* marshal.c (Init_marshal): new constant Marshal::MAJOR_VERSION

and Marshal::MINOR_VERSION.

* marshal.c (marshal_load): ruby_verbose test should be wrapped by
  RTEST().

* hash.c (rb_hash_index): should return nil (not the default
  value) if value is not in the hash.

* numeric.c (num_div): new method added.  alias to '/' which
  should be preserved even if '/' is redefined (e.g. by
  mathn). [new]

* bignum.c (rb_cstr2inum): "0 ff".hex should return 0, not 255.

* file.c (rb_file_s_expand_path): fixed using CharNext().


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@1658 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/singleton.rb

@@ -16,12 +16,18 @@ module Singleton
     klass.instance_eval %{
       @__instance__ = nil
       def instance
-	unless @__instance__
+	if defined? @__allocating__
+	  until @__instance__
+	    sleep 0.5
+	  end
+	elsif ! @__instance__
 	  Thread.critical = true
+	  @__allocating__ = true
+	  Thread.critical = false
 	  begin
-	    @__instance__ ||= new
+	    @__instance__ = new
 	  ensure
-	    Thread.critical = false
+	    remove_instance_variable(:@__allocating__)
 	  end
 	end
 	return @__instance__