diff options
Diffstat (limited to 'gprof/hertz.c')
| -rw-r--r-- | gprof/hertz.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/gprof/hertz.c b/gprof/hertz.c new file mode 100644 index 0000000..1c2927f --- /dev/null +++ b/gprof/hertz.c @@ -0,0 +1,45 @@ +/* + * 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. + */ + +#ifndef lint +static char sccsid[] = "@(#)hertz.c 5.4 (Berkeley) 6/1/90"; +#endif /* not lint */ + +#include <sys/time.h> + + /* + * discover the tick frequency of the machine + * if something goes wrong, we return 0, an impossible hertz. + */ +#define HZ_WRONG 0 + +hertz() +{ + 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); +} |