Add a second kind of HandleScope that ties the lifetime of Handles created in its scope to the life…

src/handles.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 940 matching lines @@
   const int kRecursionBudget = 100;
   do {
     failure = false;
     len = Utf8LengthHelper(
         *str, 0, str->length(), false, kRecursionBudget, &failure, &dummy);
     if (failure) FlattenString(str);
   } while (failure);
   return len;
 }
 
+
+DeferredHandleScope::DeferredHandleScope(Isolate* isolate)
+    : impl_(isolate->handle_scope_implementer()) {
+  impl_->BeginDeferredScope();
+  Object** new_next = impl_->GetSpareOrNewBlock();
+  Object** new_limit = &new_next[kHandleBlockSize];
+  impl_->blocks()->Add(new_next);
+
+  v8::ImplementationUtilities::HandleScopeData* data =
+      impl_->isolate()->handle_scope_data();
+#ifdef DEBUG
+  prev_level_ = data->level;
+#endif
+  data->level++;
+  prev_limit_ = data->limit;
+  prev_next_ = data->next;
+  data->next = new_next;
+  data->limit = new_limit;
+}
+
+
+DeferredHandleScope::~DeferredHandleScope() {
+  impl_->isolate()->handle_scope_data()->level--;
+  ASSERT(handles_detached_);
+  ASSERT(impl_->isolate()->handle_scope_data()->level == prev_level_);
+}
+
+
+DeferredHandles* DeferredHandleScope::Detach() {
+  DeferredHandles* deferred = impl_->Detach(prev_limit_);
+  v8::ImplementationUtilities::HandleScopeData* data =
+      impl_->isolate()->handle_scope_data();
+  data->next = prev_next_;
+  data->limit = prev_limit_;
+#ifdef DEBUG
+  handles_detached_ = true;
+#endif
+  return deferred;
+}
+
+
 } }  // namespace v8::internal