Add Isolate.onExit.

sdk/lib/_internal/lib/isolate_helper.dart

Index: sdk/lib/_internal/lib/isolate_helper.dart
diff --git a/sdk/lib/_internal/lib/isolate_helper.dart b/sdk/lib/_internal/lib/isolate_helper.dart
index 691cfe20ccf03d34063c5f351ae489a0cd24d4b1..2cf7c9272cf4cac9f7f71f48935a624ebb9e735a 100644
--- a/sdk/lib/_internal/lib/isolate_helper.dart
+++ b/sdk/lib/_internal/lib/isolate_helper.dart
@@ -32,7 +32,6 @@ _callInIsolate(_IsolateContext isolate, Function function) {
   return result;
 }
 
-/// Marks entering a javascript async operation to keep the worker alive.
 /// Marks entering a JavaScript async operation to keep the worker alive.
 ///
 /// To be called by library code before starting an async operation controlled
@@ -270,6 +269,7 @@ class _IsolateContext implements IsolateContext {
   final RawReceivePortImpl controlPort = new RawReceivePortImpl._controlPort();
 
   final Capability pauseCapability = new Capability();
+  final Capability inspectCapability = new Capability();
 
   // TODO(lrn): Store these in single "PauseState" object, so they don't take
   // up as much room when not pausing.
@@ -277,6 +277,9 @@ class _IsolateContext implements IsolateContext {
   List<_IsolateEvent> delayedEvents = [];
   Set<Capability> pauseTokens = new Set();
 
+  // Container with the "on exit" handler send-ports.
+  var doneHandlers;
+
   _IsolateContext() {
     this.registerWeak(controlPort._id, controlPort);
   }
@@ -302,6 +305,17 @@ class _IsolateContext implements IsolateContext {
     _updateGlobalState();
   }
 
+  void addDoneListener(Capability inspect, SendPort response) {
+    if (inspectCapability != inspect) return;
+    if (doneHandlers == null) {
+      doneHandlers = [];
+    }
+    // If necessary, we can switch doneHandlers to a Set if it gets larget.

[floitsch, 2014/02/25 19:25:48]

larger.

+    // That is not expected to happen in practice.
+    if (doneHandlers.contains(response)) return;
+    doneHandlers.add(response);
+  }
+
   /**
    * Run [code] in the context of the isolate represented by [this].
    */
@@ -331,8 +345,11 @@ class _IsolateContext implements IsolateContext {
       case "resume":
         removePause(message[1]);
         break;
+      case 'ondone':
+        addDoneListener(message[1], message[2]);
+        break;
       default:
-        print("UNKOWN MESSAGE: $message");
+        print("UNKNOWN MESSAGE: $message");
     }
   }
 
@@ -362,11 +379,22 @@ class _IsolateContext implements IsolateContext {
     _addRegistration(portId, port);
   }
 
-  _updateGlobalState() {
+  void _updateGlobalState() {
     if (ports.length - weakPorts.length > 0 || isPaused) {
       _globalState.isolates[id] = this; // indicate this isolate is active
     } else {
-      _globalState.isolates.remove(id); // indicate this isolate is not active
+      _shutdown();
+    }
+  }
+
+  void _shutdown() {
+    _globalState.isolates.remove(id); // indicate this isolate is not active

[floitsch, 2014/02/25 19:25:48]

"I"ndicate ... active"."

+    // Send "done" event to all listeners. This must be done after deactivating
+    // the current isolate, or it may get events if listening to itself.
+    if (doneHandlers != null) {
+      for (SendPort port in doneHandlers) {
+        port.send(null);
+      }
     }
   }
 
@@ -520,7 +548,7 @@ class IsolateNatives {
   static final Expando<int> workerIds = new Expando<int>();
 
   /**
-   * The src url for the script tag that loaded this code. Used to create
+   * The src url for the script tag that loaded this Used to create

[floitsch, 2014/02/25 19:25:48]

missing ".".

    * JavaScript workers.
    */
   static String computeThisScript() {
@@ -788,7 +816,8 @@ class IsolateNatives {
     // The isolate's port does not keep the isolate open.
     replyTo.send([_SPAWNED_SIGNAL,
                   context.controlPort.sendPort,
-                  context.pauseCapability]);
+                  context.pauseCapability,
+                  context.inspectCapability]);
 
     void runStartFunction() {
       if (!isSpawnUri) {