55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
|
/*
|
||
|
|
* 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 "hertz.h"
|
||
|
|
|
||
|
|
|
||
|
|
#ifdef __MSDOS__
|
||
|
|
#define HERTZ 18
|
||
|
|
#endif
|
||
|
|
|
||
|
|
int
|
||
|
|
hertz ()
|
||
|
|
{
|
||
|
|
#ifdef HERTZ
|
||
|
|
return HERTZ;
|
||
|
|
#else /* ! defined (HERTZ) */
|
||
|
|
#ifdef HAVE_SETITIMER
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
return 1000000 / tim.it_interval.tv_usec;
|
||
|
|
#else /* ! defined (HAVE_SETITIMER) */
|
||
|
|
#if defined (HAVE_SYSCONF) && defined (_SC_CLK_TCK)
|
||
|
|
return sysconf (_SC_CLK_TCK);
|
||
|
|
#else /* ! defined (HAVE_SYSCONF) || ! defined (_SC_CLK_TCK) */
|
||
|
|
return HZ_WRONG;
|
||
|
|
#endif /* ! defined (HAVE_SYSCONF) || ! defined (_SC_CLK_TCK) */
|
||
|
|
#endif /* ! defined (HAVE_SETITIMER) */
|
||
|
|
#endif /* ! defined (HERTZ) */
|
||
|
|
}
|