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- /*
- * 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) */
- }
-