liblzma/m4/lc_cpucores.m4
Lasse Collin 3084d662d2 Cleanups to the code that detects the amount of RAM and
the number of CPU cores. Added support for using sysinfo()
on Linux systems whose libc lacks appropriate sysconf()
support (at least dietlibc). The Autoconf macros were
split into separate files, and CPU core count detection
was moved from hardware.c to cpucores.h. The core count
isn't used for anything real for now, so a problematic
part in process.c was commented out.
2009-02-14 00:45:29 +02:00

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dnl ###########################################################################
dnl
dnl lc_CPUCORES - Check how to find out the number of online CPU cores
dnl
dnl Check how to find out the number of available CPU cores in the system.
dnl sysconf(_SC_NPROCESSORS_ONLN) works on most systems, except that BSDs
dnl use sysctl().
dnl
dnl ###########################################################################
dnl
dnl Author: Lasse Collin
dnl
dnl This file has been put into the public domain.
dnl You can do whatever you want with this file.
dnl
dnl ###########################################################################
AC_DEFUN([lc_CPUCORES], [
AC_MSG_CHECKING([how to detect the number of available CPU cores])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <unistd.h>
int
main(void)
{
long i;
i = sysconf(_SC_NPROCESSORS_ONLN);
return 0;
}
]])], [
AC_DEFINE([HAVE_NCPU_SYSCONF], [1],
[Define to 1 if the number of available CPU cores can be
detected with sysconf(_SC_NPROCESSORS_ONLN).])
AC_MSG_RESULT([sysconf])
], [
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, NULL);
return 0;
}
]])], [
AC_DEFINE([HAVE_NCPU_SYSCTL], [1],
[Define to 1 if the number of available CPU cores can be
detected with sysctl().])
AC_MSG_RESULT([sysctl])
], [
AC_MSG_RESULT([unknown])
])])
])dnl lc_CPUCORES