1 /*
2  * Copyright (c) 1983, 1993
3  *      The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 #include "gprof.h"
30 #include "hertz.h"
31 
32 
33 int
hertz(void)34 hertz (void)
35 {
36 #ifdef HERTZ
37   return HERTZ;
38 #else /* ! defined (HERTZ) */
39 #ifdef HAVE_SETITIMER
40   struct itimerval tim;
41 
42   tim.it_interval.tv_sec = 0;
43   tim.it_interval.tv_usec = 1;
44   tim.it_value.tv_sec = 0;
45   tim.it_value.tv_usec = 0;
46   setitimer (ITIMER_REAL, &tim, 0);
47   setitimer (ITIMER_REAL, 0, &tim);
48   if (tim.it_interval.tv_usec >= 2)
49     {
50       return 1000000 / tim.it_interval.tv_usec;
51     }
52 #endif /* ! defined (HAVE_SETITIMER) */
53 #if defined (HAVE_SYSCONF) && defined (_SC_CLK_TCK)
54   return sysconf (_SC_CLK_TCK);
55 #else /* ! defined (HAVE_SYSCONF) || ! defined (_SC_CLK_TCK) */
56 #ifdef __MSDOS__
57   return 18;
58 #else  /* ! defined (__MSDOS__) */
59   return HZ_WRONG;
60 #endif /* ! defined (__MSDOS__) */
61 #endif /* ! defined (HAVE_SYSCONF) || ! defined (_SC_CLK_TCK) */
62 #endif /* ! defined (HERTZ) */
63 }
64