Cached free list. More...

#include <cds/intrusive/free_list_cached.h>

Public Types
typedef FreeList	free_list_type
	Undelying free-list type.

typedef free_list_type::node	node
	Free-list node.

Public Member Functions
	CachedFreeList ()
	Creates empty free list.

	~CachedFreeList ()
	Destroys the free list. Free-list must be empty. More...

void	put (node *pNode)
	Puts `pNode` to the free list.

node *	get ()
	Gets a node from the free list. If the list is empty, returns `nullptr`.

bool	empty () const
	Checks whether the free list is empty.

template<typename Disposer >
void	clear (Disposer disp)
	Clears the free list (not atomic) More...

Static Public Attributes
static size_t const	c_cache_size = CacheSize
	Cache size.

static unsigned const	c_padding = Padding
	Cache element padding.

Detailed Description

template<typename FreeList, size_t CacheSize = 16, unsigned Padding = cds::c_nCacheLineSize>
class cds::intrusive::CachedFreeList< FreeList, CacheSize, Padding >

Cached free list.

The class that is a wrapper over other FreeList contains a small cache of free elements. Before placing a new item into underlying FreeList the cached free-list tryes to put that item into the cache if its corresponding slot is empty. The slot is calculated by current thread id:

int slot = std::hash<std::thread::id>()( std::this_thread::get_id()) & (CacheSize - 1);

When getting the free-list checks the corresponding cache slot. If it is not empty, its contents is returned.

In some cases such simple algorithm significantly reduces FreeList contention.

Template parameters:

FreeList - a free-list implementation: FreeList, TaggedFreeList
CacheSize - size of cache, a small power-of-two number, default is 16
Padding - padding of cache elements for solving false sharing, default is cds::c_nCacheLineSize

Constructor & Destructor Documentation

◆ ~CachedFreeList()

template<typename FreeList , size_t CacheSize = 16, unsigned Padding = cds::c_nCacheLineSize>

cds::intrusive::CachedFreeList< FreeList, CacheSize, Padding >::~CachedFreeList ( )

inline

Destroys the free list. Free-list must be empty.

Warning: dtor does not free elements of the list. To free elements you should manually call clear() with an appropriate disposer.

Member Function Documentation

◆ clear()

template<typename FreeList , size_t CacheSize = 16, unsigned Padding = cds::c_nCacheLineSize>

template<typename Disposer >

void cds::intrusive::CachedFreeList< FreeList, CacheSize, Padding >::clear ( Disposer disp )

inline

Clears the free list (not atomic)

For each element disp disposer is called to free memory. The Disposer interface:

struct disposer
{
    void operator()( FreeList::node * node );
};

This method must be explicitly called before the free list destructor.

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

cds/intrusive/free_list_cached.h

Public Types

Public Member Functions