getloadavg.c

   1 /* Get the system load averages.
   2    Copyright (C) 1985, 86, 87, 88, 89, 91, 92, 93, 1994, 1995
   3         Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  18    USA.  */
  19
  20 /* Compile-time symbols that this file uses:
  21
  22    FIXUP_KERNEL_SYMBOL_ADDR()   Adjust address in returned struct nlist.
  23    KERNEL_FILE                  Pathname of the kernel to nlist.
  24    LDAV_CVT()                   Scale the load average from the kernel.
  25                                 Returns a double.
  26    LDAV_SYMBOL                  Name of kernel symbol giving load average.
  27    LOAD_AVE_TYPE                Type of the load average array in the kernel.
  28                                 Must be defined unless one of
  29                                 apollo, DGUX, NeXT, or UMAX is defined;
  30                                 otherwise, no load average is available.
  31    NLIST_STRUCT                 Include nlist.h, not a.out.h, and
  32                                 the nlist n_name element is a pointer,
  33                                 not an array.
  34    NLIST_NAME_UNION             struct nlist has an n_un member, not n_name.
  35    LINUX_LDAV_FILE              [__linux__]: File containing load averages.
  36
  37    Specific system predefines this file uses, aside from setting
  38    default values if not emacs:
  39
  40    apollo
  41    BSD                          Real BSD, not just BSD-like.
  42    convex
  43    DGUX
  44    eunice                       UNIX emulator under VMS.
  45    hpux
  46    MSDOS                        No-op for MSDOS.
  47    NeXT
  48    sgi
  49    sequent                      Sequent Dynix 3.x.x (BSD)
  50    _SEQUENT_                    Sequent DYNIX/ptx 1.x.x (SYSV)
  51    sony_news                    NEWS-OS (works at least for 4.1C)
  52    UMAX
  53    UMAX4_3
  54    VMS
  55    WIN32                        No-op for Windows95/NT.
  56    __linux__                    Linux: assumes /proc filesystem mounted.
  57                                 Support from Michael K. Johnson.
  58    __NetBSD__                   NetBSD: assumes /kern filesystem mounted.
  59
  60    In addition, to avoid nesting many #ifdefs, we internally set
  61    LDAV_DONE to indicate that the load average has been computed.
  62
  63    We also #define LDAV_PRIVILEGED if a program will require
  64    special installation to be able to call getloadavg.  */
  65
  66 /* This should always be first.  */
  67 #ifdef HAVE_CONFIG_H
  68 #include <config.h>
  69 #endif
  70
  71 #include <sys/types.h>
  72
  73 /* Both the Emacs and non-Emacs sections want this.  Some
  74    configuration files' definitions for the LOAD_AVE_CVT macro (like
  75    sparc.h's) use macros like FSCALE, defined here.  */
  76 #ifdef unix
  77 #include <sys/param.h>
  78 #endif
  79
  80
  81 /* Exclude all the code except the test program at the end
  82    if the system has its own `getloadavg' function.
  83
  84    The declaration of `errno' is needed by the test program
  85    as well as the function itself, so it comes first.  */
  86
  87 #include <errno.h>
  88
  89 #ifndef errno
  90 extern int errno;
  91 #endif
  92
  93 #ifndef HAVE_GETLOADAVG
  94
  95
  96 /* The existing Emacs configuration files define a macro called
  97    LOAD_AVE_CVT, which accepts a value of type LOAD_AVE_TYPE, and
  98    returns the load average multiplied by 100.  What we actually want
  99    is a macro called LDAV_CVT, which returns the load average as an
 100    unmultiplied double.
