Dune::Pool< T, s > Class Template Reference

A memory pool of objects. More...

#include <dune/common/poolallocator.hh>

Inheritance diagram for Dune::Pool< T, s >:

Public Types
typedef T	MemberType
	The type of object we allocate memory for.

Public Member Functions
	Pool ()
	Constructor.
	~Pool ()
	Destructor.
void *	allocate ()
	Get a new or recycled object.
void	free (void *o)
	Free an object.
void	print (std::ostream &os)
	Print elements in pool for debugging.

Static Public Attributes
static constexpr int	unionSize
	The size of a union of Reference and MemberType.
static constexpr int	size
	Size requirement. At least one object has to stored.
static constexpr int	alignment = std::lcm(alignof(MemberType), alignof(Reference))
	The alignment that suits both the MemberType and the Reference (i.e. their least common multiple).
static constexpr int	alignedSize
	The aligned size of the type.
static constexpr int	chunkSize
	The size of each chunk memory chunk.
static constexpr int	elements = (chunkSize / alignedSize)
	The number of element each chunk can hold.

Detailed Description

template<class T, std::size_t s>
class Dune::Pool< T, s >

A memory pool of objects.

The memory for the objects is organized in chunks. Each chunks is capable of holding a specified number of objects. The allocated objects will be properly aligned for fast access. Deallocated objects are cached for reuse to prevent memory fragmentation.

Warning

If the size of the objects allocated is less than the size of a pointer memory is wasted.

Due to aligned issues at the number of bytes of the alignment prerequisite (< 4 bytes) are wasted. This effect becomes negligible for big sizes of chunkSize.

Template Parameters

T	The type that is allocated by us.
s	The size of a memory chunk in bytes.

Member Typedef Documentation

MemberType

template<class T, std::size_t s>

typedef T Dune::Pool< T, s >::MemberType

The type of object we allocate memory for.

Member Data Documentation

alignedSize

template<class T, std::size_t s>

int Dune::Pool< T, s >::alignedSize

staticconstexpr

Initial value:

= (unionSize % alignment == 0) ?
                                        unionSize :
                                        ((unionSize / alignment + 1) * alignment)

The aligned size of the type.

This size is bigger than sizeof of the type and a multiple of the alignment requirement.

alignment

template<class T, std::size_t s>

int Dune::Pool< T, s >::alignment = std::lcm(alignof(MemberType), alignof(Reference))

staticconstexpr

The alignment that suits both the MemberType and the Reference (i.e. their least common multiple).

chunkSize

template<class T, std::size_t s>

int Dune::Pool< T, s >::chunkSize

staticconstexpr

Initial value:

= (size % alignment == 0) ?
                                      size : ((size / alignment + 1)* alignment)

The size of each chunk memory chunk.

Will be adapted to be a multiple of the alignment

elements

template<class T, std::size_t s>

int Dune::Pool< T, s >::elements = (chunkSize / alignedSize)

staticconstexpr

The number of element each chunk can hold.

size

template<class T, std::size_t s>

int Dune::Pool< T, s >::size

staticconstexpr

Initial value:

= (sizeof(MemberType) <= s && sizeof(Reference) <= s) ?
                                 s : unionSize

Size requirement. At least one object has to stored.

unionSize

template<class T, std::size_t s>

int Dune::Pool< T, s >::unionSize

staticconstexpr

Initial value:

= (sizeof(MemberType) < sizeof(Reference)) ?
                                      sizeof(Reference) : sizeof(MemberType)

The size of a union of Reference and MemberType.

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

• poolallocator.hh