contrib/xz/src/common/tuklib_cpucores.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       tuklib_cpucores.c
   4 /// \brief      Get the number of CPU cores online
   5 //
   6 //  Author:     Lasse Collin
   7 //
   8 //  This file has been put into the public domain.
   9 //  You can do whatever you want with this file.
  10 //
  11 ///////////////////////////////////////////////////////////////////////////////
  12
  13 #include "tuklib_cpucores.h"
  14
  15 #if defined(TUKLIB_CPUCORES_SYSCTL)
  16 #       ifdef HAVE_SYS_PARAM_H
  17 #               include <sys/param.h>
  18 #       endif
  19 #       include <sys/sysctl.h>
  20
  21 #elif defined(TUKLIB_CPUCORES_SYSCONF)
  22 #       include <unistd.h>
  23
  24 // HP-UX
  25 #elif defined(TUKLIB_CPUCORES_PSTAT_GETDYNAMIC)
  26 #       include <sys/param.h>
  27 #       include <sys/pstat.h>
  28 #endif
  29
  30
  31 extern uint32_t
  32 tuklib_cpucores(void)
  33 {
  34         uint32_t ret = 0;
  35
  36 #if defined(TUKLIB_CPUCORES_SYSCTL)
  37         int name[2] = { CTL_HW, HW_NCPU };
  38         int cpus;
  39         size_t cpus_size = sizeof(cpus);
  40         if (sysctl(name, 2, &cpus, &cpus_size, NULL, 0) != -1
  41                         && cpus_size == sizeof(cpus) && cpus > 0)
  42                 ret = cpus;
  43
  44 #elif defined(TUKLIB_CPUCORES_SYSCONF)
  45 #       ifdef _SC_NPROCESSORS_ONLN
  46         // Most systems
  47         const long cpus = sysconf(_SC_NPROCESSORS_ONLN);
  48 #       else
  49         // IRIX
  50         const long cpus = sysconf(_SC_NPROC_ONLN);
  51 #       endif
  52         if (cpus > 0)
  53                 ret = cpus;
  54
  55 #elif defined(TUKLIB_CPUCORES_PSTAT_GETDYNAMIC)
  56         struct pst_dynamic pst;
  57         if (pstat_getdynamic(&pst, sizeof(pst), 1, 0) != -1)
  58                 ret = pst.psd_proc_cnt;
  59 #endif
  60
  61         return ret;
  62 }