1 /*! \file btGenericPoolAllocator.cpp
2 \author Francisco Leon Najera. email projectileman@yahoo.com
4 General purpose allocator class
7 Bullet Continuous Collision Detection and Physics Library
8 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
10 This software is provided 'as-is', without any express or implied warranty.
11 In no event will the authors be held liable for any damages arising from the use of this software.
12 Permission is granted to anyone to use this software for any purpose,
13 including commercial applications, and to alter it and redistribute it freely,
14 subject to the following restrictions:
16 1. 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.
17 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
18 3. This notice may not be removed or altered from any source distribution.
21 #include "btGenericPoolAllocator.h"
25 /// *************** btGenericMemoryPool ******************///////////
27 size_t btGenericMemoryPool::allocate_from_free_nodes(size_t num_elements)
29 size_t ptr = BT_UINT_MAX;
31 if(m_free_nodes_count == 0) return BT_UINT_MAX;
32 // find an avaliable free node with the correct size
33 size_t revindex = m_free_nodes_count;
35 while(revindex-- && ptr == BT_UINT_MAX)
37 if(m_allocated_sizes[m_free_nodes[revindex]]>=num_elements)
42 if(ptr == BT_UINT_MAX) return BT_UINT_MAX; // not found
46 ptr = m_free_nodes[revindex];
47 // post: ptr contains the node index, and revindex the index in m_free_nodes
49 size_t finalsize = m_allocated_sizes[ptr];
50 finalsize -= num_elements;
52 m_allocated_sizes[ptr] = num_elements;
54 // post: finalsize>=0, m_allocated_sizes[ptr] has the requested size
56 if(finalsize>0) // preserve free node, there are some free memory
58 m_free_nodes[revindex] = ptr + num_elements;
59 m_allocated_sizes[ptr + num_elements] = finalsize;
61 else // delete free node
64 m_free_nodes[revindex] = m_free_nodes[m_free_nodes_count-1];
71 size_t btGenericMemoryPool::allocate_from_pool(size_t num_elements)
73 if(m_allocated_count+num_elements>m_max_element_count) return BT_UINT_MAX;
75 size_t ptr = m_allocated_count;
77 m_allocated_sizes[m_allocated_count] = num_elements;
78 m_allocated_count+=num_elements;
84 void btGenericMemoryPool::init_pool(size_t element_size, size_t element_count)
86 m_allocated_count = 0;
87 m_free_nodes_count = 0;
89 m_element_size = element_size;
90 m_max_element_count = element_count;
95 m_pool = (unsigned char *) btAlignedAlloc(m_element_size*m_max_element_count,16);
96 m_free_nodes = (size_t *) btAlignedAlloc(sizeof(size_t)*m_max_element_count,16);
97 m_allocated_sizes = (size_t *) btAlignedAlloc(sizeof(size_t)*m_max_element_count,16);
99 for (size_t i = 0;i< m_max_element_count;i++ )
101 m_allocated_sizes[i] = 0;
105 void btGenericMemoryPool::end_pool()
107 btAlignedFree(m_pool);
108 btAlignedFree(m_free_nodes);
109 btAlignedFree(m_allocated_sizes);
110 m_allocated_count = 0;
111 m_free_nodes_count = 0;
115 //! Allocates memory in pool
117 \param size_bytes size in bytes of the buffer
119 void * btGenericMemoryPool::allocate(size_t size_bytes)
122 size_t module = size_bytes%m_element_size;
123 size_t element_count = size_bytes/m_element_size;
124 if(module>0) element_count++;
126 size_t alloc_pos = allocate_from_free_nodes(element_count);
127 // a free node is found
128 if(alloc_pos != BT_UINT_MAX)
130 return get_element_data(alloc_pos);
132 // allocate directly on pool
133 alloc_pos = allocate_from_pool(element_count);
135 if(alloc_pos == BT_UINT_MAX) return NULL; // not space
136 return get_element_data(alloc_pos);
139 bool btGenericMemoryPool::freeMemory(void * pointer)
141 unsigned char * pointer_pos = (unsigned char *)pointer;
142 unsigned char * pool_pos = (unsigned char *)m_pool;
144 if(pointer_pos<pool_pos) return false;//other pool
145 size_t offset = size_t(pointer_pos - pool_pos);
146 if(offset>=get_pool_capacity()) return false;// far away
148 // find free position
149 m_free_nodes[m_free_nodes_count] = offset/m_element_size;
150 m_free_nodes_count++;
155 /// *******************! btGenericPoolAllocator *******************!///
158 btGenericPoolAllocator::~btGenericPoolAllocator()
162 for (i=0;i<m_pool_count;i++)
164 m_pools[i]->end_pool();
165 btAlignedFree(m_pools[i]);
171 btGenericMemoryPool * btGenericPoolAllocator::push_new_pool()
173 if(m_pool_count >= BT_DEFAULT_MAX_POOLS) return NULL;
175 btGenericMemoryPool * newptr = (btGenericMemoryPool *)btAlignedAlloc(sizeof(btGenericMemoryPool),16);
177 m_pools[m_pool_count] = newptr;
179 m_pools[m_pool_count]->init_pool(m_pool_element_size,m_pool_element_count);
185 void * btGenericPoolAllocator::failback_alloc(size_t size_bytes)
188 btGenericMemoryPool * pool = NULL;
191 if(size_bytes<=get_pool_capacity())
193 pool = push_new_pool();
196 if(pool==NULL) // failback
198 return btAlignedAlloc(size_bytes,16);
201 return pool->allocate(size_bytes);
204 bool btGenericPoolAllocator::failback_free(void * pointer)
206 btAlignedFree(pointer);
211 //! Allocates memory in pool
213 \param size_bytes size in bytes of the buffer
215 void * btGenericPoolAllocator::allocate(size_t size_bytes)
220 while(i<m_pool_count && ptr == NULL)
222 ptr = m_pools[i]->allocate(size_bytes);
228 return failback_alloc(size_bytes);
231 bool btGenericPoolAllocator::freeMemory(void * pointer)
236 while(i<m_pool_count && result == false)
238 result = m_pools[i]->freeMemory(pointer);
242 if(result) return true;
244 return failback_free(pointer);
247 /// ************** STANDARD ALLOCATOR ***************************///
250 #define BT_DEFAULT_POOL_SIZE 32768
251 #define BT_DEFAULT_POOL_ELEMENT_SIZE 8
254 class GIM_STANDARD_ALLOCATOR: public btGenericPoolAllocator
257 GIM_STANDARD_ALLOCATOR():btGenericPoolAllocator(BT_DEFAULT_POOL_ELEMENT_SIZE,BT_DEFAULT_POOL_SIZE)
263 GIM_STANDARD_ALLOCATOR g_main_allocator;
266 void * btPoolAlloc(size_t size)
268 return g_main_allocator.allocate(size);
271 void * btPoolRealloc(void *ptr, size_t oldsize, size_t newsize)
273 void * newptr = btPoolAlloc(newsize);
274 size_t copysize = oldsize<newsize?oldsize:newsize;
275 memcpy(newptr,ptr,copysize);
280 void btPoolFree(void *ptr)
282 g_main_allocator.freeMemory(ptr);