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

   1 /* Get the system load averages.
   2    Copyright (C) 1985, 86, 87, 88, 89, 91, 92, 93, 1994
   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    __NetBSD__                   NetBSD: assumes /kern filesystem mounted.
  55
  56    In addition, to avoid nesting many #ifdefs, we internally set
  57    LDAV_DONE to indicate that the load average has been computed.
  58
  59    We also #define LDAV_PRIVILEGED if a program will require
  60    special installation to be able to call getloadavg.  */
  61
  62 #include <sys/types.h>
  63
  64 /* Both the Emacs and non-Emacs sections want this.  Some
  65    configuration files' definitions for the LOAD_AVE_CVT macro (like
  66    sparc.h's) use macros like FSCALE, defined here.  */
  67 #ifdef unix
  68 #include <sys/param.h>
  69 #endif
  70
  71
  72 #ifdef HAVE_CONFIG_H
  73 #if defined (emacs) || defined (CONFIG_BROKETS)
  74 /* We use <config.h> instead of "config.h" so that a compilation
  75    using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
  76    (which it would do because it found this file in $srcdir).  */
  77 #include <config.h>
  78 #else
  79 #include "config.h"
  80 #endif
  81 #endif
  82
  83 /* Exclude all the code except the test program at the end
  84    if the system has its own `getloadavg' function.
  85
  86    The declaration of `errno' is needed by the test program
  87    as well as the function itself, so it comes first.  */
  88
  89 #include <errno.h>
  90
  91 #ifndef errno
  92 extern int errno;
  93 #endif
  94
  95 #ifndef HAVE_GETLOADAVG
  96
  97
  98 /* The existing Emacs configuration files define a macro called
  99    LOAD_AVE_CVT, which accepts a value of type LOAD_AVE_TYPE, and
 100    returns the load average multiplied by 100.  What we actually want
 101    is a macro called LDAV_CVT, which returns the load average as an
 102    unmultiplied double.
 103
 104    For backwards compatibility, we'll define LDAV_CVT in terms of
 105    LOAD_AVE_CVT, but future machine config files should just define
 106    LDAV_CVT directly.  */
 107
 108 #if !defined(LDAV_CVT) && defined(LOAD_AVE_CVT)
 109 #define LDAV_CVT(n) (LOAD_AVE_CVT (n) / 100.0)
 110 #endif
 111
 112 #if !defined (BSD) && defined (ultrix)
 113 /* Ultrix behaves like BSD on Vaxen.  */
 114 #define BSD
 115 #endif
 116
 117 #ifdef NeXT
 118 /* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which
 119    conflicts with the definition understood in this file, that this
 120    really is BSD. */
 121 #undef BSD
 122
 123 /* NeXT defines FSCALE in <sys/param.h>.  However, we take FSCALE being
 124    defined to mean that the nlist method should be used, which is not true.  */
 125 #undef FSCALE
 126 #endif
 127
 128 /* Set values that are different from the defaults, which are
 129    set a little farther down with #ifndef.  */
 130
 131
 132 /* Some shorthands.  */
 133
 134 #if defined (HPUX) && !defined (hpux)
 135 #define hpux
 136 #endif
 137
 138 #if defined(hp300) && !defined(hpux)
 139 #define MORE_BSD
 140 #endif
 141
 142 #if defined(ultrix) && defined(mips)
 143 #define decstation
 144 #endif
 145
 146 #if defined(sun) && defined(SVR4)
 147 #define SUNOS_5
 148 #endif
 149
 150 #if defined (__osf__) && (defined (__alpha) || defined (__alpha__))
 151 #define OSF_ALPHA
 152 #endif
 153
 154 #if defined (__osf__) && (defined (mips) || defined (__mips__))
