getloadavg.c

   1 /* Get the system load averages.
   2    Copyright (C) 1985, 86, 87, 88, 89, 91, 92, 93
   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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  18
  19 /* Compile-time symbols that this file uses:
  20
  21    FIXUP_KERNEL_SYMBOL_ADDR()   Adjust address in returned struct nlist.
  22    KERNEL_FILE                  Pathname of the kernel to nlist.
  23    LDAV_CVT()                   Scale the load average from the kernel.
  24                                 Returns a double.
  25    LDAV_SYMBOL                  Name of kernel symbol giving load average.
  26    LOAD_AVE_TYPE                Type of the load average array in the kernel.
  27                                 Must be defined unless one of
  28                                 apollo, DGUX, NeXT, or UMAX is defined;
  29                                 otherwise, no load average is available.
  30    NLIST_STRUCT                 Include nlist.h, not a.out.h, and
  31                                 the nlist n_name element is a pointer,
  32                                 not an array.
  33    NLIST_NAME_UNION             struct nlist has an n_un member, not n_name.
  34    LINUX_LDAV_FILE              [__linux__]: File containing load averages.
  35
  36    Specific system predefines this file uses, aside from setting
  37    default values if not emacs:
  38
  39    apollo
  40    BSD                          Real BSD, not just BSD-like.
  41    DGUX
  42    eunice                       UNIX emulator under VMS.
  43    hpux
  44    NeXT
  45    sgi
  46    sequent                      Sequent Dynix 3.x.x (BSD)
  47    _SEQUENT_                    Sequent DYNIX/ptx 1.x.x (SYSV)
  48    sony_news                    NEWS-OS (works at least for 4.1C)
  49    UMAX
  50    UMAX4_3
  51    VMS
  52    __linux__                    Linux: assumes /proc filesystem mounted.
  53                                 Support from Michael K. Johnson.
  54
  55    In addition, to avoid nesting many #ifdefs, we internally set
  56    LDAV_DONE to indicate that the load average has been computed.
  57
  58    We also #define LDAV_PRIVILEGED if a program will require
  59    special installation to be able to call getloadavg.  */
  60
  61 #include <sys/types.h>
  62
  63 /* Both the Emacs and non-Emacs sections want this.  Some
  64    configuration files' definitions for the LOAD_AVE_CVT macro (like
  65    sparc.h's) use macros like FSCALE, defined here.  */
  66 #ifdef unix
  67 #include <sys/param.h>
  68 #endif
  69
  70
  71 #ifdef HAVE_CONFIG_H
  72 #if defined (emacs) || defined (CONFIG_BROKETS)
  73 /* We use <config.h> instead of "config.h" so that a compilation
  74    using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
  75    (which it would do because it found this file in $srcdir).  */
  76 #include <config.h>
  77 #else
  78 #include "config.h"
  79 #endif
  80 #endif
  81
  82
  83 /* Exclude all the code except the test program at the end
  84    if the system has its own `getloadavg' function.  */
  85
  86 #ifndef HAVE_GETLOADAVG
  87
  88
  89 /* The existing Emacs configuration files define a macro called
  90    LOAD_AVE_CVT, which accepts a value of type LOAD_AVE_TYPE, and
  91    returns the load average multiplied by 100.  What we actually want
  92    is a macro called LDAV_CVT, which returns the load average as an
  93    unmultiplied double.
