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Diffstat (limited to 'pthreads/ptw32_getprocessors.c')
-rw-r--r-- | pthreads/ptw32_getprocessors.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/pthreads/ptw32_getprocessors.c b/pthreads/ptw32_getprocessors.c new file mode 100644 index 000000000..e60c3143f --- /dev/null +++ b/pthreads/ptw32_getprocessors.c @@ -0,0 +1,91 @@ +/* + * 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); +} |