Import getloadavg module from gnulib.

1 files changed, 1044 insertions, 0 deletions

diff --git a/lib/getloadavg.c b/lib/getloadavg.c
new file mode 100644
index 00000000000..28e2ea0164b
--- /dev/null
+++ b/lib/getloadavg.c
@@ -0,0 +1,1044 @@
+/* Get the system load averages.
+
+   Copyright (C) 1985-1989, 1991-1995, 1997, 1999-2000, 2003-2011 Free Software
+   Foundation, Inc.
+
+   NOTE: The canonical source of this file is maintained with gnulib.
+   Bugs can be reported to bug-gnulib@gnu.org.
+
+   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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+/* 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.
+   HAVE_LIBPERFSTAT Define this if your system has the
+                                perfstat_cpu_total function in libperfstat (AIX).
+   FIXUP_KERNEL_SYMBOL_ADDR()   Adjust address in returned struct nlist.
+   KERNEL_FILE                  Name of the kernel file 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;
+                                or we have libkstat;
+                                otherwise, no load average is available.
+   HAVE_NLIST_H                 nlist.h is available.  NLIST_STRUCT defaults
+                                to this.
+   NLIST_STRUCT                 Include nlist.h, not a.out.h.
+   N_NAME_POINTER               The nlist n_name element is a pointer,
+                                not an array.
+   HAVE_STRUCT_NLIST_N_UN_N_NAME `n_un.n_name' is member of `struct nlist'.
+   LINUX_LDAV_FILE              [__linux__, __CYGWIN__]: 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 file system mounted.
+                                Support from Michael K. Johnson.
+   __CYGWIN__                   Cygwin emulates linux /proc/loadavg.
+   __NetBSD__                   NetBSD: assumes /kern file system 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.  */
+
+/* "configure" defines CONFIGURING_GETLOADAVG to sidestep problems
+   with partially-configured source directories.  */
+
+#ifndef CONFIGURING_GETLOADAVG
+# include <config.h>
+# include <stdbool.h>
+#endif
+
+/* Specification.  */
+#include <stdlib.h>
+
+#include <errno.h>
+#include <stdio.h>
+
+# 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.  */
+# if defined (unix) || defined (__unix)
+#  include <sys/param.h>
+# endif
+
+# include "intprops.h"
+
+/* 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
+
+/* Same issues as for NeXT apply to the HURD-based GNU system.  */
+# ifdef __GNU__
+#  undef BSD
+#  undef FSCALE
+# endif /* __GNU__ */
+
+/* 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>
+/* Tru64 4.0D's table.h redefines sys */
+#  undef sys
+# 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
+
+#  if defined _AIX && ! defined HAVE_LIBPERFSTAT
+#   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 ghazi@noc.rutgers.edu.  */
+#  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 ghazi@noc.rutgers.edu.  */
+#  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
+
+#  if defined _AIX && !defined HAVE_LIBPERFSTAT
+#   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
+
+# 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) && !defined(HAVE_LIBPERFSTAT)))
+#  define LDAV_SYMBOL "avenrun"
+# endif
+
+# include <unistd.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 <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 HAVE_LIBPERFSTAT
+#  include <sys/protosw.h>
+#  include <libperfstat.h>
+#  include <sys/proc.h>
+#  ifndef SBITS
+#   define SBITS 16
+#  endif
+# endif
+
+# 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 <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 __linux__ || defined __CYGWIN__ || defined SUNOS_5        \
+      || (defined LOAD_AVE_TYPE && ! defined __VMS))
+#  include <fcntl.h>
+# endif
+
+/* Avoid static vars inside a function since in HPUX they dump as pure.  */
+
+# ifdef NeXT
+static processor_set_t default_set;
+static bool getloadavg_initialized;
+# endif /* NeXT */
+
+# ifdef UMAX
+static unsigned int cpus = 0;
+static unsigned int samples;
+# endif /* UMAX */
+
+# ifdef DGUX
+static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
+# endif /* DGUX */
+
+# if !defined (HAVE_LIBKSTAT) && defined (LOAD_AVE_TYPE)
+/* File descriptor open to /dev/kmem or VMS load ave driver.  */
+static int channel;
+/* True if channel is valid.  */
+static bool getloadavg_initialized;
+/* Offset in kmem to seek to read load average, or 0 means invalid.  */
+static long offset;
+
+#  if ! defined __VMS && ! defined sgi && ! defined __linux__
+static struct nlist name_list[2];
+#  endif
+
+#  ifdef SUNOS_5
+static kvm_t *kd;
+#  endif /* SUNOS_5 */
+
+# endif /* LOAD_AVE_TYPE && !HAVE_LIBKSTAT */
+
+/* Put the 1 minute, 5 minute and 15 minute load averages
+   into the first NELEM elements of LOADAVG.
