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btGenericPoolAllocator.cpp
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1
6/*
7Bullet Continuous Collision Detection and Physics Library
8Copyright (c) 2003-2006 Erwin Coumans https://bulletphysics.org
9
10This software is provided 'as-is', without any express or implied warranty.
11In no event will the authors be held liable for any damages arising from the use of this software.
12Permission is granted to anyone to use this software for any purpose,
13including commercial applications, and to alter it and redistribute it freely,
14subject to the following restrictions:
15
161. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
172. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
183. This notice may not be removed or altered from any source distribution.
19*/
20
21#include "btGenericPoolAllocator.h"
22
24
25 size_t btGenericMemoryPool::allocate_from_free_nodes(size_t num_elements)
26{
27 size_t ptr = BT_UINT_MAX;
28
29 if (m_free_nodes_count == 0) return BT_UINT_MAX;
30 // find an avaliable free node with the correct size
31 size_t revindex = m_free_nodes_count;
32
33 while (revindex-- && ptr == BT_UINT_MAX)
34 {
35 if (m_allocated_sizes[m_free_nodes[revindex]] >= num_elements)
36 {
37 ptr = revindex;
38 }
39 }
40 if (ptr == BT_UINT_MAX) return BT_UINT_MAX; // not found
41
42 revindex = ptr;
43 ptr = m_free_nodes[revindex];
44 // post: ptr contains the node index, and revindex the index in m_free_nodes
45
46 size_t finalsize = m_allocated_sizes[ptr];
47 finalsize -= num_elements;
48
49 m_allocated_sizes[ptr] = num_elements;
50
51 // post: finalsize>=0, m_allocated_sizes[ptr] has the requested size
52
53 if (finalsize > 0) // preserve free node, there are some free memory
54 {
55 m_free_nodes[revindex] = ptr + num_elements;
56 m_allocated_sizes[ptr + num_elements] = finalsize;
57 }
58 else // delete free node
59 {
60 // swap with end
61 m_free_nodes[revindex] = m_free_nodes[m_free_nodes_count - 1];
62 m_free_nodes_count--;
63 }
64
65 return ptr;
66}
67
68 size_t btGenericMemoryPool::allocate_from_pool(size_t num_elements)
69{
70 if (m_allocated_count + num_elements > m_max_element_count) return BT_UINT_MAX;
71
72 size_t ptr = m_allocated_count;
73
74 m_allocated_sizes[m_allocated_count] = num_elements;
75 m_allocated_count += num_elements;
76
77 return ptr;
78}
79
80 void btGenericMemoryPool::init_pool(size_t element_size, size_t element_count)
81{
82 m_allocated_count = 0;
83 m_free_nodes_count = 0;
84
85 m_element_size = element_size;
86 m_max_element_count = element_count;
87
88 m_pool = (unsigned char *)btAlignedAlloc(m_element_size * m_max_element_count, 16);
89 m_free_nodes = (size_t *)btAlignedAlloc(sizeof(size_t) * m_max_element_count, 16);
90 m_allocated_sizes = (size_t *)btAlignedAlloc(sizeof(size_t) * m_max_element_count, 16);
91
92 for (size_t i = 0; i < m_max_element_count; i++)
93 {
94 m_allocated_sizes[i] = 0;
95 }
96}
97
98 void btGenericMemoryPool::end_pool()
99{
100 btAlignedFree(m_pool);
101 btAlignedFree(m_free_nodes);
102 btAlignedFree(m_allocated_sizes);
103 m_allocated_count = 0;
104 m_free_nodes_count = 0;
105}
106
108
111 void *btGenericMemoryPool::allocate(size_t size_bytes)
112{
113 size_t module = size_bytes % m_element_size;
114 size_t element_count = size_bytes / m_element_size;
115 if (module > 0) element_count++;
116
117 size_t alloc_pos = allocate_from_free_nodes(element_count);
118 // a free node is found
119 if (alloc_pos != BT_UINT_MAX)
120 {
121 return get_element_data(alloc_pos);
122 }
123 // allocate directly on pool
124 alloc_pos = allocate_from_pool(element_count);
125
126 if (alloc_pos == BT_UINT_MAX) return NULL; // not space
127 return get_element_data(alloc_pos);
128}
129
130 bool btGenericMemoryPool::freeMemory(void *pointer)
131{
132 unsigned char *pointer_pos = (unsigned char *)pointer;
133 unsigned char *pool_pos = (unsigned char *)m_pool;
134 // calc offset
135 if (pointer_pos < pool_pos) return false; //other pool
136 size_t offset = size_t(pointer_pos - pool_pos);
