mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-19 03:20:05 +00:00
66539a737d
* include/libc-internal.h: Add prototype for __libc_freeres. * malloc/mtrace.c: Likewise. * malloc/set-freeres.c: Likewise.
80 lines
2.2 KiB
C
80 lines
2.2 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 <string.h>
|
|
#include <unistd.h>
|
|
#include <libc-internal.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;
|
|
}
|