1 files changed, 42 insertions, 66 deletions
diff --git a/lib/weakref.rb b/lib/weakref.rb
index 49b907ba17..c7274f9664 100644
--- a/lib/weakref.rb
+++ b/lib/weakref.rb
@@ -1,83 +1,59 @@
-# Weak Reference class that does not bother GCing.
+# frozen_string_literal: true
+require "delegate"
+
+# Weak Reference class that allows a referenced object to be
+# garbage-collected.
+#
+# A WeakRef may be used exactly like the object it references.
 #
 # Usage:
-#   foo = Object.new
-#   foo = Object.new
-#   p foo.to_s			# original's class
-#   foo = WeakRef.new(foo)
-#   p foo.to_s			# should be same class
-#   ObjectSpace.garbage_collect
-#   p foo.to_s			# should raise exception (recycled)
+#
+#   foo = Object.new            # create a new object instance
+#   p foo.to_s                  # original's class
+#   foo = WeakRef.new(foo)      # reassign foo with WeakRef instance
+#   p foo.to_s                  # should be same class
+#   GC.start                    # start the garbage collector
+#   p foo.to_s                  # should raise exception (recycled)
+#
 
-require "delegate"
+class WeakRef < Delegator
+  # The version string
+  VERSION = "0.1.4"
 
-class WeakRef<Delegator
+  ##
+  # RefError is raised when a referenced object has been recycled by the
+  # garbage collector
 
-  class RefError<StandardError
+  class RefError < StandardError
   end
 
-  @@id_map =  {}                # obj -> [ref,...]
-  @@id_rev_map =  {}            # ref -> obj
-  @@final = lambda{|id|
-    __old_status = Thread.critical
-    Thread.critical = true
-    begin
-      rids = @@id_map[id]
-      if rids
-	for rid in rids
-	  @@id_rev_map.delete(rid)
-	end
-	@@id_map.delete(id)
-      end
-      rid = @@id_rev_map[id]
-      if rid
-	@@id_rev_map.delete(id)
-	@@id_map[rid].delete(id)
-	@@id_map.delete(rid) if @@id_map[rid].empty?
-      end
-    ensure
-      Thread.critical = __old_status
-    end
-  }
+  @@__map = ::ObjectSpace::WeakMap.new
+
+  ##
+  # Creates a weak reference to +orig+
 
   def initialize(orig)
-    super
-    @__id = orig.__id__
-    ObjectSpace.define_finalizer orig, @@final
-    ObjectSpace.define_finalizer self, @@final
-    __old_status = Thread.critical
-    begin
-      Thread.critical = true
-      @@id_map[@__id] = [] unless @@id_map[@__id]
-    ensure
-      Thread.critical = __old_status
+    case orig
+    when true, false, nil
+      @delegate_sd_obj = orig
+    else
+      @@__map[self] = orig
     end
-    @@id_map[@__id].push self.__id__
-    @@id_rev_map[self.__id__] = @__id
+    super
   end
 
-  def __getobj__
-    unless @@id_rev_map[self.__id__] == @__id
-      raise RefError, "Illegal Reference - probably recycled", caller(2)
-    end
-    begin
-      ObjectSpace._id2ref(@__id)
-    rescue RangeError
-      raise RefError, "Illegal Reference - probably recycled", caller(2)
-    end
+  def __getobj__(&_block) # :nodoc:
+    @@__map[self] or defined?(@delegate_sd_obj) ? @delegate_sd_obj :
+      Kernel::raise(RefError, "Invalid Reference - probably recycled", Kernel::caller(2))
   end
 
-  def weakref_alive?
-    @@id_rev_map[self.__id__] == @__id
+  def __setobj__(obj) # :nodoc:
   end
-end
 
-if __FILE__ == $0
-  require 'thread'
-  foo = Object.new
-  p foo.to_s			# original's class
-  foo = WeakRef.new(foo)
-  p foo.to_s			# should be same class
-  ObjectSpace.garbage_collect
-  p foo.to_s			# should raise exception (recycled)
+  ##
+  # Returns true if the referenced object is still alive.
+
+  def weakref_alive?
+    @@__map.key?(self) or defined?(@delegate_sd_obj)
+  end
 end