usleep(2)							System Calls Manual							 usleep(2)

NAME

       usleep - suspend execution for an interval

SYNOPSIS

DESCRIPTION

       The  function  will  cause the calling thread to be suspended from execution until either the number of real-time microseconds specified by
       the argument useconds has elapsed, or a signal is delivered to the calling thread and its action is to invoke a signal-catching function or
       to terminate the process.

       The  suspension	time may be longer than requested due to the scheduling of other activities by the system, or because of the time spent in
       processing the call.

       The useconds argument must be less than 1,000,000.  If the value of useconds is 0, then the call has no effect.

       If a signal is generated for the calling process during execution of and if the signal is being ignored or blocked  from  delivery,  it	is
       unspecified whether returns when the signal is scheduled; if the signal is being blocked, it is also unspecified whether it remains pending
       after returns or it is discarded.

       If a signal is generated for the calling process during execution of except as a result of a prior call to and if the signal is	not  being
       ignored or blocked from delivery, it is unspecified whether that signal has any effect other than causing to return.

       If a signal-catching function interrupts and examines or changes either the time a is scheduled to be generated, the action associated with
       the signal, or whether the signal is blocked from delivery, the results are unspecified.

       If a signal-catching function interrupts and calls or to restore an environment saved prior to the call, the  action  associated  with  the
       signal  and  the time at which a signal is scheduled to be generated are unspecified, it is also unspecified whether the signal is blocked,
       unless the process's signal mask is restored as part of the environment.

       Implementations may place limitations on the granularity of timer values. For each interval timer, if the requested timer value requires  a
       finer granularity than the implementation supports, the actual timer value will be rounded up to the next supported value.

       Interactions between and any of the following are unspecified:

RETURN VALUE

       On successful completion, returns 0. Otherwise, it returns -1 and sets to indicate the error.

ERRORS

       The function may fail if:

	      [EINVAL]		       The time interval specified 1,000,000 or more microseconds.

APPLICATION USAGE

       The  function  is  included  for its historical usage. The function is preferred over this function. Multi-threaded applications are recom-
       mended to use instead of is also a thread canceling point.

SEE ALSO

       alarm(2), getitimer(2), nanosleep(2), sigaction(2), sleep(3C),  timer_create(2),  timer_delete(2),  timer_getoverrun(2),  timer_gettime(2),
       timer_settime(2), <unistd.h>.

CHANGE HISTORY

       First released in Issue 4, Version 2.

																	 usleep(2)