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xz-archive/m4/tuklib_physmem.m4

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#
# SYNOPSIS
#
# TUKLIB_PHYSMEM
#
# DESCRIPTION
#
# Check how to get the amount of physical memory.
# This information is used in tuklib_physmem.c.
#
# Supported methods:
#
# - Windows (including Cygwin), OS/2, DJGPP (DOS), and OpenVMS have
# operating-system specific functions.
#
# - sysconf() works on GNU/Linux and Solaris, and possibly on
# some BSDs.
#
# - BSDs use sysctl().
#
# - sysinfo() works on Linux/dietlibc and probably on other Linux
# systems whose libc may lack sysconf().
#
# 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_PHYSMEM], [
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 amount of physical memory],
[tuklib_cv_physmem_method], [
# Maybe checking $host_os would be enough but this matches what
# tuklib_physmem.c does.
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#if defined(_WIN32) || defined(__CYGWIN__) || defined(__OS2__) \
|| defined(__DJGPP__) || defined(__VMS)
int main(void) { return 0; }
#else
#error
#endif
]])], [tuklib_cv_physmem_method=special], [
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <unistd.h>
int
main(void)
{
long i;
i = sysconf(_SC_PAGESIZE);
i = sysconf(_SC_PHYS_PAGES);
return 0;
}
]])], [tuklib_cv_physmem_method=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_PHYSMEM };
unsigned long mem;
size_t mem_ptr_size = sizeof(mem);
sysctl(name, 2, &mem, &mem_ptr_size, NULL, 0);
return 0;
}
]])], [tuklib_cv_physmem_method=sysctl], [
# This version of sysinfo() is Linux-specific. Some non-Linux systems have
# different sysinfo() so we must check $host_os.
case $host_os in
linux*)
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <sys/sysinfo.h>
int
main(void)
{
struct sysinfo si;
sysinfo(&si);
return 0;
}
]])], [
tuklib_cv_physmem_method=sysinfo
], [
tuklib_cv_physmem_method=unknown
])
;;
*)
tuklib_cv_physmem_method=unknown
;;
esac
])])])])
case $tuklib_cv_physmem_method in
sysconf)
AC_DEFINE([TUKLIB_PHYSMEM_SYSCONF], [1],
[Define to 1 if the amount of physical memory can
be detected with sysconf(_SC_PAGESIZE) and
sysconf(_SC_PHYS_PAGES).])
;;
sysctl)
AC_DEFINE([TUKLIB_PHYSMEM_SYSCTL], [1],
[Define to 1 if the amount of physical memory can
be detected with sysctl().])
;;
sysinfo)
AC_DEFINE([TUKLIB_PHYSMEM_SYSINFO], [1],
[Define to 1 if the amount of physical memory
can be detected with Linux sysinfo().])
;;
esac
])dnl