cleaning list first make it less hurting in concurrent environment

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/jcs/trunk@1594075 13f79535-47bb-0310-9956-ffa450edef68
some more synch not needed

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/jcs/trunk@1594081 13f79535-47bb-0310-9956-ffa450edef68