  94
  95    For backwards compatibility, we'll define LDAV_CVT in terms of
  96    LOAD_AVE_CVT, but future machine config files should just define
  97    LDAV_CVT directly.  */
  98
  99 #if !defined(LDAV_CVT) && defined(LOAD_AVE_CVT)
 100 #define LDAV_CVT(n) (LOAD_AVE_CVT (n) / 100.0)
 101 #endif
 102
 103 #if !defined (BSD) && defined (ultrix)
 104 /* Ultrix behaves like BSD on Vaxen.  */
 105 #define BSD
 106 #endif
 107
 108 #ifdef NeXT
 109 /* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which
 110    conflicts with the definition understood in this file, that this
 111    really is BSD. */
 112 #undef BSD
 113
 114 /* NeXT defines FSCALE in <sys/param.h>.  However, we take FSCALE being
 115    defined to mean that the nlist method should be used, which is not true.  */
 116 #undef FSCALE
 117 #endif
 118
 119 /* Set values that are different from the defaults, which are
 120    set a little farther down with #ifndef.  */
 121
 122
 123 /* Some shorthands.  */
 124
 125 #if defined (HPUX) && !defined (hpux)
 126 #define hpux
 127 #endif
 128
 129 #if defined(hp300) && !defined(hpux)
 130 #define MORE_BSD
 131 #endif
 132
 133 #if defined(ultrix) && defined(mips)
 134 #define decstation
 135 #endif
 136
 137 #if defined(sun) && defined(SVR4)
 138 #define SUNOS_5
 139 #endif
 140
 141 #if defined (__osf__) && (defined (__alpha) || defined (__alpha__))
 142 #define OSF_ALPHA
 143 #endif
 144
 145 #if defined (__osf__) && (defined (mips) || defined (__mips__))
 146 #define OSF_MIPS
 147 #include <sys/table.h>
 148 #endif
 149
 150 /* UTek's /bin/cc on the 4300 has no architecture specific cpp define by
 151    default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>.  Combine
 152    that with a couple of other things and we'll have a unique match.  */
 153 #if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES)
 154 #define tek4300                 /* Define by emacs, but not by other users.  */
 155 #endif
 156
 157
 158 /* VAX C can't handle multi-line #ifs, or lines longer than 256 chars.  */
 159 #ifndef LOAD_AVE_TYPE
 160
 161 #ifdef MORE_BSD
 162 #define LOAD_AVE_TYPE long
 163 #endif
 164
 165 #ifdef sun
 166 #define LOAD_AVE_TYPE long
 167 #endif
 168
 169 #ifdef decstation
 170 #define LOAD_AVE_TYPE long
 171 #endif
 172
 173 #ifdef _SEQUENT_
 174 #define LOAD_AVE_TYPE long
 175 #endif
 176
 177 #ifdef sgi
 178 #define LOAD_AVE_TYPE long
 179 #endif
 180
 181 #ifdef SVR4
 182 #define LOAD_AVE_TYPE long
 183 #endif
 184
 185 #ifdef sony_news
 186 #define LOAD_AVE_TYPE long
 187 #endif
 188
 189 #ifdef sequent
 190 #define LOAD_AVE_TYPE long
 191 #endif
 192
 193 #ifdef OSF_ALPHA
 194 #define LOAD_AVE_TYPE long
 195 #endif
 196
 197 #if defined (ardent) && defined (titan)
 198 #define LOAD_AVE_TYPE long
 199 #endif
 200
 201 #ifdef tek4300
 202 #define LOAD_AVE_TYPE long
 203 #endif
 204
 205 #endif /* No LOAD_AVE_TYPE.  */
 206
 207 #ifdef OSF_ALPHA
 208 /* <sys/param.h> defines an incorrect value for FSCALE on Alpha OSF/1,
 209    according to ghazi@noc.rutgers.edu.  */
 210 #undef FSCALE
 211 #define FSCALE 1024.0
 212 #endif
 213
 214
 215 #ifndef FSCALE
 216
 217 /* SunOS and some others define FSCALE in sys/param.h.  */
 218
 219 #ifdef MORE_BSD
 220 #define FSCALE 2048.0
 221 #endif
 222
 223 #if defined(MIPS) || defined(SVR4) || defined(decstation)
 224 #define FSCALE 256
 225 #endif
 226
 227 #if defined (sgi) || defined (sequent)
 228 /* Sometimes both MIPS and sgi are defined, so FSCALE was just defined
 229    above under #ifdef MIPS.  But we want the sgi value.  */
 230 #undef FSCALE
 231 #define FSCALE 1000.0
 232 #endif
 233
