add getvfsbyname

[unix-history] / usr / src / lib / libc / gen / sleep.c

/*
* Copyright (c) 1989, 1993
*      The Regents of the University of California.  All rights reserved.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)sleep.c     8.1 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/time.h>
#include <sys/signal.h>
#include <unistd.h>

#define setvec(vec, a) \
       vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0

static int ringring;

unsigned int
sleep(seconds)
       unsigned int seconds;
{
       register struct itimerval *itp;
       struct itimerval itv, oitv;
       struct sigvec vec, ovec;
       long omask;
       static void sleephandler();

       itp = &itv;
       if (!seconds)
               return 0;
       timerclear(&itp->it_interval);
       timerclear(&itp->it_value);
       if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
               return seconds;
       itp->it_value.tv_sec = seconds;
       if (timerisset(&oitv.it_value)) {
               if (timercmp(&oitv.it_value, &itp->it_value, >))
                       oitv.it_value.tv_sec -= itp->it_value.tv_sec;
               else {
                       itp->it_value = oitv.it_value;
                       /*
                        * This is a hack, but we must have time to return
                        * from the setitimer after the alarm or else it'll
                        * be restarted.  And, anyway, sleep never did
                        * anything more than this before.
                        */
                       oitv.it_value.tv_sec = 1;
                       oitv.it_value.tv_usec = 0;
               }
       }
       setvec(vec, sleephandler);
       (void) sigvec(SIGALRM, &vec, &ovec);
       omask = sigblock(sigmask(SIGALRM));
       ringring = 0;
       (void) setitimer(ITIMER_REAL, itp, (struct itimerval *)0);
       while (!ringring)
               sigpause(omask &~ sigmask(SIGALRM));
       (void) sigvec(SIGALRM, &ovec, (struct sigvec *)0);
       (void) sigsetmask(omask);
       (void) setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0);
       return 0;
}

static void
sleephandler()
{
       ringring = 1;
}