines @@
   _updateSize() {
     HtmlElement e = $['main'];
     final totalHeight = window.innerHeight;
     final top = e.offset.top;
     final bottomMargin = 32;
     final mainHeight = totalHeight - top - bottomMargin;
     e.style.setProperty('height', '${mainHeight}px');
   }
 
   isolateChanged() {
-    _getCpuProfile().whenComplete(checkParameters);
+    _getCpuProfile()
+      .catchError(app.handleException)
+      .whenComplete(checkParameters);
   }
 
   checkParameters() {
     var functionId = app.locationManager.uri.queryParameters['functionId'];
     if (functionId == null) {
       _focusOnFunction(null);
       return;
     }
     if (isolate == null) {
       return;
     }
     isolate.getObject(functionId).then((func) => _focusOnFunction(func));
   }
 
   void directionSelectorChanged(oldValue) {
     _updateFunctionTreeView();
   }
 
-  void refresh(var done) {
-    _getCpuProfile().whenComplete(done);
-  }
-
-  void clear(var done) {
-    _clearCpuProfile().whenComplete(done);
+  Future refresh() {
+    return _getCpuProfile();
   }
 
   _onFetchStarted() {
     _sw.reset();
     _sw.start();
     state = 'Requested';
   }
 
   _onFetchFinished() {
     _sw.stop();
     fetchTime = formatTimeMilliseconds(_sw.elapsedMilliseconds);
   }
 
   _onLoadStarted() {
     _sw.reset();
     _sw.start();
     state = 'Loading';
   }
 
   _onLoadFinished() {
     _sw.stop();
     loadTime = formatTimeMilliseconds(_sw.elapsedMilliseconds);
     state = 'Loaded';
   }
 
-  Future _clearCpuProfile() {
+  Future clearCpuProfile() {
     profile.clear();
     _clearView();
     if (isolate == null) {
       return new Future.value(null);
     }
     return isolate.invokeRpc('clearCpuProfile', { })
     .then((ServiceMap response) {
       _updateView();
     });
   }
 
-  Future _getCpuProfile() {
+  Future _getCpuProfile() async {
     profile.clear();
     _clearView();
     if (isolate == null) {
       return new Future.value(null);
     }
     _onFetchStarted();
-    return isolate.invokeRpc('getCpuProfile', { 'tags': 'None' })
-    .then((response) {
+    try {
+      var params = { 'tags': 'None' };
+      var response = await isolate.invokeRpc('getCpuProfile', params);
       _onFetchFinished();
       _onLoadStarted();
-      try {
-        profile.load(isolate, response);
-        profile.buildFunctionCallerAndCallees();
-        _onLoadFinished();
-        _updateView();
-      } catch (e, st) {
+      profile.load(isolate, response);
+      profile.buildFunctionCallerAndCallees();
+      _onLoadFinished();
+      _updateView();
+    } catch (e, st) {
+      bool handled = false;
+      if (e is ServerRpcException) {
+        ServerRpcException se = e;
+        if (se.code == ServerRpcException.kProfilingDisabled) {
+          state = 'Disabled';
+          handled = true;
+        }
+      }
+      if (!handled) {
         state = 'Exception';
         exception = e;
         stackTrace = st;
+        rethrow;
       }
-    }).catchError((e, st) {
-      state = 'Exception';
-      exception = e;
-      stackTrace = st;
-    });
+    }
   }
 
   _clearView() {
     profileTable.clearRows();
     _renderTable();
   }
 
   _updateView() {
     sampleCount = profile.sampleCount.toString();
     refreshTime = new DateTime.now().toString();
@@ skipping 222 matching lines @@
     }
     var filter = (FunctionCallTreeNode node) {
       return node.profileFunction.function == focusedFunction;
     };
     tree = tree.filtered(filter);
     var rootRow =
         new FunctionProfileTreeRow(functionTree, null, profile, tree.root);
     functionTree.initialize(rootRow);
   }
 }