84 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C++
		
	
	
	
		
		
			
		
	
	
			84 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C++
		
	
	
	
|  | /*
 | ||
|  | * Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
 | ||
|  | * | ||
|  | * This software is provided 'as-is', without any express or implied | ||
|  | * warranty.  In no event will the authors be held liable for any damages | ||
|  | * arising from the use of this software. | ||
|  | * Permission is granted to anyone to use this software for any purpose, | ||
|  | * including commercial applications, and to alter it and redistribute it | ||
|  | * freely, subject to the following restrictions: | ||
|  | * 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. | ||
|  | * 2. Altered source versions must be plainly marked as such, and must not be | ||
|  | * misrepresented as being the original software. | ||
|  | * 3. This notice may not be removed or altered from any source distribution. | ||
|  | */ | ||
|  | 
 | ||
|  | #include "Box2D/Common/b2StackAllocator.h"
 | ||
|  | #include "Box2D/Common/b2Math.h"
 | ||
|  | 
 | ||
|  | b2StackAllocator::b2StackAllocator() | ||
|  | { | ||
|  | 	m_index = 0; | ||
|  | 	m_allocation = 0; | ||
|  | 	m_maxAllocation = 0; | ||
|  | 	m_entryCount = 0; | ||
|  | } | ||
|  | 
 | ||
|  | b2StackAllocator::~b2StackAllocator() | ||
|  | { | ||
|  | 	b2Assert(m_index == 0); | ||
|  | 	b2Assert(m_entryCount == 0); | ||
|  | } | ||
|  | 
 | ||
|  | void* b2StackAllocator::Allocate(int32 size) | ||
|  | { | ||
|  | 	b2Assert(m_entryCount < b2_maxStackEntries); | ||
|  | 
 | ||
|  | 	b2StackEntry* entry = m_entries + m_entryCount; | ||
|  | 	entry->size = size; | ||
|  | 	if (m_index + size > b2_stackSize) | ||
|  | 	{ | ||
|  | 		entry->data = (char*)b2Alloc(size); | ||
|  | 		entry->usedMalloc = true; | ||
|  | 	} | ||
|  | 	else | ||
|  | 	{ | ||
|  | 		entry->data = m_data + m_index; | ||
|  | 		entry->usedMalloc = false; | ||
|  | 		m_index += size; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	m_allocation += size; | ||
|  | 	m_maxAllocation = b2Max(m_maxAllocation, m_allocation); | ||
|  | 	++m_entryCount; | ||
|  | 
 | ||
|  | 	return entry->data; | ||
|  | } | ||
|  | 
 | ||
|  | void b2StackAllocator::Free(void* p) | ||
|  | { | ||
|  | 	b2Assert(m_entryCount > 0); | ||
|  | 	b2StackEntry* entry = m_entries + m_entryCount - 1; | ||
|  | 	b2Assert(p == entry->data); | ||
|  | 	if (entry->usedMalloc) | ||
|  | 	{ | ||
|  | 		b2Free(p); | ||
|  | 	} | ||
|  | 	else | ||
|  | 	{ | ||
|  | 		m_index -= entry->size; | ||
|  | 	} | ||
|  | 	m_allocation -= entry->size; | ||
|  | 	--m_entryCount; | ||
|  | 
 | ||
|  | 	p = nullptr; | ||
|  | } | ||
|  | 
 | ||
|  | int32 b2StackAllocator::GetMaxAllocation() const | ||
|  | { | ||
|  | 	return m_maxAllocation; | ||
|  | } |