Monotonic Condition::clock_time for JRuby 1.7.x

Author: jdantonio

lib/concurrent/atomic/condition.rb

@@ -72,11 +72,14 @@ def broadcast
       def clock_time
         Process.clock_gettime Process::CLOCK_MONOTONIC
       end
+    elsif RUBY_PLATFORM == 'java'
+      def clock_time
+        java.lang.System.nanoTime() / 1_000_000_000.0
+      end
     else
       def clock_time
         Time.now.to_f
       end
     end
-
   end
 end