 234 #if defined (ardent) && defined (titan)
 235 #define FSCALE 65536.0
 236 #endif
 237
 238 #ifdef tek4300
 239 #define FSCALE 100.0
 240 #endif
 241
 242 #endif  /* Not FSCALE.  */
 243
 244 #if !defined (LDAV_CVT) && defined (FSCALE)
 245 #define LDAV_CVT(n) (((double) (n)) / FSCALE)
 246 #endif
 247
 248 /* VAX C can't handle multi-line #ifs, or lines longer that 256 characters.  */
 249 #ifndef NLIST_STRUCT
 250
 251 #ifdef MORE_BSD
 252 #define NLIST_STRUCT
 253 #endif
 254
 255 #ifdef sun
 256 #define NLIST_STRUCT
 257 #endif
 258
 259 #ifdef decstation
 260 #define NLIST_STRUCT
 261 #endif
 262
 263 #ifdef hpux
 264 #define NLIST_STRUCT
 265 #endif
 266
 267 #if defined (_SEQUENT_) || defined (sequent)
 268 #define NLIST_STRUCT
 269 #endif
 270
 271 #ifdef sgi
 272 #define NLIST_STRUCT
 273 #endif
 274
 275 #ifdef SVR4
 276 #define NLIST_STRUCT
 277 #endif
 278
 279 #ifdef sony_news
 280 #define NLIST_STRUCT
 281 #endif
 282
 283 #ifdef OSF_ALPHA
 284 #define NLIST_STRUCT
 285 #endif
 286
 287 #if defined (ardent) && defined (titan)
 288 #define NLIST_STRUCT
 289 #endif
 290
 291 #ifdef tex4300
 292 #define NLIST_STRUCT
 293 #endif
 294
 295 #ifdef butterfly
 296 #define NLIST_STRUCT
 297 #endif
 298
 299 #endif /* defined (NLIST_STRUCT) */
 300
 301
 302 #if defined(sgi) || (defined(mips) && !defined(BSD))
 303 #define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31))
 304 #endif
 305
 306
 307 #if !defined (KERNEL_FILE) && defined (sequent)
 308 #define KERNEL_FILE "/dynix"
 309 #endif
 310
 311 #if !defined (KERNEL_FILE) && defined (hpux)
 312 #define KERNEL_FILE "/hp-ux"
 313 #endif
 314
 315 #if !defined(KERNEL_FILE) && (defined(_SEQUENT_) || defined(MIPS) || defined(SVR4) || defined(ISC) || defined (sgi) || defined(SVR4) || (defined (ardent) && defined (titan)))
 316 #define KERNEL_FILE "/unix"
 317 #endif
 318
 319
 320 #if !defined (LDAV_SYMBOL) && defined (alliant)
 321 #define LDAV_SYMBOL "_Loadavg"
 322 #endif
 323
 324 #if !defined(LDAV_SYMBOL) && ((defined(hpux) && !defined(hp9000s300)) || defined(_SEQUENT_) || defined(SVR4) || defined(ISC) || defined(sgi) || (defined (ardent) && defined (titan)))
 325 #define LDAV_SYMBOL "avenrun"
 326 #endif
 327
 328 #ifdef HAVE_UNISTD_H
 329 #include <unistd.h>
 330 #endif
 331
 332 #include <stdio.h>
 333 #include <errno.h>
 334
 335 #ifndef errno
 336 extern int errno;
 337 #endif
 338
 339 /* LOAD_AVE_TYPE should only get defined if we're going to use the
 340    nlist method.  */
 341 #if !defined(LOAD_AVE_TYPE) && (defined(BSD) || defined(LDAV_CVT) || defined(KERNEL_FILE) || defined(LDAV_SYMBOL))
 342 #define LOAD_AVE_TYPE double
 343 #endif
 344
 345 #ifdef LOAD_AVE_TYPE
 346
 347 #ifndef VMS
 348 #ifndef NLIST_STRUCT
 349 #include <a.out.h>
 350 #else /* NLIST_STRUCT */
 351 #include <nlist.h>
 352 #endif /* NLIST_STRUCT */
 353
 354 #ifdef SUNOS_5
 355 #include <fcntl.h>
 356 #include <kvm.h>
 357 #endif
 358
 359 #ifndef KERNEL_FILE
 360 #define KERNEL_FILE "/vmunix"
 361 #endif /* KERNEL_FILE */
 362
 363 #ifndef LDAV_SYMBOL
 364 #define LDAV_SYMBOL "_avenrun"
 365 #endif /* LDAV_SYMBOL */
 366
 367 #else /* VMS */
 368
 369 #ifndef eunice
 370 #include <iodef.h>
 371 #include <descrip.h>
 372 #else /* eunice */
 373 #include <vms/iodef.h>
 374 #endif /* eunice */
 375 #endif /* VMS */
 376
 377 #ifndef LDAV_CVT
 378 #define LDAV_CVT(n) ((double) (n))
 379 #endif /* !LDAV_CVT */
 380
 381 #endif /* LOAD_AVE_TYPE */
 382
 383 #ifdef NeXT
 384 #ifdef HAVE_MACH_MACH_H
 385 #include <mach/mach.h>
 386 #else
 387 #include <mach.h>
 388 #endif
 389 #endif /* NeXT */
 390
 391 #ifdef sgi
 392 #include <sys/sysmp.h>
 393 #endif /* sgi */
