/*
* libringbuffer/smp.c
*
* Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; only
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define _GNU_SOURCE
#include <unistd.h>
#include <pthread.h>
#include "smp.h"
int __num_possible_cpus;
void _get_num_possible_cpus(void)
{
int result;
/* On Linux, when some processors are offline
* _SC_NPROCESSORS_CONF counts the offline
* processors, whereas _SC_NPROCESSORS_ONLN
* does not. If we used _SC_NPROCESSORS_ONLN,
* getcpu() could return a value greater than
* this sysconf, in which case the arrays
* indexed by processor would overflow.
*/
result = sysconf(_SC_NPROCESSORS_CONF);
if (result == -1)
return;
__num_possible_cpus = result;
}