 155 #define OSF_MIPS
 156 #include <sys/table.h>
 157 #endif
 158
 159 /* UTek's /bin/cc on the 4300 has no architecture specific cpp define by
 160    default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>.  Combine
 161    that with a couple of other things and we'll have a unique match.  */
 162 #if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES)
 163 #define tek4300                 /* Define by emacs, but not by other users.  */
 164 #endif
 165
 166
 167 /* VAX C can't handle multi-line #ifs, or lines longer than 256 chars.  */
 168 #ifndef LOAD_AVE_TYPE
 169
 170 #ifdef MORE_BSD
 171 #define LOAD_AVE_TYPE long
 172 #endif
 173
 174 #ifdef sun
 175 #define LOAD_AVE_TYPE long
 176 #endif
 177
 178 #ifdef decstation
 179 #define LOAD_AVE_TYPE long
 180 #endif
 181
 182 #ifdef _SEQUENT_
 183 #define LOAD_AVE_TYPE long
 184 #endif
 185
 186 #ifdef sgi
 187 #define LOAD_AVE_TYPE long
 188 #endif
 189
 190 #ifdef SVR4
 191 #define LOAD_AVE_TYPE long
 192 #endif
 193
 194 #ifdef sony_news
 195 #define LOAD_AVE_TYPE long
 196 #endif
 197
 198 #ifdef sequent
 199 #define LOAD_AVE_TYPE long
 200 #endif
 201
 202 #ifdef OSF_ALPHA
 203 #define LOAD_AVE_TYPE long
 204 #endif
 205
 206 #if defined (ardent) && defined (titan)
 207 #define LOAD_AVE_TYPE long
 208 #endif
 209
 210 #ifdef tek4300
 211 #define LOAD_AVE_TYPE long
 212 #endif
 213
 214 #endif /* No LOAD_AVE_TYPE.  */
 215
 216 #ifdef OSF_ALPHA
 217 /* <sys/param.h> defines an incorrect value for FSCALE on Alpha OSF/1,
 218    according to ghazi@noc.rutgers.edu.  */
 219 #undef FSCALE
 220 #define FSCALE 1024.0
 221 #endif
 222
 223
 224 #ifndef FSCALE
 225
 226 /* SunOS and some others define FSCALE in sys/param.h.  */
 227
 228 #ifdef MORE_BSD
 229 #define FSCALE 2048.0
 230 #endif
 231
 232 #if defined(MIPS) || defined(SVR4) || defined(decstation)
 233 #define FSCALE 256
 234 #endif
 235
 236 #if defined (sgi) || defined (sequent)
 237 /* Sometimes both MIPS and sgi are defined, so FSCALE was just defined
 238    above under #ifdef MIPS.  But we want the sgi value.  */
 239 #undef FSCALE
 240 #define FSCALE 1000.0
 241 #endif
 242
 243 #if defined (ardent) && defined (titan)
 244 #define FSCALE 65536.0
 245 #endif
 246
 247 #ifdef tek4300
 248 #define FSCALE 100.0
 249 #endif
 250
 251 #endif  /* Not FSCALE.  */
 252
 253 #if !defined (LDAV_CVT) && defined (FSCALE)
 254 #define LDAV_CVT(n) (((double) (n)) / FSCALE)
 255 #endif
 256
 257 /* VAX C can't handle multi-line #ifs, or lines longer that 256 characters.  */
 258 #ifndef NLIST_STRUCT
 259
 260 #ifdef MORE_BSD
 261 #define NLIST_STRUCT
 262 #endif
 263
 264 #ifdef sun
 265 #define NLIST_STRUCT
 266 #endif
 267
 268 #ifdef decstation
 269 #define NLIST_STRUCT
 270 #endif
 271
 272 #ifdef hpux
 273 #define NLIST_STRUCT
 274 #endif
 275
 276 #if defined (_SEQUENT_) || defined (sequent)
 277 #define NLIST_STRUCT
 278 #endif
 279
 280 #ifdef sgi
 281 #define NLIST_STRUCT
 282 #endif
 283
 284 #ifdef SVR4
 285 #define NLIST_STRUCT
 286 #endif
 287
 288 #ifdef sony_news
 289 #define NLIST_STRUCT
 290 #endif
 291
 292 #ifdef OSF_ALPHA
 293 #define NLIST_STRUCT
 294 #endif
 295
 296 #if defined (ardent) && defined (titan)
 297 #define NLIST_STRUCT
 298 #endif
 299
 300 #ifdef tex4300
 301 #define NLIST_STRUCT
 302 #endif
 303
 304 #ifdef butterfly
 305 #define NLIST_STRUCT
 306 #endif
 307
 308 #endif /* defined (NLIST_STRUCT) */
 309
 310
 311 #if defined(sgi) || (defined(mips) && !defined(BSD))
