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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:00:34 +0000 |
commit | 3f619478f796eddbba6e39502fe941b285dd97b1 (patch) | |
tree | e2c7b5777f728320e5b5542b6213fd3591ba51e2 /mysys/my_getncpus.c | |
parent | Initial commit. (diff) | |
download | mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.tar.xz mariadb-3f619478f796eddbba6e39502fe941b285dd97b1.zip |
Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mysys/my_getncpus.c')
-rw-r--r-- | mysys/my_getncpus.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/mysys/my_getncpus.c b/mysys/my_getncpus.c new file mode 100644 index 00000000..1f5fa794 --- /dev/null +++ b/mysys/my_getncpus.c @@ -0,0 +1,85 @@ +/* + Copyright (c) 2006, 2010, Oracle and/or its affiliates + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +/* get the number of (online) CPUs */ + +#include "mysys_priv.h" +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#if defined(__FreeBSD__) && defined(HAVE_PTHREAD_GETAFFINITY_NP) +#include <pthread_np.h> +#include <sys/cpuset.h> +#endif + +static int ncpus=0; + +int my_getncpus(void) +{ + if (!ncpus) + { + /* + First attempt to get the total number of available cores. sysconf is + the fallback, but it can return a larger number. It will return the + total number of cores, not the ones available to the process - as + configured via core affinity. + */ +#if (defined(__linux__) || defined(__FreeBSD__)) && defined(HAVE_PTHREAD_GETAFFINITY_NP) +#ifdef __linux__ + cpu_set_t set; +#else + cpuset_t set; +#endif + if (pthread_getaffinity_np(pthread_self(), sizeof(set), &set) == 0) + { +#ifdef CPU_COUNT + /* CPU_COUNT was introduced with glibc 2.6. */ + ncpus= CPU_COUNT(&set); +#else + /* Implementation for platforms with glibc < 2.6 */ + size_t i; + + for (i= 0; i < CPU_SETSIZE; i++) + if (CPU_ISSET(i, &set)) + ncpus++; +#endif + return ncpus; + } +#endif /* (__linux__ || __FreeBSD__) && HAVE_PTHREAD_GETAFFINITY_NP */ + +#ifdef _SC_NPROCESSORS_ONLN + ncpus= sysconf(_SC_NPROCESSORS_ONLN); +#elif defined(_WIN32) + SYSTEM_INFO sysinfo; + + /* + We are not calling GetNativeSystemInfo here because (1) we + don't believe that they return different values for number + of processors and (2) if WOW64 limits processors for Win32 + then we don't want to try to override that. + */ + GetSystemInfo(&sysinfo); + + ncpus= sysinfo.dwNumberOfProcessors; +#else + /* Unknown so play safe: assume SMP and forbid uniprocessor build */ + ncpus= 2; +#endif + } + + return ncpus; +} |