Bit memory allocator. More...

#include <BitAllocator.h>

Inheritance diagram for BitAllocator:

Public Member Functions
	BitAllocator (const Range range, const Size chunkSize, u8 *bitmap=ZERO)
	Constructor function. More...

Size	chunkSize () const
	Get chunk size. More...

virtual Size	available () const
	Get available memory. More...

virtual Result	allocate (Range &args)
	Allocate memory. More...

Result	allocateFrom (Range &args, const Size startBit)
	Allocate memory from defined starting address. More...

Result	allocateAt (const Address addr)
	Allocate a specific address. More...

bool	isAllocated (const Address page) const
	Check if a chunk is allocated. More...

virtual Result	release (const Address chunk)
	Release memory chunk. More...

Public Member Functions inherited from Allocator
	Allocator ()
	Default class constructor. More...

	Allocator (const Range range)
	Class constructor with Range input. More...

virtual	~Allocator ()
	Class destructor. More...

void	setParent (Allocator *parent)
	Set parent allocator. More...

Allocator *	parent ()
	Get parent Allocator. More...

Address	base () const
	Get memory base address for allocations. More...

Size	alignment () const
	Get memory alignment in bytes for allocations. More...

virtual Size	size () const
	Get memory size. More...

Private Attributes
BitArray	m_array
	Marks which chunks are (un)used. More...

const Size	m_chunkSize
	Size of each chunk. More...

Size	m_lastBit
	Last bit that was set. More...

Additional Inherited Members
Public Types inherited from Allocator
enum	Result { Success = 0, InvalidAddress, InvalidSize, InvalidAlignment, OutOfMemory }
	Allocation results. More...

typedef struct Allocator::Range	Range
	Describes a range of memory. More...

Static Public Member Functions inherited from Allocator
static void	setDefault (Allocator *alloc)
	Makes the given Allocator the default. More...

static Allocator *	getDefault ()
	Retrieve the currently default Allocator. More...

Protected Member Functions inherited from Allocator
Address	aligned (const Address addr, const Size boundary) const
	Align memory address. More...

Detailed Description

Bit memory allocator.

Allocates memory by using a BitArray. All memory is divided in same sized parts called chunks. 1 in the BitArray means the chunk is used, 0 means unused.

Definition at line 40 of file BitAllocator.h.

Constructor & Destructor Documentation

◆ BitAllocator()

BitAllocator::BitAllocator	(	const Range	range,
		const Size	chunkSize,
		u8 *	bitmap = `ZERO`
	)

Constructor function.

Parameters

range	Block of continguous memory to manage.
chunkSize	The input memory range will be divided into equally sized chunks. The chunkSize must be greater than zero.
bitmap	Pointer to existing bitmap array or ZERO to allocate new.

Definition at line 21 of file BitAllocator.cpp.

Member Function Documentation

◆ allocate()

Allocator::Result BitAllocator::allocate ( Allocator::Range & args )

virtual

Allocate memory.

Parameters

args	Contains the requested size and alignment on input. The alignment value must be a multiple of the chunk size. On output, contains the actual allocated address.

Returns: Result value.

Reimplemented from Allocator.

Definition at line 41 of file BitAllocator.cpp.

References allocateFrom(), m_lastBit, and Allocator::OutOfMemory.

Referenced by SplitAllocator::allocate().

◆ allocateAt()

Allocator::Result BitAllocator::allocateAt ( const Address addr )

Allocate a specific address.

Parameters

addr	Allocate a specific address.

Returns: Result value.

Definition at line 80 of file BitAllocator.cpp.

References assert, Allocator::base(), isAllocated(), m_array, m_chunkSize, BitArray::set(), and Allocator::Success.

Referenced by SplitAllocator::allocate().

◆ allocateFrom()

Allocator::Result BitAllocator::allocateFrom	(	Allocator::Range &	args,
		const Size	startBit
	)

Allocate memory from defined starting address.

Parameters

args	Contains the requested size and alignment on input. The alignment value must be a multiple of the chunk size. On output, contains the actual allocated address.
startBit	Bit position in the bitmap array to start searching at.