1 /* 2 * Copyright (c) 1985, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char rcsid[] = "$OpenBSD: ualarm.c,v 1.4 1997/11/06 01:25:48 millert Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/types.h> 39 #include <sys/time.h> 40 #include <unistd.h> 41 42 #define USPS 1000000 /* # of microseconds in a second */ 43 44 /* 45 * Generate a SIGALRM signal in ``usecs'' microseconds. 46 * If ``reload'' is non-zero, keep generating SIGALRM 47 * every ``reload'' microseconds after the first signal. 48 */ 49 useconds_t 50 ualarm(usecs, reload) 51 register useconds_t usecs; 52 register useconds_t reload; 53 { 54 struct itimerval new, old; 55 56 new.it_interval.tv_usec = reload % USPS; 57 new.it_interval.tv_sec = reload / USPS; 58 59 new.it_value.tv_usec = usecs % USPS; 60 new.it_value.tv_sec = usecs / USPS; 61 62 if (setitimer(ITIMER_REAL, &new, &old) == 0) 63 return ((useconds_t)(old.it_value.tv_sec * USPS + old.it_value.tv_usec)); 64 /* else */ 65 return ((useconds_t)-1); 66 } 67