refcnt.hh revision 2665
1/* 2 * Copyright (c) 2002-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Nathan Binkert 29 */ 30 31#ifndef __REFCNT_HH__ 32#define __REFCNT_HH__ 33 34#include <stddef.h> //For the NULL macro definition 35 36class RefCounted 37{ 38 private: 39 int count; 40 41 private: 42 RefCounted(const RefCounted &); 43 44 public: 45 RefCounted() : count(0) {} 46 virtual ~RefCounted() {} 47 48 void incref() { ++count; } 49 void decref() { if (--count <= 0) delete this; } 50}; 51 52template <class T> 53class RefCountingPtr 54{ 55 protected: 56 T *data; 57 58 void copy(T *d) 59 { 60 data = d; 61 if (data) 62 data->incref(); 63 } 64 void del() 65 { 66 if (data) 67 data->decref(); 68 } 69 void set(T *d) 70 { 71 if (data == d) 72 return; 73 74 del(); 75 copy(d); 76 } 77 78 79 public: 80 RefCountingPtr() : data(NULL) {} 81 RefCountingPtr(T *data) { copy(data); } 82 RefCountingPtr(const RefCountingPtr &r) { copy(r.data); } 83 ~RefCountingPtr() { del(); } 84 85 T *operator->() { return data; } 86 T &operator*() { return *data; } 87 T *get() { return data; } 88 89 const T *operator->() const { return data; } 90 const T &operator*() const { return *data; } 91 const T *get() const { return data; } 92 93 RefCountingPtr &operator=(T *p) { set(p); return *this; } 94 RefCountingPtr &operator=(const RefCountingPtr &r) 95 { return operator=(r.data); } 96 97 bool operator!() const { return data == 0; } 98 operator bool() const { return data != 0; } 99}; 100 101template<class T> 102bool operator==(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r) 103{ return l.get() == r.get(); } 104 105template<class T> 106bool operator==(const RefCountingPtr<T> &l, const T *r) 107{ return l.get() == r; } 108 109template<class T> 110bool operator==(const T &l, const RefCountingPtr<T> &r) 111{ return l == r.get(); } 112 113template<class T> 114bool operator!=(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r) 115{ return l.get() != r.get(); } 116 117template<class T> 118bool operator!=(const RefCountingPtr<T> &l, const T *r) 119{ return l.get() != r; } 120 121template<class T> 122bool operator!=(const T &l, const RefCountingPtr<T> &r) 123{ return l != r.get(); } 124 125#endif // __REFCNT_HH__ 126