|
|
1.1 ! root 1: /* ! 2: * Copyright (c) 1983 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: #ifndef lint ! 19: static char sccsid[] = "@(#)hertz.c 5.3 (Berkeley) 6/29/88"; ! 20: #endif /* not lint */ ! 21: ! 22: #include <sys/time.h> ! 23: ! 24: /* ! 25: * discover the tick frequency of the machine ! 26: * if something goes wrong, we return 0, an impossible hertz. ! 27: */ ! 28: #define HZ_WRONG 0 ! 29: ! 30: hertz() ! 31: { ! 32: struct itimerval tim; ! 33: ! 34: tim.it_interval.tv_sec = 0; ! 35: tim.it_interval.tv_usec = 1; ! 36: tim.it_value.tv_sec = 0; ! 37: tim.it_value.tv_usec = 0; ! 38: setitimer(ITIMER_REAL, &tim, 0); ! 39: setitimer(ITIMER_REAL, 0, &tim); ! 40: if (tim.it_interval.tv_usec < 2) ! 41: return(HZ_WRONG); ! 42: return (1000000 / tim.it_interval.tv_usec); ! 43: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.