* Copyright (c) 1989 The Regents of the University of California.
* %sccs.include.redist.c%
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid
[] = "@(#)usleep.c 5.5 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
#define TICK 10000 /* system clock resolution in microseconds */
#define USPS 1000000 /* number of microseconds in a second */
vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0
register struct itimerval
*itp
;
struct itimerval itv
, oitv
;
timerclear(&itp
->it_interval
);
timerclear(&itp
->it_value
);
if (setitimer(ITIMER_REAL
, itp
, &oitv
) < 0)
itp
->it_value
.tv_sec
= useconds
/ USPS
;
itp
->it_value
.tv_usec
= useconds
% USPS
;
if (timerisset(&oitv
.it_value
)) {
if (timercmp(&oitv
.it_value
, &itp
->it_value
, >)) {
oitv
.it_value
.tv_sec
-= itp
->it_value
.tv_sec
;
oitv
.it_value
.tv_usec
-= itp
->it_value
.tv_usec
;
if (oitv
.it_value
.tv_usec
< 0) {
oitv
.it_value
.tv_usec
+= USPS
;
itp
->it_value
= oitv
.it_value
;
oitv
.it_value
.tv_sec
= 0;
oitv
.it_value
.tv_usec
= 2 * TICK
;
setvec(vec
, sleephandler
);
(void) sigvec(SIGALRM
, &vec
, &ovec
);
omask
= sigblock(sigmask(SIGALRM
));
(void) setitimer(ITIMER_REAL
, itp
, (struct itimerval
*)0);
sigpause(omask
&~ sigmask(SIGALRM
));
(void) sigvec(SIGALRM
, &ovec
, (struct sigvec
*)0);
(void) sigsetmask(omask
);
(void) setitimer(ITIMER_REAL
, &oitv
, (struct itimerval
*)0);