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 61