/*
* ptw32_getprocessors.c
*
* Description:
* This translation unit implements routines which are private to
* the implementation and may be used throughout it.
*
* --------------------------------------------------------------------------
*
* Pthreads-win32 - POSIX Threads Library for Win32
* Copyright(C) 1998 John E. Bossom
* Copyright(C) 1999,2005 Pthreads-win32 contributors
*
* Contact Email: rpj@callisto.canberra.edu.au
*
* The current list of contributors is contained
* in the file CONTRIBUTORS included with the source
* code distribution. The list can also be seen at the
* following World Wide Web location:
* http://sources.redhat.com/pthreads-win32/contributors.html
*
* 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; either
* version 2 of the License, or (at your option) any later version.
*
* 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 in the file COPYING.LIB;
* if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "pthread.h"
#include "implement.h"
/*
* ptw32_getprocessors()
*
* Get the number of CPUs available to the process.
*
* If the available number of CPUs is 1 then pthread_spin_lock()
* will block rather than spin if the lock is already owned.
*
* pthread_spin_init() calls this routine when initialising
* a spinlock. If the number of available processors changes
* (after a call to SetProcessAffinityMask()) then only
* newly initialised spinlocks will notice.
*/
int
ptw32_getprocessors (int *count)
{
DWORD_PTR vProcessCPUs;
DWORD_PTR vSystemCPUs;
int result = 0;
#if defined(NEED_PROCESS_AFFINITY_MASK)
*count = 1;
#else
if (GetProcessAffinityMask (GetCurrentProcess (),
&vProcessCPUs, &vSystemCPUs))
{
DWORD_PTR bit;
int CPUs = 0;
for (bit = 1; bit != 0; bit <<= 1)
{
if (vProcessCPUs & bit)
{
CPUs++;
}
}
*count = CPUs;
}
else
{
result = EAGAIN;
}
#endif
return (result);
}