 312 #define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31))
 313 #endif
 314
 315
 316 #if !defined (KERNEL_FILE) && defined (sequent)
 317 #define KERNEL_FILE "/dynix"
 318 #endif
 319
 320 #if !defined (KERNEL_FILE) && defined (hpux)
 321 #define KERNEL_FILE "/hp-ux"
 322 #endif
 323
 324 #if !defined(KERNEL_FILE) && (defined(_SEQUENT_) || defined(MIPS) || defined(SVR4) || defined(ISC) || defined (sgi) || defined(SVR4) || (defined (ardent) && defined (titan)))
 325 #define KERNEL_FILE "/unix"
 326 #endif
 327
 328
 329 #if !defined (LDAV_SYMBOL) && defined (alliant)
 330 #define LDAV_SYMBOL "_Loadavg"
 331 #endif
 332
 333 #if !defined(LDAV_SYMBOL) && ((defined(hpux) && !defined(hp9000s300)) || defined(_SEQUENT_) || defined(SVR4) || defined(ISC) || defined(sgi) || (defined (ardent) && defined (titan)))
 334 #define LDAV_SYMBOL "avenrun"
 335 #endif
 336
 337 #ifdef HAVE_UNISTD_H
 338 #include <unistd.h>
 339 #endif
 340
 341 #include <stdio.h>
 342
 343 /* LOAD_AVE_TYPE should only get defined if we're going to use the
 344    nlist method.  */
 345 #if !defined(LOAD_AVE_TYPE) && (defined(BSD) || defined(LDAV_CVT) || defined(KERNEL_FILE) || defined(LDAV_SYMBOL))
 346 #define LOAD_AVE_TYPE double
 347 #endif
 348
 349 #ifdef LOAD_AVE_TYPE
 350
 351 #ifndef VMS
 352 #ifndef NLIST_STRUCT
 353 #include <a.out.h>
 354 #else /* NLIST_STRUCT */
 355 #include <nlist.h>
 356 #endif /* NLIST_STRUCT */
 357
 358 #ifdef SUNOS_5
 359 #include <fcntl.h>
 360 #include <kvm.h>
 361 #endif
 362
 363 #ifndef KERNEL_FILE
 364 #define KERNEL_FILE "/vmunix"
 365 #endif /* KERNEL_FILE */
 366
 367 #ifndef LDAV_SYMBOL
 368 #define LDAV_SYMBOL "_avenrun"
 369 #endif /* LDAV_SYMBOL */
 370
 371 #else /* VMS */
 372
 373 #ifndef eunice
 374 #include <iodef.h>
 375 #include <descrip.h>
 376 #else /* eunice */
 377 #include <vms/iodef.h>
 378 #endif /* eunice */
 379 #endif /* VMS */
 380
 381 #ifndef LDAV_CVT
 382 #define LDAV_CVT(n) ((double) (n))
 383 #endif /* !LDAV_CVT */
 384
 385 #endif /* LOAD_AVE_TYPE */
 386
 387 #ifdef NeXT
 388 #ifdef HAVE_MACH_MACH_H
 389 #include <mach/mach.h>
 390 #else
 391 #include <mach.h>
 392 #endif
 393 #endif /* NeXT */
 394
 395 #ifdef sgi
 396 #include <sys/sysmp.h>
 397 #endif /* sgi */
 398
 399 #ifdef UMAX
 400 #include <stdio.h>
 401 #include <signal.h>
 402 #include <sys/time.h>
 403 #include <sys/wait.h>
 404 #include <sys/syscall.h>
 405
 406 #ifdef UMAX_43
 407 #include <machine/cpu.h>
 408 #include <inq_stats/statistics.h>
 409 #include <inq_stats/sysstats.h>
 410 #include <inq_stats/cpustats.h>
 411 #include <inq_stats/procstats.h>
 412 #else /* Not UMAX_43.  */
 413 #include <sys/sysdefs.h>
 414 #include <sys/statistics.h>
 415 #include <sys/sysstats.h>
 416 #include <sys/cpudefs.h>
 417 #include <sys/cpustats.h>
 418 #include <sys/procstats.h>
 419 #endif /* Not UMAX_43.  */
 420 #endif /* UMAX */
 421
 422 #ifdef DGUX
 423 #include <sys/dg_sys_info.h>
 424 #endif
 425
 426 #if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION)
 427 #include <fcntl.h>
 428 #else
 429 #include <sys/file.h>
 430 #endif
 431 \f
 432 /* Avoid static vars inside a function since in HPUX they dump as pure.  */
 433
 434 #ifdef NeXT
 435 static processor_set_t default_set;
 436 static int getloadavg_initialized;
 437 #endif /* NeXT */
 438
 439 #ifdef UMAX
 440 static unsigned int cpus = 0;
 441 static unsigned int samples;
 442 #endif /* UMAX */
