aboutsummaryrefslogtreecommitdiff
path: root/cmake/tuklib_cpucores.cmake
diff options
context:
space:
mode:
Diffstat (limited to 'cmake/tuklib_cpucores.cmake')
-rw-r--r--cmake/tuklib_cpucores.cmake173
1 files changed, 173 insertions, 0 deletions
diff --git a/cmake/tuklib_cpucores.cmake b/cmake/tuklib_cpucores.cmake
new file mode 100644
index 00000000..34546b0d
--- /dev/null
+++ b/cmake/tuklib_cpucores.cmake
@@ -0,0 +1,173 @@
+#
+# tuklib_cpucores.cmake - see tuklib_cpucores.m4 for description and comments
+#
+# Author: Lasse Collin
+#
+# This file has been put into the public domain.
+# You can do whatever you want with this file.
+#
+
+include(${CMAKE_CURRENT_LIST_DIR}/tuklib_common.cmake)
+include(CheckCSourceCompiles)
+include(CheckIncludeFile)
+
+function(tuklib_cpucores_internal_check)
+ if(CACHE{TUKLIB_CPUCORES_DEFINITIONS})
+ return()
+ endif()
+
+ if(WIN32 OR CYGWIN)
+ # Nothing to do, the tuklib_cpucores.c handles it.
+ set(TUKLIB_CPUCORES_DEFINITIONS "" CACHE INTERNAL "")
+ return()
+ endif()
+
+ # glibc-based systems (GNU/Linux and GNU/kFreeBSD) have
+ # sched_getaffinity(). The CPU_COUNT() macro was added in glibc 2.9.
+ # glibc 2.9 is old enough that if someone uses the code on older glibc,
+ # the fallback to sysconf() should be good enough.
+ #
+ # NOTE: This required that _GNU_SOURCE is defined. We assume that whatever
+ # feature test macros the caller wants to use are already set in
+ # CMAKE_REQUIRED_DEFINES and in the target defines.
+ check_c_source_compiles("
+ #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_CPUCORES_SCHED_GETAFFINITY)
+ if(TUKLIB_CPUCORES_SCHED_GETAFFINITY)
+ set(TUKLIB_CPUCORES_DEFINITIONS
+ "TUKLIB_CPUCORES_SCHED_GETAFFINITY"
+ CACHE INTERNAL "")
+ return()
+ endif()
+
+ # 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.
+ check_c_source_compiles("
+ #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_CPUCORES_CPUSET)
+ if(TUKLIB_CPUCORES_CPUSET)
+ set(TUKLIB_CPUCORES_DEFINITIONS "HAVE_PARAM_H;TUKLIB_CPUCORES_CPUSET"
+ CACHE INTERNAL "")
+ return()
+ endif()
+
+ # 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.
+ check_include_file(sys/param.h HAVE_SYS_PARAM_H)
+ if(HAVE_SYS_PARAM_H)
+ list(APPEND CMAKE_REQUIRED_DEFINITIONS -DHAVE_SYS_PARAM_H)
+ endif()
+ check_c_source_compiles("
+ #ifdef __QNX__
+ compile error
+ #endif
+ #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_CPUCORES_SYSCTL)
+ if(TUKLIB_CPUCORES_SYSCTL)
+ if(HAVE_SYS_PARAM_H)
+ set(TUKLIB_CPUCORES_DEFINITIONS
+ "HAVE_PARAM_H;TUKLIB_CPUCORES_SYSCTL"
+ CACHE INTERNAL "")
+ else()
+ set(TUKLIB_CPUCORES_DEFINITIONS
+ "TUKLIB_CPUCORES_SYSCTL"
+ CACHE INTERNAL "")
+ endif()
+ return()
+ endif()
+
+ # Many platforms support sysconf().
+ check_c_source_compiles("
+ #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_CPUCORES_SYSCONF)
+ if(TUKLIB_CPUCORES_SYSCONF)
+ set(TUKLIB_CPUCORES_DEFINITIONS "TUKLIB_CPUCORES_SYSCONF"
+ CACHE INTERNAL "")
+ return()
+ endif()
+
+ # HP-UX
+ check_c_source_compiles("
+ #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_CPUCORES_PSTAT_GETDYNAMIC)
+ if(TUKLIB_CPUCORES_PSTAT_GETDYNAMIC)
+ set(TUKLIB_CPUCORES_DEFINITIONS "TUKLIB_CPUCORES_PSTAT_GETDYNAMIC"
+ CACHE INTERNAL "")
+ return()
+ endif()
+endfunction()
+
+function(tuklib_cpucores TARGET_OR_ALL)
+ message(STATUS "Checking how to detect the number of available CPU cores")
+
+ tuklib_cpucores_internal_check()
+
+ if(NOT DEFINED CACHE{TUKLIB_CPUCORES_DEFINITIONS})
+ set(TUKLIB_CPUCORES_FOUND 0 PARENT_SCOPE)
+ message(WARNING
+ "No method to detect the number of CPU cores was found")
+ else()
+ set(TUKLIB_CPUCORES_FOUND 1 PARENT_SCOPE)
+ tuklib_add_definitions(${TARGET_OR_ALL} ${TUKLIB_CPUCORES_DEFINITIONS})
+ endif()
+endfunction()