137 if (offset >= get_pool_capacity()) return false; // far away
138
139 // find free position
140 m_free_nodes[m_free_nodes_count] = offset / m_element_size;
141 m_free_nodes_count++;
142 return true;
143}
144
146
147btGenericPoolAllocator::~btGenericPoolAllocator()
148{
149 // destroy pools
150 size_t i;
151 for (i = 0; i < m_pool_count; i++)
152 {
153 m_pools[i]->end_pool();
154 btAlignedFree(m_pools[i]);
155 }
156}
157
158// creates a pool
159 btGenericMemoryPool *btGenericPoolAllocator::push_new_pool()
160{
161 if (m_pool_count >= BT_DEFAULT_MAX_POOLS) return NULL;
162
163 btGenericMemoryPool *newptr = (btGenericMemoryPool *)btAlignedAlloc(sizeof(btGenericMemoryPool), 16);
164
165 m_pools[m_pool_count] = newptr;
166
167 m_pools[m_pool_count]->init_pool(m_pool_element_size, m_pool_element_count);
168
169 m_pool_count++;
170 return newptr;
171}
172
173 void *btGenericPoolAllocator::failback_alloc(size_t size_bytes)
174{
175 btGenericMemoryPool *pool = NULL;
176
177 if (size_bytes <= get_pool_capacity())
178 {
179 pool = push_new_pool();
180 }
181
182 if (pool == NULL) // failback
183 {
184 return btAlignedAlloc(size_bytes, 16);
185 }
186
187 return pool->allocate(size_bytes);
188}
189
190 bool btGenericPoolAllocator::failback_free(void *pointer)
191{
192 btAlignedFree(pointer);
193 return true;
194}
195
197
200 void *btGenericPoolAllocator::allocate(size_t size_bytes)
201{
202 void *ptr = NULL;
203
204 size_t i = 0;
205 while (i < m_pool_count && ptr == NULL)
206 {
207 ptr = m_pools[i]->allocate(size_bytes);
208 ++i;
209 }
210
211 if (ptr) return ptr;
212
213 return failback_alloc(size_bytes);
214}
215
216 bool btGenericPoolAllocator::freeMemory(void *pointer)
217{
218 bool result = false;
219
220 size_t i = 0;
221 while (i < m_pool_count && result == false)
222 {
223 result = m_pools[i]->freeMemory(pointer);
224 ++i;
225 }
226
227 if (result) return true;
228
229 return failback_free(pointer);
230}
231
233
234#define BT_DEFAULT_POOL_SIZE 32768
235#define BT_DEFAULT_POOL_ELEMENT_SIZE 8
236
237// main allocator
238 class GIM_STANDARD_ALLOCATOR : public btGenericPoolAllocator
239{
240public:
241 GIM_STANDARD_ALLOCATOR() : btGenericPoolAllocator(BT_DEFAULT_POOL_ELEMENT_SIZE, BT_DEFAULT_POOL_SIZE)
242 {
243 }
244};
245
246// global allocator
247 GIM_STANDARD_ALLOCATOR g_main_allocator;
248
249 void *btPoolAlloc(size_t size)
250{
251 return g_main_allocator.allocate(size);
252}
253
254 void *btPoolRealloc(void *ptr, size_t oldsize, size_t newsize)
255{
256 void *newptr = btPoolAlloc(newsize);
257 size_t copysize = oldsize < newsize ? oldsize : newsize;
258 memcpy(newptr, ptr, copysize);
259 btPoolFree(ptr);
260 return newptr;
261}
262
263 void btPoolFree(void *ptr)
264{
265 g_main_allocator.freeMemory(ptr);
266}
btAlignedFree
#define btAlignedFree(ptr)
Definition: btAlignedAllocator.h:47
btAlignedAlloc
#define btAlignedAlloc(size, alignment)
Definition: btAlignedAllocator.h:46
size
static DBVT_INLINE btScalar size(const btDbvtVolume &a)
Definition: btDbvt.cpp:52
BT_DEFAULT_POOL_SIZE
#define BT_DEFAULT_POOL_SIZE
************** STANDARD ALLOCATOR ***************************‍///
Definition: btGenericPoolAllocator.cpp:234
g_main_allocator
GIM_STANDARD_ALLOCATOR g_main_allocator
Definition: btGenericPoolAllocator.cpp:247
btPoolRealloc
void * btPoolRealloc(void *ptr, size_t oldsize, size_t newsize)
Definition: btGenericPoolAllocator.cpp:254
btPoolAlloc
void * btPoolAlloc(size_t size)
Definition: btGenericPoolAllocator.cpp:249
BT_DEFAULT_POOL_ELEMENT_SIZE
#define BT_DEFAULT_POOL_ELEMENT_SIZE
Definition: btGenericPoolAllocator.cpp:235
btPoolFree
void btPoolFree(void *ptr)
Definition: btGenericPoolAllocator.cpp:263
btGenericPoolAllocator.h
BT_DEFAULT_MAX_POOLS
#define BT_DEFAULT_MAX_POOLS
Definition: btGenericPoolAllocator.h:30
BT_UINT_MAX
#define BT_UINT_MAX
Definition: btGenericPoolAllocator.h:29
GIM_STANDARD_ALLOCATOR
Definition: btGenericPoolAllocator.cpp:239
GIM_STANDARD_ALLOCATOR::GIM_STANDARD_ALLOCATOR
GIM_STANDARD_ALLOCATOR()
Definition: btGenericPoolAllocator.cpp:241
btGenericMemoryPool
Generic Pool class.
