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

src/handles.cc

Index: src/handles.cc
diff --git a/src/handles.cc b/src/handles.cc
index def1604ac7438c5769a0cb6287fd009dee54758d..cffbaf85af02288ad4bbecd73ebcf03a63addda0 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -958,4 +958,42 @@ int Utf8Length(Handle<String> str) {
   return len;
 }
 
+
+GatheringHandleScope::GatheringHandleScope(CompilationInfo* info)
+    : info_(info) {
+  Isolate* isolate = info->isolate();

[danno, 2012/06/24 11:07:03]

You should be able to put the code below in the ScopeHandleImplementation if you
here call:

impl->BeginDeferredHandleScope() 

here and remember the deferred handle scope. BTW, BeginDeferredHandleScope
should take a HandleScope as parameter rather than the explicit prev_limit_
parameter to encapsulate the implementation.

+  v8::ImplementationUtilities::HandleScopeData* current =
+      isolate->handle_scope_data();
+  prev_next_ = current->next;
+  prev_limit_ = current->limit;
+
+  HandleScopeImplementer* impl = isolate->handle_scope_implementer();
+  impl->begin_persistence();
+  Object** new_next = impl->GetSpareOrNewBlock();
+  Object** new_limit = &new_next[kHandleBlockSize];
+  impl->blocks()->Add(new_next);
+
+  current->next = new_next;
+  current->limit = new_limit;
+  current->level++;
+}
+
+
+GatheringHandleScope::~GatheringHandleScope() {
+  Isolate* isolate = info_->isolate();
+  HandleScopeImplementer* impl = isolate->handle_scope_implementer();
+  HandleScopeImplementer::PersistentExtensions* extensions =
+      impl->PersistExtensions(prev_limit_);

[danno, 2012/06/24 11:07:03]

All of the code below can be pushed to the impl if you call the DeferHandleScope
method here on the result of the BeginDeferredHandleScope method that you called
in the constructor.

+  info_->StorePersistentExtensions(extensions);
+
+  v8::ImplementationUtilities::HandleScopeData* current =
+      isolate->handle_scope_data();
+  current->next = prev_next_;
+  current->limit = prev_limit_;
+
+  impl->end_persistence();
+  current->level--;
+}
+
+
 } }  // namespace v8::internal