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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2009 Sun Microsystems
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef DRIZZLED_ATOMIC_GCC_TRAITS_H
#define DRIZZLED_ATOMIC_GCC_TRAITS_H
namespace drizzled {
namespace internal {
template<typename T, typename D>
class gcc_traits
{
public:
typedef T value_type;
gcc_traits() {}
/* YES. I know these are semantically backwards...
* so... TODO: Ensure we're doing the "right" thing here
*/
inline value_type fetch_and_add(volatile value_type *value, D addend )
{
return __sync_add_and_fetch(value, addend);
}
inline value_type fetch_and_increment(volatile value_type *value)
{
return __sync_add_and_fetch(value, 1);
}
inline value_type fetch_and_decrement(volatile value_type *value)
{
return __sync_sub_and_fetch(value, 1);
}
inline value_type fetch_and_store(volatile value_type *value,
value_type new_value)
{
/* TODO: Is this the right one? */
return __sync_lock_test_and_set(value, new_value);
}
inline value_type compare_and_swap(volatile value_type *value,
value_type new_value,
value_type comparand )
{
return __sync_val_compare_and_swap(value, comparand, new_value);
}
inline value_type fetch(const volatile value_type *value) const volatile
{
/*
* This is necessary to ensure memory barriers are respected when
* simply returning the value pointed at. However, this does not
* compile on ICC.
*
* @todo
*
* Look at how to rewrite the below to something that ICC feels is
* OK and yet respects memory barriers.
*/
return __sync_add_and_fetch(const_cast<value_type *>(value), 0);
}
inline value_type store_with_release(volatile value_type *value,
value_type new_value)
{
*value= new_value;
return *value;
}
}; /* gcc_traits */
} /* namespace internal */
} /* namespace drizzled */
#endif /* DRIZZLED_ATOMIC_GCC_TRAITS_H */
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