+   Return the number written (never more than 3, but may be less than NELEM),
+   or -1 (setting errno) if an error occurred.  */
+
+int
+getloadavg (double loadavg[], int nelem)
+{
+  int elem = 0;                 /* Return value.  */
+
+# ifdef NO_GET_LOAD_AVG
+#  define LDAV_DONE
+  errno = ENOSYS;
+  elem = -1;
+# endif
+
+# if !defined (LDAV_DONE) && defined (HAVE_LIBKSTAT)
+/* Use libkstat because we don't have to be root.  */
+#  define LDAV_DONE
+  kstat_ctl_t *kc;
+  kstat_t *ksp;
+  kstat_named_t *kn;
+  int saved_errno;
+
+  kc = kstat_open ();
+  if (kc == 0)
+    return -1;
+  ksp = kstat_lookup (kc, "unix", 0, "system_misc");
+  if (ksp == 0)
+    return -1;
+  if (kstat_read (kc, ksp, 0) == -1)
+    return -1;
+
+
+  kn = kstat_data_lookup (ksp, "avenrun_1min");
+  if (kn == 0)
+    {
+      /* Return -1 if no load average information is available.  */
+      nelem = 0;
+      elem = -1;
+    }
+
+  if (nelem >= 1)
+    loadavg[elem++] = (double) kn->value.ul / FSCALE;
+
+  if (nelem >= 2)
+    {
+      kn = kstat_data_lookup (ksp, "avenrun_5min");
+      if (kn != 0)
+        {
+          loadavg[elem++] = (double) kn->value.ul / FSCALE;
+
+          if (nelem >= 3)
+            {
+              kn = kstat_data_lookup (ksp, "avenrun_15min");
+              if (kn != 0)
+                loadavg[elem++] = (double) kn->value.ul / FSCALE;
+            }
+        }
+    }
+
+  saved_errno = errno;
+  kstat_close (kc);
+  errno = saved_errno;
+# endif /* HAVE_LIBKSTAT */
+
+# if !defined (LDAV_DONE) && defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
+/* Use pstat_getdynamic() because we don't have to be root.  */
+#  define LDAV_DONE
+#  undef LOAD_AVE_TYPE
+
+  struct pst_dynamic dyn_info;
+  if (pstat_getdynamic (&dyn_info, sizeof (dyn_info), 0, 0) < 0)
+    return -1;
+  if (nelem > 0)
+    loadavg[elem++] = dyn_info.psd_avg_1_min;
+  if (nelem > 1)
+    loadavg[elem++] = dyn_info.psd_avg_5_min;
+  if (nelem > 2)
+    loadavg[elem++] = dyn_info.psd_avg_15_min;
+
+# endif /* hpux && HAVE_PSTAT_GETDYNAMIC */
+
+# if ! defined LDAV_DONE && defined HAVE_LIBPERFSTAT
+#  define LDAV_DONE
+#  undef LOAD_AVE_TYPE
+/* Use perfstat_cpu_total because we don't have to be root. */
+  {
+    perfstat_cpu_total_t cpu_stats;
+    int result = perfstat_cpu_total (NULL, &cpu_stats, sizeof cpu_stats, 1);
+    if (result == -1)
+      return result;
+    loadavg[0] = cpu_stats.loadavg[0] / (double)(1 << SBITS);
+    loadavg[1] = cpu_stats.loadavg[1] / (double)(1 << SBITS);
+    loadavg[2] = cpu_stats.loadavg[2] / (double)(1 << SBITS);
+    elem = 3;
+  }
+# endif
+
+# if !defined (LDAV_DONE) && (defined (__linux__) || defined (__CYGWIN__))
+#  define LDAV_DONE
+#  undef LOAD_AVE_TYPE
+
+#  ifndef LINUX_LDAV_FILE
+#   define LINUX_LDAV_FILE "/proc/loadavg"
+#  endif
+
+  char ldavgbuf[3 * (INT_STRLEN_BOUND (int) + sizeof ".00 ")];
+  char const *ptr = ldavgbuf;
+  int fd, count, saved_errno;
+
+  fd = open (LINUX_LDAV_FILE, O_RDONLY);
+  if (fd == -1)
+    return -1;
