Arena Class Reference

An arena manages a contiguous region of memory by dividing it into chunks. More...

#include <lockedpool.h>

Inheritance diagram for Arena:

Classes
struct	Stats
	Memory statistics. More...

Public Member Functions
	Arena (void *base, size_t size, size_t alignment)
virtual	~Arena ()
	Arena (const Arena &other)=delete
Arena &	operator= (const Arena &)=delete
void *	alloc (size_t size)
	Allocate size bytes from this arena.
void	free (void *ptr)
	Free a previously allocated chunk of memory.
Stats	stats () const
	Get arena usage statistics.
bool	addressInArena (void *ptr) const
	Return whether a pointer points inside this arena.

Private Types
typedef std::multimap< size_t, char * >	SizeToChunkSortedMap
typedef std::unordered_map< char *, SizeToChunkSortedMap::const_iterator >	ChunkToSizeMap

Private Attributes
SizeToChunkSortedMap	size_to_free_chunk
	Map to enable O(log(n)) best-fit allocation, as it's sorted by size.
ChunkToSizeMap	chunks_free
	Map from begin of free chunk to its node in size_to_free_chunk.
ChunkToSizeMap	chunks_free_end
	Map from end of free chunk to its node in size_to_free_chunk.
std::unordered_map< char *, size_t >	chunks_used
	Map from begin of used chunk to its size.
char *	base
	Base address of arena.
char *	end
	End address of arena.
size_t	alignment
	Minimum chunk alignment.

Detailed Description

An arena manages a contiguous region of memory by dividing it into chunks.

Definition at line 50 of file lockedpool.h.

Member Typedef Documentation

ChunkToSizeMap

typedef std::unordered_map<char *, SizeToChunkSortedMap::const_iterator> Arena::ChunkToSizeMap

private

Definition at line 101 of file lockedpool.h.

SizeToChunkSortedMap

typedef std::multimap<size_t, char *> Arena::SizeToChunkSortedMap

private

Definition at line 96 of file lockedpool.h.

Constructor & Destructor Documentation

Arena() [1/2]

Arena::Arena	(	void *	base,
		size_t	size,
		size_t	alignment
	)

Definition at line 46 of file lockedpool.cpp.

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~Arena()

Arena::~Arena ( )

virtual

Definition at line 55 of file lockedpool.cpp.

Arena() [2/2]

Arena::Arena ( const Arena &  other )

delete

Member Function Documentation

addressInArena()

bool Arena::addressInArena ( void *  ptr ) const

inline

Return whether a pointer points inside this arena.

This returns base <= ptr < (base+size) so only use it for (inclusive) chunk starting addresses.

Definition at line 93 of file lockedpool.h.

alloc()

void * Arena::alloc

(

size_t

size

)

Allocate size bytes from this arena.

Returns pointer on success, or 0 if memory is full or the application tried to allocate 0 bytes.

Definition at line 57 of file lockedpool.cpp.

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free()

void Arena::free

(

void *

ptr

)

Free a previously allocated chunk of memory.

Freeing the zero pointer has no effect. Raises std::runtime_error in case of error.

Definition at line 98 of file lockedpool.cpp.

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operator=()

Arena & Arena::operator= ( const Arena &  )

delete

stats()

Arena::Stats Arena::stats

(

)

const

Get arena usage statistics.

Definition at line 135 of file lockedpool.cpp.

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Member Data Documentation

alignment

size_t Arena::alignment

private

Minimum chunk alignment.

Definition at line 115 of file lockedpool.h.

base

char* Arena::base

private

Base address of arena.

Definition at line 111 of file lockedpool.h.

chunks_free

ChunkToSizeMap Arena::chunks_free

private

Map from begin of free chunk to its node in size_to_free_chunk.

Definition at line 103 of file lockedpool.h.

chunks_free_end

ChunkToSizeMap Arena::chunks_free_end

private

Map from end of free chunk to its node in size_to_free_chunk.

Definition at line 105 of file lockedpool.h.

chunks_used

std::unordered_map<char *, size_t> Arena::chunks_used

private

Map from begin of used chunk to its size.

Definition at line 108 of file lockedpool.h.

end

char* Arena::end

private

End address of arena.

Definition at line 113 of file lockedpool.h.

size_to_free_chunk

SizeToChunkSortedMap Arena::size_to_free_chunk

private

Map to enable O(log(n)) best-fit allocation, as it's sorted by size.

Definition at line 98 of file lockedpool.h.

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

• src/support/lockedpool.h
• src/support/lockedpool.cpp