1 /* 2 * Copyright (c) 1985 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 */ 6 7 #if defined(LIBC_SCCS) && !defined(lint) 8 static char sccsid[] = "@(#)ualarm.c 5.2 (Berkeley) 03/09/86"; 9 #endif LIBC_SCCS and not lint 10 11 #include <sys/time.h> 12 13 #define USPS 1000000 /* # of microseconds in a second */ 14 15 /* 16 * Generate a SIGALRM signal in ``usecs'' microseconds. 17 * If ``reload'' is non-zero, keep generating SIGALRM 18 * every ``reload'' microseconds after the first signal. 19 */ 20 unsigned 21 ualarm(usecs, reload) 22 register unsigned usecs; 23 register unsigned reload; 24 { 25 struct itimerval new, old; 26 27 new.it_interval.tv_usec = reload % USPS; 28 new.it_interval.tv_sec = reload / USPS; 29 30 new.it_value.tv_usec = usecs % USPS; 31 new.it_value.tv_sec = usecs / USPS; 32 33 if (setitimer(ITIMER_REAL, &new, &old) == 0) 34 return (old.it_value.tv_sec * USPS + old.it_value.tv_usec); 35 /* else */ 36 return (-1); 37 } 38