USLEEP(3)USLEEP(3)NAMEusleep - suspend execution for interval
SYNOPSISusleep(useconds)
unsigned useconds;
DESCRIPTION
The current process is suspended from execution for the number of
microseconds specified by the argument. The actual suspension time may
be an arbitrary amount longer because of other activity in the system
or because of the time spent in processing the call.
The routine is implemented by setting an interval timer and pausing
until it occurs. The previous state of this timer is saved and
restored. If the sleep time exceeds the time to the expiration of the
previous timer, the process sleeps only until the signal would have
occurred, and the signal is sent a short time later.
This routine is implemented using setitimer(2); it requires eight sys‐
tem calls each time it is invoked. A similar but less compatible func‐
tion can be obtained with a single select(2); it would not restart
after signals, but would not interfere with other uses of setitimer.
SEE ALSOsetitimer(2), getitimer(2), sigpause(2), ualarm(3), sleep(3), alarm(3)4.3 Berkeley Distribution May 15, 1986 USLEEP(3)