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;
+}