cds::intrusive::TaggedFreeList Class Reference

Lock-free free list based on tagged pointers (required double-width CAS) More...

#include <cds/intrusive/free_list_tagged.h>

Data Structures
struct	node

Public Member Functions
	TaggedFreeList ()
	Creates empty free-list.
	~TaggedFreeList ()
	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...

Detailed Description

Lock-free free list based on tagged pointers (required double-width CAS)

This variant of FreeList is intended for processor architectures that support double-width CAS. It uses tagged pointer technique to solve ABA problem.

How to use

#include <cds/intrusive/free_list_tagged.h>

// Your struct should be derived from TaggedFreeList::node
struct Foo: public cds::intrusive::TaggedFreeList::node
{
    // Foo fields
};

// Simplified Foo allocator
class FooAllocator
{
public:
    // free-list clear() must be explicitly called before destroying the free-list object
    ~FooAllocator()
    {
        m_FreeList.clear( []( freelist_node * p ) { delete static_cast<Foo *>( p ); });
    }

    Foo * alloc()
    {
        freelist_node * p = m_FreeList.get();
        if ( p )
            return static_cast<Foo *>( p );
        return new Foo;
    };

    void dealloc( Foo * p )
    {
        m_FreeList.put( static_cast<freelist_node *>( p ));
    };

private:
    typedef cds::intrusive::TaggedFreeList::node freelist_node;
    cds::intrusive::TaggedFreeList m_FreeList;
};

Constructor & Destructor Documentation

~TaggedFreeList()

cds::intrusive::TaggedFreeList::~TaggedFreeList ( )

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 Disposer >

void cds::intrusive::TaggedFreeList::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.

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

• cds/intrusive/free_list_tagged.h