1 /* $NetBSD: ualarm.c,v 1.4 1995/02/25 15:39:33 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1985, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)ualarm.c 8.1 (Berkeley) 6/4/93"; 39 #else 40 static char rcsid[] = "$NetBSD: ualarm.c,v 1.4 1995/02/25 15:39:33 cgd Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <sys/time.h> 45 #include <unistd.h> 46 47 #define USPS 1000000 /* # of microseconds in a second */ 48 49 /* 50 * Generate a SIGALRM signal in ``usecs'' microseconds. 51 * If ``reload'' is non-zero, keep generating SIGALRM 52 * every ``reload'' microseconds after the first signal. 53 */ 54 unsigned 55 ualarm(usecs, reload) 56 register unsigned usecs; 57 register unsigned reload; 58 { 59 struct itimerval new, old; 60 61 new.it_interval.tv_usec = reload % USPS; 62 new.it_interval.tv_sec = reload / USPS; 63 64 new.it_value.tv_usec = usecs % USPS; 65 new.it_value.tv_sec = usecs / USPS; 66 67 if (setitimer(ITIMER_REAL, &new, &old) == 0) 68 return (old.it_value.tv_sec * USPS + old.it_value.tv_usec); 69 /* else */ 70 return (-1); 71 } 72