Definition: btGenericPoolAllocator.h:34
btGenericMemoryPool::m_free_nodes_count
size_t m_free_nodes_count
Definition: btGenericPoolAllocator.h:40
btGenericMemoryPool::get_element_data
void * get_element_data(size_t element_index)
Definition: btGenericPoolAllocator.h:89
btGenericMemoryPool::m_allocated_count
size_t m_allocated_count
Definition: btGenericPoolAllocator.h:39
btGenericMemoryPool::freeMemory
bool freeMemory(void *pointer)
Definition: btGenericPoolAllocator.cpp:130
btGenericMemoryPool::allocate_from_pool
size_t allocate_from_pool(size_t num_elements)
Definition: btGenericPoolAllocator.cpp:68
btGenericMemoryPool::init_pool
void init_pool(size_t element_size, size_t element_count)
Definition: btGenericPoolAllocator.cpp:80
btGenericMemoryPool::end_pool
void end_pool()
Definition: btGenericPoolAllocator.cpp:98
btGenericMemoryPool::m_allocated_sizes
size_t * m_allocated_sizes
Definition: btGenericPoolAllocator.h:38
btGenericMemoryPool::allocate_from_free_nodes
size_t allocate_from_free_nodes(size_t num_elements)
*************** btGenericMemoryPool ******************‍///////////
Definition: btGenericPoolAllocator.cpp:25
btGenericMemoryPool::m_free_nodes
size_t * m_free_nodes
Definition: btGenericPoolAllocator.h:37
btGenericMemoryPool::allocate
void * allocate(size_t size_bytes)
Allocates memory in pool.
Definition: btGenericPoolAllocator.cpp:111
btGenericMemoryPool::get_pool_capacity
size_t get_pool_capacity()
Definition: btGenericPoolAllocator.h:64
btGenericMemoryPool::m_max_element_count
size_t m_max_element_count
Definition: btGenericPoolAllocator.h:44
btGenericMemoryPool::m_pool
unsigned char * m_pool
Definition: btGenericPoolAllocator.h:36
btGenericMemoryPool::m_element_size
size_t m_element_size
Definition: btGenericPoolAllocator.h:43
btGenericPoolAllocator
Generic Allocator with pools.
Definition: btGenericPoolAllocator.h:108
btGenericPoolAllocator::m_pool_element_count
size_t m_pool_element_count
Definition: btGenericPoolAllocator.h:111
btGenericPoolAllocator::push_new_pool
btGenericMemoryPool * push_new_pool()
Definition: btGenericPoolAllocator.cpp:159
btGenericPoolAllocator::~btGenericPoolAllocator
virtual ~btGenericPoolAllocator()
*******************! btGenericPoolAllocator *******************!///
Definition: btGenericPoolAllocator.cpp:147
btGenericPoolAllocator::m_pool_count
size_t m_pool_count
Definition: btGenericPoolAllocator.h:115
btGenericPoolAllocator::freeMemory
bool freeMemory(void *pointer)
Definition: btGenericPoolAllocator.cpp:216
btGenericPoolAllocator::m_pools
btGenericMemoryPool * m_pools[BT_DEFAULT_MAX_POOLS]
Definition: btGenericPoolAllocator.h:114
btGenericPoolAllocator::failback_alloc
void * failback_alloc(size_t size_bytes)
Definition: btGenericPoolAllocator.cpp:173
btGenericPoolAllocator::failback_free
bool failback_free(void *pointer)
Definition: btGenericPoolAllocator.cpp:190
btGenericPoolAllocator::get_pool_capacity
size_t get_pool_capacity()
Definition: btGenericPoolAllocator.h:117
btGenericPoolAllocator::allocate
void * allocate(size_t size_bytes)
Allocates memory in pool.
Definition: btGenericPoolAllocator.cpp:200
btGenericPoolAllocator::m_pool_element_size
size_t m_pool_element_size
Definition: btGenericPoolAllocator.h:110