ParaEngine::Pool_Char_alloc< T, UserAllocator > Class Template Reference

This class can be used as a custom allocator for stl containers, which constantly create and delete small or medium sized objects. More...

#include <ParaMemPool.h>

Classes
struct	rebind
struct	SingletonMemPool_Type

Public Types
typedef T	value_type
typedef UserAllocator	user_allocator
typedef value_type *	pointer
typedef const value_type *	const_pointer
typedef value_type &	reference
typedef const value_type &	const_reference
typedef boost::pool< UserAllocator >	pool_type
typedef pool_type::size_type	size_type
typedef pool_type::difference_type	difference_type

Public Member Functions
	Pool_Char_alloc (Pool_Char_alloc const &)
template<typename U >
	Pool_Char_alloc (const Pool_Char_alloc< U, UserAllocator > &)
pointer	address (reference r)
const_pointer	address (const_reference r)
size_type	max_size () const
pointer	allocate (size_type cnt, typename std::allocator< void >::const_pointer=0)
void	deallocate (pointer ptr, size_type cnt)
void	construct (pointer p, const T &t)
void	destroy (pointer p)
bool	operator== (Pool_Char_alloc const &)
bool	operator!= (Pool_Char_alloc const &a)

Static Public Attributes
static const int	char_pool_init_size_bytes = 32
	the initial smallest fixed sized chunk that the memory pool will create. More...
static const int	char_pool_init_size = 5
	this should be log2(char_pool_init_size_bytes)
static const int	char_pool_count = 7
	how many free lists are there in the pool. More...
static SingletonMemPool_Type	s_mem_pools
	predefined memory pool (free lists)

Detailed Description

template<typename T, typename UserAllocator>
class ParaEngine::Pool_Char_alloc< T, UserAllocator >

This class can be used as a custom allocator for stl containers, which constantly create and delete small or medium sized objects.

it is optimized for frequently used temporary objects. it is faster than std::allocator and boost::pool_alloc. But it costs more (double at most) memory than boost::pool_alloc, because we may return more memory than requested.

Internally, it has 7 free lists (boost::pool). Each free list only serves one fixed-sized object at a time. Each pool has their own light weighted locks for thread-safe access. The free list sizes are 32,64,128,256,512,1024,2048; we will use the default allocator for sizes over 2048. One can configure the internal freelists by editing the macro char_pool_init_size_bytes, char_pool_init_size, char_pool_count

[NOT thread safe]: for a thread safe implementation, refer to CNPLPool_Char_alloc in NPLMemPool.h Example: typedef std::list<void*, Pool_Char_alloc<void*> > MyList;

Member Data Documentation

char_pool_count

template<typename T , typename UserAllocator >

const int ParaEngine::Pool_Char_alloc< T, UserAllocator >::char_pool_count = 7

static

how many free lists are there in the pool.

char_pool_init_size_bytes^2 is the biggest chunk. currently it is 2048 bytes

char_pool_init_size_bytes

template<typename T , typename UserAllocator >

const int ParaEngine::Pool_Char_alloc< T, UserAllocator >::char_pool_init_size_bytes = 32

static

the initial smallest fixed sized chunk that the memory pool will create.

default to 32 bytes

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The documentation for this class was generated from the following file:

• Client/trunk/ParaEngineClient/util/ParaMemPool.h