(labels ((gzip ()
           (let* ((process (run-program "/bin/gzip" '("-9" "-f")
                                        :input :stream :output "/dev/null"
                                        :if-output-exists :supersede :wait nil))
                  (in (process-input process)))
             (write nil :stream in)
             (close in)
             (process-wait process)
             (process-close process))))
  (dotimes (i 3)
    (sb-thread:make-thread (lambda () 
                             (dotimes (n 100) 
                               (gzip))))))