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Diffstat (limited to 'cmake/tuklib_cpucores.cmake')
| -rw-r--r-- | cmake/tuklib_cpucores.cmake | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/cmake/tuklib_cpucores.cmake b/cmake/tuklib_cpucores.cmake new file mode 100644 index 00000000..5844e4b2 --- /dev/null +++ b/cmake/tuklib_cpucores.cmake @@ -0,0 +1,175 @@ +# +# 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(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) + if(NOT DEFINED CACHE{TUKLIB_CPUCORES_FOUND}) + message(STATUS + "Checking how to detect the number of available CPU cores") + tuklib_cpucores_internal_check() + + if(DEFINED CACHE{TUKLIB_CPUCORES_DEFINITIONS}) + set(TUKLIB_CPUCORES_FOUND 1 CACHE INTERNAL "") + else() + set(TUKLIB_CPUCORES_FOUND 0 CACHE INTERNAL "") + message(WARNING + "No method to detect the number of CPU cores was found") + endif() + endif() + + if(TUKLIB_CPUCORES_FOUND) + tuklib_add_definitions("${TARGET_OR_ALL}" + "${TUKLIB_CPUCORES_DEFINITIONS}") + endif() +endfunction() |