 394
 395 #ifdef UMAX
 396 #include <stdio.h>
 397 #include <signal.h>
 398 #include <sys/time.h>
 399 #include <sys/wait.h>
 400 #include <sys/syscall.h>
 401
 402 #ifdef UMAX_43
 403 #include <machine/cpu.h>
 404 #include <inq_stats/statistics.h>
 405 #include <inq_stats/sysstats.h>
 406 #include <inq_stats/cpustats.h>
 407 #include <inq_stats/procstats.h>
 408 #else /* Not UMAX_43.  */
 409 #include <sys/sysdefs.h>
 410 #include <sys/statistics.h>
 411 #include <sys/sysstats.h>
 412 #include <sys/cpudefs.h>
 413 #include <sys/cpustats.h>
 414 #include <sys/procstats.h>
 415 #endif /* Not UMAX_43.  */
 416 #endif /* UMAX */
 417
 418 #ifdef DGUX
 419 #include <sys/dg_sys_info.h>
 420 #endif
 421
 422 #if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION)
 423 #include <fcntl.h>
 424 #else
 425 #include <sys/file.h>
 426 #endif
 427 \f
 428 /* Avoid static vars inside a function since in HPUX they dump as pure.  */
 429
 430 #ifdef NeXT
 431 static processor_set_t default_set;
 432 static int getloadavg_initialized;
 433 #endif /* NeXT */
 434
 435 #ifdef UMAX
 436 static unsigned int cpus = 0;
 437 static unsigned int samples;
 438 #endif /* UMAX */
 439
 440 #ifdef DGUX
 441 static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
 442 #endif /* DGUX */
 443
 444 #ifdef LOAD_AVE_TYPE
 445 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 446 static int channel;
 447 /* Nonzero iff channel is valid.  */
 448 static int getloadavg_initialized;
 449 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 450 static long offset;
 451
 452 #if !defined(VMS) && !defined(sgi)
 453 static struct nlist nl[2];
 454 #endif /* Not VMS or sgi */
 455
 456 #ifdef SUNOS_5
 457 static kvm_t *kd;
 458 #endif /* SUNOS_5 */
 459
 460 #endif /* LOAD_AVE_TYPE */
 461 \f
 462 /* Put the 1 minute, 5 minute and 15 minute load averages
 463    into the first NELEM elements of LOADAVG.
 464    Return the number written (never more than 3, but may be less than NELEM),
 465    or -1 if an error occurred.  */
 466
 467 int
 468 getloadavg (loadavg, nelem)
 469      double loadavg[];
 470      int nelem;
 471 {
 472   int elem = 0;                 /* Return value.  */
 473
 474 #ifdef NO_GET_LOAD_AVG
 475 #define LDAV_DONE
 476   /* Set errno to zero to indicate that there was no particular error;
 477      this function just can't work at all on this system.  */
 478   errno = 0;
 479   elem = -1;
 480 #endif
 481
 482 #if !defined (LDAV_DONE) && defined (__linux__)
 483 #define LDAV_DONE
 484 #undef LOAD_AVE_TYPE
 485
 486 #ifndef LINUX_LDAV_FILE
 487 #define LINUX_LDAV_FILE "/proc/loadavg"
 488 #endif
 489
 490   char ldavgbuf[40];
 491   double load_ave[3];
 492   int fd, count;
 493
 494   fd = open (LINUX_LDAV_FILE, O_RDONLY);
 495   if (fd == -1)
 496     return -1;
 497   count = read (fd, ldavgbuf, 40);
 498   (void) close (fd);
 499   if (count <= 0)
 500     return -1;
 501
 502   count = sscanf (ldavgbuf, "%lf %lf %lf",
 503                   &load_ave[0], &load_ave[1], &load_ave[2]);
 504   if (count < 1)
 505     return -1;
 506
 507   for (elem = 0; elem < nelem && elem < count; elem++)
 508     loadavg[elem] = load_ave[elem];
 509
 510   return elem;
 511
 512 #endif /* __linux__ */
 513
 514 #if !defined (LDAV_DONE) && defined (NeXT)
 515 #define LDAV_DONE
 516   /* The NeXT code was adapted from iscreen 3.2.  */
 517
 518   host_t host;
 519   struct processor_set_basic_info info;
 520   unsigned info_count;
 521
 522   /* We only know how to get the 1-minute average for this system,
 523      so even if the caller asks for more than 1, we only return 1.  */
 524
