1 /* 2 * Copyright (c) 1985 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)ualarm.c 5.3 (Berkeley) 08/02/88"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 #include <sys/time.h> 23 24 #define USPS 1000000 /* # of microseconds in a second */ 25 26 /* 27 * Generate a SIGALRM signal in ``usecs'' microseconds. 28 * If ``reload'' is non-zero, keep generating SIGALRM 29 * every ``reload'' microseconds after the first signal. 30 */ 31 unsigned 32 ualarm(usecs, reload) 33 register unsigned usecs; 34 register unsigned reload; 35 { 36 struct itimerval new, old; 37 38 new.it_interval.tv_usec = reload % USPS; 39 new.it_interval.tv_sec = reload / USPS; 40 41 new.it_value.tv_usec = usecs % USPS; 42 new.it_value.tv_sec = usecs / USPS; 43 44 if (setitimer(ITIMER_REAL, &new, &old) == 0) 45 return (old.it_value.tv_sec * USPS + old.it_value.tv_usec); 46 /* else */ 47 return (-1); 48 } 49