leave_mutex.notify();
leave_mutex.notifyAll();
    public void handleViewChange(ViewId new_view, Vector mbrs) {        if(leaving) {            if(mbrs.contains(gms.local_addr)) {                if(log.isWarnEnabled()) log.warn("received view in which I'm still a member, cannot quit yet");                gms.installView(new_view, mbrs);  // +++ modify            }            else {                synchronized(leave_mutex) {                    received_last_view=true;                    leave_mutex.notify();                }            }            return;        }        gms.installView(new_view, mbrs);  // +++ modify    }