+  count = read (fd, ldavgbuf, sizeof ldavgbuf - 1);
+  saved_errno = errno;
+  (void) close (fd);
+  errno = saved_errno;
+  if (count <= 0)
+    return -1;
+  ldavgbuf[count] = '\0';
+
+  for (elem = 0; elem < nelem; elem++)
+    {
+      double numerator = 0;
+      double denominator = 1;
+
+      while (*ptr == ' ')
+        ptr++;
+
+      /* Finish if this number is missing, and report an error if all
+         were missing.  */
+      if (! ('0' <= *ptr && *ptr <= '9'))
+        {
+          if (elem == 0)
+            {
+              errno = ENOTSUP;
+              return -1;
+            }
+          break;
+        }
+
+      while ('0' <= *ptr && *ptr <= '9')
+        numerator = 10 * numerator + (*ptr++ - '0');
+
+      if (*ptr == '.')
+        for (ptr++; '0' <= *ptr && *ptr <= '9'; ptr++)
+          numerator = 10 * numerator + (*ptr - '0'), denominator *= 10;
+
+      loadavg[elem++] = numerator / denominator;
+    }
+
+  return elem;
+
+# endif /* __linux__ || __CYGWIN__ */
+
+# if !defined (LDAV_DONE) && defined (__NetBSD__)
+#  define LDAV_DONE
+#  undef LOAD_AVE_TYPE
+
+#  ifndef NETBSD_LDAV_FILE
+#   define NETBSD_LDAV_FILE "/kern/loadavg"
+#  endif
+
+  unsigned long int load_ave[3], scale;
+  int count;
+  FILE *fp;
+
+  fp = fopen (NETBSD_LDAV_FILE, "r");
+  if (fp == NULL)
+    return -1;
+  count = fscanf (fp, "%lu %lu %lu %lu\n",
+                  &load_ave[0], &load_ave[1], &load_ave[2],
+                  &scale);
+  (void) fclose (fp);
+  if (count != 4)
+    {
+      errno = ENOTSUP;
+      return -1;
+    }
+
+  for (elem = 0; elem < nelem; elem++)
+    loadavg[elem] = (double) load_ave[elem] / (double) scale;
+
+  return elem;
+
+# endif /* __NetBSD__ */
+
+# if !defined (LDAV_DONE) && defined (NeXT)
+#  define LDAV_DONE
+  /* The NeXT code was adapted from iscreen 3.2.  */
+
+  host_t host;
+  struct processor_set_basic_info info;
+  unsigned int info_count;
+
+  /* We only know how to get the 1-minute average for this system,
+     so even if the caller asks for more than 1, we only return 1.  */
+
+  if (!getloadavg_initialized)
+    {
+      if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
+        getloadavg_initialized = true;
+    }
+
+  if (getloadavg_initialized)
+    {
+      info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
+      if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
+                              (processor_set_info_t) &info, &info_count)
+          != KERN_SUCCESS)
+        getloadavg_initialized = false;
+      else
+        {
+          if (nelem > 0)
+            loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
+        }
+    }
+
+  if (!getloadavg_initialized)
+    {
+      errno = ENOTSUP;
+      return -1;
+    }
+# endif /* NeXT */
+
+# if !defined (LDAV_DONE) && defined (UMAX)
+#  define LDAV_DONE
+/* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
+   have a /dev/kmem.  Information about the workings of the running kernel
+   can be gathered with inq_stats system calls.
