/* Detect the number of processors.
Copyright (C) 2009 Free Software Foundation, Inc.
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; either version 2, or (at your option)
any later version.
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 Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Written by Glen Lenker. */
#include <config.h>
#include "nproc.h"
#include <unistd.h>
#include <sys/types.h>
#if HAVE_SYS_PSTAT_H
# include <sys/pstat.h>
#endif
#if HAVE_SYS_SYSMP_H
# include <sys/sysmp.h>
#endif
#if HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif
#if HAVE_SYS_SYSCTL_H
# include <sys/sysctl.h>
#endif
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
#endif
#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
/* Return the total number of processors. The result is guaranteed to
be at least 1. */
unsigned long int
num_processors (void)
{
#if defined _SC_NPROCESSORS_ONLN
{ /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris, Cygwin,
Haiku. */
long int nprocs = sysconf (_SC_NPROCESSORS_ONLN);
if (0 < nprocs)
return nprocs;
}
#endif
#if HAVE_PSTAT_GETDYNAMIC
{ /* This works on HP-UX. */
struct pst_dynamic psd;
if (0 <= pstat_getdynamic (&psd, sizeof psd, 1, 0)
&& 0 < psd.psd_proc_cnt)
return psd.psd_proc_cnt;
}
#endif
#if HAVE_SYSMP && defined MP_NAPROCS
{ /* This works on IRIX. */
/* MP_NPROCS yields the number of installed processors.
MP_NAPROCS yields the number of processors available to unprivileged
processes. We need the latter. */
int nprocs = sysmp (MP_NAPROCS);
if (0 < nprocs)
return nprocs;
}
#endif
#if HAVE_SYSCTL && defined HW_NCPU
{ /* This works on MacOS X, FreeBSD, NetBSD, OpenBSD. */
int nprocs;
size_t len = sizeof (nprocs);
static int mib[2] = { CTL_HW, HW_NCPU };
if (sysctl (mib, ARRAY_SIZE (mib), &nprocs, &len, NULL, 0) == 0
&& len == sizeof (nprocs)
&& 0 < nprocs)
return nprocs;
}
#endif
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
{ /* This works on native Windows platforms. */
SYSTEM_INFO system_info;
GetSystemInfo (&system_info);
if (0 < system_info.dwNumberOfProcessors)
return system_info.dwNumberOfProcessors;
}
#endif
return 1;
}
