Cache resolution of two static functions frequently used in I/O.

runtime/lib/isolate.cc

 // Copyright (c) 2012, 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.
 
 #include "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 33 matching lines @@
 
 static void StoreError(Isolate* isolate, const Object& obj) {
   ASSERT(obj.IsError());
   Error& error = Error::Handle();
   error ^= obj.raw();
   isolate->object_store()->set_sticky_error(error);
 }
 
 
 // TODO(turnidge): Move to DartLibraryCalls.
-RawObject* ReceivePortCreate(intptr_t port_id) {
-  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("_get_or_create"));
+static RawObject* ReceivePortCreate(intptr_t port_id) {
+  Isolate* isolate = Isolate::Current();
+  Function& func =
+      Function::Handle(isolate,
+                       isolate->object_store()->receive_port_create_function());
   const int kNumArguments = 1;
-  const Array& kNoArgumentNames = Array::Handle();
-  const Function& func = 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(func, args));
+  if (func.IsNull()) {
+    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("_get_or_create"));
+    const Array& kNoArgumentNames = Array::Handle();
+    func = Resolver::ResolveStatic(isolate_lib,
+                                   class_name,
+                                   function_name,
+                                   kNumArguments,
+                                   kNoArgumentNames,
+                                   Resolver::kIsQualified);
+    isolate->object_store()->set_receive_port_create_function(func);
+  }
+  const Array& args = Array::Handle(isolate, Array::New(kNumArguments));
+  args.SetAt(0, Integer::Handle(isolate, Integer::New(port_id)));
+  const Object& result =
+      Object::Handle(isolate, DartEntry::InvokeStatic(func, args));
   if (!result.IsError()) {
     PortMap::SetLive(port_id);
   }
   return result.raw();
 }
 
 
 static void ShutdownIsolate(uword parameter) {
   Isolate* isolate = reinterpret_cast<Isolate*>(parameter);
   {
@@ skipping 402 matching lines @@
 
 DEFINE_NATIVE_ENTRY(isolate_getPortInternal, 0) {
   const Object& port = Object::Handle(ReceivePortCreate(isolate->main_port()));
   if (port.IsError()) {
     Exceptions::PropagateError(Error::Cast(port));
   }
   return port.raw();
 }
 
 }  // namespace dart