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