+   We only know how to get the 1-minute average for this system.  */
+
+  struct proc_summary proc_sum_data;
+  struct stat_descr proc_info;
+  double load;
+  register unsigned int i, j;
+
+  if (cpus == 0)
+    {
+      register unsigned int c, i;
+      struct cpu_config conf;
+      struct stat_descr desc;
+
+      desc.sd_next = 0;
+      desc.sd_subsys = SUBSYS_CPU;
+      desc.sd_type = CPUTYPE_CONFIG;
+      desc.sd_addr = (char *) &conf;
+      desc.sd_size = sizeof conf;
+
+      if (inq_stats (1, &desc))
+        return -1;
+
+      c = 0;
+      for (i = 0; i < conf.config_maxclass; ++i)
+        {
+          struct class_stats stats;
+          memset (&stats, 0, sizeof stats);
+
+          desc.sd_type = CPUTYPE_CLASS;
+          desc.sd_objid = i;
+          desc.sd_addr = (char *) &stats;
+          desc.sd_size = sizeof stats;
+
+          if (inq_stats (1, &desc))
+            return -1;
+
+          c += stats.class_numcpus;
+        }
+      cpus = c;
+      samples = cpus < 2 ? 3 : (2 * cpus / 3);
+    }
+
+  proc_info.sd_next = 0;
+  proc_info.sd_subsys = SUBSYS_PROC;
+  proc_info.sd_type = PROCTYPE_SUMMARY;
+  proc_info.sd_addr = (char *) &proc_sum_data;
+  proc_info.sd_size = sizeof (struct proc_summary);
+  proc_info.sd_sizeused = 0;
+
+  if (inq_stats (1, &proc_info) != 0)
+    return -1;
+
+  load = proc_sum_data.ps_nrunnable;
+  j = 0;
+  for (i = samples - 1; i > 0; --i)
+    {
+      load += proc_sum_data.ps_nrun[j];
+      if (j++ == PS_NRUNSIZE)
+        j = 0;
+    }
+
+  if (nelem > 0)
+    loadavg[elem++] = load / samples / cpus;
+# endif /* UMAX */
+
+# if !defined (LDAV_DONE) && defined (DGUX)
+#  define LDAV_DONE
+  /* This call can return -1 for an error, but with good args
+     it's not supposed to fail.  The first argument is for no
+     apparent reason of type `long int *'.  */
+  dg_sys_info ((long int *) &load_info,
+               DG_SYS_INFO_LOAD_INFO_TYPE,
+               DG_SYS_INFO_LOAD_VERSION_0);
+
+  if (nelem > 0)
+    loadavg[elem++] = load_info.one_minute;
+  if (nelem > 1)
+    loadavg[elem++] = load_info.five_minute;
+  if (nelem > 2)
+    loadavg[elem++] = load_info.fifteen_minute;
+# endif /* DGUX */
+
+# if !defined (LDAV_DONE) && defined (apollo)
+#  define LDAV_DONE
+/* Apollo code from lisch@mentorg.com (Ray Lischner).
+
+   This system call is not documented.  The load average is obtained as
+   three long integers, for the load average over the past minute,
+   five minutes, and fifteen minutes.  Each value is a scaled integer,
+   with 16 bits of integer part and 16 bits of fraction part.
