swap.c

来自「linux 操作系统下对系统资源监控程序的编写」· C语言 代码 · 共 103 行

/* $Id: swap.c,v 1.24 2003/12/23 10:44:33 hadess Exp $ */

/* Copyright (C) 1998-99 Martin Baulig
   This file is part of LibGTop 1.0.

   Contributed by Martin Baulig <[e-mail]>, April 1998.

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

   LibGTop 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 LibGTop; see the file COPYING. If not, write to the
   Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.
*/

#include <config.h>
#include <glibtop/error.h>
#include <glibtop/swap.h>

#include <fcntl.h>

static unsigned long _glibtop_sysdeps_swap =
(1L << GLIBTOP_SWAP_TOTAL) + (1L << GLIBTOP_SWAP_USED) +
(1L << GLIBTOP_SWAP_FREE);

static unsigned long _glibtop_sysdeps_swap_paging =
(1L << GLIBTOP_SWAP_PAGEIN) + (1L << GLIBTOP_SWAP_PAGEOUT);

/* Init function. */

void
glibtop_init_swap_s (glibtop *server)
{
	server->sysdeps.swap = _glibtop_sysdeps_swap |
		_glibtop_sysdeps_swap_paging;
}

/* Provides information about swap usage. */

#define MEMINFO		"/proc/meminfo"
#define PROC_STAT	"/proc/stat"

void
glibtop_get_swap_s (glibtop *server, glibtop_swap *buf)
{
	char buffer [BUFSIZ], *p;
	int fd, len;

	glibtop_init_s (&server, GLIBTOP_SYSDEPS_SWAP, 0);

	memset (buf, 0, sizeof (glibtop_swap));

	fd = open (MEMINFO, O_RDONLY);
	if (fd < 0)
		glibtop_error_io_r (server, "open (%s)", MEMINFO);

	len = read (fd, buffer, BUFSIZ-1);
	if (len < 0)
		glibtop_error_io_r (server, "read (%s)", MEMINFO);

	close (fd);

	buffer [len] = '\0';

	/* Kernel 2.6 with multiple lines */
 
	buf->total = get_scaled(buffer, "SwapTotal:");
	buf->free = get_scaled(buffer, "SwapFree:");
	buf->used = buf->total - buf->free;

	buf->flags = _glibtop_sysdeps_swap;

	fd = open (PROC_STAT, O_RDONLY);
	if (fd < 0)
		glibtop_error_io_r (server, "open (%s)", PROC_STAT);

	len = read (fd, buffer, BUFSIZ-1);
	if (len < 0)
		glibtop_error_io_r (server, "read (%s)", PROC_STAT);

	close (fd);

	buffer [len] = '\0';

	p = strstr (buffer, "\nswap");
	if (p == NULL) return;

	p = skip_token (p);

	buf->pagein  = strtoull (p, &p, 0);
	buf->pageout = strtoull (p, &p, 0);

	buf->flags |= _glibtop_sysdeps_swap_paging;
}