code.delx.au - gnu-emacs/blob - lib/getloadavg.c

   1 /* Get the system load averages.
   2
   3    Copyright (C) 1985-1989, 1991-1995, 1997, 1999-2000, 2003-2016 Free Software
   4    Foundation, Inc.
   5
   6    NOTE: The canonical source of this file is maintained with gnulib.
   7    Bugs can be reported to bug-gnulib@gnu.org.
   8
   9    This program is free software: you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 /* Compile-time symbols that this file uses:
  23
  24    HAVE_PSTAT_GETDYNAMIC        Define this if your system has the
  25                                 pstat_getdynamic function.  I think it
  26                                 is unique to HPUX9.  The best way to get the
  27                                 definition is through the AC_FUNC_GETLOADAVG
  28                                 macro that comes with autoconf 2.13 or newer.
  29                                 If that isn't an option, then just put
  30                                 AC_CHECK_FUNCS(pstat_getdynamic) in your
  31                                 configure.ac file.
  32    HAVE_LIBPERFSTAT Define this if your system has the
  33                                 perfstat_cpu_total function in libperfstat (AIX).
  34    FIXUP_KERNEL_SYMBOL_ADDR()   Adjust address in returned struct nlist.
  35    KERNEL_FILE                  Name of the kernel file to nlist.
  36    LDAV_CVT()                   Scale the load average from the kernel.
  37                                 Returns a double.
  38    LDAV_SYMBOL                  Name of kernel symbol giving load average.
  39    LOAD_AVE_TYPE                Type of the load average array in the kernel.
  40                                 Must be defined unless one of
  41                                 apollo, DGUX, NeXT, or UMAX is defined;
  42                                 or we have libkstat;
  43                                 otherwise, no load average is available.
  44    HAVE_NLIST_H                 nlist.h is available.  NLIST_STRUCT defaults
  45                                 to this.
  46    NLIST_STRUCT                 Include nlist.h, not a.out.h.
  47    N_NAME_POINTER               The nlist n_name element is a pointer,
  48                                 not an array.
  49    HAVE_STRUCT_NLIST_N_UN_N_NAME 'n_un.n_name' is member of 'struct nlist'.
  50    LINUX_LDAV_FILE              [__linux__, __CYGWIN__]: File containing
  51                                 load averages.
  52
  53    Specific system predefines this file uses, aside from setting
  54    default values if not emacs:
  55
  56    apollo
  57    BSD                          Real BSD, not just BSD-like.
  58    convex
  59    DGUX
  60    eunice                       UNIX emulator under VMS.
  61    hpux
  62    __MSDOS__                    No-op for MSDOS.
  63    NeXT
  64    sgi
  65    sequent                      Sequent Dynix 3.x.x (BSD)
  66    _SEQUENT_                    Sequent DYNIX/ptx 1.x.x (SYSV)
  67    sony_news                    NEWS-OS (works at least for 4.1C)
  68    UMAX
  69    UMAX4_3
  70    VMS
  71    WINDOWS32                    No-op for Windows95/NT.
  72    __linux__                    Linux: assumes /proc file system mounted.
  73                                 Support from Michael K. Johnson.
  74    __CYGWIN__                   Cygwin emulates linux /proc/loadavg.
  75    __NetBSD__                   NetBSD: assumes /kern file system mounted.
