getloadavg.c

功能强大的ftp服务器源代码

/* Get the system load averages.
   Copyright (C) 1985, 86, 87, 88, 89, 91, 92, 93, 1994, 1995, 1997
   	Free Software Foundation, Inc.

   This program 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.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
   USA.  */

/* Compile-time symbols that this file uses:

   HAVE_PSTAT_GETDYNAMIC	Define this if your system has the
                                pstat_getdynamic function.  I think it
				is unique to HPUX9.  The best way to get the
				definition is through the AC_FUNC_GETLOADAVG
				macro that comes with autoconf 2.13 or newer.
				If that isn't an option, then just put
				AC_CHECK_FUNCS(pstat_getdynamic) in your
				configure.in file.
   FIXUP_KERNEL_SYMBOL_ADDR()	Adjust address in returned struct nlist.
   KERNEL_FILE			Pathname of the kernel to nlist.
   LDAV_CVT()			Scale the load average from the kernel.
				Returns a double.
   LDAV_SYMBOL			Name of kernel symbol giving load average.
   LOAD_AVE_TYPE		Type of the load average array in the kernel.
				Must be defined unless one of
				apollo, DGUX, NeXT, or UMAX is defined;
				otherwise, no load average is available.
   NLIST_STRUCT			Include nlist.h, not a.out.h, and
				the nlist n_name element is a pointer,
				not an array.
   NLIST_NAME_UNION		struct nlist has an n_un member, not n_name.
   LINUX_LDAV_FILE		[__linux__]: File containing load averages.

   Specific system predefines this file uses, aside from setting
   default values if not emacs:

   apollo
   BSD				Real BSD, not just BSD-like.
   convex
   DGUX
   eunice			UNIX emulator under VMS.
   hpux
   __MSDOS__			No-op for MSDOS.
   NeXT
   sgi
   sequent			Sequent Dynix 3.x.x (BSD)
   _SEQUENT_			Sequent DYNIX/ptx 1.x.x (SYSV)
   sony_news                    NEWS-OS (works at least for 4.1C)
   UMAX
   UMAX4_3
   VMS
   WINDOWS32			No-op for Windows95/NT.
   __linux__			Linux: assumes /proc filesystem mounted.
   				Support from Michael K. Johnson.
   __NetBSD__			NetBSD: assumes /kern filesystem mounted.

   In addition, to avoid nesting many #ifdefs, we internally set
   LDAV_DONE to indicate that the load average has been computed.

   We also #define LDAV_PRIVILEGED if a program will require
   special installation to be able to call getloadavg.  */

/* This should always be first.  */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#ifndef HAVE_GETLOADAVG

#include <sys/types.h>

/* Both the Emacs and non-Emacs sections want this.  Some
   configuration files' definitions for the LOAD_AVE_CVT macro (like
   sparc.h's) use macros like FSCALE, defined here.  */
#ifdef unix
# include <sys/param.h>
#endif


/* Exclude all the code except the test program at the end
   if the system has its own `getloadavg' function.

   The declaration of `errno' is needed by the test program
   as well as the function itself, so it comes first.  */

#include <errno.h>

#ifndef errno
extern int errno;
#endif

/* The existing Emacs configuration files define a macro called
   LOAD_AVE_CVT, which accepts a value of type LOAD_AVE_TYPE, and
   returns the load average multiplied by 100.  What we actually want
   is a macro called LDAV_CVT, which returns the load average as an
   unmultiplied double.

   For backwards compatibility, we'll define LDAV_CVT in terms of
   LOAD_AVE_CVT, but future machine config files should just define
   LDAV_CVT directly.  */

# if !defined(LDAV_CVT) && defined(LOAD_AVE_CVT)
#  define LDAV_CVT(n) (LOAD_AVE_CVT(n) / 100.0)
# endif

# if !defined (BSD) && defined (ultrix)
/* Ultrix behaves like BSD on Vaxen.  */
#  define BSD
# endif

# ifdef NeXT
/* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which
   conflicts with the definition understood in this file, that this
   really is BSD. */
#  undef BSD

/* NeXT defines FSCALE in <sys/param.h>.  However, we take FSCALE being
   defined to mean that the nlist method should be used, which is not true.  */
#  undef FSCALE
# endif

/* Set values that are different from the defaults, which are
   set a little farther down with #ifndef.  */


