/* * Copyright (c) 1983 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that: (1) source distributions retain this entire copyright * notice and comment, and (2) distributions including binaries display * the following acknowledgement: ``This product includes software * developed by the University of California, Berkeley and its contributors'' * in the documentation or other materials provided with the distribution * and in all advertising materials mentioning features or use of this * software. Neither the name of the University nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #include #include "hertz.h" #ifdef __MSDOS__ #define HERTZ 18 #endif int hertz () { #ifdef HERTZ return HERTZ; #else struct itimerval tim; tim.it_interval.tv_sec = 0; tim.it_interval.tv_usec = 1; tim.it_value.tv_sec = 0; tim.it_value.tv_usec = 0; setitimer (ITIMER_REAL, &tim, 0); setitimer (ITIMER_REAL, 0, &tim); if (tim.it_interval.tv_usec < 2) { return HZ_WRONG; } /* if */ return 1000000 / tim.it_interval.tv_usec; #endif } /* hertz */