Bullet Collision Detection & Physics Library
btPoolAllocator.h
Go to the documentation of this file.
1 /*
2 Copyright (c) 2003-2006 Gino van den Bergen / Erwin Coumans http://continuousphysics.com/Bullet/
3 
4 This software is provided 'as-is', without any express or implied warranty.
5 In no event will the authors be held liable for any damages arising from the use of this software.
6 Permission is granted to anyone to use this software for any purpose,
7 including commercial applications, and to alter it and redistribute it freely,
8 subject to the following restrictions:
9 
10 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.
11 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
12 3. This notice may not be removed or altered from any source distribution.
13 */
14 
15 #ifndef _BT_POOL_ALLOCATOR_H
16 #define _BT_POOL_ALLOCATOR_H
17 
18 #include "btScalar.h"
19 #include "btAlignedAllocator.h"
20 #include "btThreads.h"
21 
24 {
28  void* m_firstFree;
29  unsigned char* m_pool;
30  btSpinMutex m_mutex; // only used if BT_THREADSAFE
31 
32 public:
33  btPoolAllocator(int elemSize, int maxElements)
34  : m_elemSize(elemSize),
35  m_maxElements(maxElements)
36  {
37  m_pool = (unsigned char*)btAlignedAlloc(static_cast<unsigned int>(m_elemSize * m_maxElements), 16);
38 
39  unsigned char* p = m_pool;
40  m_firstFree = p;
42  int count = m_maxElements;
43  while (--count)
44  {
45  *(void**)p = (p + m_elemSize);
46  p += m_elemSize;
47  }
48  *(void**)p = 0;
49  }
50 
52  {
54  }
55 
56  int getFreeCount() const
57  {
58  return m_freeCount;
59  }
60 
61  int getUsedCount() const
62  {
63  return m_maxElements - m_freeCount;
64  }
65 
66  int getMaxCount() const
67  {
68  return m_maxElements;
69  }
70 
71  void* allocate(int size)
72  {
73  // release mode fix
74  (void)size;
76  btAssert(!size || size <= m_elemSize);
77  //btAssert(m_freeCount>0); // should return null if all full
78  void* result = m_firstFree;
79  if (NULL != m_firstFree)
80  {
81  m_firstFree = *(void**)m_firstFree;
82  --m_freeCount;
83  }
85  return result;
86  }
87 
88  bool validPtr(void* ptr)
89  {
90  if (ptr)
91  {
92  if (((unsigned char*)ptr >= m_pool && (unsigned char*)ptr < m_pool + m_maxElements * m_elemSize))
93  {
94  return true;
95  }
96  }
97  return false;
98  }
99 
100  void freeMemory(void* ptr)
101  {
102  if (ptr)
103  {
104  btAssert((unsigned char*)ptr >= m_pool && (unsigned char*)ptr < m_pool + m_maxElements * m_elemSize);
105 
107  *(void**)ptr = m_firstFree;
108  m_firstFree = ptr;
109  ++m_freeCount;
111  }
112  }
113 
114  int getElementSize() const
115  {
116  return m_elemSize;
117  }
118 
119  unsigned char* getPoolAddress()
120  {
121  return m_pool;
122  }
123 
124  const unsigned char* getPoolAddress() const
125  {
126  return m_pool;
127  }
128 };
129 
130 #endif //_BT_POOL_ALLOCATOR_H
#define btAlignedFree(ptr)
#define btAlignedAlloc(size, alignment)
static DBVT_INLINE btScalar size(const btDbvtVolume &a)
Definition: btDbvt.cpp:52
#define btAssert(x)
Definition: btScalar.h:153
void btMutexLock(btSpinMutex *mutex)
Definition: btThreads.h:70
void btMutexUnlock(btSpinMutex *mutex)
Definition: btThreads.h:79
The btPoolAllocator class allows to efficiently allocate a large pool of objects, instead of dynamica...
btPoolAllocator(int elemSize, int maxElements)
void freeMemory(void *ptr)
int getElementSize() const
bool validPtr(void *ptr)
unsigned char * getPoolAddress()
int getFreeCount() const
btSpinMutex m_mutex
int getMaxCount() const
const unsigned char * getPoolAddress() const
int getUsedCount() const
void * allocate(int size)
unsigned char * m_pool
btSpinMutex – lightweight spin-mutex implemented with atomic ops, never puts a thread to sleep becaus...
Definition: btThreads.h:46