/* Some shorthands.  */

# if defined (HPUX) && !defined (hpux)
#  define hpux
# endif

# if defined (__hpux) && !defined (hpux)
#  define hpux
# endif

# if defined (__sun) && !defined (sun)
#  define sun
# endif

# if defined(hp300) && !defined(hpux)
#  define MORE_BSD
# endif

# if defined(ultrix) && defined(mips)
#  define decstation
# endif

# if defined (__SVR4) && !defined (SVR4)
#  define SVR4
# endif

# if (defined(sun) && defined(SVR4)) || defined (SOLARIS2)
#  define SUNOS_5
# endif

# if defined (__osf__) && (defined (__alpha) || defined (__alpha__))
#  define OSF_ALPHA
#  include <sys/mbuf.h>
#  include <sys/socket.h>
#  include <net/route.h>
#  include <sys/table.h>
# endif

# if defined (__osf__) && (defined (mips) || defined (__mips__))
#  define OSF_MIPS
#  include <sys/table.h>
# endif

/* UTek's /bin/cc on the 4300 has no architecture specific cpp define by
   default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>.  Combine
   that with a couple of other things and we'll have a unique match.  */
# if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES)
#  define tek4300			/* Define by emacs, but not by other users.  */
# endif


/* VAX C can't handle multi-line #ifs, or lines longer than 256 chars.  */
# ifndef LOAD_AVE_TYPE

#  ifdef MORE_BSD
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef sun
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef decstation
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef _SEQUENT_
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef sgi
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef SVR4
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef sony_news
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef sequent
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef OSF_ALPHA
#   define LOAD_AVE_TYPE long
#  endif

#  if defined (ardent) && defined (titan)
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef tek4300
#   define LOAD_AVE_TYPE long
#  endif

#  if defined(alliant) && defined(i860) /* Alliant FX/2800 */
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef _AIX
#   define LOAD_AVE_TYPE long
#  endif

#  ifdef convex
#   define LOAD_AVE_TYPE double
#   ifndef LDAV_CVT
#    define LDAV_CVT(n) (n)
#   endif
#  endif

# endif /* No LOAD_AVE_TYPE.  */

# ifdef OSF_ALPHA
/* <sys/param.h> defines an incorrect value for FSCALE on Alpha OSF/1,
   according to [e-mail].  */
#  undef FSCALE
#  define FSCALE 1024.0
# endif

# if defined(alliant) && defined(i860) /* Alliant FX/2800 */
/* <sys/param.h> defines an incorrect value for FSCALE on an
   Alliant FX/2800 Concentrix 2.2, according to [e-mail].  */
#  undef FSCALE
#  define FSCALE 100.0
# endif


# ifndef	FSCALE

/* SunOS and some others define FSCALE in sys/param.h.  */

#  ifdef MORE_BSD
#   define FSCALE 2048.0
#  endif

#  if defined(MIPS) || defined(SVR4) || defined(decstation)
#   define FSCALE 256
#  endif

#  if defined (sgi) || defined (sequent)
/* Sometimes both MIPS and sgi are defined, so FSCALE was just defined
   above under #ifdef MIPS.  But we want the sgi value.  */
#   undef FSCALE
#   define FSCALE 1000.0
#  endif

#  if defined (ardent) && defined (titan)
#   define FSCALE 65536.0
#  endif

#  ifdef tek4300
#   define FSCALE 100.0
#  endif

#  ifdef _AIX
#   define FSCALE 65536.0
#  endif

# endif	/* Not FSCALE.  */

# if !defined (LDAV_CVT) && defined (FSCALE)
#  define LDAV_CVT(n) (((double) (n)) / FSCALE)
# endif

# ifndef NLIST_STRUCT
#  if HAVE_NLIST_H
#   define NLIST_STRUCT
#  endif
# endif

/* VAX C can't handle multi-line #ifs, or lines longer that 256 characters.  */
# ifndef NLIST_STRUCT

#  ifdef MORE_BSD
#   define NLIST_STRUCT
#  endif

#  ifdef sun
#   define NLIST_STRUCT
#  endif

#  ifdef decstation
#   define NLIST_STRUCT
#  endif

#  ifdef hpux
#   define NLIST_STRUCT
#  endif

#  if defined (_SEQUENT_) || defined (sequent)
#   define NLIST_STRUCT
#  endif

#  ifdef sgi
#   define NLIST_STRUCT
#  endif

#  ifdef SVR4
#   define NLIST_STRUCT
#  endif

#  ifdef sony_news
#   define NLIST_STRUCT
#  endif

#  ifdef OSF_ALPHA
#   define NLIST_STRUCT
#  endif

#  if defined (ardent) && defined (titan)
#   define NLIST_STRUCT
#  endif

#  ifdef tek4300
#   define NLIST_STRUCT
#  endif

#  ifdef butterfly
#   define NLIST_STRUCT
#  endif

#  if defined(alliant) && defined(i860) /* Alliant FX/2800 */
#   define NLIST_STRUCT
#  endif

#  ifdef _AIX
#   define NLIST_STRUCT
#  endif

# endif /* defined (NLIST_STRUCT) */


# if defined(sgi) || (defined(mips) && !defined(BSD))
#  define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31))
# endif


