Overview

Allocator designed to allocate a single chunk at any given time.

This restriction allows the allocator to manage its chunk metadata directly, without relying on the metadata allocator.

Inheritance diagram for pw::multibuf::v1_adapter::internal::SingleChunkAllocator:

Public Member Functions
	SingleChunkAllocator (Allocator &metadata_allocator)

void	SetRegion (ByteSpan region)

Public Member Functions inherited from pw::multibuf::v1_adapter::internal::ChunkAllocator
constexpr Allocator &	metadata_allocator () const

constexpr size_t	alignment () const

constexpr size_t	available () const

constexpr ByteSpan	buffer () const

std::optional< OwnedChunk >	AllocateChunk (size_t min_size, size_t desired_size)

std::optional< OwnedChunk >	AllocateChunk (size_t size)

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

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args>
T *	New (Args &&... args)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_bounded_array_v< T >, int > = 0>
ElementType *	New ()

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
ElementType *	New (size_t count)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
ElementType *	New (size_t count, size_t alignment)
	Constructs an `alignment`-byte aligned array of `count` objects.

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args>
UniquePtr< T >	MakeUnique (Args &&... args)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique (size_t size)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique (size_t size, size_t alignment)

template<typename T , std::enable_if_t< is_bounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique ()

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0, typename... Args>
SharedPtr< T >	MakeShared (Args &&... args)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
SharedPtr< T >	MakeShared (size_t size)

template<typename T , std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
SharedPtr< T >	MakeShared (size_t size, size_t alignment)

template<typename T , std::enable_if_t< is_bounded_array_v< T >, int > = 0>
SharedPtr< T >	MakeShared ()

bool	Resize (void *ptr, size_t new_size)

void *	Reallocate (void *ptr, Layout new_layout)

size_t	GetAllocated () const

std::optional< Fragmentation >	MeasureFragmentation () const
	Returns fragmentation information for the allocator's memory region.

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

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

void	Deallocate (void *ptr)

template<typename ElementType >
void	DeleteArray (ElementType *ptr, size_t count)

StatusWithSize	GetCapacity () const

bool	IsEqual (const Deallocator &other) const

template<typename T , int &... kExplicitGuard, std::enable_if_t<!std::is_array_v< T >, int > = 0>
void	Delete (T *ptr)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_bounded_array_v< T >, int > = 0>
void	Delete (ElementType *ptr)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
void	Delete (ElementType *ptr, size_t count)

Protected Member Functions
constexpr bool	control_block_free () const

void	DeallocateControlBlock (void *ptr)
	Release the chunk shared pointer metadata.

void *	DoAllocate (Layout layout) override

void	DoDeallocate (void *ptr) override

Region *	AllocateRegion (size_t min_size, size_t desired_size) override

size_t	TryDeallocateRegion (void *ptr) override

virtual void	Destroy ()

Protected Member Functions inherited from pw::multibuf::v1_adapter::internal::ChunkAllocator
	PW_PACKED (struct) Region

	ChunkAllocator (Allocator &metadata_allocator, size_t alignment)

constexpr size_t	num_allocations () const

void	SetRegion (ByteSpan region)

void *	DoAllocate (allocator::Layout layout) override

void	DoDeallocate (void *ptr) override

Result< Layout >	DoGetInfo (InfoType info_type, const void *ptr) const override

virtual Region *	AllocateRegion (size_t min_size, size_t desired_size)=0

virtual size_t	TryDeallocateRegion (void *ptr)=0

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

constexpr	Allocator (const Capabilities &capabilities)

virtual void *	DoAllocate (Layout layout)=0

virtual bool	DoResize (void *ptr, size_t new_size)

virtual void *	DoReallocate (void *ptr, Layout new_layout)

virtual size_t	DoGetAllocated () const

virtual std::optional< Fragmentation >	DoMeasureFragmentation () const
	Returns fragmentation information for the allocator's memory region.

