uptime.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 74 行

/* $Id: uptime.c,v 1.2 2003/10/19 16:54:39 carlos 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 <glibtop.h>
#include <glibtop/error.h>
#include <glibtop/uptime.h>

#include <glibtop/cpu.h>

#include <glibtop_suid.h>

static const unsigned long _glibtop_sysdeps_uptime =
(1L << GLIBTOP_UPTIME_UPTIME) + (1L << GLIBTOP_UPTIME_IDLETIME);

static const unsigned long _required_cpu_flags =
(1L << GLIBTOP_CPU_TOTAL) + (1L << GLIBTOP_CPU_IDLE) +
(1L << GLIBTOP_CPU_FREQUENCY);

/* Init function. */

void
glibtop_init_uptime_p (glibtop *server)
{
	server->sysdeps.uptime = _glibtop_sysdeps_uptime;
}

/* Provides uptime and idle time. */

void
glibtop_get_uptime_p (glibtop *server, glibtop_uptime *buf)
{
	glibtop_cpu cpu;

	glibtop_init_p (server, (1L << GLIBTOP_SYSDEPS_UPTIME), 0);
	
	memset (buf, 0, sizeof (glibtop_uptime));

	/* We simply calculate it from the CPU usage. */

	glibtop_get_cpu_p (server, &cpu);

	/* Make sure all required fields are present. */

	if ((cpu.flags & _required_cpu_flags) != _required_cpu_flags)
		return;

	/* Calculate values. */

	buf->uptime = (double) cpu.total / (double) cpu.frequency;
	buf->idletime = (double) cpu.idle / (double) cpu.frequency;

	buf->flags = _glibtop_sysdeps_uptime;
}