 525   if (!getloadavg_initialized)
 526     {
 527       if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
 528         getloadavg_initialized = 1;
 529     }
 530
 531   if (getloadavg_initialized)
 532     {
 533       info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
 534       if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
 535                              (processor_set_info_t) &info, &info_count)
 536           != KERN_SUCCESS)
 537         getloadavg_initialized = 0;
 538       else
 539         {
 540           if (nelem > 0)
 541             loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
 542         }
 543     }
 544
 545   if (!getloadavg_initialized)
 546     return -1;
 547 #endif /* NeXT */
 548
 549 #if !defined (LDAV_DONE) && defined (UMAX)
 550 #define LDAV_DONE
 551 /* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
 552    have a /dev/kmem.  Information about the workings of the running kernel
 553    can be gathered with inq_stats system calls.
 554    We only know how to get the 1-minute average for this system.  */
 555
 556   struct proc_summary proc_sum_data;
 557   struct stat_descr proc_info;
 558   double load;
 559   register unsigned int i, j;
 560
 561   if (cpus == 0)
 562     {
 563       register unsigned int c, i;
 564       struct cpu_config conf;
 565       struct stat_descr desc;
 566
 567       desc.sd_next = 0;
 568       desc.sd_subsys = SUBSYS_CPU;
 569       desc.sd_type = CPUTYPE_CONFIG;
 570       desc.sd_addr = (char *) &conf;
 571       desc.sd_size = sizeof conf;
 572
 573       if (inq_stats (1, &desc))
 574         return -1;
 575
 576       c = 0;
 577       for (i = 0; i < conf.config_maxclass; ++i)
 578         {
 579           struct class_stats stats;
 580           bzero ((char *) &stats, sizeof stats);
 581
 582           desc.sd_type = CPUTYPE_CLASS;
 583           desc.sd_objid = i;
 584           desc.sd_addr = (char *) &stats;
 585           desc.sd_size = sizeof stats;
 586
 587           if (inq_stats (1, &desc))
 588             return -1;
 589
 590           c += stats.class_numcpus;
 591         }
 592       cpus = c;
 593       samples = cpus < 2 ? 3 : (2 * cpus / 3);
 594     }
 595
 596   proc_info.sd_next = 0;
 597   proc_info.sd_subsys = SUBSYS_PROC;
 598   proc_info.sd_type = PROCTYPE_SUMMARY;
 599   proc_info.sd_addr = (char *) &proc_sum_data;
 600   proc_info.sd_size = sizeof (struct proc_summary);
 601   proc_info.sd_sizeused = 0;
 602
 603   if (inq_stats (1, &proc_info) != 0)
 604     return -1;
 605
 606   load = proc_sum_data.ps_nrunnable;
 607   j = 0;
 608   for (i = samples - 1; i > 0; --i)
 609     {
 610       load += proc_sum_data.ps_nrun[j];
 611       if (j++ == PS_NRUNSIZE)
 612         j = 0;
 613     }
 614
 615   if (nelem > 0)
 616     loadavg[elem++] = load / samples / cpus;
 617 #endif /* UMAX */
 618
 619 #if !defined (LDAV_DONE) && defined (DGUX)
 620 #define LDAV_DONE
 621   /* This call can return -1 for an error, but with good args
 622      it's not supposed to fail.  The first argument is for no
 623      apparent reason of type `long int *'.  */
 624   dg_sys_info ((long int *) &load_info,
 625                DG_SYS_INFO_LOAD_INFO_TYPE,
 626                DG_SYS_INFO_LOAD_VERSION_0);
 627
 628   if (nelem > 0)
 629     loadavg[elem++] = load_info.one_minute;
 630   if (nelem > 1)
 631     loadavg[elem++] = load_info.five_minute;
 632   if (nelem > 2)
 633     loadavg[elem++] = load_info.fifteen_minute;
 634 #endif /* DGUX */
 635
 636 #if !defined (LDAV_DONE) && defined (apollo)
 637 #define LDAV_DONE
 638 /* Apollo code from lisch@mentorg.com (Ray Lischner).