# if !defined (KERNEL_FILE) && defined (sequent)
#  define KERNEL_FILE "/dynix"
# endif

# if !defined (KERNEL_FILE) && defined (hpux)
#  define KERNEL_FILE "/hp-ux"
# endif

# if !defined(KERNEL_FILE) && (defined(_SEQUENT_) || defined(MIPS) || defined(SVR4) || defined(ISC) || defined (sgi) || (defined (ardent) && defined (titan)))
#  define KERNEL_FILE "/unix"
# endif


# if !defined (LDAV_SYMBOL) && defined (alliant)
#  define LDAV_SYMBOL "_Loadavg"
# endif

# if !defined(LDAV_SYMBOL) && ((defined(hpux) && !defined(hp9000s300)) || defined(_SEQUENT_) || defined(SVR4) || defined(ISC) || defined(sgi) || (defined (ardent) && defined (titan)) || defined (_AIX))
#  define LDAV_SYMBOL "avenrun"
# endif

# ifdef HAVE_UNISTD_H
#  include <unistd.h>
# endif

# include <stdio.h>

/* LOAD_AVE_TYPE should only get defined if we're going to use the
   nlist method.  */
# if !defined(LOAD_AVE_TYPE) && (defined(BSD) || defined(LDAV_CVT) || defined(KERNEL_FILE) || defined(LDAV_SYMBOL))
#  define LOAD_AVE_TYPE double
# endif

# ifdef LOAD_AVE_TYPE

#  ifndef VMS
#   ifndef __linux__
#    ifndef NLIST_STRUCT
#     include <a.out.h>
#    else /* NLIST_STRUCT */
#     include <nlist.h>
#    endif /* NLIST_STRUCT */

#    ifdef SUNOS_5
#     include <fcntl.h>
#     include <kvm.h>
#     include <kstat.h>
#    endif

#    if defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
#     include <sys/pstat.h>
#    endif

#    ifndef KERNEL_FILE
#     define KERNEL_FILE "/vmunix"
#    endif /* KERNEL_FILE */

#    ifndef LDAV_SYMBOL
#     define LDAV_SYMBOL "_avenrun"
#    endif /* LDAV_SYMBOL */
#   endif /* __linux__ */

#  else /* VMS */

#   ifndef eunice
#    include <iodef.h>
#    include <descrip.h>
#   else /* eunice */
#    include <vms/iodef.h>
#   endif /* eunice */
#  endif /* VMS */

#  ifndef LDAV_CVT
#   define LDAV_CVT(n) ((double) (n))
#  endif /* !LDAV_CVT */

# endif /* LOAD_AVE_TYPE */

# if defined(__GNU__) && !defined (NeXT)
/* Note that NeXT Openstep defines __GNU__ even though it should not.  */
/* GNU system acts much like NeXT, for load average purposes,
   but not exactly.  */
#  define NeXT
#  define host_self mach_host_self
# endif

# ifdef NeXT
#  ifdef HAVE_MACH_MACH_H
#   include <mach/mach.h>
#  else
#   include <mach.h>
#  endif
# endif /* NeXT */

# ifdef sgi
#  include <sys/sysmp.h>
# endif /* sgi */

# ifdef UMAX
#  include <stdio.h>
#  include <signal.h>
#  include <sys/time.h>
#  include <sys/wait.h>
#  include <sys/syscall.h>

#  ifdef UMAX_43
#   include <machine/cpu.h>
#   include <inq_stats/statistics.h>
#   include <inq_stats/sysstats.h>
#   include <inq_stats/cpustats.h>
#   include <inq_stats/procstats.h>
#  else /* Not UMAX_43.  */
#   include <sys/sysdefs.h>
#   include <sys/statistics.h>
#   include <sys/sysstats.h>
#   include <sys/cpudefs.h>
#   include <sys/cpustats.h>
#   include <sys/procstats.h>
#  endif /* Not UMAX_43.  */
# endif /* UMAX */

# ifdef DGUX
#  include <sys/dg_sys_info.h>
# endif

# if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION)
#  include <fcntl.h>
# else
#  include <sys/file.h>
# endif

/* Avoid static vars inside a function since in HPUX they dump as pure.  */

# ifdef NeXT