 101
 102    For backwards compatibility, we'll define LDAV_CVT in terms of
 103    LOAD_AVE_CVT, but future machine config files should just define
 104    LDAV_CVT directly.  */
 105
 106 #if !defined(LDAV_CVT) && defined(LOAD_AVE_CVT)
 107 #define LDAV_CVT(n) (LOAD_AVE_CVT (n) / 100.0)
 108 #endif
 109
 110 #if !defined (BSD) && defined (ultrix)
 111 /* Ultrix behaves like BSD on Vaxen.  */
 112 #define BSD
 113 #endif
 114
 115 #ifdef NeXT
 116 /* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which
 117    conflicts with the definition understood in this file, that this
 118    really is BSD. */
 119 #undef BSD
 120
 121 /* NeXT defines FSCALE in <sys/param.h>.  However, we take FSCALE being
 122    defined to mean that the nlist method should be used, which is not true.  */
 123 #undef FSCALE
 124 #endif
 125
 126 /* Set values that are different from the defaults, which are
 127    set a little farther down with #ifndef.  */
 128
 129
 130 /* Some shorthands.  */
 131
 132 #if defined (HPUX) && !defined (hpux)
 133 #define hpux
 134 #endif
 135
 136 #if defined(hp300) && !defined(hpux)
 137 #define MORE_BSD
 138 #endif
 139
 140 #if defined(ultrix) && defined(mips)
 141 #define decstation
 142 #endif
 143
 144 #if (defined(sun) && defined(SVR4)) || defined (SOLARIS2)
 145 #define SUNOS_5
 146 #endif
 147
 148 #if defined (__osf__) && (defined (__alpha) || defined (__alpha__))
 149 #define OSF_ALPHA
 150 #include <sys/table.h>
 151 #endif
 152
 153 #if defined (__osf__) && (defined (mips) || defined (__mips__))
 154 #define OSF_MIPS
 155 #include <sys/table.h>
 156 #endif
 157
 158 /* UTek's /bin/cc on the 4300 has no architecture specific cpp define by
 159    default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>.  Combine
 160    that with a couple of other things and we'll have a unique match.  */
 161 #if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES)
 162 #define tek4300                 /* Define by emacs, but not by other users.  */
 163 #endif
 164
 165
 166 /* VAX C can't handle multi-line #ifs, or lines longer than 256 chars.  */
 167 #ifndef LOAD_AVE_TYPE
 168
 169 #ifdef MORE_BSD
 170 #define LOAD_AVE_TYPE long
 171 #endif
 172
 173 #ifdef sun
 174 #define LOAD_AVE_TYPE long
 175 #endif
 176
 177 #ifdef decstation
 178 #define LOAD_AVE_TYPE long
 179 #endif
 180
 181 #ifdef _SEQUENT_
 182 #define LOAD_AVE_TYPE long
 183 #endif
 184
 185 #ifdef sgi
 186 #define LOAD_AVE_TYPE long
 187 #endif
 188
 189 #ifdef SVR4
 190 #define LOAD_AVE_TYPE long
 191 #endif
 192
 193 #ifdef sony_news
 194 #define LOAD_AVE_TYPE long
 195 #endif
 196
 197 #ifdef sequent
 198 #define LOAD_AVE_TYPE long
 199 #endif
 200
 201 #ifdef OSF_ALPHA
 202 #define LOAD_AVE_TYPE long
 203 #endif
 204
 205 #if defined (ardent) && defined (titan)
 206 #define LOAD_AVE_TYPE long
 207 #endif
 208
 209 #ifdef tek4300
 210 #define LOAD_AVE_TYPE long
 211 #endif
 212
 213 #if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 214 #define LOAD_AVE_TYPE long
 215 #endif
 216
 217 #ifdef _AIX
 218 #define LOAD_AVE_TYPE long
 219 #endif
 220
 221 #ifdef convex
 222 #define LOAD_AVE_TYPE double
 223 #ifndef LDAV_CVT
 224 #define LDAV_CVT(n) (n)
 225 #endif
 226 #endif
 227
 228 #endif /* No LOAD_AVE_TYPE.  */
 229
 230 #ifdef OSF_ALPHA
 231 /* <sys/param.h> defines an incorrect value for FSCALE on Alpha OSF/1,
