~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2009 Sun Microsystems, Inc.

 *

 *  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

 */

#pragma once

namespace drizzled {

namespace internal {

template<typename T, typename D>

class gcc_traits

{

public:

  typedef T value_type;

  gcc_traits() {}

  inline value_type add_and_fetch(volatile value_type *value, D addend )

  {

    return __sync_add_and_fetch(value, addend);

  }

  inline value_type fetch_and_add(volatile value_type *value, D addend )

  {

    return __sync_fetch_and_add(value, addend);

  }

  inline value_type fetch_and_increment(volatile value_type *value)

  {

    return __sync_fetch_and_add(value, 1);

  }

  inline value_type fetch_and_decrement(volatile value_type *value)

  {

    return __sync_fetch_and_sub(value, 1);

  }

  inline value_type fetch_and_store(volatile value_type *value,

                                    value_type new_value)

  {

    return __sync_lock_test_and_set(value, new_value);

  }

  inline bool compare_and_swap(volatile value_type *value,

                                     value_type new_value,

                                     value_type comparand )

  {

    return __sync_bool_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_fetch_and_add(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 */