times.c

UNIX下SH的实现源码

/* times.c - times(3) library function */

/* Copyright (C) 1999 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash is free software; you can redistribute it and/or modify it under
   the terms of the GNU General Public License as published by the Free
   Software Foundation; either version 2, or (at your option) any later
   version.

   Bash 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 General Public License
   for more details.

   You should have received a copy of the GNU General Public License along
   with Bash; see the file COPYING.  If not, write to the Free Software
   Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */

#include <config.h>

#if !defined (HAVE_TIMES)

#include <sys/types.h>
#include <posixtime.h>
#include <systimes.h>

#if defined (HAVE_SYS_RESOURCE_H) && defined (HAVE_GETRUSAGE)
#  include <sys/resource.h>
#endif /* HAVE_SYS_RESOURCE_H && HAVE_GETRUSAGE */

extern long	get_clk_tck();

#define CONVTCK(r)      (r.tv_sec * clk_tck + r.tv_usec / (1000000 / clk_tck))

clock_t
times(tms)
	struct tms *tms;
{
	clock_t rv;
	static long clk_tck = -1;

#if defined (HAVE_GETRUSAGE)
	struct timeval tv;
	struct rusage ru;

	if (clk_tck == -1)
		clk_tck = get_clk_tck();

	if (getrusage(RUSAGE_SELF, &ru) < 0)
		return ((clock_t)-1);
	tms->tms_utime = CONVTCK(ru.ru_utime);
	tms->tms_stime = CONVTCK(ru.ru_stime);

	if (getrusage(RUSAGE_CHILDREN, &ru) < 0)
		return ((clock_t)-1);
	tms->tms_cutime = CONVTCK(ru.ru_utime);
	tms->tms_cstime = CONVTCK(ru.ru_stime);

	if (gettimeofday(&tv, (struct timezone *) 0) < 0)
		return ((clock_t)-1);
        rv = (clock_t)(CONVTCK(tv));
#else /* !HAVE_GETRUSAGE */
	if (clk_tck == -1)
		clk_tck = get_clk_tck();

	/* We can't do anything. */
	tms->tms_utime = tms->tms_stime = (clock_t)0;
	tms->tms_cutime = tms->tms_cstime = (clock_t)0;

	rv = (clock_t)time((time_t *)0) * clk_tck;
# endif /* HAVE_GETRUSAGE */

	return rv;
}
#endif /* !HAVE_TIMES */