Import xz 5.2.2 (as of svn r86089)

m4/tuklib_cpucores.m4

@@ -0,0 +1,148 @@
+#
+# 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, QNX, 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], [
+
+# FreeBSD has both cpuset and sysctl. Look for cpuset first because
+# it's a better approach.
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+#include <sys/param.h>
+#include <sys/cpuset.h>
+
+int
+main(void)
+{
+	cpuset_t set;
+	cpuset_getaffinity(CPU_LEVEL_WHICH, CPU_WHICH_PID, -1,
+			sizeof(set), &set);
+	return 0;
+}
+]])], [tuklib_cv_cpucores_method=cpuset], [
+
+# On OS/2, both sysconf() and sysctl() pass the tests in this file,
+# but only sysctl() works. On QNX it's the opposite: only sysconf() works
+# (although it assumes that _POSIX_SOURCE, _XOPEN_SOURCE, and _POSIX_C_SOURCE
+# are undefined or alternatively _QNX_SOURCE is defined).
+#
+# We test sysctl() first and intentionally break the sysctl() test on QNX
+# so that sysctl() is never used on QNX.
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+#ifdef __QNX__
+compile error
+#endif
+#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
+	cpuset)
+		AC_DEFINE([TUKLIB_CPUCORES_CPUSET], [1],
+			[Define to 1 if the number of available CPU cores
+			can be detected with cpuset(2).])
+		;;
+	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