}


    /**
     * @return session increased usage count
     */
    public SmbSessionImpl acquire () {
        long usage = this.usageCount.incrementAndGet();
        if ( log.isTraceEnabled() ) {
            log.trace("Acquire session " + usage + " " + this);
        }

        if ( usage == 1 ) {
            synchronized ( this ) {

            if ( ssn.matches(tf, targetHost, targetDomain) ) {
                if ( log.isTraceEnabled() ) {
                    log.trace("Reusing existing session " + ssn);
                }
                return ssn.acquire();
            }
            else if ( log.isTraceEnabled() ) {
                log.trace("Existing session " + ssn + " does not match " + tf.getCredentials());
            }