#include <dual_first_fit_block_allocator.h>

Public Types
using	Base = BlockAllocator< OffsetType, kPoisonInterval, kAlign >

using	BlockType = typename Base::BlockType

Public Types inherited from pw::allocator::BlockAllocator< OffsetType, kPoisonInterval, kAlign >
using	BlockType = Block< OffsetType, kAlign, kPoisonInterval !=0 >

using	Range = typename BlockType::Range

Public Types inherited from pw::Deallocator
using	Capabilities = allocator::Capabilities

using	Capability = allocator::Capability

using	Layout = allocator::Layout

Public Member Functions
constexpr	DualFirstFitBlockAllocator ()
	Constexpr constructor. Callers must explicitly call `Init`.

	DualFirstFitBlockAllocator (ByteSpan region, size_t threshold)

void	set_threshold (size_t threshold)
	Sets the threshold value for which requests are considered "large".

Public Member Functions inherited from pw::allocator::BlockAllocator< OffsetType, kPoisonInterval, kAlign >
constexpr	BlockAllocator ()
	Constexpr constructor. Callers must explicitly call `Init`.

	BlockAllocator (ByteSpan region)

Range	blocks () const
	Returns a `Range` of blocks tracking the memory of this allocator.

void	Init (ByteSpan region)

void	Init (BlockType *begin)

virtual void	Init (BlockType begin, BlockType end)

Fragmentation	MeasureFragmentation () const
	Returns fragmentation information for the block allocator's memory region.

void	Reset ()

Public Member Functions inherited from pw::allocator::internal::GenericBlockAllocator
	GenericBlockAllocator (const GenericBlockAllocator &)=delete

GenericBlockAllocator &	operator= (const GenericBlockAllocator &)=delete

	GenericBlockAllocator (GenericBlockAllocator &&)=delete

GenericBlockAllocator &	operator= (GenericBlockAllocator &&)=delete

Public Member Functions inherited from pw::Allocator
void *	Allocate (Layout layout)

template<typename T , int &... ExplicitGuard, typename... Args>
T *	New (Args &&... args)

template<typename T , int &... ExplicitGuard, typename... Args>
UniquePtr< T >	MakeUnique (Args &&... args)

bool	Resize (void *ptr, size_t new_size)

bool	Resize (void *ptr, Layout layout, size_t new_size)

void *	Reallocate (void *ptr, Layout new_layout)

void *	Reallocate (void *ptr, Layout old_layout, size_t new_size)

allocator::AsPmrAllocator	as_pmr ()

Public Member Functions inherited from pw::Deallocator
const Capabilities &	capabilities () const

bool	HasCapability (Capability capability) const
	Returns whether a given capabilityis enabled for this object.

void	Deallocate (void *ptr)

void	Deallocate (void *ptr, Layout layout)

template<typename T >
void	Delete (T *ptr)

StatusWithSize	GetCapacity () const

bool	IsEqual (const Deallocator &other) const

Additional Inherited Members
Static Public Attributes inherited from pw::allocator::internal::GenericBlockAllocator
static constexpr Capabilities	kCapabilities

Protected Types inherited from pw::allocator::BlockAllocator< OffsetType, kPoisonInterval, kAlign >
using	ReverseRange = typename BlockType::ReverseRange

Protected Member Functions inherited from pw::allocator::BlockAllocator< OffsetType, kPoisonInterval, kAlign >
ReverseRange	rblocks ()

template<typename PtrType , typename BlockPtrType = std::conditional_t< std::is_const_v<std::remove_pointer_t<PtrType>>, const BlockType, BlockType>>
Result< BlockPtrType >	FromUsableSpace (PtrType ptr) const

virtual void	ReserveBlock (BlockType *)

virtual void	RecycleBlock (BlockType *)

Protected Member Functions inherited from pw::Allocator
constexpr	Allocator ()=default
	TODO(b/326509341): Remove when downstream consumers migrate.

constexpr	Allocator (const Capabilities &capabilities)

Protected Member Functions inherited from pw::Deallocator
constexpr	Deallocator ()=default
	TODO(b/326509341): Remove when downstream consumers migrate.

constexpr	Deallocator (const Capabilities &capabilities)

template<typename T >
UniquePtr< T >	WrapUnique (T *ptr)

Static Protected Member Functions inherited from pw::allocator::internal::GenericBlockAllocator
static void	CrashOnAllocated (void *allocated)

static void	CrashOnInvalidFree (void *freed)

static void	CrashOnDoubleFree (void *freed)
	Crashes with an informational message that a given block was freed twice.

Detailed Description

template<typename OffsetType = uintptr_t, size_t kPoisonInterval = 0, size_t kAlign = alignof(OffsetType)>
class pw::allocator::DualFirstFitBlockAllocator< OffsetType, kPoisonInterval, kAlign >

Block allocator that uses a "dual first-fit" allocation strategy split between large and small allocations.

In this strategy, the strategy includes a threshold value. Requests for more than this threshold are handled similarly to FirstFit, while requests for less than this threshold are handled similarly to LastFit.

This algorithm approaches the performance of FirstFit and LastFit while improving on those algorithms fragmentation.

Constructor & Destructor Documentation

◆ DualFirstFitBlockAllocator()

template<typename OffsetType = uintptr_t, size_t kPoisonInterval = 0, size_t kAlign = alignof(OffsetType)>

pw::allocator::DualFirstFitBlockAllocator< OffsetType, kPoisonInterval, kAlign >::DualFirstFitBlockAllocator	(	ByteSpan	region,
		size_t	threshold
	)

inline

Non-constexpr constructor that automatically calls Init.

Parameters

[in] region Region of memory to use when satisfying allocation requests. The region MUST be large enough to fit an aligned block with overhead. It MUST NOT be larger than what is addressable by OffsetType.

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

/b/s/w/ir/x/w/co/pw_allocator/public/pw_allocator/dual_first_fit_block_allocator.h

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ DualFirstFitBlockAllocator()