only use 'ref' gem for MRI

ext/v8/backref.cc

@@ -7,7 +7,7 @@ namespace rr {
   ID Backref::object;
 
   void Backref::Init() {
-    Storage = rb_eval_string("Ref::WeakReference");
+    Storage = rb_eval_string("V8::Weak::Ref");
     rb_gc_register_address(&Storage);
     _new = rb_intern("new");
     object = rb_intern("object");

lib/v8.rb

@@ -1,8 +1,7 @@
 require "v8/version"
 
-require 'ref'
+require 'v8/weak'
 require 'v8/init'
-require 'v8/util/weakcell'
 require 'v8/error'
 require 'v8/conversion/fundamental'
 require 'v8/conversion/indentity'

lib/v8/conversion/code.rb

@@ -1,6 +1,6 @@
 class V8::Conversion
   module Code
-    include V8::Util::Weakcell
+    include V8::Weak::Cell
 
     def to_v8
       fn = to_template.GetFunction()

lib/v8/conversion/indentity.rb

@@ -21,11 +21,11 @@ class V8::Conversion
     end
 
     def v8_idmap
-      @v8_idmap ||= Ref::WeakValueMap.new
+      @v8_idmap ||= V8::Weak::WeakValueMap.new
     end
 
     def rb_idmap
-      @ruby_idmap ||= Ref::WeakValueMap.new
+      @ruby_idmap ||= V8::Weak::WeakValueMap.new
     end
   end
 end

lib/v8/conversion/method.rb

@@ -9,7 +9,7 @@ class V8::Conversion
 
     class MethodCache
       def initialize
-        @map = Ref::WeakValueMap.new
+        @map = V8::Weak::WeakValueMap.new
       end
 
       def [](method)

lib/v8/util/weakcell.rb

@@ -1,29 +0,0 @@
-module V8
-  module Util
-    module Weakcell
-      def weakcell(name, &block)
-        unless storage = instance_variable_get("@#{name}")
-          storage = instance_variable_set("@#{name}", Storage.new)
-        end
-        storage.access(&block)
-      end
-      class Storage
-        def access(&block)
-          if @ref
-            @ref.object || populate(block)
-          else
-            populate(block)
-          end
-        end
-
-        private
-
-        def populate(block)
-          occupant = block.call()
-          @ref = Ref::WeakReference.new(occupant)
-          return occupant
-        end
-      end
-    end
-  end
-end

lib/v8/weak.rb

@@ -0,0 +1,70 @@
+module V8
+  module Weak
+    # weak refs are broken on MRI 1.9 and merely slow on 1.8
+    # so we mitigate this by using the 'ref' gem. However, this
+    # only mitigates the problem. Under heavy load, you will still
+    # get different or terminated objects being returned. bad stuff
+    #
+    # for other platforms we just use the stdlib 'weakref'
+    # implementation
+    if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'ruby'
+      require 'ref'
+      Ref = ::Ref::WeakReference
+      WeakValueMap = ::Ref::WeakValueMap
+    else
+      require 'weakref'
+      class Ref
+        def initialize(object)
+          @ref = ::WeakRef.new(object)
+        end
+        def object
+          @ref.__getobj__
+        rescue ::WeakRef::RefError
+          nil
+        end
+      end
+
+      class WeakValueMap
+        def initialize
+          @values = {}
+        end
+
+        def [](key)
+          if ref = @values[key]
+            ref.object
+          end
+        end
+
+        def []=(key, value)
+          @values[key] = V8::Weak::Ref.new(value)
+        end
+      end
+    end
+
+    module Cell
+      def weakcell(name, &block)
+        unless storage = instance_variable_get("@#{name}")
+          storage = instance_variable_set("@#{name}", Storage.new)
+        end
+        storage.access(&block)
+      end
+      class Storage
+        def access(&block)
+          if @ref
+            @ref.object || populate(block)
+          else
+            populate(block)
+          end
+        end
+
+        private
+
+        def populate(block)
+          occupant = block.call()
+          @ref = V8::Weak::Ref.new(occupant)
+          return occupant
+        end
+      end
+    end
+  end
+end