gum::SmallObjectAllocator Class Reference

<agrum/tools/core/smallObjectAllocator.h> More...

#include <smallObjectAllocator.h>

Collaboration diagram for gum::SmallObjectAllocator:

Public Member Functions
void	displayStats ()
	Displays the number of allocation and deallocation made so far. More...
Idx	nbAlloc ()
Idx	nbDealloc ()
Allocator / Deallocator
void *	allocate (const size_t &objectSize)
	Allocates a block. More...
void	deallocate (void *pDeallocatedObject, const size_t &objectSize)
	Deallocates an object. More...

Static Public Attributes
static const size_t	GUM_DEFAULT_CHUNK_SIZE = 8096
static const size_t	GUM_DEFAULT_MAX_OBJECT_SIZE = 512

Static Public Member Functions
static SmallObjectAllocator &	instance ()

Constructors / Destructors
	SmallObjectAllocator ()
	Constructor. More...
	SmallObjectAllocator (const SmallObjectAllocator &)
	Copy Constructor (does nothing since we use a Singleton) More...
SmallObjectAllocator &	operator= (const SmallObjectAllocator &)
	Operator = (does nothing since we use a Singleton) More...
virtual	~SmallObjectAllocator ()
	Destructor. More...

Detailed Description

<agrum/tools/core/smallObjectAllocator.h>

Allocates objects of any size

SmallObjectAllocator does so by aggregating several FixedAllocator objects. When SmallObjectAllocator receives an allocation request, it either forwards it to the best matching FixedAllocator object or passes it to the default operator new

Definition at line 55 of file smallObjectAllocator.h.

Member Typedef Documentation

_Pool_

typedef HashTable< Size, FixedAllocator* > gum::SmallObjectAllocator::_Pool_

private

The pool containing FixedAllocator.

Definition at line 139 of file smallObjectAllocator.h.

Constructor & Destructor Documentation

SmallObjectAllocator() [1/2]

INLINE gum::SmallObjectAllocator::SmallObjectAllocator ( )

private

Constructor.

Greater object than maxObjectSize will be forwarded to op new.

Definition at line 50 of file smallObjectAllocator_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                    :
      _chunkSize_(GUM_DEFAULT_CHUNK_SIZE), _maxObjectSize_(GUM_DEFAULT_MAX_OBJECT_SIZE) {
    _pool_.setKeyUniquenessPolicy(false);
    GUM_CONSTRUCTOR(SmallObjectAllocator);
    nbAllocation   = 0;
    nbDeallocation = 0;

    // SmallObjectAllocator::Instance will create a static SmallObjectAllocator and
    // a HashTable that will not be deleted ...
    // so we inform our leak detector not to count those 2 objects
    GUM_DESTRUCTOR(SmallObjectAllocator);
    GUM_DESTRUCTOR(HashTable);
  }

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SmallObjectAllocator() [2/2]

gum::SmallObjectAllocator::SmallObjectAllocator ( const SmallObjectAllocator &  )

inlineprivate

Copy Constructor (does nothing since we use a Singleton)

Definition at line 88 of file smallObjectAllocator.h.

{};

~SmallObjectAllocator()

INLINE gum::SmallObjectAllocator::~SmallObjectAllocator ( )

virtual

Destructor.

Definition at line 67 of file smallObjectAllocator_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                     {
    GUM_DESTRUCTOR(SmallObjectAllocator);
    for (_Pool_::iterator pit = _pool_.begin(); pit != _pool_.end(); ++pit)
      delete pit.val();
  }

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Member Function Documentation

allocate()

INLINE void * gum::SmallObjectAllocator::allocate

(

const size_t &

objectSize

)

Allocates a block.

Definition at line 86 of file smallObjectAllocator_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                                      {
    // Small Object Allocator called for an object of size equals to 0
    GUM_ASSERT(objectSize > 0);

    // If objectSize is greater than maxObjectSize, normal new is called
    if (objectSize > _maxObjectSize_) return new unsigned char[objectSize];

    void* ret;
#pragma omp critical(soa)
    {
      //
      if (!_pool_.exists(Size(objectSize))) {
        // Calcul du nombre de block par chunk pour des objets de cette taille
        std::size_t nb = _chunkSize_ / Size(objectSize);
        if (nb > UCHAR_MAX) nb = UCHAR_MAX;
        unsigned char numBlocks = static_cast< unsigned char >(nb);

        FixedAllocator* newFa = new FixedAllocator(Size(objectSize), numBlocks);
        _pool_.set(Size(objectSize), newFa);
      }
      nbAllocation++;

      ret = _pool_[Size(objectSize)]->allocate();
    }
    return ret;
  }

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deallocate()

INLINE void gum::SmallObjectAllocator::deallocate	(	void *	pDeallocatedObject,
		const size_t &	objectSize
	)

Deallocates an object.

