libgcc/config/arc/gmon/prof-freq.c

   1 /* Return frequency of ticks reported by profil.  Generic version. */
   2 /*-
   3  * Copyright (c) 1983, 1992, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Copyright (C) 2007-2012 Free Software Foundation, Inc.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33
  34 #include <sys/types.h>
  35 #include <sys/time.h>
  36 #if 0
  37 #include <libc-internal.h>
  38 #else
  39 #include "sys/gmon.h"
  40 #endif
  41
  42 int
  43 __profile_frequency (void)
  44 {
  45   /*
  46    * Discover the tick frequency of the machine if something goes wrong,
  47    * we return 0, an impossible hertz.
  48    */
  49   struct itimerval tim;
  50
  51   tim.it_interval.tv_sec = 0;
  52   tim.it_interval.tv_usec = 1;
  53   tim.it_value.tv_sec = 0;
  54   tim.it_value.tv_usec = 0;
  55   setitimer(ITIMER_REAL, &tim, 0);
  56   setitimer(ITIMER_REAL, 0, &tim);
  57   if (tim.it_interval.tv_usec < 2)
  58     return 0;
  59   return (1000000 / tim.it_interval.tv_usec);
  60 }