OpenTTD
pool_type.hpp
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1 /* $Id: pool_type.hpp 26333 2014-02-11 20:34:48Z frosch $ */
2 
3 /*
4  * This file is part of OpenTTD.
5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
8  */
9 
12 #ifndef POOL_TYPE_HPP
13 #define POOL_TYPE_HPP
14 
15 #include "smallvec_type.hpp"
16 #include "enum_type.hpp"
17 
19 enum PoolType {
20  PT_NONE = 0x00,
21  PT_NORMAL = 0x01,
22  PT_NCLIENT = 0x02,
23  PT_NADMIN = 0x04,
24  PT_DATA = 0x08,
25  PT_ALL = 0x0F,
26 };
28 
29 typedef SmallVector<struct PoolBase *, 4> PoolVector;
30 
32 struct PoolBase {
33  const PoolType type;
34 
39  static PoolVector *GetPools()
40  {
41  static PoolVector *pools = new PoolVector();
42  return pools;
43  }
44 
45  static void Clean(PoolType);
46 
51  PoolBase(PoolType pt) : type(pt)
52  {
53  *PoolBase::GetPools()->Append() = this;
54  }
55 
56  virtual ~PoolBase();
57 
61  virtual void CleanPool() = 0;
62 
63 private:
68  PoolBase(const PoolBase &other);
69 };
70 
82 template <class Titem, typename Tindex, size_t Tgrowth_step, size_t Tmax_size, PoolType Tpool_type = PT_NORMAL, bool Tcache = false, bool Tzero = true>
83 struct Pool : PoolBase {
84  /* Ensure Tmax_size is within the bounds of Tindex. */
85  assert_compile((uint64)(Tmax_size - 1) >> 8 * sizeof(Tindex) == 0);
86 
87  static const size_t MAX_SIZE = Tmax_size;
88 
89  const char * const name;
90 
91  size_t size;
92  size_t first_free;
93  size_t first_unused;
94  size_t items;
95 #ifdef OTTD_ASSERT
96  size_t checked;
97 #endif /* OTTD_ASSERT */
98  bool cleaning;
99 
100  Titem **data;
101 
102  Pool(const char *name);
103  virtual void CleanPool();
104 
111  inline Titem *Get(size_t index)
112  {
113  assert(index < this->first_unused);
114  return this->data[index];
115  }
116 
122  inline bool IsValidID(size_t index)
123  {
124  return index < this->first_unused && this->Get(index) != NULL;
125  }
126 
132  inline bool CanAllocate(size_t n = 1)
133  {
134  bool ret = this->items <= Tmax_size - n;
135 #ifdef OTTD_ASSERT
136  this->checked = ret ? n : 0;
137 #endif /* OTTD_ASSERT */
138  return ret;
139  }
140 
145  template <struct Pool<Titem, Tindex, Tgrowth_step, Tmax_size, Tpool_type, Tcache, Tzero> *Tpool>
146  struct PoolItem {
147  Tindex index;
148 
155  inline void *operator new(size_t size)
156  {
157  return Tpool->GetNew(size);
158  }
159 
165  inline void operator delete(void *p)
166  {
167  if (p == NULL) return;
168  Titem *pn = (Titem *)p;
169  assert(pn == Tpool->Get(pn->index));
170  Tpool->FreeItem(pn->index);
171  }
172 
181  inline void *operator new(size_t size, size_t index)
182  {
183  return Tpool->GetNew(size, index);
184  }
185 
194  inline void *operator new(size_t size, void *ptr)
195  {
196  for (size_t i = 0; i < Tpool->first_unused; i++) {
197  /* Don't allow creating new objects over existing.
198  * Even if we called the destructor and reused this memory,
199  * we don't know whether 'size' and size of currently allocated
200  * memory are the same (because of possible inheritance).
201  * Use { size_t index = item->index; delete item; new (index) item; }
202  * instead to make sure destructor is called and no memory leaks. */
203  assert(ptr != Tpool->data[i]);
204  }
205  return ptr;
206  }
207 
208 
216  static inline bool CanAllocateItem(size_t n = 1)
217  {
218  return Tpool->CanAllocate(n);
219  }
220 
225  static inline bool CleaningPool()
226  {
227  return Tpool->cleaning;
228  }
229 
235  static inline bool IsValidID(size_t index)
236  {
237  return Tpool->IsValidID(index);
238  }
239 
246  static inline Titem *Get(size_t index)
247  {
248  return Tpool->Get(index);
249  }
250 
257  static inline Titem *GetIfValid(size_t index)
258  {
259  return index < Tpool->first_unused ? Tpool->Get(index) : NULL;
260  }
261 
267  static inline size_t GetPoolSize()
268  {
269  return Tpool->first_unused;
270  }
271 
276  static inline size_t GetNumItems()
277  {
278  return Tpool->items;
279  }
280 
288  static inline void PostDestructor(size_t index) { }
289  };
290 
291 private:
292  static const size_t NO_FREE_ITEM = MAX_UVALUE(size_t);
293 
298  struct AllocCache {
301  };
302 
305 
306  void *AllocateItem(size_t size, size_t index);
307  void ResizeFor(size_t index);
308  size_t FindFirstFree();
309 
310  void *GetNew(size_t size);
311  void *GetNew(size_t size, size_t index);
312 
313  void FreeItem(size_t index);
314 };
315 
316 #define FOR_ALL_ITEMS_FROM(type, iter, var, start) \
317  for (size_t iter = start; var = NULL, iter < type::GetPoolSize(); iter++) \
318  if ((var = type::Get(iter)) != NULL)
319 
320 #define FOR_ALL_ITEMS(type, iter, var) FOR_ALL_ITEMS_FROM(type, iter, var, 0)
321 
322 #endif /* POOL_TYPE_HPP */