  76
  77    In addition, to avoid nesting many #ifdefs, we internally set
  78    LDAV_DONE to indicate that the load average has been computed.
  79
  80    We also #define LDAV_PRIVILEGED if a program will require
  81    special installation to be able to call getloadavg.  */
  82
  83 #include <config.h>
  84
  85 /* Specification.  */
  86 #include <stdlib.h>
  87
  88 #include <errno.h>
  89 #include <stdbool.h>
  90 #include <stdio.h>
  91
  92 # include <sys/types.h>
  93
  94 # if HAVE_SYS_PARAM_H
  95 #  include <sys/param.h>
  96 # endif
  97
  98 # include "intprops.h"
  99
 100 # if !defined (BSD) && defined (ultrix)
 101 /* Ultrix behaves like BSD on Vaxen.  */
 102 #  define BSD
 103 # endif
 104
 105 # ifdef NeXT
 106 /* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which
 107    conflicts with the definition understood in this file, that this
 108    really is BSD. */
 109 #  undef BSD
 110
 111 /* NeXT defines FSCALE in <sys/param.h>.  However, we take FSCALE being
 112    defined to mean that the nlist method should be used, which is not true.  */
 113 #  undef FSCALE
 114 # endif
 115
 116 /* Same issues as for NeXT apply to the HURD-based GNU system.  */
 117 # ifdef __GNU__
 118 #  undef BSD
 119 #  undef FSCALE
 120 # endif /* __GNU__ */
 121
 122 /* Set values that are different from the defaults, which are
 123    set a little farther down with #ifndef.  */
 124
 125
 126 /* Some shorthands.  */
 127
 128 # if defined (HPUX) && !defined (hpux)
 129 #  define hpux
 130 # endif
 131
 132 # if defined (__hpux) && !defined (hpux)
 133 #  define hpux
 134 # endif
 135
 136 # if defined (__sun) && !defined (sun)
 137 #  define sun
 138 # endif
 139
 140 # if defined (hp300) && !defined (hpux)
 141 #  define MORE_BSD
 142 # endif
 143
 144 # if defined (ultrix) && defined (mips)
 145 #  define decstation
 146 # endif
 147
 148 # if defined (__SVR4) && !defined (SVR4)
 149 #  define SVR4
 150 # endif
 151
 152 # if (defined (sun) && defined (SVR4)) || defined (SOLARIS2)
 153 #  define SUNOS_5
 154 # endif
 155
 156 # if defined (__osf__) && (defined (__alpha) || defined (__alpha__))
 157 #  define OSF_ALPHA
 158 #  include <sys/mbuf.h>
 159 #  include <sys/socket.h>
 160 #  include <net/route.h>
 161 #  include <sys/table.h>
 162 /* Tru64 4.0D's table.h redefines sys */
 163 #  undef sys
 164 # endif
 165
 166 # if defined (__osf__) && (defined (mips) || defined (__mips__))
 167 #  define OSF_MIPS
 168 #  include <sys/table.h>
 169 # endif
 170
 171 /* UTek's /bin/cc on the 4300 has no architecture specific cpp define by
 172    default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>.  Combine
 173    that with a couple of other things and we'll have a unique match.  */
 174 # if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES)
 175 #  define tek4300                       /* Define by emacs, but not by other users.  */
 176 # endif
 177
 178
 179 /* VAX C can't handle multi-line #ifs, or lines longer than 256 chars.  */
 180 # ifndef LOAD_AVE_TYPE
 181
 182 #  ifdef MORE_BSD
 183 #   define LOAD_AVE_TYPE long
 184 #  endif
 185
 186 #  ifdef sun
 187 #   define LOAD_AVE_TYPE long
 188 #  endif
 189
 190 #  ifdef decstation
 191 #   define LOAD_AVE_TYPE long
 192 #  endif
 193
 194 #  ifdef _SEQUENT_
 195 #   define LOAD_AVE_TYPE long
 196 #  endif
 197
 198 #  ifdef sgi
 199 #   define LOAD_AVE_TYPE long
 200 #  endif
 201
 202 #  ifdef SVR4
 203 #   define LOAD_AVE_TYPE long
 204 #  endif
 205
 206 #  ifdef sony_news
 207 #   define LOAD_AVE_TYPE long
 208 #  endif
 209
 210 #  ifdef sequent
 211 #   define LOAD_AVE_TYPE long
 212 #  endif
 213
 214 #  ifdef OSF_ALPHA
 215 #   define LOAD_AVE_TYPE long
 216 #  endif
 217
 218 #  if defined (ardent) && defined (titan)
 219 #   define LOAD_AVE_TYPE long
 220 #  endif
 221
 222 #  ifdef tek4300
