Box2D: /build/box2d/src/box2d-adaedf1772ede7420bc9ee569c8cba7952db91a0/include/box2d/b2_stack_allocator.h Source File

| Box2D 2.4.0 A 2D physics engine for games

b2_stack_allocator.h
1 // MIT License
2
3 // Copyright (c) 2019 Erin Catto
4
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
11
12 // The above copyright notice and this permission notice shall be included in all
13 // copies or substantial portions of the Software.
14
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 // SOFTWARE.
22
23 #ifndef B2_STACK_ALLOCATOR_H
24 #define B2_STACK_ALLOCATOR_H
25
26 #include "b2_api.h"
27 #include "b2_settings.h"
28
29 const int32 b2_stackSize = 100 * 1024; // 100k
30 const int32 b2_maxStackEntries = 32;
31
32 struct B2_API b2StackEntry
33 {
34 char* data;
35 int32 size;
36 bool usedMalloc;
37 };
38
39 // This is a stack allocator used for fast per step allocations.
40 // You must nest allocate/free pairs. The code will assert
41 // if you try to interleave multiple allocate/free pairs.
42 class B2_API b2StackAllocator
43 {
44 public:
45 b2StackAllocator();
46 ~b2StackAllocator();
47
48 void* Allocate(int32 size);
49 void Free(void* p);
50
51 int32 GetMaxAllocation() const;
52
53 private:
54
55 char m_data[b2_stackSize];
56 int32 m_index;
57
58 int32 m_allocation;
59 int32 m_maxAllocation;
60
61 b2StackEntry m_entries[b2_maxStackEntries];
62 int32 m_entryCount;
63 };
64
65 #endif
b2_settings.h
b2StackAllocator
Definition: b2_stack_allocator.h:43
b2StackEntry
Definition: b2_stack_allocator.h:33