sleep(3C) — sys5



SLEEP(3C)       DOMAIN/IX Reference Manual (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 that requested for two reasons:

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

     (2)  Because any caught signal will terminate the sleep fol-
          lowing execution of that signal's catching routine.
          Also, the suspension time may be longer than requested
          by an arbitrary amount 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 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 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 5/10/85                                           SLEEP-1
Museum