 223 #   define LOAD_AVE_TYPE long
 224 #  endif
 225
 226 #  if defined (alliant) && defined (i860) /* Alliant FX/2800 */
 227 #   define LOAD_AVE_TYPE long
 228 #  endif
 229
 230 #  if defined _AIX && ! defined HAVE_LIBPERFSTAT
 231 #   define LOAD_AVE_TYPE long
 232 #  endif
 233
 234 #  ifdef convex
 235 #   define LOAD_AVE_TYPE double
 236 #   ifndef LDAV_CVT
 237 #    define LDAV_CVT(n) (n)
 238 #   endif
 239 #  endif
 240
 241 # endif /* No LOAD_AVE_TYPE.  */
 242
 243 # ifdef OSF_ALPHA
 244 /* <sys/param.h> defines an incorrect value for FSCALE on Alpha OSF/1,
 245    according to ghazi@noc.rutgers.edu.  */
 246 #  undef FSCALE
 247 #  define FSCALE 1024.0
 248 # endif
 249
 250 # if defined (alliant) && defined (i860) /* Alliant FX/2800 */
 251 /* <sys/param.h> defines an incorrect value for FSCALE on an
 252    Alliant FX/2800 Concentrix 2.2, according to ghazi@noc.rutgers.edu.  */
 253 #  undef FSCALE
 254 #  define FSCALE 100.0
 255 # endif
 256
 257
 258 # ifndef FSCALE
 259
 260 /* SunOS and some others define FSCALE in sys/param.h.  */
 261
 262 #  ifdef MORE_BSD
 263 #   define FSCALE 2048.0
 264 #  endif
 265
 266 #  if defined (MIPS) || defined (SVR4) || defined (decstation)
 267 #   define FSCALE 256
 268 #  endif
 269
 270 #  if defined (sgi) || defined (sequent)
 271 /* Sometimes both MIPS and sgi are defined, so FSCALE was just defined
 272    above under #ifdef MIPS.  But we want the sgi value.  */
 273 #   undef FSCALE
 274 #   define FSCALE 1000.0
 275 #  endif
 276
 277 #  if defined (ardent) && defined (titan)
 278 #   define FSCALE 65536.0
 279 #  endif
 280
 281 #  ifdef tek4300
 282 #   define FSCALE 100.0
 283 #  endif
 284
 285 #  if defined _AIX && !defined HAVE_LIBPERFSTAT
 286 #   define FSCALE 65536.0
 287 #  endif
 288
 289 # endif /* Not FSCALE.  */
 290
 291 # if !defined (LDAV_CVT) && defined (FSCALE)
 292 #  define LDAV_CVT(n) (((double) (n)) / FSCALE)
 293 # endif
 294
 295 # ifndef NLIST_STRUCT
 296 #  if HAVE_NLIST_H
 297 #   define NLIST_STRUCT
 298 #  endif
 299 # endif
 300
 301 # if defined (sgi) || (defined (mips) && !defined (BSD))
 302 #  define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31))
 303 # endif
 304
 305
 306 # if !defined (KERNEL_FILE) && defined (sequent)
 307 #  define KERNEL_FILE "/dynix"
 308 # endif
 309
 310 # if !defined (KERNEL_FILE) && defined (hpux)
 311 #  define KERNEL_FILE "/hp-ux"
 312 # endif
 313
 314 # if !defined (KERNEL_FILE) && (defined (_SEQUENT_) || defined (MIPS) || defined (SVR4) || defined (ISC) || defined (sgi) || (defined (ardent) && defined (titan)))
 315 #  define KERNEL_FILE "/unix"
 316 # endif
 317
 318
 319 # if !defined (LDAV_SYMBOL) && defined (alliant)
 320 #  define LDAV_SYMBOL "_Loadavg"
 321 # endif
 322
 323 # 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)))
 324 #  define LDAV_SYMBOL "avenrun"
 325 # endif
 326
 327 # include <unistd.h>
 328
 329 /* LOAD_AVE_TYPE should only get defined if we're going to use the
 330    nlist method.  */
 331 # if !defined (LOAD_AVE_TYPE) && (defined (BSD) || defined (LDAV_CVT) || defined (KERNEL_FILE) || defined (LDAV_SYMBOL))
 332 #  define LOAD_AVE_TYPE double
 333 # endif
 334
 335 # ifdef LOAD_AVE_TYPE
 336
 337 #  ifndef __VMS
 338 #   ifndef __linux__
 339 #    ifndef NLIST_STRUCT
 340 #     include <a.out.h>
 341 #    else /* NLIST_STRUCT */
 342 #     include <nlist.h>
 343 #    endif /* NLIST_STRUCT */
 344
 345 #    ifdef SUNOS_5
 346 #     include <kvm.h>
 347 #     include <kstat.h>
 348 #    endif
 349
 350 #    if defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
 351 #     include <sys/pstat.h>
 352 #    endif
 353
 354 #    ifndef KERNEL_FILE
 355 #     define KERNEL_FILE "/vmunix"
 356 #    endif /* KERNEL_FILE */
 357
 358 #    ifndef LDAV_SYMBOL
 359 #     define LDAV_SYMBOL "_avenrun"
 360 #    endif /* LDAV_SYMBOL */