 443
 444 #ifdef DGUX
 445 static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
 446 #endif /* DGUX */
 447
 448 #ifdef LOAD_AVE_TYPE
 449 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 450 static int channel;
 451 /* Nonzero iff channel is valid.  */
 452 static int getloadavg_initialized;
 453 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 454 static long offset;
 455
 456 #if !defined(VMS) && !defined(sgi)
 457 static struct nlist nl[2];
 458 #endif /* Not VMS or sgi */
 459
 460 #ifdef SUNOS_5
 461 static kvm_t *kd;
 462 #endif /* SUNOS_5 */
 463
 464 #endif /* LOAD_AVE_TYPE */
 465 \f
 466 /* Put the 1 minute, 5 minute and 15 minute load averages
 467    into the first NELEM elements of LOADAVG.
 468    Return the number written (never more than 3, but may be less than NELEM),
 469    or -1 if an error occurred.  */
 470
 471 int
 472 getloadavg (loadavg, nelem)
 473      double loadavg[];
 474      int nelem;
 475 {
 476   int elem = 0;                 /* Return value.  */
 477
 478 #ifdef NO_GET_LOAD_AVG
 479 #define LDAV_DONE
 480   /* Set errno to zero to indicate that there was no particular error;
 481      this function just can't work at all on this system.  */
 482   errno = 0;
 483   elem = -1;
 484 #endif
 485
 486 #if !defined (LDAV_DONE) && defined (__linux__)
 487 #define LDAV_DONE
 488 #undef LOAD_AVE_TYPE
 489
 490 #ifndef LINUX_LDAV_FILE
 491 #define LINUX_LDAV_FILE "/proc/loadavg"
 492 #endif
 493
 494   char ldavgbuf[40];
 495   double load_ave[3];
 496   int fd, count;
 497
 498   fd = open (LINUX_LDAV_FILE, O_RDONLY);
 499   if (fd == -1)
 500     return -1;
 501   count = read (fd, ldavgbuf, 40);
 502   (void) close (fd);
 503   if (count <= 0)
 504     return -1;
 505
 506   count = sscanf (ldavgbuf, "%lf %lf %lf",
 507                   &load_ave[0], &load_ave[1], &load_ave[2]);
 508   if (count < 1)
 509     return -1;
 510
 511   for (elem = 0; elem < nelem && elem < count; elem++)
 512     loadavg[elem] = load_ave[elem];
 513
 514   return elem;
 515
 516 #endif /* __linux__ */
 517
 518 #if !defined (LDAV_DONE) && defined (__NetBSD__)
 519 #define LDAV_DONE
 520 #undef LOAD_AVE_TYPE
 521
 522 #ifndef NETBSD_LDAV_FILE
 523 #define NETBSD_LDAV_FILE "/kern/loadavg"
 524 #endif
 525
 526   unsigned long int load_ave[3], scale;
 527   int count;
 528   FILE *fp;
 529
 530   fp = fopen (NETBSD_LDAV_FILE, "r");
 531   if (fp == NULL)
 532     return -1;
 533   count = fscanf (fp, "%lu %lu %lu %lu\n",
 534                   &load_ave[0], &load_ave[1], &load_ave[2],
 535                   &scale);
 536   (void) fclose (fp);
 537   if (count != 4)
 538     return -1;
 539
 540   for (elem = 0; elem < nelem; elem++)
 541     loadavg[elem] = (double) load_ave[elem] / (double) scale;
 542
 543   return elem;
 544
 545 #endif /* __NetBSD__ */
 546
 547 #if !defined (LDAV_DONE) && defined (NeXT)
 548 #define LDAV_DONE
 549   /* The NeXT code was adapted from iscreen 3.2.  */
 550
 551   host_t host;
 552   struct processor_set_basic_info info;
 553   unsigned info_count;
 554
 555   /* We only know how to get the 1-minute average for this system,
 556      so even if the caller asks for more than 1, we only return 1.  */
 557
 558   if (!getloadavg_initialized)
 559     {
 560       if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
 561         getloadavg_initialized = 1;
 562     }
 563
 564   if (getloadavg_initialized)
 565     {