 232    according to ghazi@noc.rutgers.edu.  */
 233 #undef FSCALE
 234 #define FSCALE 1024.0
 235 #endif
 236
 237 #if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 238 /* <sys/param.h> defines an incorrect value for FSCALE on an
 239    Alliant FX/2800 Concentrix 2.2, according to ghazi@noc.rutgers.edu.  */
 240 #undef FSCALE
 241 #define FSCALE 100.0
 242 #endif
 243
 244
 245 #ifndef FSCALE
 246
 247 /* SunOS and some others define FSCALE in sys/param.h.  */
 248
 249 #ifdef MORE_BSD
 250 #define FSCALE 2048.0
 251 #endif
 252
 253 #if defined(MIPS) || defined(SVR4) || defined(decstation)
 254 #define FSCALE 256
 255 #endif
 256
 257 #if defined (sgi) || defined (sequent)
 258 /* Sometimes both MIPS and sgi are defined, so FSCALE was just defined
 259    above under #ifdef MIPS.  But we want the sgi value.  */
 260 #undef FSCALE
 261 #define FSCALE 1000.0
 262 #endif
 263
 264 #if defined (ardent) && defined (titan)
 265 #define FSCALE 65536.0
 266 #endif
 267
 268 #ifdef tek4300
 269 #define FSCALE 100.0
 270 #endif
 271
 272 #ifdef _AIX
 273 #define FSCALE 65536.0
 274 #endif
 275
 276 #endif  /* Not FSCALE.  */
 277
 278 #if !defined (LDAV_CVT) && defined (FSCALE)
 279 #define LDAV_CVT(n) (((double) (n)) / FSCALE)
 280 #endif
 281
 282 /* VAX C can't handle multi-line #ifs, or lines longer that 256 characters.  */
 283 #ifndef NLIST_STRUCT
 284
 285 #ifdef MORE_BSD
 286 #define NLIST_STRUCT
 287 #endif
 288
 289 #ifdef sun
 290 #define NLIST_STRUCT
 291 #endif
 292
 293 #ifdef decstation
 294 #define NLIST_STRUCT
 295 #endif
 296
 297 #ifdef hpux
 298 #define NLIST_STRUCT
 299 #endif
 300
 301 #if defined (_SEQUENT_) || defined (sequent)
 302 #define NLIST_STRUCT
 303 #endif
 304
 305 #ifdef sgi
 306 #define NLIST_STRUCT
 307 #endif
 308
 309 #ifdef SVR4
 310 #define NLIST_STRUCT
 311 #endif
 312
 313 #ifdef sony_news
 314 #define NLIST_STRUCT
 315 #endif
 316
 317 #ifdef OSF_ALPHA
 318 #define NLIST_STRUCT
 319 #endif
 320
 321 #if defined (ardent) && defined (titan)
 322 #define NLIST_STRUCT
 323 #endif
 324
 325 #ifdef tek4300
 326 #define NLIST_STRUCT
 327 #endif
 328
 329 #ifdef butterfly
 330 #define NLIST_STRUCT
 331 #endif
 332
 333 #if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 334 #define NLIST_STRUCT
 335 #endif
 336
 337 #ifdef _AIX
 338 #define NLIST_STRUCT
 339 #endif
 340
 341 #endif /* defined (NLIST_STRUCT) */
 342
 343
 344 #if defined(sgi) || (defined(mips) && !defined(BSD))
 345 #define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31))
 346 #endif
 347
 348
 349 #if !defined (KERNEL_FILE) && defined (sequent)
 350 #define KERNEL_FILE "/dynix"
 351 #endif
 352
 353 #if !defined (KERNEL_FILE) && defined (hpux)
 354 #define KERNEL_FILE "/hp-ux"
 355 #endif
 356
 357 #if !defined(KERNEL_FILE) && (defined(_SEQUENT_) || defined(MIPS) || defined(SVR4) || defined(ISC) || defined (sgi) || defined(SVR4) || (defined (ardent) && defined (titan)))
 358 #define KERNEL_FILE "/unix"
 359 #endif
 360
 361
 362 #if !defined (LDAV_SYMBOL) && defined (alliant)
 363 #define LDAV_SYMBOL "_Loadavg"
 364 #endif
 365
 366 #if !defined(LDAV_SYMBOL) && ((defined(hpux) && !defined(hp9000s300)) || defined(_SEQUENT_) || defined(SVR4) || defined(ISC) || defined(sgi) || (defined (ardent) && defined (titan)) || defined (_AIX))
