instance.hxx

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you 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 .
 */

/*
 * This file is part of LibreOffice published API.
 */

#ifndef INCLUDED_RTL_INSTANCE_HXX
#define INCLUDED_RTL_INSTANCE_HXX

#include "sal/config.h"

#include <cstddef>

#include "osl/doublecheckedlocking.h"
#include "osl/getglobalmutex.hxx"

namespace {

template< typename Inst, typename InstCtor,
          typename Guard, typename GuardCtor,
          typename Data = int, typename DataCtor = int >
class rtl_Instance
{
public:
    static Inst * create(InstCtor aInstCtor, GuardCtor aGuardCtor)
    {
#if defined _MSC_VER
        static Inst * m_pInstance = NULL;
#endif // _MSC_VER
        Inst * p = m_pInstance;
        if (!p)
        {
            Guard aGuard(aGuardCtor());
            p = m_pInstance;
            if (!p)
            {
                p = aInstCtor();
                OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
                m_pInstance = p;
            }
        }
        else
        {
            OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
        }
        return p;
    }

    static Inst * create(InstCtor aInstCtor, GuardCtor aGuardCtor,
                                DataCtor aDataCtor)
    {
#if defined _MSC_VER
        static Inst * m_pInstance = NULL;
#endif // _MSC_VER
        Inst * p = m_pInstance;
        if (!p)
        {
            Data aData(aDataCtor());
            Guard aGuard(aGuardCtor());
            p = m_pInstance;
            if (!p)
            {
                p = aInstCtor(aData);
                OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
                m_pInstance = p;
            }
        }
        else
        {
            OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
        }
        return p;
    }

    static Inst * create(InstCtor aInstCtor, GuardCtor aGuardCtor,
                                const Data &rData)
    {
#if defined _MSC_VER
        static Inst * m_pInstance = 0;
#endif // _MSC_VER
        Inst * p = m_pInstance;
        if (!p)
        {
            Guard aGuard(aGuardCtor());
            p = m_pInstance;
            if (!p)
            {
                p = aInstCtor(rData);
                OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
                m_pInstance = p;
            }
        }
        else
        {
            OSL_DOUBLE_CHECKED_LOCKING_MEMORY_BARRIER();
        }
        return p;
    }

private:
#if !defined _MSC_VER
    static Inst * m_pInstance;
#endif // _MSC_VER
};

#if !defined _MSC_VER
template< typename Inst, typename InstCtor,
          typename Guard, typename GuardCtor,
          typename Data, typename DataCtor >
Inst *
rtl_Instance< Inst, InstCtor, Guard, GuardCtor, Data, DataCtor >::m_pInstance
= NULL;
#endif // _MSC_VER

}

namespace rtl {

#if defined LIBO_INTERNAL_ONLY
template<typename T, typename Unique>
class Static {
public:
    static T & get() {
        static T instance;
        return instance;
    }
};
#else
template<typename T, typename Unique>
class Static {
public:
    static T & get() {
        return *rtl_Instance<
            T, StaticInstance,
            ::osl::MutexGuard, ::osl::GetGlobalMutex >::create(
                StaticInstance(), ::osl::GetGlobalMutex() );
    }
private:
    struct StaticInstance {
        T * operator () () {
            static T instance;
            return &instance;
        }
    };
};
#endif

#if defined LIBO_INTERNAL_ONLY
template<typename T, typename Data, typename Unique>
class StaticWithArg {
public:
    static T & get(const Data& rData) {
        static T instance(rData);
        return instance;
    }

    static T & get(Data& rData) {
        static T instance(rData);
        return instance;
    }
};
#else
template<typename T, typename Data, typename Unique>
class StaticWithArg {
public:
    static T & get(const Data& rData) {
        return *rtl_Instance<
            T, StaticInstanceWithArg,
            ::osl::MutexGuard, ::osl::GetGlobalMutex,
            Data >::create( StaticInstanceWithArg(),
                                      ::osl::GetGlobalMutex(),
                                      rData );
    }

    static T & get(Data& rData) {
        return *rtl_Instance<
            T, StaticInstanceWithArg,
            ::osl::MutexGuard, ::osl::GetGlobalMutex,
            Data >::create( StaticInstanceWithArg(),
                                      ::osl::GetGlobalMutex(),
                                      rData );
    }
private:
    struct StaticInstanceWithArg {
        T * operator () (const Data& rData) {
            static T instance(rData);
            return &instance;
        }

        T * operator () (Data& rData) {
            static T instance(rData);
            return &instance;
         }
    };
};
#endif

#if defined LIBO_INTERNAL_ONLY
template<typename T, typename InitAggregate>
class StaticAggregate {
public:
    static T * get() {
        static T *instance = InitAggregate()();
        return instance;
    }
};
#else
template<typename T, typename InitAggregate>
class StaticAggregate {
public:
    static T * get() {
        return rtl_Instance<
            T, InitAggregate,
            ::osl::MutexGuard, ::osl::GetGlobalMutex >::create(
                InitAggregate(), ::osl::GetGlobalMutex() );
    }
};
#endif

#if defined LIBO_INTERNAL_ONLY
template<typename T, typename InitData,
         typename Unique = InitData, typename Data = T>
class StaticWithInit {
public:
    static T & get() {
        static T instance = InitData()();
        return instance;
    }
};
#else
template<typename T, typename InitData,
         typename Unique = InitData, typename Data = T>
class StaticWithInit {
public:
    static T & get() {
        return *rtl_Instance<
            T, StaticInstanceWithInit,
            ::osl::MutexGuard, ::osl::GetGlobalMutex,
            Data, InitData >::create( StaticInstanceWithInit(),
                                      ::osl::GetGlobalMutex(),
                                      InitData() );
    }
private:
    struct StaticInstanceWithInit {
        T * operator () ( Data d ) {
            static T instance(d);
            return &instance;
        }
    };
};
#endif
} // namespace rtl

#endif // INCLUDED_RTL_INSTANCE_HXX

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