- Create isolate specific resuable handles and use them in the hot lookup paths.

runtime/vm/handles.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 "vm/handles.h"
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/flags.h"
 #include "vm/isolate.h"
@@ skipping 103 matching lines @@
 
 
 NoHandleScope::NoHandleScope() : StackResource(Isolate::Current()) {
   isolate()->IncrementNoHandleScopeDepth();
 }
 
 
 NoHandleScope::~NoHandleScope() {
   isolate()->DecrementNoHandleScopeDepth();
 }
+
+
+ReusableHandleScope::ReusableHandleScope(BaseIsolate* isolate)
+    : StackResource(isolate) {
+  ASSERT(!isolate->reusable_handle_scope_active());
+  isolate->set_reusable_handle_scope_active(true);
+}
+
+
+ReusableHandleScope::ReusableHandleScope() : StackResource(Isolate::Current()) {
+  ASSERT(!isolate()->reusable_handle_scope_active());
+  isolate()->set_reusable_handle_scope_active(true);
+}
+
+
+ReusableHandleScope::~ReusableHandleScope() {
+  ASSERT(isolate()->reusable_handle_scope_active());
+  isolate()->set_reusable_handle_scope_active(false);
+}
 #endif  // defined(DEBUG)
 
 }  // namespace dart