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