SLEEP(3C)                DOMAIN/IX SYS5                 SLEEP(3C)



NAME
     sleep - suspend execution for interval

USAGE
     unsigned sleep (seconds)
     unsigned seconds;


DESCRIPTION
     Sleep suspends execution of the current process for the
     number of seconds specified by the argument.  The actual
     time may be less than the requested time because:

     ⊕  scheduled wakeups occur at fixed 1-second intervals, (on
        the second, according to an internal clock)

     ⊕  any caught signal will terminate the sleep following exe-
        cution of that signal's catching routine.  The the
        suspension time may also be longer than requested, due to
        the scheduling of other activity in the system.

     The value returned by sleep will be the "unslept" amount
     (the requested time minus the time actually slept), in case
     the caller had an alarm set to go off earlier than the end
     of the requested sleep time, or in case another caught sig-
     nal terminated sleep prematurely.

     The routine is implemented by setting an alarm signal and
     pausing until it (or some other signal) occurs.  The previ-
     ous state of the alarm signal is saved and restored.  The
     calling program may set up an alarm signal before calling
     sleep.  If the sleep time exceeds the time till such an
     alarm signal, the process sleeps only until the alarm signal
     would have occurred.  The caller's alarm catch routine is
     executed just before the sleep routine returns.  But if the
     sleep time is less than the time till such an alarm, the
     prior alarm time is reset to go off at the same time it
     would have without the intervening sleep.

RELATED INFORMATION
     alarm(2), pause(2), signal(2)












Printed 12/4/86                                           SLEEP-1