gem5/src/base/refcnt.hh
Nathan Binkert 9e90bfafb5 No need to use NULL, just use 0
The result of operator= cannot be an l-value

--HG--
extra : convert_revision : df97a57f466e3498bd5a29638cb9912c7f3e1bd4
2006-12-27 10:52:25 -08:00

123 lines
3.6 KiB
C++

/*
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Nathan 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__