 367 #define LDAV_SYMBOL "avenrun"
 368 #endif
 369
 370 #ifdef HAVE_UNISTD_H
 371 #include <unistd.h>
 372 #endif
 373
 374 #include <stdio.h>
 375
 376 /* LOAD_AVE_TYPE should only get defined if we're going to use the
 377    nlist method.  */
 378 #if !defined(LOAD_AVE_TYPE) && (defined(BSD) || defined(LDAV_CVT) || defined(KERNEL_FILE) || defined(LDAV_SYMBOL))
 379 #define LOAD_AVE_TYPE double
 380 #endif
 381
 382 #ifdef LOAD_AVE_TYPE
 383
 384 #ifndef VMS
 385 #ifndef NLIST_STRUCT
 386 #include <a.out.h>
 387 #else /* NLIST_STRUCT */
 388 #include <nlist.h>
 389 #endif /* NLIST_STRUCT */
 390
 391 #ifdef SUNOS_5
 392 #include <fcntl.h>
 393 #include <kvm.h>
 394 #endif
 395
 396 #ifndef KERNEL_FILE
 397 #define KERNEL_FILE "/vmunix"
 398 #endif /* KERNEL_FILE */
 399
 400 #ifndef LDAV_SYMBOL
 401 #define LDAV_SYMBOL "_avenrun"
 402 #endif /* LDAV_SYMBOL */
 403
 404 #else /* VMS */
 405
 406 #ifndef eunice
 407 #include <iodef.h>
 408 #include <descrip.h>
 409 #else /* eunice */
 410 #include <vms/iodef.h>
 411 #endif /* eunice */
 412 #endif /* VMS */
 413
 414 #ifndef LDAV_CVT
 415 #define LDAV_CVT(n) ((double) (n))
 416 #endif /* !LDAV_CVT */
 417
 418 #endif /* LOAD_AVE_TYPE */
 419
 420 #ifdef NeXT
 421 #ifdef HAVE_MACH_MACH_H
 422 #include <mach/mach.h>
 423 #else
 424 #include <mach.h>
 425 #endif
 426 #endif /* NeXT */
 427
 428 #ifdef sgi
 429 #include <sys/sysmp.h>
 430 #endif /* sgi */
 431
 432 #ifdef UMAX
 433 #include <stdio.h>
 434 #include <signal.h>
 435 #include <sys/time.h>
 436 #include <sys/wait.h>
 437 #include <sys/syscall.h>
 438
 439 #ifdef UMAX_43
 440 #include <machine/cpu.h>
 441 #include <inq_stats/statistics.h>
 442 #include <inq_stats/sysstats.h>
 443 #include <inq_stats/cpustats.h>
 444 #include <inq_stats/procstats.h>
 445 #else /* Not UMAX_43.  */
 446 #include <sys/sysdefs.h>
 447 #include <sys/statistics.h>
 448 #include <sys/sysstats.h>
 449 #include <sys/cpudefs.h>
 450 #include <sys/cpustats.h>
 451 #include <sys/procstats.h>
 452 #endif /* Not UMAX_43.  */
 453 #endif /* UMAX */
 454
 455 #ifdef DGUX
 456 #include <sys/dg_sys_info.h>
 457 #endif
 458
 459 #if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION)
 460 #include <fcntl.h>
 461 #else
 462 #include <sys/file.h>
 463 #endif
 464 \f
 465 /* Avoid static vars inside a function since in HPUX they dump as pure.  */
 466
 467 #ifdef NeXT
 468 static processor_set_t default_set;
 469 static int getloadavg_initialized;
 470 #endif /* NeXT */
 471
 472 #ifdef UMAX
 473 static unsigned int cpus = 0;
 474 static unsigned int samples;
 475 #endif /* UMAX */
 476
 477 #ifdef DGUX
 478 static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
 479 #endif /* DGUX */
 480
 481 #ifdef LOAD_AVE_TYPE
 482 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 483 static int channel;
 484 /* Nonzero iff channel is valid.  */
 485 static int getloadavg_initialized;
 486 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 487 static long offset;
 488
 489 #if !defined(VMS) && !defined(sgi)
 490 static struct nlist nl[2];
 491 #endif /* Not VMS or sgi */
 492
 493 #ifdef SUNOS_5
 494 static kvm_t *kd;
 495 #endif /* SUNOS_5 */
 496
 497 #endif /* LOAD_AVE_TYPE */
 498 \f
 499 /* Put the 1 minute, 5 minute and 15 minute load averages
 500    into the first NELEM elements of LOADAVG.
