1 /* 2 * ptw32_getprocessors.c 3 * 4 * Description: 5 * This translation unit implements routines which are private to 6 * the implementation and may be used throughout it. 7 * 8 * -------------------------------------------------------------------------- 9 * 10 * Pthreads-win32 - POSIX Threads Library for Win32 11 * Copyright(C) 1998 John E. Bossom 12 * Copyright(C) 1999,2005 Pthreads-win32 contributors 13 * 14 * Contact Email: rpj (at) callisto.canberra.edu.au 15 * 16 * The current list of contributors is contained 17 * in the file CONTRIBUTORS included with the source 18 * code distribution. The list can also be seen at the 19 * following World Wide Web location: 20 * http://sources.redhat.com/pthreads-win32/contributors.html 21 * 22 * This library is free software; you can redistribute it and/or 23 * modify it under the terms of the GNU Lesser General Public 24 * License as published by the Free Software Foundation; either 25 * version 2 of the License, or (at your option) any later version. 26 * 27 * This library is distributed in the hope that it will be useful, 28 * but WITHOUT ANY WARRANTY; without even the implied warranty of 29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 30 * Lesser General Public License for more details. 31 * 32 * You should have received a copy of the GNU Lesser General Public 33 * License along with this library in the file COPYING.LIB; 34 * if not, write to the Free Software Foundation, Inc., 35 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 36 */ 37 38 #include "pthread.h" 39 #include "implement.h" 40 41 42 /* 43 * ptw32_getprocessors() 44 * 45 * Get the number of CPUs available to the process. 46 * 47 * If the available number of CPUs is 1 then pthread_spin_lock() 48 * will block rather than spin if the lock is already owned. 49 * 50 * pthread_spin_init() calls this routine when initialising 51 * a spinlock. If the number of available processors changes 52 * (after a call to SetProcessAffinityMask()) then only 53 * newly initialised spinlocks will notice. 54 */ 55 int 56 ptw32_getprocessors (int *count) 57 { 58 DWORD_PTR vProcessCPUs; 59 DWORD_PTR vSystemCPUs; 60 int result = 0; 61 62 #if defined(NEED_PROCESS_AFFINITY_MASK) 63 64 *count = 1; 65 66 #else 67 68 if (GetProcessAffinityMask (GetCurrentProcess (), 69 &vProcessCPUs, &vSystemCPUs)) 70 { 71 DWORD_PTR bit; 72 int CPUs = 0; 73 74 for (bit = 1; bit != 0; bit <<= 1) 75 { 76 if (vProcessCPUs & bit) 77 { 78 CPUs++; 79 } 80 } 81 *count = CPUs; 82 } 83 else 84 { 85 result = EAGAIN; 86 } 87 88 #endif 89 90 return (result); 91 } 92