 639
 640    This system call is not documented.  The load average is obtained as
 641    three long integers, for the load average over the past minute,
 642    five minutes, and fifteen minutes.  Each value is a scaled integer,
 643    with 16 bits of integer part and 16 bits of fraction part.
 644
 645    I'm not sure which operating system first supported this system call,
 646    but I know that SR10.2 supports it.  */
 647
 648   extern void proc1_$get_loadav ();
 649   unsigned long load_ave[3];
 650
 651   proc1_$get_loadav (load_ave);
 652
 653   if (nelem > 0)
 654     loadavg[elem++] = load_ave[0] / 65536.0;
 655   if (nelem > 1)
 656     loadavg[elem++] = load_ave[1] / 65536.0;
 657   if (nelem > 2)
 658     loadavg[elem++] = load_ave[2] / 65536.0;
 659 #endif /* apollo */
 660
 661 #if !defined (LDAV_DONE) && defined (OSF_MIPS)
 662 #define LDAV_DONE
 663
 664   struct tbl_loadavg load_ave;
 665   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 666   loadavg[elem++]
 667     = (load_ave.tl_lscale == 0
 668        ? load_ave.tl_avenrun.d[0]
 669        : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
 670 #endif  /* OSF_MIPS */
 671
 672 #if !defined (LDAV_DONE) && defined (VMS)
 673   /* VMS specific code -- read from the Load Ave driver.  */
 674
 675   LOAD_AVE_TYPE load_ave[3];
 676   static int getloadavg_initialized = 0;
 677 #ifdef eunice
 678   struct
 679   {
 680     int dsc$w_length;
 681     char *dsc$a_pointer;
 682   } descriptor;
 683 #endif
 684
 685   /* Ensure that there is a channel open to the load ave device.  */
 686   if (!getloadavg_initialized)
 687     {
 688       /* Attempt to open the channel.  */
 689 #ifdef eunice
 690       descriptor.dsc$w_length = 18;
 691       descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
 692 #else
 693       $DESCRIPTOR (descriptor, "LAV0:");
 694 #endif
 695       if (sys$assign (&descriptor, &channel, 0, 0) & 1)
 696         getloadavg_initialized = 1;
 697     }
 698
 699   /* Read the load average vector.  */
 700   if (getloadavg_initialized
 701       && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
 702                      load_ave, 12, 0, 0, 0, 0) & 1))
 703     {
 704       sys$dassgn (channel);
 705       getloadavg_initialized = 0;
 706     }
 707
 708   if (!getloadavg_initialized)
 709     return -1;
 710 #endif /* VMS */
 711
 712 #if !defined (LDAV_DONE) && defined(LOAD_AVE_TYPE) && !defined(VMS)
 713
 714   /* UNIX-specific code -- read the average from /dev/kmem.  */
 715
 716 #define LDAV_PRIVILEGED         /* This code requires special installation.  */
 717
 718   LOAD_AVE_TYPE load_ave[3];
 719
 720   /* Get the address of LDAV_SYMBOL.  */
 721   if (offset == 0)
 722     {
 723 #ifndef sgi
 724 #ifndef NLIST_STRUCT
 725       strcpy (nl[0].n_name, LDAV_SYMBOL);
 726       strcpy (nl[1].n_name, "");
 727 #else /* NLIST_STRUCT */
 728 #ifdef NLIST_NAME_UNION
 729       nl[0].n_un.n_name = LDAV_SYMBOL;
 730       nl[1].n_un.n_name = 0;
 731 #else /* not NLIST_NAME_UNION */
 732       nl[0].n_name = LDAV_SYMBOL;
 733       nl[1].n_name = 0;
 734 #endif /* not NLIST_NAME_UNION */
 735 #endif /* NLIST_STRUCT */
 736
 737 #ifndef SUNOS_5
 738       if (nlist (KERNEL_FILE, nl) >= 0)
 739         /* Omit "&& nl[0].n_type != 0 " -- it breaks on Sun386i.  */
 740         {
 741 #ifdef FIXUP_KERNEL_SYMBOL_ADDR
 742           FIXUP_KERNEL_SYMBOL_ADDR (nl);
 743 #endif
