refcnt.hh

来自「M5,一个功能强大的多处理器系统模拟器.很多针对处理器架构,性能的研究都使用它作」· HH 代码 · 共 124 行

/*
 * Copyright (c) 2002, 2003, 2004, 2005
 * The Regents of The University of Michigan
 * All Rights Reserved
 *
 * This code is part of the M5 simulator.
 *
 * Permission is granted to use, copy, create derivative works and
 * redistribute this software and such derivative works for any
 * purpose, so long as the copyright notice above, this grant of
 * permission, and the disclaimer below appear in all copies made; and
 * so long as the name of The University of Michigan is not used in
 * any advertising or publicity pertaining to the use or distribution
 * of this software without specific, written prior authorization.
 *
 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE
 * UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND
 * WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE
 * LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT,
 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGES.
 *
 * Authors: Nathan L. Binkert
 */

#ifndef __BASE_REFCNT_HH__
#define __BASE_REFCNT_HH__

class RefCounted
{
  private:
    int count;

  private:
    RefCounted(const RefCounted &);

  public:
    RefCounted() : count(0) {}
    virtual ~RefCounted() {}

    void incref() { ++count; }
    void decref() { if (--count <= 0) delete this; }
};

template <class T>
class RefCountingPtr
{
  protected:
    T *data;

    void copy(T *d)
    {
        data = d;
        if (data)
            data->incref();
    }
    void del()
    {
        if (data)
            data->decref();
    }
    void set(T *d)
    {
        if (data == d)
            return;

        del();
        copy(d);
    }


  public:
    RefCountingPtr() : data(0) {}
    RefCountingPtr(T *data) { copy(data); }
    RefCountingPtr(const RefCountingPtr &r) { copy(r.data); }
    ~RefCountingPtr() { del(); }

    T *operator->() { return data; }
    T &operator*() { return *data; }
    T *get() { return data; }

    const T *operator->() const { return data; }
    const T &operator*() const { return *data; }
    const T *get() const { return data; }

    const RefCountingPtr &operator=(T *p) { set(p); return *this; }
    const RefCountingPtr &operator=(const RefCountingPtr &r)
    { return operator=(r.data); }

    bool operator!() const { return data == 0; }
    operator bool() const { return data != 0; }
};

template<class T>
bool operator==(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r)
{ return l.get() == r.get(); }

template<class T>
bool operator==(const RefCountingPtr<T> &l, const T *r)
{ return l.get() == r; }

template<class T>
bool operator==(const T &l, const RefCountingPtr<T> &r)
{ return l == r.get(); }

template<class T>
bool operator!=(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r)
{ return l.get() != r.get(); }

template<class T>
bool operator!=(const RefCountingPtr<T> &l, const T *r)
{ return l.get() != r; }

template<class T>
bool operator!=(const T &l, const RefCountingPtr<T> &r)
{ return l != r.get(); }

#endif // __BASE_REFCNT_HH__