#include <block_allocator.h>

Inheritance diagram for pw::allocator::BlockAllocator< BlockType_ >:

Public Types
using	BlockType = BlockType_

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

void	Init (ByteSpan region)

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

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

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)

template<typename T >
T *	NewArray (size_t count)

template<typename T >
T *	NewArray (size_t count, size_t alignment)

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 , int &... kExplicitGuard, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique (size_t size)

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

template<typename T >
UniquePtr< T[]>	MakeUniqueArray (size_t size)

template<typename T >
UniquePtr< T[]>	MakeUniqueArray (size_t size, size_t alignment)

template<typename T , int &... kExplicitGuard, std::enable_if_t< is_bounded_array_v< T >, int > = 0, typename... Args>
void	MakeUnique (Args &&...)=delete

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 , int &... kExplicitGuard, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
SharedPtr< T >	MakeShared (size_t size)

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

template<typename T , int &... kExplicitGuard, std::enable_if_t< is_bounded_array_v< T >, int > = 0, typename... Args>
std::enable_if_t< is_bounded_array_v< T > >	MakeShared (Args &&...)=delete

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)

size_t	GetAllocated () const

Public Member Functions inherited from pw::Deallocator
constexpr 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

template<typename T , int &... kExplicitGuard, std::enable_if_t< is_bounded_array_v< T >, int > = 0, typename... Args>
void	WrapUnique (Args &&...)=delete

Static Public Attributes
static constexpr Capabilities	kCapabilities

static constexpr size_t	kPoisonInterval = PW_ALLOCATOR_BLOCK_POISON_INTERVAL

Protected Member Functions
void	Init (BlockType *begin)

template<typename Ptr >
internal::copy_const_ptr_t< Ptr, BlockType * >	FromUsableSpace (Ptr ptr) const

virtual void	DeallocateBlock (BlockType *&&block)

Protected Member Functions inherited from pw::allocator::internal::GenericBlockAllocator
constexpr	GenericBlockAllocator (Capabilities capabilities)

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 , std::enable_if_t<!std::is_array_v< T >, int > = 0>
UniquePtr< T >	WrapUnique (T *ptr)

template<typename T , int &... kExplicitGuard, typename ElementType = std::remove_extent_t<T>, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
UniquePtr< T >	WrapUnique (ElementType *ptr, size_t size)

template<typename T >
UniquePtr< T[]>	WrapUniqueArray (T *ptr, size_t size)

Private Member Functions
void *	DoAllocate (Layout layout) override

void	DoDeallocate (void *ptr) override

void	DoDeallocate (void *ptr, Layout) override

bool	DoResize (void *ptr, size_t new_size) override

size_t	DoGetAllocated () const override

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

virtual BlockResult< BlockType >	ChooseBlock (Layout layout)=0

virtual void	ReserveBlock (BlockType &)

virtual void	RecycleBlock (BlockType &)

virtual void	Flush ()

Friends
template<typename , size_t >
class	test::BlockAllocatorTest

Additional Inherited Members
Static Protected Member Functions inherited from pw::allocator::internal::GenericBlockAllocator
template<typename BlockType >
static constexpr Capabilities	GetCapabilities ()

static void	CrashOnAllocated (const void *allocated)

static void	CrashOnOutOfRange (const void *freed)

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

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

template<typename T >
static constexpr bool	is_unbounded_array_v

Detailed Description

template<typename BlockType_>
class pw::allocator::BlockAllocator< BlockType_ >

A memory allocator that uses a list of blocks.

This class does not implement ChooseBlock and cannot be used directly. Instead, use one of its specializations.

NOTE!! Do NOT use memory returned from this allocator as the backing for another allocator. If this is done, the Query method may incorrectly think pointers returned by that allocator were created by this one, and report that this allocator can de/reallocate them.

Member Function Documentation

◆ ChooseBlock()

template<typename BlockType_ >

virtual BlockResult< BlockType > pw::allocator::BlockAllocator< BlockType_ >::ChooseBlock ( Layout layout )

privatepure virtual

Selects a free block to allocate from.

This method represents the allocator-specific strategy of choosing which block should be used to satisfy allocation requests. If the returned result indicates success, block will be replaced by the chosen block.

Parameters

block	Used to return the chosen block.
layout	Same as `Allocator::Allocate`.

Implemented in pw::allocator::BestFitAllocator< BlockType >, pw::allocator::BucketAllocator< BlockType, kMinInnerSize, kNumBuckets >, pw::allocator::DlAllocator< BlockType >, pw::allocator::FirstFitAllocator< BlockType >, pw::allocator::TlsfAllocator< BlockType, kMinSize, kNumShelves >, and pw::allocator::WorstFitAllocator< BlockType >.

◆ DeallocateBlock()

template<typename BlockType >

void pw::allocator::BlockAllocator< BlockType >::DeallocateBlock ( BlockType *&& block )

protectedvirtual

Frees the given block.

Derived classes may override this method to hook or even defer freeing blocks.

Reimplemented in pw::allocator::DlAllocator< BlockType >.

◆ DoAllocate()

template<typename BlockType >

void * pw::allocator::BlockAllocator< BlockType >::DoAllocate ( Layout layout )

overrideprivatevirtual

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.

Implements pw::Allocator.

◆ DoDeallocate() [1/2]

template<typename BlockType >

void pw::allocator::BlockAllocator< BlockType >::DoDeallocate ( void * ptr )

overrideprivate

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.

◆ DoDeallocate() [2/2]

template<typename BlockType_ >

void pw::allocator::BlockAllocator< BlockType_ >::DoDeallocate	(	void *	ptr,
		Layout
	)

inlineoverrideprivate

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.

