Add some synch. (volatile) just in case
Add some synch. (volatile) just in case

git-svn-id: https://svn.apache.org/repos/asf/jakarta/jmeter/trunk@772243 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: 3f4025e908c14fef61d1698275c3a90ae9f30e04
benbenw/jmeter,etnetera/jmeter,benbenw/jmeter,apache/jmeter,apache/jmeter,ham1/jmeter,apache/jmeter,etnetera/jmeter,etnetera/jmeter,apache/jmeter,ham1/jmeter,ham1/jmeter,apache/jmeter,benbenw/jmeter,ham1/jmeter,benbenw/jmeter,ham1/jmeter,etnetera/jmeter,etnetera/jmeter