use weakcell to manage template reference.

lib/v8.rb

@@ -1,6 +1,7 @@
 require "v8/version"
 
 require 'v8/init'
+require 'v8/util/weakcell'
 require 'v8/conversion/fundamental'
 require 'v8/conversion/indentity'
 require 'v8/conversion/primitive'
@@ -20,4 +21,3 @@ require 'v8/access'
 require 'v8/context'
 require 'v8/object'
 require 'v8/array'
-require 'v8/util/weakcell'

lib/v8/conversion/method.rb

@@ -3,7 +3,7 @@ class V8::Conversion
     include V8::Conversion::Proc
 
     def to_v8
-      (@@method_cache[self] ||= v8_template).GetFunction()
+      (@@method_cache[self] ||= to_v8_template).GetFunction()
     end
 
 

lib/v8/conversion/proc.rb

@@ -1,17 +1,17 @@
 class V8::Conversion
   module Proc
+    include V8::Util::Weakcell
 
     def to_v8
-      return v8_template.GetFunction()
+      return to_v8_template.GetFunction()
     end
 
-    def v8_template
-      unless @v8_template && @v8_template.weakref_alive?
+    def to_v8_template
+      weakcell(:v8_template) do
         template = V8::C::FunctionTemplate::New()
         template.SetCallHandler(InvocationHandler.new, V8::C::External::New(self))
-        @v8_template = WeakRef.new(template)
+        template
       end
-      return @v8_template.__getobj__
     end
 
     class InvocationHandler