+
+   I'm not sure which operating system first supported this system call,
+   but I know that SR10.2 supports it.  */
+
+  extern void proc1_$get_loadav ();
+  unsigned long load_ave[3];
+
+  proc1_$get_loadav (load_ave);
+
+  if (nelem > 0)
+    loadavg[elem++] = load_ave[0] / 65536.0;
+  if (nelem > 1)
+    loadavg[elem++] = load_ave[1] / 65536.0;
+  if (nelem > 2)
+    loadavg[elem++] = load_ave[2] / 65536.0;
+# endif /* apollo */
+
+# if !defined (LDAV_DONE) && defined (OSF_MIPS)
+#  define LDAV_DONE
+
+  struct tbl_loadavg load_ave;
+  table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
+  loadavg[elem++]
+    = (load_ave.tl_lscale == 0
+       ? load_ave.tl_avenrun.d[0]
+       : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
+# endif /* OSF_MIPS */
+
+# if !defined (LDAV_DONE) && (defined (__MSDOS__) || defined (WINDOWS32))
+#  define LDAV_DONE
+
+  /* A faithful emulation is going to have to be saved for a rainy day.  */
+  for ( ; elem < nelem; elem++)
+    {
+      loadavg[elem] = 0.0;
+    }
+# endif  /* __MSDOS__ || WINDOWS32 */
+
+# if !defined (LDAV_DONE) && defined (OSF_ALPHA)
+#  define LDAV_DONE
+
+  struct tbl_loadavg load_ave;
+  table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
+  for (elem = 0; elem < nelem; elem++)
+    loadavg[elem]
+      = (load_ave.tl_lscale == 0
+         ? load_ave.tl_avenrun.d[elem]
+         : (load_ave.tl_avenrun.l[elem] / (double) load_ave.tl_lscale));
+# endif /* OSF_ALPHA */
+
+# if ! defined LDAV_DONE && defined __VMS
+  /* VMS specific code -- read from the Load Ave driver.  */
+
+  LOAD_AVE_TYPE load_ave[3];
+  static bool getloadavg_initialized;
+#  ifdef eunice
+  struct
+  {
+    int dsc$w_length;
+    char *dsc$a_pointer;
+  } descriptor;
+#  endif
+
+  /* Ensure that there is a channel open to the load ave device.  */
+  if (!getloadavg_initialized)
+    {
+      /* Attempt to open the channel.  */
+#  ifdef eunice
+      descriptor.dsc$w_length = 18;
+      descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
+#  else
+      $DESCRIPTOR (descriptor, "LAV0:");
+#  endif
+      if (sys$assign (&descriptor, &channel, 0, 0) & 1)
+        getloadavg_initialized = true;
+    }
+
+  /* Read the load average vector.  */
+  if (getloadavg_initialized
+      && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
+                     load_ave, 12, 0, 0, 0, 0) & 1))
+    {
+      sys$dassgn (channel);
+      getloadavg_initialized = false;
+    }
+
+  if (!getloadavg_initialized)
+    {
+      errno = ENOTSUP;
+      return -1;
+    }
+# endif /* ! defined LDAV_DONE && defined __VMS */
+
+# if ! defined LDAV_DONE && defined LOAD_AVE_TYPE && ! defined __VMS
+
+  /* UNIX-specific code -- read the average from /dev/kmem.  */
+
+#  define LDAV_PRIVILEGED               /* This code requires special installation.  */
+
+  LOAD_AVE_TYPE load_ave[3];
+
+  /* Get the address of LDAV_SYMBOL.  */
+  if (offset == 0)
+    {
+#  ifndef sgi
+#   if ! defined NLIST_STRUCT || ! defined N_NAME_POINTER
+      strcpy (name_list[0].n_name, LDAV_SYMBOL);
+      strcpy (name_list[1].n_name, "");
+#   else /* NLIST_STRUCT */
+#    ifdef HAVE_STRUCT_NLIST_N_UN_N_NAME
+      name_list[0].n_un.n_name = LDAV_SYMBOL;
+      name_list[1].n_un.n_name = 0;
+#    else /* not HAVE_STRUCT_NLIST_N_UN_N_NAME */
