83 lines
2.7 KiB
C
83 lines
2.7 KiB
C
/* Copyright (C) 2007 Free Software Foundation, Inc.
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Contributed by Danny Smith <dannysmith@users.sourceforge.net>
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This file is part of the GNU OpenMP Library (libgomp).
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Libgomp is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
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more details.
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You should have received a copy of the GNU Lesser General Public License
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along with libgomp; see the file COPYING.LIB. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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MA 02110-1301, USA. */
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/* As a special exception, if you link this library with other files, some
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of which are compiled with GCC, to produce an executable, this library
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does not by itself cause the resulting executable to be covered by the
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GNU General Public License. This exception does not however invalidate
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any other reasons why the executable file might be covered by the GNU
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General Public License. */
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/* This file contains system specific routines related to counting
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online processors and dynamic load balancing. It is expected that
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a system may well want to write special versions of each of these.
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The following implementation uses win32 API routines. */
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#include "libgomp.h"
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#include <windows.h>
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/* Count the CPU's currently available to this process. */
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static int
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count_avail_process_cpus ()
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{
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DWORD_PTR process_cpus;
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DWORD_PTR system_cpus;
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if (GetProcessAffinityMask (GetCurrentProcess (),
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&process_cpus, &system_cpus))
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{
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unsigned int count;
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for (count = 0; process_cpus != 0; process_cpus >>= 1)
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if (process_cpus & 1)
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count++;
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return count;
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}
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return 1;
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}
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/* At startup, determine the default number of threads. It would seem
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this should be related to the number of cpus available to the process. */
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void
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gomp_init_num_threads (void)
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{
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gomp_nthreads_var = count_avail_process_cpus ();
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}
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/* When OMP_DYNAMIC is set, at thread launch determine the number of
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threads we should spawn for this team. FIXME: How do we adjust for
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load average on MS Windows? */
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unsigned
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gomp_dynamic_max_threads (void)
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{
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int n_onln = count_avail_process_cpus ();
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return n_onln > gomp_nthreads_var ? gomp_nthreads_var : n_onln;
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}
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int
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omp_get_num_procs (void)
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{
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return count_avail_process_cpus ();
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}
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ialias (omp_get_num_procs)
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