Add support for asynchronous event notification to the observatory.

runtime/vm/service.h

Index: runtime/vm/service.h
diff --git a/runtime/vm/service.h b/runtime/vm/service.h
index c3cdce955197214b8a5ffc9eb1f15c020f397df2..2ee5ad4f9c2aa9f11cc922ae514465a5568bbe49 100644
--- a/runtime/vm/service.h
+++ b/runtime/vm/service.h
@@ -11,11 +11,13 @@
 
 namespace dart {
 
+class DebuggerEvent;
 class EmbedderServiceHandler;
 class Instance;
 class Isolate;
 class JSONStream;
 class RawInstance;
+class String;
 
 class Service : public AllStatic {
  public:
@@ -28,7 +30,19 @@ class Service : public AllStatic {
   static Isolate* GetServiceIsolate(void* callback_data);
   static bool SendIsolateStartupMessage();
   static bool SendIsolateShutdownMessage();
-  static bool IsRunning();
+
+  static bool IsRunning() {
+    return port_ != ILLEGAL_PORT;
+  }
+
+  static void SetEventMask(uint32_t mask);
+
+  // Is the service interested in debugger events?
+  static bool NeedsDebuggerEvents() {
+    return IsRunning() && ((event_mask_ & kEventFamilyDebugMask) != 0);
+  }
+
+  static void HandleDebuggerEvent(DebuggerEvent* event);
 
   static void RegisterIsolateEmbedderCallback(
       const char* name,
@@ -45,18 +59,26 @@ class Service : public AllStatic {
   }
 
  private:
+  // These must be kept in sync with service/constants.dart
+  static const int kEventFamilyDebug = 0;
+  static const uint32_t kEventFamilyDebugMask = (1 << kEventFamilyDebug);
+
   static void EmbedderHandleMessage(EmbedderServiceHandler* handler,
                                     JSONStream* js);
   static EmbedderServiceHandler* FindIsolateEmbedderHandler(const char* name);
-  static EmbedderServiceHandler* isolate_service_handler_head_;
   static EmbedderServiceHandler* FindRootEmbedderHandler(const char* name);
+  static Dart_Handle GetSource(const char* name);
+  static Dart_Handle LibraryTagHandler(Dart_LibraryTag tag, Dart_Handle library,
+                                       Dart_Handle url);
+  static void SendEvent(intptr_t eventId, const String& eventMessage);
+
+  static EmbedderServiceHandler* isolate_service_handler_head_;
   static EmbedderServiceHandler* root_service_handler_head_;
+
   static Isolate* service_isolate_;
   static Dart_LibraryTagHandler default_handler_;
   static Dart_Port port_;
-  static Dart_Handle GetSource(const char* name);
-  static Dart_Handle LibraryTagHandler(Dart_LibraryTag tag, Dart_Handle library,
-                                       Dart_Handle url);
+  static uint32_t event_mask_;
 };
 
 }  // namespace dart