Parameters

pDeallocatedObject	is the object to be deallocated
objectSize	is the size of that object (useful for faster deallocation)

Definition at line 119 of file smallObjectAllocator_inl.h.

References gum::Set< Key, Alloc >::emplace().

                                                                                                 {
    // Small Object Allocator called for an object of size equals to 0
    GUM_ASSERT(objectSize > 0);

    // If objectSize is greater than maxObjectSize, normal new is called
    if (objectSize > _maxObjectSize_) {
      delete[](unsigned char*) pDeallocatedObject;
      return;
    }

#pragma omp critical(soa)
    {
      //      std::cout << "Deallocating " << pDeallocatedObject << std::endl;
      _pool_[Size(objectSize)]->deallocate(pDeallocatedObject);
      nbDeallocation++;
    }
  }

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displayStats()

void gum::SmallObjectAllocator::displayStats ( )

inline

Displays the number of allocation and deallocation made so far.

Definition at line 127 of file smallObjectAllocator.h.

                        {
      GUM_TRACE("Nb Small Allocation : " << nbAllocation
                                         << " -  Nb Small Deallocation : " << nbDeallocation);
    }

instance()

INLINE SmallObjectAllocator & gum::SmallObjectAllocator::instance ( )

static

Definition at line 73 of file smallObjectAllocator_inl.h.

References gum::Set< Key, Alloc >::emplace().

Referenced by operator=().

                                                              {
    static SmallObjectAllocator soa;

    return soa;
  }

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nbAlloc()

Idx gum::SmallObjectAllocator::nbAlloc ( )

inline

Definition at line 132 of file smallObjectAllocator.h.

{ return nbAllocation; }

nbDealloc()

Idx gum::SmallObjectAllocator::nbDealloc ( )

inline

Definition at line 133 of file smallObjectAllocator.h.

{ return nbDeallocation; }

operator=()

SmallObjectAllocator& gum::SmallObjectAllocator::operator= ( const SmallObjectAllocator &  )

inlineprivate

Operator = (does nothing since we use a Singleton)

Definition at line 93 of file smallObjectAllocator.h.

References instance().

{ return instance(); }

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Member Data Documentation

_chunkSize_

std::size_t gum::SmallObjectAllocator::_chunkSize_

private

The memory that a chunk allocates.

Definition at line 145 of file smallObjectAllocator.h.

_maxObjectSize_

std::size_t gum::SmallObjectAllocator::_maxObjectSize_

private

The maximal size of an object befor new is called.

Definition at line 150 of file smallObjectAllocator.h.

_pool_

_Pool_ gum::SmallObjectAllocator::_pool_

private

Definition at line 140 of file smallObjectAllocator.h.

GUM_DEFAULT_CHUNK_SIZE

const size_t gum::SmallObjectAllocator::GUM_DEFAULT_CHUNK_SIZE = 8096

static

Parameters

The	default size of chunck of memory. These chuncks are pre-allocated memory space which are then split in small memory space of the size of a small object

Definition at line 62 of file smallObjectAllocator.h.

GUM_DEFAULT_MAX_OBJECT_SIZE

const size_t gum::SmallObjectAllocator::GUM_DEFAULT_MAX_OBJECT_SIZE = 512

static

Parameters

The	default maximal size under which an object is considered small. If an object size is over this limit, the normal new allocator is called.

Definition at line 69 of file smallObjectAllocator.h.

nbAllocation

Idx gum::SmallObjectAllocator::nbAllocation

private

Definition at line 152 of file smallObjectAllocator.h.

nbDeallocation

Idx gum::SmallObjectAllocator::nbDeallocation

private

Definition at line 153 of file smallObjectAllocator.h.

---

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

• agrum/tools/core/smallobjectallocator/smallObjectAllocator.h
• agrum/tools/core/smallobjectallocator/smallObjectAllocator.cpp
• agrum/tools/core/smallobjectallocator/smallObjectAllocator_inl.h