 501    Return the number written (never more than 3, but may be less than NELEM),
 502    or -1 if an error occurred.  */
 503
 504 int
 505 getloadavg (loadavg, nelem)
 506      double loadavg[];
 507      int nelem;
 508 {
 509   int elem = 0;                 /* Return value.  */
 510
 511 #ifdef NO_GET_LOAD_AVG
 512 #define LDAV_DONE
 513   /* Set errno to zero to indicate that there was no particular error;
 514      this function just can't work at all on this system.  */
 515   errno = 0;
 516   elem = -1;
 517 #endif
 518
 519 #if !defined (LDAV_DONE) && defined (__linux__)
 520 #define LDAV_DONE
 521 #undef LOAD_AVE_TYPE
 522
 523 #ifndef LINUX_LDAV_FILE
 524 #define LINUX_LDAV_FILE "/proc/loadavg"
 525 #endif
 526
 527   char ldavgbuf[40];
 528   double load_ave[3];
 529   int fd, count;
 530
 531   fd = open (LINUX_LDAV_FILE, O_RDONLY);
 532   if (fd == -1)
 533     return -1;
 534   count = read (fd, ldavgbuf, 40);
 535   (void) close (fd);
 536   if (count <= 0)
 537     return -1;
 538
 539   count = sscanf (ldavgbuf, "%lf %lf %lf",
 540                   &load_ave[0], &load_ave[1], &load_ave[2]);
 541   if (count < 1)
 542     return -1;
 543
 544   for (elem = 0; elem < nelem && elem < count; elem++)
 545     loadavg[elem] = load_ave[elem];
 546
 547   return elem;
 548
 549 #endif /* __linux__ */
 550
 551 #if !defined (LDAV_DONE) && defined (__NetBSD__)
 552 #define LDAV_DONE
 553 #undef LOAD_AVE_TYPE
 554
 555 #ifndef NETBSD_LDAV_FILE
 556 #define NETBSD_LDAV_FILE "/kern/loadavg"
 557 #endif
 558
 559   unsigned long int load_ave[3], scale;
 560   int count;
 561   FILE *fp;
 562
 563   fp = fopen (NETBSD_LDAV_FILE, "r");
 564   if (fp == NULL)
 565     return -1;
 566   count = fscanf (fp, "%lu %lu %lu %lu\n",
 567                   &load_ave[0], &load_ave[1], &load_ave[2],
 568                   &scale);
 569   (void) fclose (fp);
 570   if (count != 4)
 571     return -1;
 572
 573   for (elem = 0; elem < nelem; elem++)
 574     loadavg[elem] = (double) load_ave[elem] / (double) scale;
 575
 576   return elem;
 577
 578 #endif /* __NetBSD__ */
 579
 580 #if !defined (LDAV_DONE) && defined (NeXT)
 581 #define LDAV_DONE
 582   /* The NeXT code was adapted from iscreen 3.2.  */
 583
 584   host_t host;
 585   struct processor_set_basic_info info;
 586   unsigned info_count;
 587
 588   /* We only know how to get the 1-minute average for this system,
 589      so even if the caller asks for more than 1, we only return 1.  */
 590
 591   if (!getloadavg_initialized)
 592     {
 593       if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
 594         getloadavg_initialized = 1;
 595     }
 596
 597   if (getloadavg_initialized)
 598     {
 599       info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
 600       if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
 601                              (processor_set_info_t) &info, &info_count)
 602           != KERN_SUCCESS)
 603         getloadavg_initialized = 0;
 604       else
 605         {
 606           if (nelem > 0)
 607             loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
 608         }
 609     }
 610
 611   if (!getloadavg_initialized)
 612     return -1;
 613 #endif /* NeXT */
 614
 615 #if !defined (LDAV_DONE) && defined (UMAX)
 616 #define LDAV_DONE
 617 /* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
 618    have a /dev/kmem.  Information about the workings of the running kernel
 619    can be gathered with inq_stats system calls.
