(use srfi-18 posix)

(set-signal-handler!
 signal/alrm (lambda (n) (print "ring ring") (set-alarm! 1)))

(set-alarm! 1)

(thread-start! (lambda ()
                 (let lp ()
                   (print "spinning")
                   (thread-sleep! 0.1)
                   (lp))))

(thread-join!
 (thread-start! (lambda ()
                  (let lp ((ln (read-line)))
                    (unless (eof-object? ln)
                      (print ln)
                      (lp (read-line)))))))