liblzma/m4/tuklib_cpucores.m4
Lasse Collin 124eb69c78 Windows: Add Windows support to tuklib_cpucores().
It is used for Cygwin too. I'm not sure if that is
a good or bad idea.

Thanks to Vincent Torri.
2013-08-03 13:52:58 +03:00

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#
# SYNOPSIS
#
# TUKLIB_CPUCORES
#
# DESCRIPTION
#
# Check how to find out the number of available CPU cores in the system.
# This information is used by tuklib_cpucores.c.
#
# Supported methods:
# - GetSystemInfo(): Windows (including Cygwin)
# - sysctl(): BSDs, OS/2
# - sysconf(): GNU/Linux, Solaris, Tru64, IRIX, AIX, Cygwin (but
# GetSystemInfo() is used on Cygwin)
# - pstat_getdynamic(): HP-UX
#
# COPYING
#
# Author: Lasse Collin
#
# This file has been put into the public domain.
# You can do whatever you want with this file.
#
AC_DEFUN_ONCE([TUKLIB_CPUCORES], [
AC_REQUIRE([TUKLIB_COMMON])
# sys/param.h might be needed by sys/sysctl.h.
AC_CHECK_HEADERS([sys/param.h])
AC_CACHE_CHECK([how to detect the number of available CPU cores],
[tuklib_cv_cpucores_method], [
# Maybe checking $host_os would be enough but this matches what
# tuklib_cpucores.c does.
#
# NOTE: IRIX has a compiler that doesn't error out with #error, so use
# a non-compilable text instead of #error to generate an error.
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#if defined(_WIN32) || defined(__CYGWIN__)
int main(void) { return 0; }
#else
compile error
#endif
]])], [tuklib_cv_cpucores_method=special], [
# Look for sysctl() solution first, because on OS/2, both sysconf()
# and sysctl() pass the tests in this file, but only sysctl()
# actually works.
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <sys/types.h>
#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif
#include <sys/sysctl.h>
int
main(void)
{
int name[2] = { CTL_HW, HW_NCPU };
int cpus;
size_t cpus_size = sizeof(cpus);
sysctl(name, 2, &cpus, &cpus_size, NULL, 0);
return 0;
}
]])], [tuklib_cv_cpucores_method=sysctl], [
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <unistd.h>
int
main(void)
{
long i;
#ifdef _SC_NPROCESSORS_ONLN
/* Many systems using sysconf() */
i = sysconf(_SC_NPROCESSORS_ONLN);
#else
/* IRIX */
i = sysconf(_SC_NPROC_ONLN);
#endif
return 0;
}
]])], [tuklib_cv_cpucores_method=sysconf], [
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <sys/param.h>
#include <sys/pstat.h>
int
main(void)
{
struct pst_dynamic pst;
pstat_getdynamic(&pst, sizeof(pst), 1, 0);
(void)pst.psd_proc_cnt;
return 0;
}
]])], [tuklib_cv_cpucores_method=pstat_getdynamic], [
tuklib_cv_cpucores_method=unknown
])])])])])
case $tuklib_cv_cpucores_method in
sysctl)
AC_DEFINE([TUKLIB_CPUCORES_SYSCTL], [1],
[Define to 1 if the number of available CPU cores
can be detected with sysctl().])
;;
sysconf)
AC_DEFINE([TUKLIB_CPUCORES_SYSCONF], [1],
[Define to 1 if the number of available CPU cores
can be detected with sysconf(_SC_NPROCESSORS_ONLN)
or sysconf(_SC_NPROC_ONLN).])
;;
pstat_getdynamic)
AC_DEFINE([TUKLIB_CPUCORES_PSTAT_GETDYNAMIC], [1],
[Define to 1 if the number of available CPU cores
can be detected with pstat_getdynamic().])
;;
esac
])dnl