Optimize the message queue for many active ports with few messages.

runtime/vm/dart_entry.cc

Index: runtime/vm/dart_entry.cc
diff --git a/runtime/vm/dart_entry.cc b/runtime/vm/dart_entry.cc
index 035440d859782b10037b327ffb158c0720d339ee..6b3856dee2936b3a68db70d2c236afaf7574561f 100644
--- a/runtime/vm/dart_entry.cc
+++ b/runtime/vm/dart_entry.cc
@@ -318,7 +318,33 @@ RawObject* DartLibraryCalls::Equals(const Instance& left,
 }
 
 
-RawObject* DartLibraryCalls::HandleMessage(Dart_Port dest_port_id,
+RawObject* DartLibraryCalls::LookupReceivePort(Dart_Port port_id) {

[Ivan Posva, 2012/12/20 17:19:43]

Please coordinate with +fschneider as he has relevant changes in this general
area.

+  Library& isolate_lib = Library::Handle(Library::IsolateLibrary());
+  ASSERT(!isolate_lib.IsNull());
+  const String& public_class_name =
+      String::Handle(Symbols::New("_ReceivePortImpl"));
+  const String& class_name =
+      String::Handle(isolate_lib.PrivateName(public_class_name));
+  const String& function_name =
+      String::Handle(Symbols::New("_lookupReceivePort"));
+  const int kNumArguments = 1;
+  const Array& kNoArgumentNames = Array::Handle();
+  const Function& function = Function::Handle(
+      Resolver::ResolveStatic(isolate_lib,
+                              class_name,
+                              function_name,
+                              kNumArguments,
+                              kNoArgumentNames,
+                              Resolver::kIsQualified));
+  const Array& args = Array::Handle(Array::New(kNumArguments));
+  args.SetAt(0, Integer::Handle(Integer::New(port_id)));
+  const Object& result =
+      Object::Handle(DartEntry::InvokeStatic(function, args));
+  return result.raw();
+}
+
+
+RawObject* DartLibraryCalls::HandleMessage(const Object& receive_port,
                                            Dart_Port reply_port_id,
                                            const Instance& message) {
   Library& isolate_lib = Library::Handle(Library::IsolateLibrary());
@@ -339,11 +365,11 @@ RawObject* DartLibraryCalls::HandleMessage(Dart_Port dest_port_id,
                               kNoArgumentNames,
                               Resolver::kIsQualified));
   const Array& args = Array::Handle(Array::New(kNumArguments));
-  args.SetAt(0, Integer::Handle(Integer::New(dest_port_id)));
+  args.SetAt(0, receive_port);
   args.SetAt(1, Integer::Handle(Integer::New(reply_port_id)));
   args.SetAt(2, message);
-  const Object& result = Object::Handle(DartEntry::InvokeStatic(function,
-                                                                args));
+  const Object& result = Object::Handle(
+      DartEntry::InvokeStatic(function, args));
   ASSERT(result.IsNull() || result.IsError());
   return result.raw();
 }