1/*
2 * Copyright 2005 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_PIXELFLINGER_SMART_POINTER_H
18#define ANDROID_PIXELFLINGER_SMART_POINTER_H
19
20#include <stdint.h>
21#include <sys/types.h>
22#include <stdlib.h>
23
24// ---------------------------------------------------------------------------
25namespace android {
26namespace tinyutils {
27
28// ---------------------------------------------------------------------------
29
30#define COMPARE(_op_)                                           \
31inline bool operator _op_ (const sp<T>& o) const {              \
32    return m_ptr _op_ o.m_ptr;                                  \
33}                                                               \
34inline bool operator _op_ (const T* o) const {                  \
35    return m_ptr _op_ o;                                        \
36}                                                               \
37template<typename U>                                            \
38inline bool operator _op_ (const sp<U>& o) const {              \
39    return m_ptr _op_ o.m_ptr;                                  \
40}                                                               \
41template<typename U>                                            \
42inline bool operator _op_ (const U* o) const {                  \
43    return m_ptr _op_ o;                                        \
44}
45
46// ---------------------------------------------------------------------------
47
48template <typename T>
49class sp
50{
51public:
52    inline sp() : m_ptr(0) { }
53
54    sp(T* other);
55    sp(const sp<T>& other);
56    template<typename U> sp(U* other);
57    template<typename U> sp(const sp<U>& other);
58
59    ~sp();
60
61    // Assignment
62
63    sp& operator = (T* other);
64    sp& operator = (const sp<T>& other);
65
66    template<typename U> sp& operator = (const sp<U>& other);
67    template<typename U> sp& operator = (U* other);
68
69    // Reset
70    void clear();
71
72    // Accessors
73
74    inline  T&      operator* () const  { return *m_ptr; }
75    inline  T*      operator-> () const { return m_ptr;  }
76    inline  T*      get() const         { return m_ptr; }
77
78    // Operators
79
80    COMPARE(==)
81    COMPARE(!=)
82    COMPARE(>)
83    COMPARE(<)
84    COMPARE(<=)
85    COMPARE(>=)
86
87private:
88    template<typename Y> friend class sp;
89
90    T*              m_ptr;
91};
92
93// ---------------------------------------------------------------------------
94// No user serviceable parts below here.
95
96template<typename T>
97sp<T>::sp(T* other)
98    : m_ptr(other)
99{
100    if (other) other->incStrong(this);
101}
102
103template<typename T>
104sp<T>::sp(const sp<T>& other)
105    : m_ptr(other.m_ptr)
106{
107    if (m_ptr) m_ptr->incStrong(this);
108}
109
110template<typename T> template<typename U>
111sp<T>::sp(U* other) : m_ptr(other)
112{
113    if (other) other->incStrong(this);
114}
115
116template<typename T> template<typename U>
117sp<T>::sp(const sp<U>& other)
118    : m_ptr(other.m_ptr)
119{
120    if (m_ptr) m_ptr->incStrong(this);
121}
122
123template<typename T>
124sp<T>::~sp()
125{
126    if (m_ptr) m_ptr->decStrong(this);
127}
128
129template<typename T>
130sp<T>& sp<T>::operator = (const sp<T>& other) {
131    if (other.m_ptr) other.m_ptr->incStrong(this);
132    if (m_ptr) m_ptr->decStrong(this);
133    m_ptr = other.m_ptr;
134    return *this;
135}
136
137template<typename T>
138sp<T>& sp<T>::operator = (T* other)
139{
140    if (other) other->incStrong(this);
141    if (m_ptr) m_ptr->decStrong(this);
142    m_ptr = other;
143    return *this;
144}
145
146template<typename T> template<typename U>
147sp<T>& sp<T>::operator = (const sp<U>& other)
148{
149    if (other.m_ptr) other.m_ptr->incStrong(this);
150    if (m_ptr) m_ptr->decStrong(this);
151    m_ptr = other.m_ptr;
152    return *this;
153}
154
155template<typename T> template<typename U>
156sp<T>& sp<T>::operator = (U* other)
157{
158    if (other) other->incStrong(this);
159    if (m_ptr) m_ptr->decStrong(this);
160    m_ptr = other;
161    return *this;
162}
163
164template<typename T>
165void sp<T>::clear()
166{
167    if (m_ptr) {
168        m_ptr->decStrong(this);
169        m_ptr = 0;
170    }
171}
172
173// ---------------------------------------------------------------------------
174
175} // namespace tinyutils
176} // namespace android
177
178// ---------------------------------------------------------------------------
179
180#endif // ANDROID_PIXELFLINGER_SMART_POINTER_H
181