pinger_thread=null;
    void stopPingerThread() {        synchronized(pinger_mutex) {            if(pinger_thread != null && pinger_thread.isAlive()) {                regular_sock_close=true;                sendPingTermination(); // PATCH by Bruce Schuchardt (http://jira.jboss.com/jira/browse/JGRP-246)                teardownPingSocket();            }            pinger_thread=null;        }    }