+      name_list[0].n_name = LDAV_SYMBOL;
+      name_list[1].n_name = 0;
+#    endif /* not HAVE_STRUCT_NLIST_N_UN_N_NAME */
+#   endif /* NLIST_STRUCT */
+
+#   ifndef SUNOS_5
+      if (
+#    if !(defined (_AIX) && !defined (ps2))
+          nlist (KERNEL_FILE, name_list)
+#    else  /* _AIX */
+          knlist (name_list, 1, sizeof (name_list[0]))
+#    endif
+          >= 0)
+          /* Omit "&& name_list[0].n_type != 0 " -- it breaks on Sun386i.  */
+          {
+#    ifdef FIXUP_KERNEL_SYMBOL_ADDR
+            FIXUP_KERNEL_SYMBOL_ADDR (name_list);
+#    endif
+            offset = name_list[0].n_value;
+          }
+#   endif /* !SUNOS_5 */
+#  else  /* sgi */
+      int ldav_off;
+
+      ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
+      if (ldav_off != -1)
+        offset = (long int) ldav_off & 0x7fffffff;
+#  endif /* sgi */
+    }
+
+  /* Make sure we have /dev/kmem open.  */
+  if (!getloadavg_initialized)
+    {
+#  ifndef SUNOS_5
+      /* Set the channel to close on exec, so it does not
+         litter any child's descriptor table.  */
+#   ifndef O_CLOEXEC
+#    define O_CLOEXEC 0
+#   endif
+      int fd = open ("/dev/kmem", O_RDONLY | O_CLOEXEC);
+      if (0 <= fd)
+        {
+#   if F_DUPFD_CLOEXEC
+          if (fd <= STDERR_FILENO)
+            {
+              int fd1 = fcntl (fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1);
+              close (fd);
+              fd = fd1;
+            }
+#   endif
+          if (0 <= fd)
+            {
+              channel = fd;
+              getloadavg_initialized = true;
+            }
+        }
+#  else /* SUNOS_5 */
+      /* We pass 0 for the kernel, corefile, and swapfile names
+         to use the currently running kernel.  */
+      kd = kvm_open (0, 0, 0, O_RDONLY, 0);
+      if (kd != 0)
+        {
+          /* nlist the currently running kernel.  */
+          kvm_nlist (kd, name_list);
+          offset = name_list[0].n_value;
+          getloadavg_initialized = true;
+        }
+#  endif /* SUNOS_5 */
+    }
+
+  /* If we can, get the load average values.  */
+  if (offset && getloadavg_initialized)
+    {
+      /* Try to read the load.  */
+#  ifndef SUNOS_5
+      if (lseek (channel, offset, 0) == -1L
+          || read (channel, (char *) load_ave, sizeof (load_ave))
+          != sizeof (load_ave))
+        {
+          close (channel);
+          getloadavg_initialized = false;
+        }
+#  else  /* SUNOS_5 */
+      if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
+          != sizeof (load_ave))
+        {
+          kvm_close (kd);
+          getloadavg_initialized = false;
+        }
+#  endif /* SUNOS_5 */
+    }
+
+  if (offset == 0 || !getloadavg_initialized)
+    {
+      errno = ENOTSUP;
+      return -1;
+    }
+# endif /* ! defined LDAV_DONE && defined LOAD_AVE_TYPE && ! defined __VMS */
+
+# if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
+  if (nelem > 0)
+    loadavg[elem++] = LDAV_CVT (load_ave[0]);
+  if (nelem > 1)
+    loadavg[elem++] = LDAV_CVT (load_ave[1]);
+  if (nelem > 2)
+    loadavg[elem++] = LDAV_CVT (load_ave[2]);
+
+#  define LDAV_DONE
+# endif /* !LDAV_DONE && LOAD_AVE_TYPE */
+
+# if !defined LDAV_DONE
+  errno = ENOSYS;
+  elem = -1;
+# endif
+  return elem;
+}