Open Source Projects Europe

/* Copyright (C) 2017-2018 J.F.Dockes

 *   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 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 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.,

 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 */

#ifndef _SYSVIPC_H_INCLUDED_

#define _SYSVIPC_H_INCLUDED_

#include <sys/types.h>

#include <sys/ipc.h>

#include <sys/msg.h>

#include <sys/sem.h>

#include <sys/shm.h>

class ShmSeg {

public:

    ShmSeg(key_t ky, size_t size, bool create = false, int perms = 0600);

    ShmSeg(const char*pathname, int proj_id, size_t size,  bool create = false, int perms = 0600);

    ShmSeg(int size) : ShmSeg(IPC_PRIVATE, size) {}

    virtual ~ShmSeg();

    virtual void setremove(bool onoff = true);

    virtual void *getseg();

    virtual size_t getsize();

    virtual bool ok();

    class Internal;

protected:

    Internal *m;

};

// Shm segment with integrated lock. Note that the lock initialization

// is not protected, and that an external method is needed for the

// creating process to be left alone while it is creating the segment

// and initializing the lock.

// 

// You need to use an Accessor object to get to the segment. This

// takes the lock on construction and releases it on deletion

class LockableShmSeg : public ShmSeg {

public:

    LockableShmSeg(key_t ky, size_t size, bool create = false, int perms = 0600);

    LockableShmSeg(const char*pathname, int proj_id, size_t size,

                    bool create = false, int perms = 0600);

    LockableShmSeg(int size) : LockableShmSeg(IPC_PRIVATE, size) {}

    virtual ~LockableShmSeg();

    class Accessor {

    public:

        Accessor(LockableShmSeg&);

        ~Accessor();

        void *getseg();

    private:

        LockableShmSeg& lss;

    };

    friend class Accessor;

private:

    virtual void *getseg();

};

#endif /* _SYSVIPC_H_INCLUDED_ */