 620    We only know how to get the 1-minute average for this system.  */
 621
 622   struct proc_summary proc_sum_data;
 623   struct stat_descr proc_info;
 624   double load;
 625   register unsigned int i, j;
 626
 627   if (cpus == 0)
 628     {
 629       register unsigned int c, i;
 630       struct cpu_config conf;
 631       struct stat_descr desc;
 632
 633       desc.sd_next = 0;
 634       desc.sd_subsys = SUBSYS_CPU;
 635       desc.sd_type = CPUTYPE_CONFIG;
 636       desc.sd_addr = (char *) &conf;
 637       desc.sd_size = sizeof conf;
 638
 639       if (inq_stats (1, &desc))
 640         return -1;
 641
 642       c = 0;
 643       for (i = 0; i < conf.config_maxclass; ++i)
 644         {
 645           struct class_stats stats;
 646           bzero ((char *) &stats, sizeof stats);
 647
 648           desc.sd_type = CPUTYPE_CLASS;
 649           desc.sd_objid = i;
 650           desc.sd_addr = (char *) &stats;
 651           desc.sd_size = sizeof stats;
 652
 653           if (inq_stats (1, &desc))
 654             return -1;
 655
 656           c += stats.class_numcpus;
 657         }
 658       cpus = c;
 659       samples = cpus < 2 ? 3 : (2 * cpus / 3);
 660     }
 661
 662   proc_info.sd_next = 0;
 663   proc_info.sd_subsys = SUBSYS_PROC;
 664   proc_info.sd_type = PROCTYPE_SUMMARY;
 665   proc_info.sd_addr = (char *) &proc_sum_data;
 666   proc_info.sd_size = sizeof (struct proc_summary);
 667   proc_info.sd_sizeused = 0;
 668
 669   if (inq_stats (1, &proc_info) != 0)
 670     return -1;
 671
 672   load = proc_sum_data.ps_nrunnable;
 673   j = 0;
 674   for (i = samples - 1; i > 0; --i)
 675     {
 676       load += proc_sum_data.ps_nrun[j];
 677       if (j++ == PS_NRUNSIZE)
 678         j = 0;
 679     }
 680
 681   if (nelem > 0)
 682     loadavg[elem++] = load / samples / cpus;
 683 #endif /* UMAX */
 684
 685 #if !defined (LDAV_DONE) && defined (DGUX)
 686 #define LDAV_DONE
 687   /* This call can return -1 for an error, but with good args
 688      it's not supposed to fail.  The first argument is for no
 689      apparent reason of type `long int *'.  */
 690   dg_sys_info ((long int *) &load_info,
 691                DG_SYS_INFO_LOAD_INFO_TYPE,
 692                DG_SYS_INFO_LOAD_VERSION_0);
 693
 694   if (nelem > 0)
 695     loadavg[elem++] = load_info.one_minute;
 696   if (nelem > 1)
 697     loadavg[elem++] = load_info.five_minute;
 698   if (nelem > 2)
 699     loadavg[elem++] = load_info.fifteen_minute;
 700 #endif /* DGUX */
 701
 702 #if !defined (LDAV_DONE) && defined (apollo)
 703 #define LDAV_DONE
 704 /* Apollo code from lisch@mentorg.com (Ray Lischner).
 705
 706    This system call is not documented.  The load average is obtained as
 707    three long integers, for the load average over the past minute,
 708    five minutes, and fifteen minutes.  Each value is a scaled integer,
 709    with 16 bits of integer part and 16 bits of fraction part.
