--- sleep([sec])

    sec äץμ¹Ԥߤޤsec
    ˤưǤޤsec ά줿
    硢(SIGALRM ޤ¾åɤ
    Thread#run [Thread/run]) ʤɤŪ˵ʤ¤
    פ˥꡼פޤͤϼºݤߤƤÿ()Ǥ