 566       info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
 567       if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
 568                              (processor_set_info_t) &info, &info_count)
 569           != KERN_SUCCESS)
 570         getloadavg_initialized = 0;
 571       else
 572         {
 573           if (nelem > 0)
 574             loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
 575         }
 576     }
 577
 578   if (!getloadavg_initialized)
 579     return -1;
 580 #endif /* NeXT */
 581
 582 #if !defined (LDAV_DONE) && defined (UMAX)
 583 #define LDAV_DONE
 584 /* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
 585    have a /dev/kmem.  Information about the workings of the running kernel
 586    can be gathered with inq_stats system calls.
 587    We only know how to get the 1-minute average for this system.  */
 588
 589   struct proc_summary proc_sum_data;
 590   struct stat_descr proc_info;
 591   double load;
 592   register unsigned int i, j;
 593
 594   if (cpus == 0)
 595     {
 596       register unsigned int c, i;
 597       struct cpu_config conf;
 598       struct stat_descr desc;
 599
 600       desc.sd_next = 0;
 601       desc.sd_subsys = SUBSYS_CPU;
 602       desc.sd_type = CPUTYPE_CONFIG;
 603       desc.sd_addr = (char *) &conf;
 604       desc.sd_size = sizeof conf;
 605
 606       if (inq_stats (1, &desc))
 607         return -1;
 608
 609       c = 0;
 610       for (i = 0; i < conf.config_maxclass; ++i)
 611         {
 612           struct class_stats stats;
 613           bzero ((char *) &stats, sizeof stats);
 614
 615           desc.sd_type = CPUTYPE_CLASS;
 616           desc.sd_objid = i;
 617           desc.sd_addr = (char *) &stats;
 618           desc.sd_size = sizeof stats;
 619
 620           if (inq_stats (1, &desc))
 621             return -1;
 622
 623           c += stats.class_numcpus;
 624         }
 625       cpus = c;
 626       samples = cpus < 2 ? 3 : (2 * cpus / 3);
 627     }
 628
 629   proc_info.sd_next = 0;
 630   proc_info.sd_subsys = SUBSYS_PROC;
 631   proc_info.sd_type = PROCTYPE_SUMMARY;
 632   proc_info.sd_addr = (char *) &proc_sum_data;
 633   proc_info.sd_size = sizeof (struct proc_summary);
 634   proc_info.sd_sizeused = 0;
 635
 636   if (inq_stats (1, &proc_info) != 0)
 637     return -1;
 638
 639   load = proc_sum_data.ps_nrunnable;
 640   j = 0;
 641   for (i = samples - 1; i > 0; --i)
 642     {
 643       load += proc_sum_data.ps_nrun[j];
 644       if (j++ == PS_NRUNSIZE)
 645         j = 0;
 646     }
 647
 648   if (nelem > 0)
 649     loadavg[elem++] = load / samples / cpus;
 650 #endif /* UMAX */
 651
 652 #if !defined (LDAV_DONE) && defined (DGUX)
 653 #define LDAV_DONE
 654   /* This call can return -1 for an error, but with good args
 655      it's not supposed to fail.  The first argument is for no
 656      apparent reason of type `long int *'.  */
 657   dg_sys_info ((long int *) &load_info,
 658                DG_SYS_INFO_LOAD_INFO_TYPE,
 659                DG_SYS_INFO_LOAD_VERSION_0);
 660
 661   if (nelem > 0)
 662     loadavg[elem++] = load_info.one_minute;
 663   if (nelem > 1)
 664     loadavg[elem++] = load_info.five_minute;
 665   if (nelem > 2)
 666     loadavg[elem++] = load_info.fifteen_minute;
 667 #endif /* DGUX */
 668
 669 #if !defined (LDAV_DONE) && defined (apollo)
 670 #define LDAV_DONE
 671 /* Apollo code from lisch@mentorg.com (Ray Lischner).
