Box2D: b2StackAllocator.h Source File

| Box2D 2.3.0 A 2D Physics Engine for Games

b2StackAllocator.h
1 /*
2 * Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
3 *
4 * This software is provided 'as-is', without any express or implied
5 * warranty. In no event will the authors be held liable for any damages
6 * arising from the use of this software.
7 * Permission is granted to anyone to use this software for any purpose,
8 * including commercial applications, and to alter it and redistribute it
9 * freely, subject to the following restrictions:
10 * 1. The origin of this software must not be misrepresented; you must not
11 * claim that you wrote the original software. If you use this software
12 * in a product, an acknowledgment in the product documentation would be
13 * appreciated but is not required.
14 * 2. Altered source versions must be plainly marked as such, and must not be
15 * misrepresented as being the original software.
16 * 3. This notice may not be removed or altered from any source distribution.
17 */
18
19 #ifndef B2_STACK_ALLOCATOR_H
20 #define B2_STACK_ALLOCATOR_H
21
22 #include <Box2D/Common/b2Settings.h>
23
24 const int32 b2_stackSize = 100 * 1024; // 100k
25 const int32 b2_maxStackEntries = 32;
26
27 struct b2StackEntry
28 {
29 char* data;
30 int32 size;
31 bool usedMalloc;
32 };
33
34 // This is a stack allocator used for fast per step allocations.
35 // You must nest allocate/free pairs. The code will assert
36 // if you try to interleave multiple allocate/free pairs.
37 class b2StackAllocator
38 {
39 public:
40 b2StackAllocator();
41 ~b2StackAllocator();
42
43 void* Allocate(int32 size);
44 void Free(void* p);
45
46 int32 GetMaxAllocation() const;
47
48 private:
49
50 char m_data[b2_stackSize];
51 int32 m_index;
52
53 int32 m_allocation;
54 int32 m_maxAllocation;
55
56 b2StackEntry m_entries[b2_maxStackEntries];
57 int32 m_entryCount;
58 };
59
60 #endif
b2StackAllocator
Definition: b2StackAllocator.h:37
b2StackEntry
Definition: b2StackAllocator.h:27
b2Settings.h