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

constexpr	Deallocator (const Capabilities &capabilities)

Result< Layout >	GetInfo (InfoType info_type, const void *ptr) const

Result< Layout >	GetRequestedLayout (const void *ptr) const

Result< Layout >	GetUsableLayout (const void *ptr) const

Result< Layout >	GetAllocatedLayout (const void *ptr) const

bool	Recognizes (const void *ptr) const

virtual void	DoDeallocate (void *ptr)=0

virtual Result< Layout >	DoGetInfo (InfoType, const void *) const

Additional Inherited Members
Public Types inherited from pw::Allocator
using	Fragmentation = allocator::Fragmentation

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

using	Capability = allocator::Capability

using	Layout = allocator::Layout

Protected Types inherited from pw::multibuf::v1_adapter::internal::ChunkAllocator
using	ControlBlock = allocator::internal::ControlBlock

Protected Types inherited from pw::Deallocator
enum class	InfoType { kRequestedLayoutOf , kUsableLayoutOf , kAllocatedLayoutOf , kCapacity , kRecognizes }

Static Protected Member Functions inherited from pw::Deallocator
static Result< Layout >	GetInfo (const Deallocator &deallocator, InfoType info_type, const void *ptr)

static Result< Layout >	GetRequestedLayout (const Deallocator &deallocator, const void *ptr)

static Result< Layout >	GetUsableLayout (const Deallocator &deallocator, const void *ptr)

static Result< Layout >	GetAllocatedLayout (const Deallocator &deallocator, const void *ptr)

static bool	Recognizes (const Deallocator &deallocator, const void *ptr)

Static Protected Attributes inherited from pw::Deallocator
template<typename T >
static constexpr bool	is_bounded_array_v = ::pw::is_bounded_array_v<T>

template<typename T >
static constexpr bool	is_unbounded_array_v = ::pw::is_unbounded_array_v<T>

Member Function Documentation

◆ AllocateRegion()

Region * pw::multibuf::v1_adapter::internal::SingleChunkAllocator::AllocateRegion	(	size_t	min_size,
		size_t	desired_size
	)

overrideprotectedvirtual

Returns a pointer to a region describing allocated memory of at least min_size and up to desired_size, or null if allocation failed.

Implements pw::multibuf::v1_adapter::internal::ChunkAllocator.

◆ Destroy()

virtual void pw::multibuf::v1_adapter::internal::SingleChunkAllocator::Destroy ( )

inlineprotectedvirtual

Destroys the ChunkRegionTracker.

Typical implementations will call std::destroy_at(this) and then free the memory associated with the region and the tracker.

Reimplemented in pw::multibuf::v1_adapter::SingleChunkRegionTracker.

◆ DoAllocate()

void * pw::multibuf::v1_adapter::internal::SingleChunkAllocator::DoAllocate ( Layout layout )

overrideprotectedvirtual

Allocates a block of memory with the specified size and alignment.

Returns nullptr if the allocation cannot be made, or the layout has a size of 0.

Parameters

[in] layout Describes the memory to be allocated.

Reimplemented from pw::multibuf::v1_adapter::internal::ChunkAllocator.

◆ DoDeallocate()

void pw::multibuf::v1_adapter::internal::SingleChunkAllocator::DoDeallocate ( void * ptr )

overrideprotectedvirtual

Releases a previously-allocated block of memory.

The given pointer must have been previously provided by this memory resource; otherwise the behavior is undefined.

Parameters

[in] ptr Pointer to previously-allocated memory.

Reimplemented from pw::multibuf::v1_adapter::internal::ChunkAllocator.

◆ SetRegion()

void pw::multibuf::v1_adapter::internal::ChunkAllocator::SetRegion ( ByteSpan region )

Sets the region used to provide chunks.

At most one region may be set by this method or a constructor.

◆ TryDeallocateRegion()

size_t pw::multibuf::v1_adapter::internal::SingleChunkAllocator::TryDeallocateRegion ( void * ptr )

overrideprotectedvirtual

Returns the number of bytes deallocated if the given pointer refers to memory described by a region previously returned by AllocateRegion, or 0 if it does not.

Implements pw::multibuf::v1_adapter::internal::ChunkAllocator.

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

pw_multibuf/v1_adapter/public/pw_multibuf/v1_adapter/internal/chunk_allocator.h

Overview

Public Member Functions

Protected Member Functions

Additional Inherited Members

Member Function Documentation

◆ AllocateRegion()

◆ Destroy()

◆ DoAllocate()

◆ DoDeallocate()

◆ SetRegion()

◆ TryDeallocateRegion()