1 | /*
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2 | * Copyright (c) 1985, 1993
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3 | * The Regents of the University of California. All rights reserved.
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4 | *
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5 | * Redistribution and use in source and binary forms, with or without
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6 | * modification, are permitted provided that the following conditions
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7 | * are met:
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8 | * 1. Redistributions of source code must retain the above copyright
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9 | * notice, this list of conditions and the following disclaimer.
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10 | * 2. Redistributions in binary form must reproduce the above copyright
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11 | * notice, this list of conditions and the following disclaimer in the
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12 | * documentation and/or other materials provided with the distribution.
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13 | * 3. All advertising materials mentioning features or use of this software
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14 | * must display the following acknowledgement:
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15 | * This product includes software developed by the University of
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16 | * California, Berkeley and its contributors.
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17 | * 4. Neither the name of the University nor the names of its contributors
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18 | * may be used to endorse or promote products derived from this software
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19 | * without specific prior written permission.
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20 | *
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21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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31 | * SUCH DAMAGE.
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32 | */
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33 |
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34 | #if defined(LIBC_SCCS) && !defined(lint)
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35 | static char sccsid[] = "@(#)ualarm.c 8.1 (Berkeley) 6/4/93";
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36 | #endif /* LIBC_SCCS and not lint */
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37 | #include <sys/cdefs.h>
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38 | __FBSDID("$FreeBSD: src/lib/libc/gen/ualarm.c,v 1.4 2002/12/29 00:59:09 mike Exp $");
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39 |
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40 | #include <sys/time.h>
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41 | #include <unistd.h>
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42 |
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43 | #define USPS 1000000 /* # of microseconds in a second */
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44 |
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45 | /*
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46 | * Generate a SIGALRM signal in ``usecs'' microseconds.
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47 | * If ``reload'' is non-zero, keep generating SIGALRM
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48 | * every ``reload'' microseconds after the first signal.
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49 | */
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50 | useconds_t
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51 | ualarm(usecs, reload)
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52 | useconds_t usecs;
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53 | useconds_t reload;
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54 | {
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55 | struct itimerval new, old;
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56 |
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57 | new.it_interval.tv_usec = reload % USPS;
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58 | new.it_interval.tv_sec = reload / USPS;
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59 |
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60 | new.it_value.tv_usec = usecs % USPS;
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61 | new.it_value.tv_sec = usecs / USPS;
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62 |
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63 | if (setitimer(ITIMER_REAL, &new, &old) == 0)
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64 | return (old.it_value.tv_sec * USPS + old.it_value.tv_usec);
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65 | /* else */
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66 | return (-1);
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67 | }
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