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Annotation of 42BSD/lib/libc/gen/sleep.c, revision 1.1

1.1     ! root        1: #ifndef lint
        !             2: static char sccsid[] = "@(#)sleep.c    4.6 (Berkeley) 9/11/83";
        !             3: #endif
        !             4: 
        !             5: #include <sys/time.h>
        !             6: #include <signal.h>
        !             7: 
        !             8: #define        mask(s) (1<<((s)-1))
        !             9: #define        setvec(vec, a) \
        !            10:        vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0
        !            11: 
        !            12: static int ringring;
        !            13: 
        !            14: sleep(n)
        !            15:        unsigned n;
        !            16: {
        !            17:        int sleepx(), omask;
        !            18:        struct itimerval itv, oitv;
        !            19:        register struct itimerval *itp = &itv;
        !            20:        struct sigvec vec, ovec;
        !            21: 
        !            22:        if (n == 0)
        !            23:                return;
        !            24:        timerclear(&itp->it_interval);
        !            25:        timerclear(&itp->it_value);
        !            26:        if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
        !            27:                return;
        !            28:        setvec(ovec, SIG_DFL);
        !            29:        omask = sigblock(0);
        !            30:        itp->it_value.tv_sec = n;
        !            31:        if (timerisset(&oitv.it_value)) {
        !            32:                if (timercmp(&oitv.it_value, &itp->it_value, >))
        !            33:                        oitv.it_value.tv_sec -= itp->it_value.tv_sec;
        !            34:                else {
        !            35:                        itp->it_value = oitv.it_value;
        !            36:                        /*
        !            37:                         * This is a hack, but we must have time to
        !            38:                         * return from the setitimer after the alarm
        !            39:                         * or else it'll be restarted.  And, anyway,
        !            40:                         * sleep never did anything more than this before.
        !            41:                         */
        !            42:                        oitv.it_value.tv_sec = 1;
        !            43:                        oitv.it_value.tv_usec = 0;
        !            44:                }
        !            45:        }
        !            46:        setvec(vec, sleepx);
        !            47:        (void) sigvec(SIGALRM, &vec, &ovec);
        !            48:        ringring = 0;
        !            49:        (void) setitimer(ITIMER_REAL, itp, (struct itimerval *)0);
        !            50:        while (!ringring)
        !            51:                sigpause(omask &~ mask(SIGALRM));
        !            52:        (void) sigvec(SIGALRM, &ovec, (struct sigvec *)0);
        !            53:        (void) setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0);
        !            54: }
        !            55: 
        !            56: static
        !            57: sleepx()
        !            58: {
        !            59: 
        !            60:        ringring = 1;
        !            61: }

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