 361 #   endif /* __linux__ */
 362
 363 #  else /* __VMS */
 364
 365 #   ifndef eunice
 366 #    include <iodef.h>
 367 #    include <descrip.h>
 368 #   else /* eunice */
 369 #    include <vms/iodef.h>
 370 #   endif /* eunice */
 371 #  endif /* __VMS */
 372
 373 #  ifndef LDAV_CVT
 374 #   define LDAV_CVT(n) ((double) (n))
 375 #  endif /* !LDAV_CVT */
 376
 377 # endif /* LOAD_AVE_TYPE */
 378
 379 # if defined HAVE_LIBPERFSTAT
 380 #  include <sys/protosw.h>
 381 #  include <libperfstat.h>
 382 #  include <sys/proc.h>
 383 #  ifndef SBITS
 384 #   define SBITS 16
 385 #  endif
 386 # endif
 387
 388 # if defined (__GNU__) && !defined (NeXT)
 389 /* Note that NeXT Openstep defines __GNU__ even though it should not.  */
 390 /* GNU system acts much like NeXT, for load average purposes,
 391    but not exactly.  */
 392 #  define NeXT
 393 #  define host_self mach_host_self
 394 # endif
 395
 396 # ifdef NeXT
 397 #  ifdef HAVE_MACH_MACH_H
 398 #   include <mach/mach.h>
 399 #  else
 400 #   include <mach.h>
 401 #  endif
 402 # endif /* NeXT */
 403
 404 # ifdef sgi
 405 #  include <sys/sysmp.h>
 406 # endif /* sgi */
 407
 408 # ifdef UMAX
 409 #  include <signal.h>
 410 #  include <sys/time.h>
 411 #  include <sys/wait.h>
 412 #  include <sys/syscall.h>
 413
 414 #  ifdef UMAX_43
 415 #   include <machine/cpu.h>
 416 #   include <inq_stats/statistics.h>
 417 #   include <inq_stats/sysstats.h>
 418 #   include <inq_stats/cpustats.h>
 419 #   include <inq_stats/procstats.h>
 420 #  else /* Not UMAX_43.  */
 421 #   include <sys/sysdefs.h>
 422 #   include <sys/statistics.h>
 423 #   include <sys/sysstats.h>
 424 #   include <sys/cpudefs.h>
 425 #   include <sys/cpustats.h>
 426 #   include <sys/procstats.h>
 427 #  endif /* Not UMAX_43.  */
 428 # endif /* UMAX */
 429
 430 # ifdef DGUX
 431 #  include <sys/dg_sys_info.h>
 432 # endif
 433
 434 # if (defined __linux__ || defined __CYGWIN__ || defined SUNOS_5        \
 435       || (defined LOAD_AVE_TYPE && ! defined __VMS))
 436 #  include <fcntl.h>
 437 # endif
 438 \f
 439 /* Avoid static vars inside a function since in HPUX they dump as pure.  */
 440
 441 # ifdef NeXT
 442 static processor_set_t default_set;
 443 static bool getloadavg_initialized;
 444 # endif /* NeXT */
 445
 446 # ifdef UMAX
 447 static unsigned int cpus = 0;
 448 static unsigned int samples;
 449 # endif /* UMAX */
 450
 451 # ifdef DGUX
 452 static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
 453 # endif /* DGUX */
 454
 455 # if !defined (HAVE_LIBKSTAT) && defined (LOAD_AVE_TYPE)
 456 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 457 static int channel;
 458 /* True if channel is valid.  */
 459 static bool getloadavg_initialized;
 460 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 461 static long offset;
 462
 463 #  if ! defined __VMS && ! defined sgi && ! defined __linux__
 464 static struct nlist name_list[2];
 465 #  endif
 466
 467 #  ifdef SUNOS_5
 468 static kvm_t *kd;
 469 #  endif /* SUNOS_5 */
 470
 471 # endif /* LOAD_AVE_TYPE && !HAVE_LIBKSTAT */
 472 \f
 473 /* Put the 1 minute, 5 minute and 15 minute load averages
 474    into the first NELEM elements of LOADAVG.
 475    Return the number written (never more than 3, but may be less than NELEM),
 476    or -1 (setting errno) if an error occurred.  */
 477
 478 int
 479 getloadavg (double loadavg[], int nelem)
 480 {
 481   int elem = 0;                 /* Return value.  */
 482
 483 # ifdef NO_GET_LOAD_AVG
 484 #  define LDAV_DONE
 485   errno = ENOSYS;
 486   elem = -1;
 487 # endif
 488
 489 # if !defined (LDAV_DONE) && defined (HAVE_LIBKSTAT)       /* Solaris <= 2.6 */
 490 /* Use libkstat because we don't have to be root.  */
 491 #  define LDAV_DONE
 492   kstat_ctl_t *kc;
 493   kstat_t *ksp;
 494   kstat_named_t *kn;
 495   int saved_errno;
 496
 497   kc = kstat_open ();
