pw::allocator::TypedPool< T > Class Template Reference

Overview

template<typename T>
class pw::allocator::TypedPool< T >

Typed pool that can be used for slab allocation.

This class is a special purpose pool designed to allocate objects of one specific type, T. It is useful when you need a dynamic pool of objects with very low performance and memory overhead costs. For example, a dispatcher might use such an allocator to manage memory for a set of task objects.

Template Parameters

T	The type of object to allocate memory for.

Inheritance diagram for pw::allocator::TypedPool< T >:

Classes
struct	Buffer
	Provides aligned storage for kNumObjects of type T. More...

Public Member Functions
template<size_t kNumObjects>
	TypedPool (Buffer< kNumObjects > &buffer)
	TypedPool (ByteSpan region)
template<int &... kExplicitGuard, typename... Args>
T *	New (Args &&... args)
template<int &... kExplicitGuard, typename... Args>
UniquePtr< T >	MakeUnique (Args &&... args)
Public Member Functions inherited from pw::allocator::ChunkPool
	ChunkPool (ByteSpan region, const Layout &layout)
Public Member Functions inherited from pw::allocator::Pool
constexpr	Pool (const Capabilities &capabilities, const Layout &layout)
constexpr const Layout &	layout () const
void *	Allocate ()
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 ()
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_bounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique ()
template<typename T , int &... kExplicitGuard, std::enable_if_t< is_unbounded_array_v< T >, int > = 0>
UniquePtr< T >	MakeUnique ()
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)

Static Public Member Functions
static constexpr size_t	SizeNeeded (size_t num_objects)
	Returns the amount of memory needed to allocate num_objects.
static constexpr size_t	AlignmentNeeded ()
	Returns the optimal alignment for the backing memory region.

Additional Inherited Members
Public Types inherited from pw::Deallocator
using	Capabilities = allocator::Capabilities
using	Capability = allocator::Capability
using	Layout = allocator::Layout
Static Public Attributes inherited from pw::allocator::ChunkPool
static constexpr Capabilities	kCapabilities
static constexpr size_t	kMinSize = sizeof(void*)
static constexpr size_t	kMinAlignment = alignof(void*)
Protected Member Functions inherited from pw::Deallocator
constexpr	Deallocator ()=default
	TODO(b/326509341): Remove when downstream consumers migrate.
constexpr	Deallocator (const Capabilities &capabilities)
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

Constructor & Destructor Documentation

TypedPool() [1/2]

template<typename T >

template<size_t kNumObjects>

pw::allocator::TypedPool< T >::TypedPool ( Buffer< kNumObjects > &  buffer )

inline

Construct a TypedPool.

This constructor uses the Buffer type to minimize wasted memory. For example:

TypedPool<MyObject>::Buffer<100> buffer;
TypedPool<MyObject> my_pool(buffer);

Parameters

buffer

The memory to allocate from.

TypedPool() [2/2]

template<typename T >

pw::allocator::TypedPool< T >::TypedPool ( ByteSpan  region )

inline

Construct a TypedPool.

To minimize wasted memory, align the buffer provided to the allocator to the object type's alignment. For example:

alignas(MyObject) std::array<std::byte, 0x1000> buffer;
TypedPool<MyObject> my_pool(buffer);

Parameters

region

The memory to allocate from. Must be large enough to allocate memory for at least one object.

Member Function Documentation

MakeUnique()

template<typename T >

template<int &... kExplicitGuard, typename... Args>

UniquePtr< T > pw::allocator::TypedPool< T >::MakeUnique ( Args &&...  args )

inline

Constructs and object from the given args, and wraps it in a UniquePtr

This method is similar to Allocator::MakeUnique, except that it is specific to the pool's object type.

Parameters

[in]

args...

Arguments passed to the object constructor.

New()

template<typename T >

template<int &... kExplicitGuard, typename... Args>

T * pw::allocator::TypedPool< T >::New ( Args &&...  args )

inline

Constructs and object from the given args

This method is similar to Allocator::New, except that it is specific to the pool's object type.

Parameters

[in]

args...

Arguments passed to the object constructor.

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

• pw_allocator/public/pw_allocator/typed_pool.h