external/public-domain/xz/dist/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(_WIN32) || defined(__CYGWIN__)
  16 #       ifndef _WIN32_WINNT
  17 #               define _WIN32_WINNT 0x0500
  18 #       endif
  19 #       include <windows.h>
  20
  21 // FreeBSD
  22 #elif defined(TUKLIB_CPUCORES_CPUSET)
  23 #       include <sys/param.h>
  24 #       include <sys/cpuset.h>
  25
  26 #elif defined(TUKLIB_CPUCORES_SYSCTL)
  27 #       ifdef HAVE_SYS_PARAM_H
  28 #               include <sys/param.h>
  29 #       endif
  30 #       include <sys/sysctl.h>
  31
  32 #elif defined(TUKLIB_CPUCORES_SYSCONF)
  33 #       include <unistd.h>
  34
  35 // HP-UX
  36 #elif defined(TUKLIB_CPUCORES_PSTAT_GETDYNAMIC)
  37 #       include <sys/param.h>
  38 #       include <sys/pstat.h>
  39 #endif
  40
  41
  42 extern uint32_t
  43 tuklib_cpucores(void)
  44 {
  45         uint32_t ret = 0;
  46
  47 #if defined(_WIN32) || defined(__CYGWIN__)
  48         SYSTEM_INFO sysinfo;
  49         GetSystemInfo(&sysinfo);
  50         ret = sysinfo.dwNumberOfProcessors;
  51
  52 #elif defined(TUKLIB_CPUCORES_CPUSET)
  53         cpuset_t set;
  54         if (cpuset_getaffinity(CPU_LEVEL_WHICH, CPU_WHICH_PID, -1,
  55                         sizeof(set), &set) == 0) {
  56 #       ifdef CPU_COUNT
  57                 ret = CPU_COUNT(&set);
  58 #       else
  59                 for (unsigned i = 0; i < CPU_SETSIZE; ++i)
  60                         if (CPU_ISSET(i, &set))
  61                                 ++ret;
  62 #       endif
  63         }
  64
  65 #elif defined(TUKLIB_CPUCORES_SYSCTL)
  66         int name[2] = { CTL_HW, HW_NCPU };
  67         int cpus;
  68         size_t cpus_size = sizeof(cpus);
  69         if (sysctl(name, 2, &cpus, &cpus_size, NULL, 0) != -1
  70                         && cpus_size == sizeof(cpus) && cpus > 0)
  71                 ret = cpus;
  72
  73 #elif defined(TUKLIB_CPUCORES_SYSCONF)
  74 #       ifdef _SC_NPROCESSORS_ONLN
  75         // Most systems
  76         const long cpus = sysconf(_SC_NPROCESSORS_ONLN);
  77 #       else
  78         // IRIX
  79         const long cpus = sysconf(_SC_NPROC_ONLN);
  80 #       endif
  81         if (cpus > 0)
  82                 ret = cpus;
  83
  84 #elif defined(TUKLIB_CPUCORES_PSTAT_GETDYNAMIC)
  85         struct pst_dynamic pst;
  86         if (pstat_getdynamic(&pst, sizeof(pst), 1, 0) != -1)
  87                 ret = pst.psd_proc_cnt;
  88 #endif
  89
  90         return ret;
  91 }