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39 | |
40 | #ifndef QRECYCLEPOOL_P_H |
41 | #define QRECYCLEPOOL_P_H |
42 | |
43 | // |
44 | // W A R N I N G |
45 | // ------------- |
46 | // |
47 | // This file is not part of the Qt API. It exists purely as an |
48 | // implementation detail. This header file may change from version to |
49 | // version without notice, or even be removed. |
50 | // |
51 | // We mean it. |
52 | // |
53 | |
54 | QT_BEGIN_NAMESPACE |
55 | |
56 | #define QRECYCLEPOOLCOOKIE 0x33218ADF |
57 | |
58 | template<typename T, int Step> |
59 | class QRecyclePoolPrivate |
60 | { |
61 | public: |
62 | QRecyclePoolPrivate() |
63 | : recyclePoolHold(true), outstandingItems(0), cookie(QRECYCLEPOOLCOOKIE), |
64 | currentPage(nullptr), nextAllocated(nullptr) |
65 | { |
66 | } |
67 | |
68 | bool recyclePoolHold; |
69 | int outstandingItems; |
70 | quint32 cookie; |
71 | |
72 | struct PoolType : public T { |
73 | union { |
74 | QRecyclePoolPrivate<T, Step> *pool; |
75 | PoolType *nextAllocated; |
76 | }; |
77 | }; |
78 | |
79 | struct Page { |
80 | Page *nextPage; |
81 | unsigned int free; |
82 | union { |
83 | char array[Step * sizeof(PoolType)]; |
84 | qint64 q_for_alignment_1; |
85 | double q_for_alignment_2; |
86 | }; |
87 | }; |
88 | |
89 | Page *currentPage; |
90 | PoolType *nextAllocated; |
91 | |
92 | inline T *allocate(); |
93 | static inline void dispose(T *); |
94 | inline void releaseIfPossible(); |
95 | }; |
96 | |
97 | template<typename T, int Step = 1024> |
98 | class QRecyclePool |
99 | { |
100 | public: |
101 | inline QRecyclePool(); |
102 | inline ~QRecyclePool(); |
103 | |
104 | inline T *New(); |
105 | template<typename T1> |
106 | inline T *New(const T1 &); |
107 | template<typename T1> |
108 | inline T *New(T1 &); |
109 | |
110 | static inline void Delete(T *); |
111 | |
112 | private: |
113 | QRecyclePoolPrivate<T, Step> *d; |
114 | }; |
115 | |
116 | template<typename T, int Step> |
117 | QRecyclePool<T, Step>::QRecyclePool() |
118 | : d(new QRecyclePoolPrivate<T, Step>()) |
119 | { |
120 | } |
121 | |
122 | template<typename T, int Step> |
123 | QRecyclePool<T, Step>::~QRecyclePool() |
124 | { |
125 | d->recyclePoolHold = false; |
126 | d->releaseIfPossible(); |
127 | } |
128 | |
129 | template<typename T, int Step> |
130 | T *QRecyclePool<T, Step>::New() |
131 | { |
132 | T *rv = d->allocate(); |
133 | new (rv) T; |
134 | return rv; |
135 | } |
136 | |
137 | template<typename T, int Step> |
138 | template<typename T1> |
139 | T *QRecyclePool<T, Step>::New(const T1 &a) |
140 | { |
141 | T *rv = d->allocate(); |
142 | new (rv) T(a); |
143 | return rv; |
144 | } |
145 | |
146 | template<typename T, int Step> |
147 | template<typename T1> |
148 | T *QRecyclePool<T, Step>::New(T1 &a) |
149 | { |
150 | T *rv = d->allocate(); |
151 | new (rv) T(a); |
152 | return rv; |
153 | } |
154 | |
155 | template<typename T, int Step> |
156 | void QRecyclePool<T, Step>::Delete(T *t) |
157 | { |
158 | t->~T(); |
159 | QRecyclePoolPrivate<T, Step>::dispose(t); |
160 | } |
161 | |
162 | template<typename T, int Step> |
163 | void QRecyclePoolPrivate<T, Step>::releaseIfPossible() |
164 | { |
165 | if (recyclePoolHold || outstandingItems) |
166 | return; |
167 | |
168 | Page *p = currentPage; |
169 | while (p) { |
170 | Page *n = p->nextPage; |
171 | free(p); |
172 | p = n; |
173 | } |
174 | |
175 | delete this; |
176 | } |
177 | |
178 | template<typename T, int Step> |
179 | T *QRecyclePoolPrivate<T, Step>::allocate() |
180 | { |
181 | PoolType *rv = nullptr; |
182 | if (nextAllocated) { |
183 | rv = nextAllocated; |
184 | nextAllocated = rv->nextAllocated; |
185 | } else if (currentPage && currentPage->free) { |
186 | rv = (PoolType *)(currentPage->array + (Step - currentPage->free) * sizeof(PoolType)); |
187 | currentPage->free--; |
188 | } else { |
189 | Page *p = (Page *)malloc(size: sizeof(Page)); |
190 | p->nextPage = currentPage; |
191 | p->free = Step; |
192 | currentPage = p; |
193 | |
194 | rv = (PoolType *)currentPage->array; |
195 | currentPage->free--; |
196 | } |
197 | |
198 | rv->pool = this; |
199 | ++outstandingItems; |
200 | return rv; |
201 | } |
202 | |
203 | template<typename T, int Step> |
204 | void QRecyclePoolPrivate<T, Step>::dispose(T *t) |
205 | { |
206 | PoolType *pt = static_cast<PoolType *>(t); |
207 | Q_ASSERT(pt->pool && pt->pool->cookie == QRECYCLEPOOLCOOKIE); |
208 | |
209 | QRecyclePoolPrivate<T, Step> *This = pt->pool; |
210 | pt->nextAllocated = This->nextAllocated; |
211 | This->nextAllocated = pt; |
212 | --This->outstandingItems; |
213 | This->releaseIfPossible(); |
214 | } |
215 | |
216 | QT_END_NAMESPACE |
217 | |
218 | #endif // QRECYCLEPOOL_P_H |
219 | |