gprof/hertz.c

   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
  34 hertz ()
  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 }