69 lines
2.3 KiB
C
69 lines
2.3 KiB
C
/* Copyright (C) 2008 Free Software Foundation, Inc.
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Contributed by Jakub Jelinek <jakub@redhat.com>.
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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 is a Linux specific implementation of a mutex synchronization
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mechanism for libgomp. This type is private to the library. This
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implementation uses atomic instructions and the futex syscall. */
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#ifndef GOMP_WAIT_H
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#define GOMP_WAIT_H 1
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#include "libgomp.h"
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#include <errno.h>
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#define FUTEX_WAIT 0
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#define FUTEX_WAKE 1
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#define FUTEX_PRIVATE_FLAG 128L
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#ifdef HAVE_ATTRIBUTE_VISIBILITY
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# pragma GCC visibility push(hidden)
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#endif
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extern long int gomp_futex_wait, gomp_futex_wake;
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#include "futex.h"
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static inline void do_wait (int *addr, int val)
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{
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unsigned long long i, count = gomp_spin_count_var;
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if (__builtin_expect (gomp_managed_threads > gomp_available_cpus, 0))
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count = gomp_throttled_spin_count_var;
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for (i = 0; i < count; i++)
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if (__builtin_expect (*addr != val, 0))
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return;
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else
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cpu_relax ();
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futex_wait (addr, val);
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}
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#ifdef HAVE_ATTRIBUTE_VISIBILITY
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# pragma GCC visibility pop
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#endif
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#endif /* GOMP_WAIT_H */
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