 710
 711    I'm not sure which operating system first supported this system call,
 712    but I know that SR10.2 supports it.  */
 713
 714   extern void proc1_$get_loadav ();
 715   unsigned long load_ave[3];
 716
 717   proc1_$get_loadav (load_ave);
 718
 719   if (nelem > 0)
 720     loadavg[elem++] = load_ave[0] / 65536.0;
 721   if (nelem > 1)
 722     loadavg[elem++] = load_ave[1] / 65536.0;
 723   if (nelem > 2)
 724     loadavg[elem++] = load_ave[2] / 65536.0;
 725 #endif /* apollo */
 726
 727 #if !defined (LDAV_DONE) && defined (OSF_MIPS)
 728 #define LDAV_DONE
 729
 730   struct tbl_loadavg load_ave;
 731   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 732   loadavg[elem++]
 733     = (load_ave.tl_lscale == 0
 734        ? load_ave.tl_avenrun.d[0]
 735        : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
 736 #endif  /* OSF_MIPS */
 737
 738 #if !defined (LDAV_DONE) && (defined (MSDOS) || defined (WIN32))
 739 #define LDAV_DONE
 740
 741   /* A faithful emulation is going to have to be saved for a rainy day.  */
 742   for ( ; elem < nelem; elem++)
 743     {
 744       loadavg[elem] = 0.0;
 745     }
 746 #endif  /* MSDOS */
 747
 748 #if !defined (LDAV_DONE) && defined (OSF_ALPHA)
 749 #define LDAV_DONE
 750
 751   struct tbl_loadavg load_ave;
 752   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 753   for (elem = 0; elem < nelem; elem++)
 754     loadavg[elem]
 755       = (load_ave.tl_lscale == 0
 756        ? load_ave.tl_avenrun.d[elem]
 757        : (load_ave.tl_avenrun.l[elem] / (double) load_ave.tl_lscale));
 758 #endif /* OSF_ALPHA */
 759
 760 #if !defined (LDAV_DONE) && defined (VMS)
 761   /* VMS specific code -- read from the Load Ave driver.  */
 762
 763   LOAD_AVE_TYPE load_ave[3];
 764   static int getloadavg_initialized = 0;
 765 #ifdef eunice
 766   struct
 767   {
 768     int dsc$w_length;
 769     char *dsc$a_pointer;
 770   } descriptor;
 771 #endif
 772
 773   /* Ensure that there is a channel open to the load ave device.  */
 774   if (!getloadavg_initialized)
 775     {
 776       /* Attempt to open the channel.  */
 777 #ifdef eunice
 778       descriptor.dsc$w_length = 18;
 779       descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
 780 #else
 781       $DESCRIPTOR (descriptor, "LAV0:");
 782 #endif
 783       if (sys$assign (&descriptor, &channel, 0, 0) & 1)
 784         getloadavg_initialized = 1;
 785     }
 786
 787   /* Read the load average vector.  */
 788   if (getloadavg_initialized
 789       && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
 790                      load_ave, 12, 0, 0, 0, 0) & 1))
 791     {
 792       sys$dassgn (channel);
 793       getloadavg_initialized = 0;
 794     }
 795
 796   if (!getloadavg_initialized)
 797     return -1;
 798 #endif /* VMS */
 799
 800 #if !defined (LDAV_DONE) && defined(LOAD_AVE_TYPE) && !defined(VMS)
 801
 802   /* UNIX-specific code -- read the average from /dev/kmem.  */
 803
 804 #define LDAV_PRIVILEGED         /* This code requires special installation.  */
 805
 806   LOAD_AVE_TYPE load_ave[3];
 807
 808   /* Get the address of LDAV_SYMBOL.  */
 809   if (offset == 0)
 810     {
 811 #ifndef sgi
 812 #ifndef NLIST_STRUCT
 813       strcpy (nl[0].n_name, LDAV_SYMBOL);
 814       strcpy (nl[1].n_name, "");
 815 #else /* NLIST_STRUCT */
 816 #ifdef NLIST_NAME_UNION
 817       nl[0].n_un.n_name = LDAV_SYMBOL;
 818       nl[1].n_un.n_name = 0;
 819 #else /* not NLIST_NAME_UNION */
 820       nl[0].n_name = LDAV_SYMBOL;
 821       nl[1].n_name = 0;
 822 #endif /* not NLIST_NAME_UNION */
 823 #endif /* NLIST_STRUCT */
 824
 825 #ifndef SUNOS_5
 826       if (
 827 #if !(defined (_AIX) && !defined (ps2))
 828           nlist (KERNEL_FILE, nl)
 829 #else  /* _AIX */
 830           knlist (nl, 1, sizeof (nl[0]))
 831 #endif
 832           >= 0)
 833           /* Omit "&& nl[0].n_type != 0 " -- it breaks on Sun386i.  */
