113 lines
2.3 KiB
C
113 lines
2.3 KiB
C
/*
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* Copyright (C) 2008-2014 Tobias Brunner
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* Copyright (C) 2005-2008 Martin Willi
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* HSR Hochschule fuer Technik Rapperswil
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*/
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#include <utils/utils.h>
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#if !defined(HAVE_GCC_ATOMIC_OPERATIONS) && !defined(HAVE_GCC_SYNC_OPERATIONS)
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#include <threading/spinlock.h>
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/**
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* Spinlock for ref_get/put
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*/
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static spinlock_t *ref_lock;
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/**
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* Increase refcount
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*/
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refcount_t ref_get(refcount_t *ref)
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{
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refcount_t current;
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ref_lock->lock(ref_lock);
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current = ++(*ref);
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ref_lock->unlock(ref_lock);
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return current;
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}
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/**
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* Decrease refcount
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*/
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bool ref_put(refcount_t *ref)
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{
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bool more_refs;
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ref_lock->lock(ref_lock);
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more_refs = --(*ref) > 0;
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ref_lock->unlock(ref_lock);
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return !more_refs;
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}
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/**
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* Current refcount
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*/
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refcount_t ref_cur(refcount_t *ref)
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{
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refcount_t current;
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ref_lock->lock(ref_lock);
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current = *ref;
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ref_lock->unlock(ref_lock);
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return current;
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}
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/**
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* Spinlock for all compare and swap operations.
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*/
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static spinlock_t *cas_lock;
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/**
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* Compare and swap if equal to old value
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*/
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#define _cas_impl(name, type) \
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bool cas_##name(type *ptr, type oldval, type newval) \
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{ \
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bool swapped; \
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cas_lock->lock(cas_lock); \
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if ((swapped = (*ptr == oldval))) { *ptr = newval; } \
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cas_lock->unlock(cas_lock); \
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return swapped; \
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}
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_cas_impl(bool, bool)
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_cas_impl(ptr, void*)
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#endif /* !HAVE_GCC_ATOMIC_OPERATIONS && !HAVE_GCC_SYNC_OPERATIONS */
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/**
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* See header
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*/
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void atomics_init()
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{
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#if !defined(HAVE_GCC_ATOMIC_OPERATIONS) && !defined(HAVE_GCC_SYNC_OPERATIONS)
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ref_lock = spinlock_create();
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cas_lock = spinlock_create();
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#endif
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}
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/**
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* See header
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*/
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void atomics_deinit()
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{
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#if !defined(HAVE_GCC_ATOMIC_OPERATIONS) && !defined(HAVE_GCC_SYNC_OPERATIONS)
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ref_lock->destroy(ref_lock);
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cas_lock->destroy(cas_lock);
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#endif
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}
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