OpenTTD Source: src/core/pool_func.hpp Source File

OpenTTD Source 14.0-RC3

pool_func.hpp
Go to the documentation of this file.
1 /*
2 * This file is part of OpenTTD.
3 * 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.
4 * 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.
5 * 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/>.
6 */
7
10 #ifndef POOL_FUNC_HPP
11 #define POOL_FUNC_HPP
12
13 #include "alloc_func.hpp"
14 #include "bitmath_func.hpp"
15 #include "mem_func.hpp"
16 #include "pool_type.hpp"
17 #include "../error_func.h"
18
19 #include "../saveload/saveload_error.hpp" // SlErrorCorruptFmt
20
25 #define DEFINE_POOL_METHOD(type) \
26 template <class Titem, typename Tindex, size_t Tgrowth_step, size_t Tmax_size, PoolType Tpool_type, bool Tcache, bool Tzero> \
27 type Pool<Titem, Tindex, Tgrowth_step, Tmax_size, Tpool_type, Tcache, Tzero>
28
33 DEFINE_POOL_METHOD(inline)::Pool(const char *name) :
34 PoolBase(Tpool_type),
35 name(name),
36 size(0),
37 first_free(0),
38 first_unused(0),
39 items(0),
40 #ifdef WITH_ASSERT
41 checked(0),
42 #endif /* WITH_ASSERT */
43 cleaning(false),
44 data(nullptr),
45 alloc_cache(nullptr)
46 { }
47
54 DEFINE_POOL_METHOD(inline void)::ResizeFor(size_t index)
55 {
56 assert(index >= this->size);
57 assert(index < Tmax_size);
58
59 size_t new_size = std::min(Tmax_size, Align(index + 1, Tgrowth_step));
60
61 this->data = ReallocT(this->data, new_size);
62 MemSetT(this->data + this->size, 0, new_size - this->size);
63
64 this->used_bitmap.resize(Align(new_size, BITMAP_SIZE) / BITMAP_SIZE);
65 if (this->size % BITMAP_SIZE != 0) {
66 /* Already-allocated bits above old size are now unused. */
67 this->used_bitmap[this->size / BITMAP_SIZE] &= ~((~static_cast<BitmapStorage>(0)) << (this->size % BITMAP_SIZE));
68 }
69 if (new_size % BITMAP_SIZE != 0) {
70 /* Bits above new size are considered used. */
71 this->used_bitmap[new_size / BITMAP_SIZE] |= (~static_cast<BitmapStorage>(0)) << (new_size % BITMAP_SIZE);
72 }
73
74 this->size = new_size;
75 }
76
81 DEFINE_POOL_METHOD(inline size_t)::FindFirstFree()
82 {
83 for (auto it = std::next(std::begin(this->used_bitmap), this->first_free / BITMAP_SIZE); it != std::end(this->used_bitmap); ++it) {
84 BitmapStorage available = ~(*it);
85 if (available == 0) continue;
86 return std::distance(std::begin(this->used_bitmap), it) * BITMAP_SIZE + FindFirstBit(available);
87 }
88
89 assert(this->first_unused == this->size);
90
91 if (this->first_unused < Tmax_size) {
92 this->ResizeFor(this->first_unused);
93 return this->first_unused;
94 }
95
96 assert(this->first_unused == Tmax_size);
97
98 return NO_FREE_ITEM;
99 }
100
108 DEFINE_POOL_METHOD(inline void *)::AllocateItem(size_t size, size_t index)
109 {
110 assert(this->data[index] == nullptr);
111
112 this->first_unused = std::max(this->first_unused, index + 1);
113 this->items++;
114
115 Titem *item;
116 if (Tcache && this->alloc_cache != nullptr) {
117 assert(sizeof(Titem) == size);
118 item = (Titem *)this->alloc_cache;
119 this->alloc_cache = this->alloc_cache->next;
120 if (Tzero) {
121 /* Explicitly casting to (void *) prevents a clang warning -
122 * we are actually memsetting a (not-yet-constructed) object */
123 memset((void *)item, 0, sizeof(Titem));
124 }
125 } else if (Tzero) {
126 item = (Titem *)CallocT<byte>(size);
127 } else {
128 item = (Titem *)MallocT<byte>(size);
129 }
130 this->data[index] = item;
131 SetBit(this->used_bitmap[index / BITMAP_SIZE], index % BITMAP_SIZE);
132 item->index = (Tindex)(uint)index;
133 return item;
134 }
