refcnt.hh revision 8220:d9f19c39ddba
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 __BASE_REFCNT_HH__ 32#define __BASE_REFCNT_HH__ 33 34class RefCounted 35{ 36 private: 37 mutable int count; 38 39 private: 40 // Don't allow a default copy constructor or copy operator on 41 // these objects because the default operation will copy the 42 // reference count as well and we certainly don't want that. 43 RefCounted(const RefCounted &); 44 RefCounted &operator=(const RefCounted &); 45 46 public: 47 RefCounted() : count(0) {} 48 virtual ~RefCounted() {} 49 50 void incref() { ++count; } 51 void decref() { if (--count <= 0) delete this; } 52}; 53 54template <class T> 55class RefCountingPtr 56{ 57 protected: 58 T *data; 59 60 void copy(T *d) 61 { 62 data = d; 63 if (data) 64 data->incref(); 65 } 66 void del() 67 { 68 if (data) 69 data->decref(); 70 } 71 void set(T *d) 72 { 73 if (data == d) 74 return; 75 76 del(); 77 copy(d); 78 } 79 80 81 public: 82 RefCountingPtr() : data(0) {} 83 RefCountingPtr(T *data) { copy(data); } 84 RefCountingPtr(const RefCountingPtr &r) { copy(r.data); } 85 ~RefCountingPtr() { del(); } 86 87 T *operator->() const { return data; } 88 T &operator*() const { return *data; } 89 T *get() const { return data; } 90 91 const RefCountingPtr &operator=(T *p) { set(p); return *this; } 92 const RefCountingPtr &operator=(const RefCountingPtr &r) 93 { return operator=(r.data); } 94 95 bool operator!() const { return data == 0; } 96 operator bool() const { return data != 0; } 97}; 98 99template<class T> 100inline bool operator==(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r) 101{ return l.get() == r.get(); } 102 103template<class T> 104inline bool operator==(const RefCountingPtr<T> &l, const T *r) 105{ return l.get() == r; } 106 107template<class T> 108inline bool operator==(const T *l, const RefCountingPtr<T> &r) 109{ return l == r.get(); } 110 111template<class T> 112inline bool operator!=(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r) 113{ return l.get() != r.get(); } 114 115template<class T> 116inline bool operator!=(const RefCountingPtr<T> &l, const T *r) 117{ return l.get() != r; } 118 119template<class T> 120inline bool operator!=(const T *l, const RefCountingPtr<T> &r) 121{ return l != r.get(); } 122 123#endif // __BASE_REFCNT_HH__ 124