 498   if (kc == 0)
 499     return -1;
 500   ksp = kstat_lookup (kc, "unix", 0, "system_misc");
 501   if (ksp == 0)
 502     return -1;
 503   if (kstat_read (kc, ksp, 0) == -1)
 504     return -1;
 505
 506
 507   kn = kstat_data_lookup (ksp, "avenrun_1min");
 508   if (kn == 0)
 509     {
 510       /* Return -1 if no load average information is available.  */
 511       nelem = 0;
 512       elem = -1;
 513     }
 514
 515   if (nelem >= 1)
 516     loadavg[elem++] = (double) kn->value.ul / FSCALE;
 517
 518   if (nelem >= 2)
 519     {
 520       kn = kstat_data_lookup (ksp, "avenrun_5min");
 521       if (kn != 0)
 522         {
 523           loadavg[elem++] = (double) kn->value.ul / FSCALE;
 524
 525           if (nelem >= 3)
 526             {
 527               kn = kstat_data_lookup (ksp, "avenrun_15min");
 528               if (kn != 0)
 529                 loadavg[elem++] = (double) kn->value.ul / FSCALE;
 530             }
 531         }
 532     }
 533
 534   saved_errno = errno;
 535   kstat_close (kc);
 536   errno = saved_errno;
 537 # endif /* HAVE_LIBKSTAT */
 538
 539 # if !defined (LDAV_DONE) && defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
 540                                                            /* HP-UX */
 541 /* Use pstat_getdynamic() because we don't have to be root.  */
 542 #  define LDAV_DONE
 543 #  undef LOAD_AVE_TYPE
 544
 545   struct pst_dynamic dyn_info;
 546   if (pstat_getdynamic (&dyn_info, sizeof (dyn_info), 0, 0) < 0)
 547     return -1;
 548   if (nelem > 0)
 549     loadavg[elem++] = dyn_info.psd_avg_1_min;
 550   if (nelem > 1)
 551     loadavg[elem++] = dyn_info.psd_avg_5_min;
 552   if (nelem > 2)
 553     loadavg[elem++] = dyn_info.psd_avg_15_min;
 554
 555 # endif /* hpux && HAVE_PSTAT_GETDYNAMIC */
 556
 557 # if ! defined LDAV_DONE && defined HAVE_LIBPERFSTAT       /* AIX */
 558 #  define LDAV_DONE
 559 #  undef LOAD_AVE_TYPE
 560 /* Use perfstat_cpu_total because we don't have to be root. */
 561   {
 562     perfstat_cpu_total_t cpu_stats;
 563     int result = perfstat_cpu_total (NULL, &cpu_stats, sizeof cpu_stats, 1);
 564     if (result == -1)
 565       return result;
 566     loadavg[0] = cpu_stats.loadavg[0] / (double)(1 << SBITS);
 567     loadavg[1] = cpu_stats.loadavg[1] / (double)(1 << SBITS);
 568     loadavg[2] = cpu_stats.loadavg[2] / (double)(1 << SBITS);
 569     elem = 3;
 570   }
 571 # endif
 572
 573 # if !defined (LDAV_DONE) && (defined (__linux__) || defined (__CYGWIN__))
 574                                               /* Linux without glibc, Cygwin */
 575 #  define LDAV_DONE
 576 #  undef LOAD_AVE_TYPE
 577
 578 #  ifndef LINUX_LDAV_FILE
 579 #   define LINUX_LDAV_FILE "/proc/loadavg"
 580 #  endif
 581
 582   char ldavgbuf[3 * (INT_STRLEN_BOUND (int) + sizeof ".00 ")];
 583   char const *ptr = ldavgbuf;
 584   int fd, count, saved_errno;
 585
 586   fd = open (LINUX_LDAV_FILE, O_RDONLY);
 587   if (fd == -1)
 588     return -1;
 589   count = read (fd, ldavgbuf, sizeof ldavgbuf - 1);
 590   saved_errno = errno;
 591   (void) close (fd);
 592   errno = saved_errno;
 593   if (count <= 0)
 594     return -1;
 595   ldavgbuf[count] = '\0';
 596
 597   for (elem = 0; elem < nelem; elem++)
 598     {
 599       double numerator = 0;
 600       double denominator = 1;
 601
 602       while (*ptr == ' ')
 603         ptr++;
 604
 605       /* Finish if this number is missing, and report an error if all
 606          were missing.  */
 607       if (! ('0' <= *ptr && *ptr <= '9'))
 608         {
 609           if (elem == 0)
 610             {
 611               errno = ENOTSUP;
 612               return -1;
 613             }
 614           break;
 615         }
 616
 617       while ('0' <= *ptr && *ptr <= '9')
 618         numerator = 10 * numerator + (*ptr++ - '0');
 619
 620       if (*ptr == '.')