135
142 DEFINE_POOL_METHOD(void *)::GetNew(size_t size)
143 {
144 size_t index = this->FindFirstFree();
145
146 #ifdef WITH_ASSERT
147 assert(this->checked != 0);
148 this->checked--;
149 #endif /* WITH_ASSERT */
150 if (index == NO_FREE_ITEM) {
151 FatalError("{}: no more free items", this->name);
152 }
153
154 this->first_free = index + 1;
155 return this->AllocateItem(size, index);
156 }
157
165 DEFINE_POOL_METHOD(void *)::GetNew(size_t size, size_t index)
166 {
167 if (index >= Tmax_size) {
168 SlErrorCorruptFmt("{} index {} out of range ({})", this->name, index, Tmax_size);
169 }
170
171 if (index >= this->size) this->ResizeFor(index);
172
173 if (this->data[index] != nullptr) {
174 SlErrorCorruptFmt("{} index {} already in use", this->name, index);
175 }
176
177 return this->AllocateItem(size, index);
178 }
179
186 DEFINE_POOL_METHOD(void)::FreeItem(size_t index)
187 {
188 assert(index < this->size);
189 assert(this->data[index] != nullptr);
190 if (Tcache) {
191 AllocCache *ac = (AllocCache *)this->data[index];
192 ac->next = this->alloc_cache;
193 this->alloc_cache = ac;
194 } else {
195 free(this->data[index]);
196 }
197 this->data[index] = nullptr;
198 this->first_free = std::min(this->first_free, index);
199 this->items--;
200 if (!this->cleaning) {
201 ClrBit(this->used_bitmap[index / BITMAP_SIZE], index % BITMAP_SIZE);
202 Titem::PostDestructor(index);
203 }
204 }
205
207 DEFINE_POOL_METHOD(void)::CleanPool()
208 {
209 this->cleaning = true;
210 for (size_t i = 0; i < this->first_unused; i++) {
211 delete this->Get(i); // 'delete nullptr;' is very valid
212 }
213 assert(this->items == 0);
214 free(this->data);
215 this->used_bitmap.clear();
216 this->used_bitmap.shrink_to_fit();
217 this->first_unused = this->first_free = this->size = 0;
218 this->data = nullptr;
219 this->cleaning = false;
220
221 if (Tcache) {
222 while (this->alloc_cache != nullptr) {
223 AllocCache *ac = this->alloc_cache;
224 this->alloc_cache = ac->next;
225 free(ac);
226 }
227 }
228 }
229
230 #undef DEFINE_POOL_METHOD
231
237 #define INSTANTIATE_POOL_METHODS(name) \
238 template void * name ## Pool::GetNew(size_t size); \
239 template void * name ## Pool::GetNew(size_t size, size_t index); \
240 template void name ## Pool::FreeItem(size_t index); \
241 template void name ## Pool::CleanPool();
242
243 #endif /* POOL_FUNC_HPP */
SetBit
constexpr T SetBit(T &x, const uint8_t y)
Set a bit in a variable.
Definition: bitmath_func.hpp:121
mem_func.hpp
ReallocT
T * ReallocT(T *t_ptr, size_t num_elements)
Simplified reallocation function that allocates the specified number of elements of the given type.
Definition: alloc_func.hpp:111
PoolBase
Base class for base of all pools.
Definition: pool_type.hpp:29
bitmath_func.hpp
free
void free(const void *ptr)
Version of the standard free that accepts const pointers.
Definition: stdafx.h:379
Pool
Base class for all pools.
Definition: pool_type.hpp:80
DEFINE_POOL_METHOD
#define DEFINE_POOL_METHOD(type)
Helper for defining the method's signature.
Definition: pool_func.hpp:25
alloc_func.hpp
MemSetT
void MemSetT(T *ptr, byte value, size_t num=1)
Type-safe version of memset().
Definition: mem_func.hpp:49
pool_type.hpp
ClrBit
constexpr T ClrBit(T &x, const uint8_t y)
Clears a bit in a variable.
Definition: bitmath_func.hpp:151
Align
constexpr T Align(const T x, uint n)
Return the smallest multiple of n equal or greater than x.
Definition: math_func.hpp:37
FindFirstBit
constexpr uint8_t FindFirstBit(T x)
Search the first set bit in a value.
Definition: bitmath_func.hpp:194