◆ DoGetAllocated()

template<typename BlockType_ >

size_t pw::allocator::BlockAllocator< BlockType_ >::DoGetAllocated ( ) const

inlineoverrideprivatevirtual

Returns the total bytes that have been allocated by this allocator, or size_t(-1) if this allocator does not track its total allocated bytes.

Reimplemented from pw::Allocator.

◆ DoGetInfo()

template<typename BlockType >

Result< Layout > pw::allocator::BlockAllocator< BlockType >::DoGetInfo	(	InfoType	info_type,
		const void *	ptr
	)		const

overrideprivate

◆ DoResize()

template<typename BlockType >

bool pw::allocator::BlockAllocator< BlockType >::DoResize	(	void *	ptr,
		size_t	new_size
	)

overrideprivatevirtual

Modifies the size of an previously-allocated block of memory without copying any data.

Returns true if its size was changed without copying data to a new allocation; otherwise returns false.

In particular, it always returns true if the old_layout.size() equals new_size, and always returns false if the given pointer is null, the old_layout.size() is 0, or the new_size is 0.

Parameters

[in]	ptr	Pointer to previously-allocated memory.
[in]	new_size	Requested new size for the memory allocation.

Reimplemented from pw::Allocator.

◆ Flush()

template<typename BlockType_ >

virtual void pw::allocator::BlockAllocator< BlockType_ >::Flush ( )

inlineprivatevirtual

Completes any pending deallocations.

After calling this method, all memory that has been passed to Deallocate will be free and available for subsequent allocations.

An allocator implementation may wish to defer doing the work of freeing a block and potentially merging it with its neighbors in case it subsequently receives a request for the block's exact size. In this case it must override this method and clear any caches of freed blocks.

Allocators that free blocks immediately upon a call to DoDeallocate can simply use the default implementation that does nothing.

Reimplemented in pw::allocator::DlAllocator< BlockType >.

◆ FromUsableSpace()

template<typename BlockType >

template<typename Ptr >

internal::copy_const_ptr_t< Ptr, BlockType * > pw::allocator::BlockAllocator< BlockType >::FromUsableSpace ( Ptr ptr ) const

protected

Returns the block associated with a pointer.

If the given pointer is to this allocator's memory region, but not to a valid block, the memory is corrupted and this method will crash to assist in uncovering the underlying bug.

Parameters

ptr	Pointer to an allocated block's usable space.

Returns

embed:rst:leading-asterisk
 
* 
*  .. pw-status-codes::
* 
*     OK: Result contains a pointer to the block.
* 
*     OUT_OF_RANGE: Given pointer is outside the allocator's memory.
* 
*

◆ Init() [1/2]

template<typename BlockType >

void pw::allocator::BlockAllocator< BlockType >::Init ( BlockType * begin )

protected

Sets the blocks to be used by this allocator.

This method will use the sequence of blocks including and following begin. These blocks which must be valid.

Parameters

[in] begin The first block for this allocator. The block must not have a previous block.

◆ Init() [2/2]

template<typename BlockType >

void pw::allocator::BlockAllocator< BlockType >::Init ( ByteSpan region )

Sets the memory region to be used by this allocator.

This method will instantiate an initial block using the memory region.

Parameters

[in] region Region of memory to use when satisfying allocation requests. The region MUST be valid as an argument to BlockType::Init.

◆ RecycleBlock()

template<typename BlockType_ >

virtual void pw::allocator::BlockAllocator< BlockType_ >::RecycleBlock ( BlockType & )

inlineprivatevirtual

Indicates that a block is now free.

Does nothing by default. Derived class may overload to do additional bookkeeeping.

Parameters

block The block being freed.

Reimplemented in pw::allocator::BestFitAllocator< BlockType >, pw::allocator::BucketAllocator< BlockType, kMinInnerSize, kNumBuckets >, pw::allocator::DlAllocator< BlockType >, pw::allocator::FirstFitAllocator< BlockType >, pw::allocator::TlsfAllocator< BlockType, kMinSize, kNumShelves >, and pw::allocator::WorstFitAllocator< BlockType >.

◆ ReserveBlock()

template<typename BlockType_ >

virtual void pw::allocator::BlockAllocator< BlockType_ >::ReserveBlock ( BlockType & )

inlineprivatevirtual

Indicates that a block will no longer be free.

Does nothing by default. Derived class may overload to do additional bookkeeeping.

Parameters

block The block being freed.

Reimplemented in pw::allocator::BestFitAllocator< BlockType >, pw::allocator::BucketAllocator< BlockType, kMinInnerSize, kNumBuckets >, pw::allocator::DlAllocator< BlockType >, pw::allocator::FirstFitAllocator< BlockType >, pw::allocator::TlsfAllocator< BlockType, kMinSize, kNumShelves >, and pw::allocator::WorstFitAllocator< BlockType >.

Member Data Documentation

◆ kCapabilities

template<typename BlockType_ >

constexpr Capabilities pw::allocator::BlockAllocator< BlockType_ >::kCapabilities

staticconstexpr

Initial value:

=

Base::GetCapabilities<BlockType>()

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

pw_allocator/public/pw_allocator/block_allocator.h

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Private Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ ChooseBlock()

◆ DeallocateBlock()

◆ DoAllocate()

◆ DoDeallocate() [1/2]

◆ DoDeallocate() [2/2]

◆ DoGetAllocated()

◆ DoGetInfo()

◆ DoResize()

◆ Flush()

◆ FromUsableSpace()

◆ Init() [1/2]

◆ Init() [2/2]

◆ RecycleBlock()

◆ ReserveBlock()

Member Data Documentation

◆ kCapabilities