 621         for (ptr++; '0' <= *ptr && *ptr <= '9'; ptr++)
 622           numerator = 10 * numerator + (*ptr - '0'), denominator *= 10;
 623
 624       loadavg[elem++] = numerator / denominator;
 625     }
 626
 627   return elem;
 628
 629 # endif /* __linux__ || __CYGWIN__ */
 630
 631 # if !defined (LDAV_DONE) && defined (__NetBSD__)          /* NetBSD < 0.9 */
 632 #  define LDAV_DONE
 633 #  undef LOAD_AVE_TYPE
 634
 635 #  ifndef NETBSD_LDAV_FILE
 636 #   define NETBSD_LDAV_FILE "/kern/loadavg"
 637 #  endif
 638
 639   unsigned long int load_ave[3], scale;
 640   int count;
 641   FILE *fp;
 642
 643   fp = fopen (NETBSD_LDAV_FILE, "r");
 644   if (fp == NULL)
 645     return -1;
 646   count = fscanf (fp, "%lu %lu %lu %lu\n",
 647                   &load_ave[0], &load_ave[1], &load_ave[2],
 648                   &scale);
 649   (void) fclose (fp);
 650   if (count != 4)
 651     {
 652       errno = ENOTSUP;
 653       return -1;
 654     }
 655
 656   for (elem = 0; elem < nelem; elem++)
 657     loadavg[elem] = (double) load_ave[elem] / (double) scale;
 658
 659   return elem;
 660
 661 # endif /* __NetBSD__ */
 662
 663 # if !defined (LDAV_DONE) && defined (NeXT)                /* NeXTStep */
 664 #  define LDAV_DONE
 665   /* The NeXT code was adapted from iscreen 3.2.  */
 666
 667   host_t host;
 668   struct processor_set_basic_info info;
 669   unsigned int info_count;
 670
 671   /* We only know how to get the 1-minute average for this system,
 672      so even if the caller asks for more than 1, we only return 1.  */
 673
 674   if (!getloadavg_initialized)
 675     {
 676       if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
 677         getloadavg_initialized = true;
 678     }
 679
 680   if (getloadavg_initialized)
 681     {
 682       info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
 683       if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
 684                               (processor_set_info_t) &info, &info_count)
 685           != KERN_SUCCESS)
 686         getloadavg_initialized = false;
 687       else
 688         {
 689           if (nelem > 0)
 690             loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
 691         }
 692     }
 693
 694   if (!getloadavg_initialized)
 695     {
 696       errno = ENOTSUP;
 697       return -1;
 698     }
 699 # endif /* NeXT */
 700
 701 # if !defined (LDAV_DONE) && defined (UMAX)
 702 #  define LDAV_DONE
 703 /* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
 704    have a /dev/kmem.  Information about the workings of the running kernel
 705    can be gathered with inq_stats system calls.
 706    We only know how to get the 1-minute average for this system.  */
 707
 708   struct proc_summary proc_sum_data;
 709   struct stat_descr proc_info;
 710   double load;
 711   register unsigned int i, j;
 712
 713   if (cpus == 0)
 714     {
 715       register unsigned int c, i;
 716       struct cpu_config conf;
 717       struct stat_descr desc;
 718
 719       desc.sd_next = 0;
 720       desc.sd_subsys = SUBSYS_CPU;
 721       desc.sd_type = CPUTYPE_CONFIG;
 722       desc.sd_addr = (char *) &conf;
 723       desc.sd_size = sizeof conf;
 724
 725       if (inq_stats (1, &desc))
 726         return -1;
 727
 728       c = 0;
 729       for (i = 0; i < conf.config_maxclass; ++i)
 730         {
 731           struct class_stats stats;
 732           memset (&stats, 0, sizeof stats);
 733
 734           desc.sd_type = CPUTYPE_CLASS;
 735           desc.sd_objid = i;
 736           desc.sd_addr = (char *) &stats;
 737           desc.sd_size = sizeof stats;
 738
 739           if (inq_stats (1, &desc))
 740             return -1;
 741
 742           c += stats.class_numcpus;
 743         }
 744       cpus = c;
 745       samples = cpus < 2 ? 3 : (2 * cpus / 3);
 746     }
 747
 748   proc_info.sd_next = 0;
 749   proc_info.sd_subsys = SUBSYS_PROC;
 750   proc_info.sd_type = PROCTYPE_SUMMARY;
 751   proc_info.sd_addr = (char *) &proc_sum_data;
 752   proc_info.sd_size = sizeof (struct proc_summary);
 753   proc_info.sd_sizeused = 0;
 754
 755   if (inq_stats (1, &proc_info) != 0)
 756     return -1;
 757
 758   load = proc_sum_data.ps_nrunnable;
 759   j = 0;
 760   for (i = samples - 1; i > 0; --i)
 761     {
 762       load += proc_sum_data.ps_nrun[j];
 763       if (j++ == PS_NRUNSIZE)
 764         j = 0;
 765     }
 766
 767   if (nelem > 0)
 768     loadavg[elem++] = load / samples / cpus;
 769 # endif /* UMAX */
 770
 771 # if !defined (LDAV_DONE) && defined (DGUX)
 772 #  define LDAV_DONE
 773   /* This call can return -1 for an error, but with good args
 774      it's not supposed to fail.  The first argument is for no
 775      apparent reason of type 'long int *'.  */
 776   dg_sys_info ((long int *) &load_info,
 777                DG_SYS_INFO_LOAD_INFO_TYPE,
 778                DG_SYS_INFO_LOAD_VERSION_0);
 779
 780   if (nelem > 0)
 781     loadavg[elem++] = load_info.one_minute;
 782   if (nelem > 1)
 783     loadavg[elem++] = load_info.five_minute;
 784   if (nelem > 2)
 785     loadavg[elem++] = load_info.fifteen_minute;
 786 # endif /* DGUX */
 787
 788 # if !defined (LDAV_DONE) && defined (apollo)
 789 #  define LDAV_DONE
 790 /* Apollo code from lisch@mentorg.com (Ray Lischner).
