VM Service isolate listing

runtime/vm/message.h

Index: runtime/vm/message.h
diff --git a/runtime/vm/message.h b/runtime/vm/message.h
index 80d1df56d1c8c210d08072e18a41da9cab03addb..e5e7796d59098649f8724502257f2a3bb64e427d 100644
--- a/runtime/vm/message.h
+++ b/runtime/vm/message.h
@@ -23,6 +23,15 @@ class Message {
     kNumPriorities = 2,
   } Priority;
 
+  typedef enum {
+    kNormalType = 0,     // Normal message.
+    kServiceType = 1,    // Service isolate message.

[siva, 2013/07/19 17:41:16]

I am not sure about this message type encoding here.

Another possible model is we have OOB messages and then
we have the Service handler taking a shot at handling the message
and if it does not recognize it then we move on to Mirror message
handler and then onto any other such handlers that we have.

Let us discuss this.

+
+    // Iteration.
+    kFirstType = 0,
+    kNumTypes = 2,
+  } Type;
+
   // A port number which is never used.
   static const Dart_Port kIllegalPort = 0;
 
@@ -31,14 +40,15 @@ class Message {
   // being destructed (after delivery or when the receiving port is closed).
   //
   // If reply_port is kIllegalPort, then there is no reply port.
-  Message(Dart_Port dest_port, Dart_Port reply_port,
-          uint8_t* data, intptr_t len, Priority priority)
+  Message(Dart_Port dest_port, Dart_Port reply_port, uint8_t* data,
+          intptr_t len, Priority priority, Type type = kNormalType)
       : next_(NULL),
         dest_port_(dest_port),
         reply_port_(reply_port),
         data_(data),
         len_(len),
-        priority_(priority) {}
+        priority_(priority),
+        type_(type) {}
   ~Message() {
     free(data_);
   }
@@ -48,8 +58,10 @@ class Message {
   uint8_t* data() const { return data_; }
   intptr_t len() const { return len_; }
   Priority priority() const { return priority_; }
+  Type type() const { return type_; }
 
   bool IsOOB() const { return priority_ == Message::kOOBPriority; }
+  bool IsService() const { return type_ == Message::kServiceType; }
 
  private:
   friend class MessageQueue;
@@ -60,6 +72,7 @@ class Message {
   uint8_t* data_;
   intptr_t len_;
   Priority priority_;
+  Type type_;
 
   DISALLOW_COPY_AND_ASSIGN(Message);
 };