 744           offset = nl[0].n_value;
 745         }
 746 #endif  /* !SUNOS_5 */
 747 #else /* sgi */
 748       int ldav_off;
 749
 750       ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
 751       if (ldav_off != -1)
 752         offset = (long) ldav_off & 0x7fffffff;
 753 #endif /* sgi */
 754     }
 755
 756   /* Make sure we have /dev/kmem open.  */
 757   if (!getloadavg_initialized)
 758     {
 759 #ifndef SUNOS_5
 760       channel = open ("/dev/kmem", 0);
 761       if (channel >= 0)
 762         getloadavg_initialized = 1;
 763 #else /* SUNOS_5 */
 764       /* We pass 0 for the kernel, corefile, and swapfile names
 765          to use the currently running kernel.  */
 766       kd = kvm_open (0, 0, 0, O_RDONLY, 0);
 767       if (kd != 0)
 768         {
 769           /* nlist the currently running kernel.  */
 770           kvm_nlist (kd, nl);
 771           offset = nl[0].n_value;
 772           getloadavg_initialized = 1;
 773         }
 774 #endif /* SUNOS_5 */
 775     }
 776
 777   /* If we can, get the load average values.  */
 778   if (offset && getloadavg_initialized)
 779     {
 780       /* Try to read the load.  */
 781 #ifndef SUNOS_5
 782       if (lseek (channel, offset, 0) == -1L
 783           || read (channel, (char *) load_ave, sizeof (load_ave))
 784           != sizeof (load_ave))
 785         {
 786           close (channel);
 787           getloadavg_initialized = 0;
 788         }
 789 #else  /* SUNOS_5 */
 790       if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
 791           != sizeof (load_ave))
 792         {
 793           kvm_close (kd);
 794           getloadavg_initialized = 0;
 795         }
 796 #endif /* SUNOS_5 */
 797     }
 798
 799   if (offset == 0 || !getloadavg_initialized)
 800     return -1;
 801 #endif /* LOAD_AVE_TYPE and not VMS */
 802
 803 #if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
 804   if (nelem > 0)
 805     loadavg[elem++] = LDAV_CVT (load_ave[0]);
 806   if (nelem > 1)
 807     loadavg[elem++] = LDAV_CVT (load_ave[1]);
 808   if (nelem > 2)
 809     loadavg[elem++] = LDAV_CVT (load_ave[2]);
 810
 811 #define LDAV_DONE
 812 #endif /* !LDAV_DONE && LOAD_AVE_TYPE */
 813
 814 #ifdef LDAV_DONE
 815   return elem;
 816 #else
 817   /* Set errno to zero to indicate that there was no particular error;
 818      this function just can't work at all on this system.  */
 819   errno = 0;
 820   return -1;
 821 #endif
 822 }
 823
 824 #endif /* ! HAVE_GETLOADAVG */
 825 \f
 826 #ifdef TEST
 827 void
 828 main (argc, argv)
 829      int argc;
 830      char **argv;
 831 {
 832   int naptime = 0;
 833
 834   if (argc > 1)
 835     naptime = atoi (argv[1]);
 836
 837   while (1)
 838     {
 839       double avg[3];
 840       int loads;
 841
 842       errno = 0;                /* Don't be misled if it doesn't set errno.  */
 843       loads = getloadavg (avg, 3);
 844       if (loads == -1)
 845         {
 846           perror ("Error getting load average");
 847           exit (1);
 848         }
 849       if (loads > 0)
 850         printf ("1-minute: %f  ", avg[0]);
 851       if (loads > 1)
 852         printf ("5-minute: %f  ", avg[1]);
 853       if (loads > 2)
 854         printf ("15-minute: %f  ", avg[2]);
 855       if (loads > 0)
 856         putchar ('\n');
 857
 858       if (naptime == 0)
 859         break;
 860       sleep (naptime);
 861     }
 862
 863   exit (0);
 864 }
 865 #endif /* TEST */