 791
 792    This system call is not documented.  The load average is obtained as
 793    three long integers, for the load average over the past minute,
 794    five minutes, and fifteen minutes.  Each value is a scaled integer,
 795    with 16 bits of integer part and 16 bits of fraction part.
 796
 797    I'm not sure which operating system first supported this system call,
 798    but I know that SR10.2 supports it.  */
 799
 800   extern void proc1_$get_loadav ();
 801   unsigned long load_ave[3];
 802
 803   proc1_$get_loadav (load_ave);
 804
 805   if (nelem > 0)
 806     loadavg[elem++] = load_ave[0] / 65536.0;
 807   if (nelem > 1)
 808     loadavg[elem++] = load_ave[1] / 65536.0;
 809   if (nelem > 2)
 810     loadavg[elem++] = load_ave[2] / 65536.0;
 811 # endif /* apollo */
 812
 813 # if !defined (LDAV_DONE) && defined (OSF_MIPS)
 814 #  define LDAV_DONE
 815
 816   struct tbl_loadavg load_ave;
 817   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 818   loadavg[elem++]
 819     = (load_ave.tl_lscale == 0
 820        ? load_ave.tl_avenrun.d[0]
 821        : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
 822 # endif /* OSF_MIPS */
 823
 824 # if !defined (LDAV_DONE) && (defined (__MSDOS__) || defined (WINDOWS32))
 825                                                            /* DJGPP */
 826 #  define LDAV_DONE
 827
 828   /* A faithful emulation is going to have to be saved for a rainy day.  */
 829   for ( ; elem < nelem; elem++)
 830     {
 831       loadavg[elem] = 0.0;
 832     }
 833 # endif  /* __MSDOS__ || WINDOWS32 */
 834
 835 # if !defined (LDAV_DONE) && defined (OSF_ALPHA)           /* OSF/1 */
 836 #  define LDAV_DONE
 837
 838   struct tbl_loadavg load_ave;
 839   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 840   for (elem = 0; elem < nelem; elem++)
 841     loadavg[elem]
 842       = (load_ave.tl_lscale == 0
 843          ? load_ave.tl_avenrun.d[elem]
 844          : (load_ave.tl_avenrun.l[elem] / (double) load_ave.tl_lscale));
 845 # endif /* OSF_ALPHA */
 846
 847 # if ! defined LDAV_DONE && defined __VMS                  /* VMS */
 848   /* VMS specific code -- read from the Load Ave driver.  */
 849
 850   LOAD_AVE_TYPE load_ave[3];
 851   static bool getloadavg_initialized;
 852 #  ifdef eunice
 853   struct
 854   {
 855     int dsc$w_length;
 856     char *dsc$a_pointer;
 857   } descriptor;
 858 #  endif
 859
 860   /* Ensure that there is a channel open to the load ave device.  */
 861   if (!getloadavg_initialized)
 862     {
 863       /* Attempt to open the channel.  */
 864 #  ifdef eunice
 865       descriptor.dsc$w_length = 18;
 866       descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
 867 #  else
 868       $DESCRIPTOR (descriptor, "LAV0:");
 869 #  endif
 870       if (sys$assign (&descriptor, &channel, 0, 0) & 1)
 871         getloadavg_initialized = true;
 872     }
 873
 874   /* Read the load average vector.  */
 875   if (getloadavg_initialized
 876       && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
 877                      load_ave, 12, 0, 0, 0, 0) & 1))
 878     {
 879       sys$dassgn (channel);
 880       getloadavg_initialized = false;
 881     }
 882
 883   if (!getloadavg_initialized)
 884     {
 885       errno = ENOTSUP;
 886       return -1;
 887     }
 888 # endif /* ! defined LDAV_DONE && defined __VMS */
 889
 890 # if ! defined LDAV_DONE && defined LOAD_AVE_TYPE && ! defined __VMS
 891                                                   /* IRIX, other old systems */
 892
 893   /* UNIX-specific code -- read the average from /dev/kmem.  */
 894
 895 #  define LDAV_PRIVILEGED               /* This code requires special installation.  */
 896
 897   LOAD_AVE_TYPE load_ave[3];
 898
 899   /* Get the address of LDAV_SYMBOL.  */
 900   if (offset == 0)
 901     {
 902 #  ifndef sgi
 903 #   if ! defined NLIST_STRUCT || ! defined N_NAME_POINTER
 904       strcpy (name_list[0].n_name, LDAV_SYMBOL);
