// Module:  Log4CPLUS

// File:    pointer.cxx

// Created: 6/2001

// Author:  Tad E. Smith

//

//

// Copyright 2001-2010 Tad E. Smith

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "dcmtk/oflog/streams.h"

#include "dcmtk/oflog/helpers/pointer.h"

#include "dcmtk/oflog/thread/threads.h"

#include "dcmtk/oflog/thread/impl/syncimpl.h"

#include "dcmtk/oflog/config/windowsh.h"

#include <cassert>

#if defined (DCMTK_LOG4CPLUS_HAVE_INTRIN_H)

#include <intrin.h>

#endif

namespace dcmtk {

namespace log4cplus { namespace helpers {

///////////////////////////////////////////////////////////////////////////////

// log4cplus::helpers::SharedObject dtor

///////////////////////////////////////////////////////////////////////////////

SharedObject::~SharedObject()

{

    assert(count == 0);

}

///////////////////////////////////////////////////////////////////////////////

// log4cplus::helpers::SharedObject public methods

///////////////////////////////////////////////////////////////////////////////

void

SharedObject::addReference() const

{

#if defined (DCMTK_LOG4CPLUS_SINGLE_THREADED)

    ++count;

#elif defined (DCMTK_LOG4CPLUS_HAVE_CXX11_ATOMICS)

    STD_NAMESPACE atomic_fetch_add_explicit (&count, 1u,

        STD_NAMESPACE memory_order_relaxed);

#elif defined (DCMTK_LOG4CPLUS_HAVE___SYNC_ADD_AND_FETCH)

    __sync_add_and_fetch (&count, 1);

#elif defined (_WIN32) && defined (DCMTK_LOG4CPLUS_HAVE_INTRIN_H)

    _InterlockedIncrement (&count);

#elif defined (_WIN32)

    InterlockedIncrement (&count);

#else

    thread::MutexGuard guard (access_mutex);

    ++count;

#endif

}

void

SharedObject::removeReference() const

{

    assert (count > 0);

    bool destroy;

#if defined (DCMTK_LOG4CPLUS_SINGLE_THREADED)

    destroy = --count == 0;

#elif defined (DCMTK_LOG4CPLUS_HAVE_CXX11_ATOMICS)

    destroy = STD_NAMESPACE atomic_fetch_sub_explicit (&count, 1u,

        STD_NAMESPACE memory_order_release) == 1;

    if (DCMTK_LOG4CPLUS_UNLIKELY (destroy))

        STD_NAMESPACE atomic_thread_fence (STD_NAMESPACE memory_order_acquire);

#elif defined (DCMTK_LOG4CPLUS_HAVE___SYNC_SUB_AND_FETCH)

    destroy = __sync_sub_and_fetch (&count, 1) == 0;

#elif defined (_WIN32) && defined (DCMTK_LOG4CPLUS_HAVE_INTRIN_H)

    destroy = _InterlockedDecrement (&count) == 0;

#elif defined (_WIN32)

    destroy = InterlockedDecrement (&count) == 0;

#else

    {

        thread::MutexGuard guard (access_mutex);

        destroy = --count == 0;

    }

#endif

    if (DCMTK_LOG4CPLUS_UNLIKELY (destroy))

        delete this;

}

} } // namespace log4cplus { namespace helpers

} // end namespace dcmtk