 834           {
 835 #ifdef FIXUP_KERNEL_SYMBOL_ADDR
 836             FIXUP_KERNEL_SYMBOL_ADDR (nl);
 837 #endif
 838             offset = nl[0].n_value;
 839           }
 840 #endif /* !SUNOS_5 */
 841 #else  /* sgi */
 842           int ldav_off;
 843
 844           ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
 845           if (ldav_off != -1)
 846           offset = (long) ldav_off & 0x7fffffff;
 847 #endif /* sgi */
 848         }
 849
 850   /* Make sure we have /dev/kmem open.  */
 851   if (!getloadavg_initialized)
 852     {
 853 #ifndef SUNOS_5
 854       channel = open ("/dev/kmem", 0);
 855       if (channel >= 0)
 856         {
 857           /* Set the channel to close on exec, so it does not
 858              litter any child's descriptor table.  */
 859 #ifdef FD_SETFD
 860 #ifndef FD_CLOEXEC
 861 #define FD_CLOEXEC 1
 862 #endif
 863           (void) fcntl (channel, F_SETFD, FD_CLOEXEC);
 864 #endif
 865           getloadavg_initialized = 1;
 866         }
 867 #else /* SUNOS_5 */
 868       /* We pass 0 for the kernel, corefile, and swapfile names
 869          to use the currently running kernel.  */
 870       kd = kvm_open (0, 0, 0, O_RDONLY, 0);
 871       if (kd != 0)
 872         {
 873           /* nlist the currently running kernel.  */
 874           kvm_nlist (kd, nl);
 875           offset = nl[0].n_value;
 876           getloadavg_initialized = 1;
 877         }
 878 #endif /* SUNOS_5 */
 879     }
 880
 881   /* If we can, get the load average values.  */
 882   if (offset && getloadavg_initialized)
 883     {
 884       /* Try to read the load.  */
 885 #ifndef SUNOS_5
 886       if (lseek (channel, offset, 0) == -1L
 887           || read (channel, (char *) load_ave, sizeof (load_ave))
 888           != sizeof (load_ave))
 889         {
 890           close (channel);
 891           getloadavg_initialized = 0;
 892         }
 893 #else  /* SUNOS_5 */
 894       if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
 895           != sizeof (load_ave))
 896         {
 897           kvm_close (kd);
 898           getloadavg_initialized = 0;
 899         }
 900 #endif /* SUNOS_5 */
 901     }
 902
 903   if (offset == 0 || !getloadavg_initialized)
 904     return -1;
 905 #endif /* LOAD_AVE_TYPE and not VMS */
 906
 907 #if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
 908   if (nelem > 0)
 909     loadavg[elem++] = LDAV_CVT (load_ave[0]);
 910   if (nelem > 1)
 911     loadavg[elem++] = LDAV_CVT (load_ave[1]);
 912   if (nelem > 2)
 913     loadavg[elem++] = LDAV_CVT (load_ave[2]);
 914
 915 #define LDAV_DONE
 916 #endif /* !LDAV_DONE && LOAD_AVE_TYPE */
 917
 918 #ifdef LDAV_DONE
 919   return elem;
 920 #else
 921   /* Set errno to zero to indicate that there was no particular error;
 922      this function just can't work at all on this system.  */
 923   errno = 0;
 924   return -1;
 925 #endif
 926 }
 927
 928 #endif /* ! HAVE_GETLOADAVG */
 929 \f
 930 #ifdef TEST
 931 void
 932 main (argc, argv)
 933      int argc;
 934      char **argv;
 935 {
 936   int naptime = 0;
 937
 938   if (argc > 1)
 939     naptime = atoi (argv[1]);
 940
 941   while (1)
 942     {
 943       double avg[3];
 944       int loads;
 945
 946       errno = 0;                /* Don't be misled if it doesn't set errno.  */
 947       loads = getloadavg (avg, 3);
 948       if (loads == -1)
 949         {
 950           perror ("Error getting load average");
 951           exit (1);
 952         }
 953       if (loads > 0)
 954         printf ("1-minute: %f  ", avg[0]);
 955       if (loads > 1)
 956         printf ("5-minute: %f  ", avg[1]);
 957       if (loads > 2)
 958         printf ("15-minute: %f  ", avg[2]);
 959       if (loads > 0)
 960         putchar ('\n');
 961
 962       if (naptime == 0)
 963         break;
 964       sleep (naptime);
 965     }
 966
 967   exit (0);
 968 }
 969 #endif /* TEST */