/* Return time used so far, in microseconds.

   Copyright (C) 1994-2025 Free Software Foundation, Inc.

This file is part of the libiberty library.

Libiberty is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 of the License, or (at your option) any later version.

Libiberty is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with libiberty; see the file COPYING.LIB.  If

not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,

Boston, MA 02110-1301, USA.  */

#include "config.h"

#include "ansidecl.h"

#include "libiberty.h"

/* On some systems (such as WindISS), you must include <sys/types.h>

   to get the definition of "time_t" before you include <time.h>.  */

#include <sys/types.h>

/* There are several ways to get elapsed execution time; unfortunately no

   single way is available for all host systems, nor are there reliable

   ways to find out which way is correct for a given host. */

#ifdef TIME_WITH_SYS_TIME

# include <sys/time.h>

# include <time.h>

#else

# if HAVE_SYS_TIME_H

#  include <sys/time.h>

# else

#  ifdef HAVE_TIME_H

#   include <time.h>

#  endif

# endif

#endif

#if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)

#include <sys/resource.h>

#endif

#ifdef HAVE_TIMES

#ifdef HAVE_SYS_PARAM_H

#include <sys/param.h>

#endif

#include <sys/times.h>

#endif

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

/* This is a fallback; if wrong, it will likely make obviously wrong

   results. */

#ifndef CLOCKS_PER_SEC

#define CLOCKS_PER_SEC 1

#endif

#ifndef RUSAGE_SELF

#define RUSAGE_SELF 0

#endif

#ifdef _SC_CLK_TCK

#define GNU_HZ  sysconf(_SC_CLK_TCK)

#else

#ifdef HZ

#define GNU_HZ  HZ

#else

#ifdef CLOCKS_PER_SEC

#define GNU_HZ  CLOCKS_PER_SEC

#endif

#endif

#endif

/*

@deftypefn Replacement long get_run_time (void)

Returns the time used so far, in microseconds.  If possible, this is

the time used by this process, else it is the elapsed time since the

process started.

@end deftypefn

*/

long

get_run_time (void)

{

#if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)

  struct rusage rusage;

  getrusage (RUSAGE_SELF, &rusage);

  return (rusage.ru_utime.tv_sec * 1000000 + rusage.ru_utime.tv_usec

    + rusage.ru_stime.tv_sec * 1000000 + rusage.ru_stime.tv_usec);

#else /* ! HAVE_GETRUSAGE */

#ifdef HAVE_TIMES

  struct tms tms;

  times (&tms);

  return (tms.tms_utime + tms.tms_stime) * (1000000 / GNU_HZ);

#else /* ! HAVE_TIMES */

  /* Fall back on clock and hope it's correctly implemented. */

  const long clocks_per_sec = CLOCKS_PER_SEC;

  if (clocks_per_sec <= 1000000)

    return clock () * (1000000 / clocks_per_sec);

  else

    return clock () / clocks_per_sec;

#endif  /* HAVE_TIMES */

#endif  /* HAVE_GETRUSAGE */

}