 672
 673    This system call is not documented.  The load average is obtained as
 674    three long integers, for the load average over the past minute,
 675    five minutes, and fifteen minutes.  Each value is a scaled integer,
 676    with 16 bits of integer part and 16 bits of fraction part.
 677
 678    I'm not sure which operating system first supported this system call,
 679    but I know that SR10.2 supports it.  */
 680
 681   extern void proc1_$get_loadav ();
 682   unsigned long load_ave[3];
 683
 684   proc1_$get_loadav (load_ave);
 685
 686   if (nelem > 0)
 687     loadavg[elem++] = load_ave[0] / 65536.0;
 688   if (nelem > 1)
 689     loadavg[elem++] = load_ave[1] / 65536.0;
 690   if (nelem > 2)
 691     loadavg[elem++] = load_ave[2] / 65536.0;
 692 #endif /* apollo */
 693
 694 #if !defined (LDAV_DONE) && defined (OSF_MIPS)
 695 #define LDAV_DONE
 696
 697   struct tbl_loadavg load_ave;
 698   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 699   loadavg[elem++]
 700     = (load_ave.tl_lscale == 0
 701        ? load_ave.tl_avenrun.d[0]
 702        : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
 703 #endif  /* OSF_MIPS */
 704
 705 #if !defined (LDAV_DONE) && defined (VMS)
 706   /* VMS specific code -- read from the Load Ave driver.  */
 707
 708   LOAD_AVE_TYPE load_ave[3];
 709   static int getloadavg_initialized = 0;
 710 #ifdef eunice
 711   struct
 712   {
 713     int dsc$w_length;
 714     char *dsc$a_pointer;
 715   } descriptor;
 716 #endif
 717
 718   /* Ensure that there is a channel open to the load ave device.  */
 719   if (!getloadavg_initialized)
 720     {
 721       /* Attempt to open the channel.  */
 722 #ifdef eunice
 723       descriptor.dsc$w_length = 18;
 724       descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
 725 #else
 726       $DESCRIPTOR (descriptor, "LAV0:");
 727 #endif
 728       if (sys$assign (&descriptor, &channel, 0, 0) & 1)
 729         getloadavg_initialized = 1;
 730     }
 731
 732   /* Read the load average vector.  */
 733   if (getloadavg_initialized
 734       && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
 735                      load_ave, 12, 0, 0, 0, 0) & 1))
 736     {
 737       sys$dassgn (channel);
 738       getloadavg_initialized = 0;
 739     }
 740
 741   if (!getloadavg_initialized)
 742     return -1;
 743 #endif /* VMS */
 744
 745 #if !defined (LDAV_DONE) && defined(LOAD_AVE_TYPE) && !defined(VMS)
 746
 747   /* UNIX-specific code -- read the average from /dev/kmem.  */
 748
 749 #define LDAV_PRIVILEGED         /* This code requires special installation.  */
 750
 751   LOAD_AVE_TYPE load_ave[3];
 752
 753   /* Get the address of LDAV_SYMBOL.  */
 754   if (offset == 0)
 755     {
 756 #ifndef sgi
 757 #ifndef NLIST_STRUCT
 758       strcpy (nl[0].n_name, LDAV_SYMBOL);
 759       strcpy (nl[1].n_name, "");
 760 #else /* NLIST_STRUCT */
 761 #ifdef NLIST_NAME_UNION
 762       nl[0].n_un.n_name = LDAV_SYMBOL;
 763       nl[1].n_un.n_name = 0;
 764 #else /* not NLIST_NAME_UNION */
 765       nl[0].n_name = LDAV_SYMBOL;
 766       nl[1].n_name = 0;
 767 #endif /* not NLIST_NAME_UNION */
 768 #endif /* NLIST_STRUCT */
 769
 770 #ifndef SUNOS_5
 771       if (nlist (KERNEL_FILE, nl) >= 0)
 772         /* Omit "&& nl[0].n_type != 0 " -- it breaks on Sun386i.  */
 773         {
 774 #ifdef FIXUP_KERNEL_SYMBOL_ADDR
 775           FIXUP_KERNEL_SYMBOL_ADDR (nl);
 776 #endif