 905       strcpy (name_list[1].n_name, "");
 906 #   else /* NLIST_STRUCT */
 907 #    ifdef HAVE_STRUCT_NLIST_N_UN_N_NAME
 908       name_list[0].n_un.n_name = LDAV_SYMBOL;
 909       name_list[1].n_un.n_name = 0;
 910 #    else /* not HAVE_STRUCT_NLIST_N_UN_N_NAME */
 911       name_list[0].n_name = LDAV_SYMBOL;
 912       name_list[1].n_name = 0;
 913 #    endif /* not HAVE_STRUCT_NLIST_N_UN_N_NAME */
 914 #   endif /* NLIST_STRUCT */
 915
 916 #   ifndef SUNOS_5
 917       if (
 918 #    if !(defined (_AIX) && !defined (ps2))
 919           nlist (KERNEL_FILE, name_list)
 920 #    else  /* _AIX */
 921           knlist (name_list, 1, sizeof (name_list[0]))
 922 #    endif
 923           >= 0)
 924           /* Omit "&& name_list[0].n_type != 0 " -- it breaks on Sun386i.  */
 925           {
 926 #    ifdef FIXUP_KERNEL_SYMBOL_ADDR
 927             FIXUP_KERNEL_SYMBOL_ADDR (name_list);
 928 #    endif
 929             offset = name_list[0].n_value;
 930           }
 931 #   endif /* !SUNOS_5 */
 932 #  else  /* sgi */
 933       ptrdiff_t ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
 934       if (ldav_off != -1)
 935         offset = (long int) ldav_off & 0x7fffffff;
 936 #  endif /* sgi */
 937     }
 938
 939   /* Make sure we have /dev/kmem open.  */
 940   if (!getloadavg_initialized)
 941     {
 942 #  ifndef SUNOS_5
 943       /* Set the channel to close on exec, so it does not
 944          litter any child's descriptor table.  */
 945 #   ifndef O_CLOEXEC
 946 #    define O_CLOEXEC 0
 947 #   endif
 948       int fd = open ("/dev/kmem", O_RDONLY | O_CLOEXEC);
 949       if (0 <= fd)
 950         {
 951 #   if F_DUPFD_CLOEXEC
 952           if (fd <= STDERR_FILENO)
 953             {
 954               int fd1 = fcntl (fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1);
 955               close (fd);
 956               fd = fd1;
 957             }
 958 #   endif
 959           if (0 <= fd)
 960             {
 961               channel = fd;
 962               getloadavg_initialized = true;
 963             }
 964         }
 965 #  else /* SUNOS_5 */
 966       /* We pass 0 for the kernel, corefile, and swapfile names
 967          to use the currently running kernel.  */
 968       kd = kvm_open (0, 0, 0, O_RDONLY, 0);
 969       if (kd != 0)
 970         {
 971           /* nlist the currently running kernel.  */
 972           kvm_nlist (kd, name_list);
 973           offset = name_list[0].n_value;
 974           getloadavg_initialized = true;
 975         }
 976 #  endif /* SUNOS_5 */
 977     }
 978
 979   /* If we can, get the load average values.  */
 980   if (offset && getloadavg_initialized)
 981     {
 982       /* Try to read the load.  */
 983 #  ifndef SUNOS_5
 984       if (lseek (channel, offset, 0) == -1L
 985           || read (channel, (char *) load_ave, sizeof (load_ave))
 986           != sizeof (load_ave))
 987         {
 988           close (channel);
 989           getloadavg_initialized = false;
 990         }
 991 #  else  /* SUNOS_5 */
 992       if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
 993           != sizeof (load_ave))
 994         {
 995           kvm_close (kd);
 996           getloadavg_initialized = false;
 997         }
 998 #  endif /* SUNOS_5 */
 999     }
1000
1001   if (offset == 0 || !getloadavg_initialized)
1002     {
1003       errno = ENOTSUP;
1004       return -1;
1005     }
1006 # endif /* ! defined LDAV_DONE && defined LOAD_AVE_TYPE && ! defined __VMS */
1007
1008 # if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
1009   if (nelem > 0)
1010     loadavg[elem++] = LDAV_CVT (load_ave[0]);
1011   if (nelem > 1)
1012     loadavg[elem++] = LDAV_CVT (load_ave[1]);
1013   if (nelem > 2)
1014     loadavg[elem++] = LDAV_CVT (load_ave[2]);
1015
1016 #  define LDAV_DONE
1017 # endif /* !LDAV_DONE && LOAD_AVE_TYPE */
1018
1019 # if !defined LDAV_DONE
1020   errno = ENOSYS;
1021   elem = -1;
1022 # endif
1023   return elem;
1024 }