sendPingTermination();
sendPingInterrupt();
    void interruptPingerThread() {        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(); // will wake up the pinger thread. less elegant than Thread.interrupt(), but does the job        }    }