ExternalPointer.h

Go to the documentation of this file.

/*CXXR $Id: ExternalPointer.h 1351 2013-03-08 15:12:28Z arr $
 *CXXR
 *CXXR This file is part of CXXR, a project to refactor the R interpreter
 *CXXR into C++.  It may consist in whole or in part of program code and
 *CXXR documentation taken from the R project itself, incorporated into
 *CXXR CXXR (and possibly MODIFIED) under the terms of the GNU General Public
 *CXXR Licence.
 *CXXR 
 *CXXR CXXR is Copyright (C) 2008-13 Andrew R. Runnalls, subject to such other
 *CXXR copyrights and copyright restrictions as may be stated below.
 *CXXR 
 *CXXR CXXR is not part of the R project, and bugs and other issues should
 *CXXR not be reported via r-bugs or other R project channels; instead refer
 *CXXR to the CXXR website.
 *CXXR */

/*
 *  R : A Computer Language for Statistical Data Analysis
 *  Copyright (C) 1995, 1996  Robert Gentleman and Ross Ihaka
 *  Copyright (C) 1999-2006   The R Development Core Team.
 *
 *  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; either version 2.1 of the License, or
 *  (at your option) any later version.
 *
 *  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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, a copy is available at
 *  http://www.r-project.org/Licenses/
 */

#ifndef EXTERNALPOINTER_H
#define EXTERNALPOINTER_H

#include "CXXR/RObject.h"

#ifdef __cplusplus

#include <boost/serialization/access.hpp>
#include <boost/serialization/base_object.hpp>
#include <boost/serialization/nvp.hpp>

#include "CXXR/SEXP_downcast.hpp"

namespace CXXR {
    class ExternalPointer : public RObject {
    public:
        explicit ExternalPointer(void* ptr = 0, RObject* tag = 0,
                                 RObject* prot = 0)
            : RObject(EXTPTRSXP), m_ptr(ptr), m_tag(tag), m_protege(prot)
            {}

        const RObject* protege() const
        {
            return m_protege;
        }

        RObject* protege()
        {
            return m_protege;
        }

        const void* ptr() const
        {
            return m_ptr;
        }

        void* ptr()
        {
            return m_ptr;
        }

        void setProtege(RObject* prot)
        {
            m_protege = prot;
        }

        void setPtr(void* ptr)
        {
            m_ptr = ptr;
        }

        void setTag(RObject* tag)
        {
            m_tag = tag;
        }

        static const char* staticTypeName()
        {
            return "externalptr";
        }

        const RObject* tag() const
        {
            return m_tag;
        }

        RObject* tag()
        {
            return m_tag;
        }

        // Virtual function of RObject:
        const char* typeName() const;

        // Virtual function of GCNode:
        void visitReferents(const_visitor* v) const;
    protected:
        // Declared protected to ensure that ExternalPointer objects are
        // allocated only using 'new':
        ~ExternalPointer() {}

        // Virtual function of GCNode:
        void detachReferents();
    private:
        friend class boost::serialization::access;

        void* m_ptr;
        GCEdge<> m_tag;
        GCEdge<> m_protege;

        // Not implemented yet.  Declared to prevent
        // compiler-generated versions:
        ExternalPointer(const ExternalPointer&);
        ExternalPointer& operator=(const ExternalPointer&);

        // FIXME: note that this doesn't at present serialise the
        // encapsulated pointer!
        template <class Archive>
        void serialize(Archive& ar, const unsigned int version);
    };
} // namespace CXXR

BOOST_CLASS_EXPORT_KEY(CXXR::ExternalPointer)

// ***** Implementation of non-inlined templated members *****

template <class Archive>
void CXXR::ExternalPointer::serialize(Archive& ar, const unsigned int version)
{
    ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(RObject);
    GCNPTR_SERIALIZE(ar, m_tag);
    GCNPTR_SERIALIZE(ar, m_protege);
}

extern "C" {
#endif  /* __cplusplus */

    SEXP R_MakeExternalPtr(void *p, SEXP tag, SEXP prot);

#ifndef __cplusplus
    void *R_ExternalPtrAddr(SEXP s);
#else
    inline void *R_ExternalPtrAddr(SEXP s)
    {
        CXXR::ExternalPointer& ep
            = *CXXR::SEXP_downcast<CXXR::ExternalPointer*>(s);
        return ep.ptr();
    }
#endif

#ifndef __cplusplus  
SEXP R_ExternalPtrTag(SEXP s);
#else
inline SEXP R_ExternalPtrTag(SEXP s)
    {
        CXXR::ExternalPointer& ep
            = *CXXR::SEXP_downcast<CXXR::ExternalPointer*>(s);
        return ep.tag();
    }
#endif

#ifndef __cplusplus
    SEXP R_ExternalPtrProtected(SEXP s);
#else
    inline SEXP R_ExternalPtrProtected(SEXP s)
    {
        CXXR::ExternalPointer& ep
            = *CXXR::SEXP_downcast<CXXR::ExternalPointer*>(s);
        return ep.protege();
    }
#endif

    void R_SetExternalPtrAddr(SEXP s, void *p);

#ifndef __cplusplus
    void R_ClearExternalPtr(SEXP s);
#else
    inline void R_ClearExternalPtr(SEXP s)
    {
        R_SetExternalPtrAddr(s, 0);
    }
#endif

    void R_SetExternalPtrTag(SEXP s, SEXP tag);

    void R_SetExternalPtrProtected(SEXP s, SEXP p);

#ifdef __cplusplus
}
#endif

#endif /* EXTERNALPOINTER_H */