glibc/sysdeps/unix/sysv/linux/i386/get_clockfreq.c
Ulrich Drepper e7c036b39e Update.
2000-04-11  Ulrich Drepper  <drepper@redhat.com>

	* posix/globtest.sh: Fix last change.

2000-04-10  Philip Blundell  <philb@gnu.org>

	* sysdeps/unix/sysv/linux/bits/in.h (IPV6_JOIN_GROUP,
	IPV6_LEAVE_GROUP): New names for IPV6_ADD_MEMBERSHIP,
	IPV6_DROP_MEMBERSHIP.
	* sysdeps/generic/bits/in.h (IPV6_JOIN_GROUP, IPV6_LEAVE_GROUP):
	Likewise.

2000-04-11  Ulrich Drepper  <drepper@redhat.com>

	* elf/readlib (process_file): Close streams in case of an error.

2000-04-09  Andreas Jaeger  <aj@suse.de>

	* elf/readlib.c (process_file): Check if file is big enough to
	contain aout and ELF headers.
	Reported by Reinhard Moosauer <RMoosauer@steinecker.com>.

2000-04-10  Jes Sorensen  <Jes.Sorensen@cern.ch>

	* elf/dl-fini.c: Include alloca.h to get proper prototype for alloca().

2000-04-11  Ulrich Drepper  <drepper@redhat.com>

	* test-skeleton.c (main): If STDOUT_UNBUFFERED is defined, make stdout
	stream unbuffered.
	* rt/Makefile (tests): Add tst-clock.
	Add rules to build tst-clock.
	* rt/tst-clock.c: New file.
	* sysdeps/unix/i386/i586/clock_getres.c: Correct expression to decide
	about initialization of nsec.
	* sysdeps/unix/i386/i586/clock_gettime.c: Correct expression to decide
	about initialization of freq.  Set retval to zero if successful.
	* sysdeps/unix/sysv/linux/i386/get_clockfreq.c: Cache result.
2000-04-11 16:27:38 +00:00

78 lines
2.1 KiB
C

/* Get frequency of the system processor. i386/Linux version.
Copyright (C) 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library 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.
The GNU C Library 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 the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
unsigned long long int
__get_clockfreq (void)
{
/* We read the information from the /proc filesystem. It contains at
least one line like
cpu MHz : 497.840237
We search for this line and convert the number in an integer. */
static unsigned long long int result;
int fd;
/* If this function was called before, we know the result. */
if (result != 0)
return result;
fd = open ("/proc/cpuinfo", O_RDONLY);
if (__builtin_expect (fd != -1, 1))
{
/* XXX AFAIK the /proc filesystem can generate "files" only up
to a size of 4096 bytes. */
char buf[4096];
ssize_t n;
n = read (fd, buf, sizeof buf);
if (__builtin_expect (n, 1) > 0)
{
char *mhz = memmem (buf, n, "cpu MHz", 7);
if (__builtin_expect (mhz != NULL, 1))
{
char *endp = buf + n;
/* Search for the beginning of the string. */
while (mhz < endp && (*mhz < '0' || *mhz > '9') && *mhz != '\n')
++mhz;
while (mhz < endp && *mhz != '\n')
{
if (*mhz >= '0' && *mhz <= '9')
{
result *= 10;
result += *mhz - '0';
}
++mhz;
}
}
}
close (fd);
}
return result;
}