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Diffstat (limited to 'm4/tuklib_cpucores.m4')
| -rw-r--r-- | m4/tuklib_cpucores.m4 | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/m4/tuklib_cpucores.m4 b/m4/tuklib_cpucores.m4 new file mode 100644 index 0000000..873812d --- /dev/null +++ b/m4/tuklib_cpucores.m4 @@ -0,0 +1,180 @@ +# +# 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) +# - sched_getaffinity(): glibc (GNU/Linux, GNU/kFreeBSD) +# - cpuset_getaffinity(): FreeBSD +# - 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], [ + +# glibc-based systems (GNU/Linux and GNU/kFreeBSD) have sched_getaffinity(). +# The CPU_COUNT() macro was added in glibc 2.9 so we try to link the +# test program instead of merely compiling it. glibc 2.9 is old enough that +# if someone uses the code on older glibc, the fallback to sysconf() should +# be good enough. +AC_LINK_IFELSE([AC_LANG_SOURCE([[ +#include <sched.h> +int +main(void) +{ + cpu_set_t cpu_mask; + sched_getaffinity(0, sizeof(cpu_mask), &cpu_mask); + return CPU_COUNT(&cpu_mask); +} +]])], [tuklib_cv_cpucores_method=sched_getaffinity], [ + +# FreeBSD has both cpuset and sysctl. Look for cpuset first because +# it's a better approach. +# +# This test would match on GNU/kFreeBSD too but it would require +# -lfreebsd-glue when linking and thus in the current form this would +# fail on GNU/kFreeBSD. The above test for sched_getaffinity() matches +# on GNU/kFreeBSD so the test below should never run on that OS. +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 +#ifdef HAVE_SYS_PARAM_H +# include <sys/param.h> +#endif +#include <sys/sysctl.h> +int +main(void) +{ +#ifdef HW_NCPUONLINE + /* This is preferred on OpenBSD, see tuklib_cpucores.c. */ + int name[2] = { CTL_HW, HW_NCPUONLINE }; +#else + int name[2] = { CTL_HW, HW_NCPU }; +#endif + 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 + sched_getaffinity) + AC_DEFINE([TUKLIB_CPUCORES_SCHED_GETAFFINITY], [1], + [Define to 1 if the number of available CPU cores + can be detected with sched_getaffinity()]) + ;; + 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 |