 777           offset = nl[0].n_value;
 778         }
 779 #endif  /* !SUNOS_5 */
 780 #else /* sgi */
 781       int ldav_off;
 782
 783       ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
 784       if (ldav_off != -1)
 785         offset = (long) ldav_off & 0x7fffffff;
 786 #endif /* sgi */
 787     }
 788
 789   /* Make sure we have /dev/kmem open.  */
 790   if (!getloadavg_initialized)
 791     {
 792 #ifndef SUNOS_5
 793       channel = open ("/dev/kmem", 0);
 794       if (channel >= 0)
 795         getloadavg_initialized = 1;
 796 #else /* SUNOS_5 */
 797       /* We pass 0 for the kernel, corefile, and swapfile names
 798          to use the currently running kernel.  */
 799       kd = kvm_open (0, 0, 0, O_RDONLY, 0);
 800       if (kd != 0)
 801         {
 802           /* nlist the currently running kernel.  */
 803           kvm_nlist (kd, nl);
 804           offset = nl[0].n_value;
 805           getloadavg_initialized = 1;
 806         }
 807 #endif /* SUNOS_5 */
 808     }
 809
 810   /* If we can, get the load average values.  */
 811   if (offset && getloadavg_initialized)
 812     {
 813       /* Try to read the load.  */
 814 #ifndef SUNOS_5
 815       if (lseek (channel, offset, 0) == -1L
 816           || read (channel, (char *) load_ave, sizeof (load_ave))
 817           != sizeof (load_ave))
 818         {
 819           close (channel);
 820           getloadavg_initialized = 0;
 821         }
 822 #else  /* SUNOS_5 */
 823       if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
 824           != sizeof (load_ave))
 825         {
 826           kvm_close (kd);
 827           getloadavg_initialized = 0;
 828         }
 829 #endif /* SUNOS_5 */
 830     }
 831
 832   if (offset == 0 || !getloadavg_initialized)
 833     return -1;
 834 #endif /* LOAD_AVE_TYPE and not VMS */
 835
 836 #if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
 837   if (nelem > 0)
 838     loadavg[elem++] = LDAV_CVT (load_ave[0]);
 839   if (nelem > 1)
 840     loadavg[elem++] = LDAV_CVT (load_ave[1]);
 841   if (nelem > 2)
 842     loadavg[elem++] = LDAV_CVT (load_ave[2]);
 843
 844 #define LDAV_DONE
 845 #endif /* !LDAV_DONE && LOAD_AVE_TYPE */
 846
 847 #ifdef LDAV_DONE
 848   return elem;
 849 #else
 850   /* Set errno to zero to indicate that there was no particular error;
 851      this function just can't work at all on this system.  */
 852   errno = 0;
 853   return -1;
 854 #endif
 855 }
 856
 857 #endif /* ! HAVE_GETLOADAVG */
 858 \f
 859 #ifdef TEST
 860 void
 861 main (argc, argv)
 862      int argc;
 863      char **argv;
 864 {
 865   int naptime = 0;
 866
 867   if (argc > 1)
 868     naptime = atoi (argv[1]);
 869
 870   while (1)
 871     {
 872       double avg[3];
 873       int loads;
 874
 875       errno = 0;                /* Don't be misled if it doesn't set errno.  */
 876       loads = getloadavg (avg, 3);
 877       if (loads == -1)
 878         {
 879           perror ("Error getting load average");
 880           exit (1);
 881         }
 882       if (loads > 0)
 883         printf ("1-minute: %f  ", avg[0]);
 884       if (loads > 1)
 885         printf ("5-minute: %f  ", avg[1]);
 886       if (loads > 2)
 887         printf ("15-minute: %f  ", avg[2]);
 888       if (loads > 0)
 889         putchar ('\n');
 890
 891       if (naptime == 0)
 892         break;
 893       sleep (naptime);
 894     }
 895
 896   exit (0);
 897 }
 898 #endif /* TEST */