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pw::Deallocator Class Reference

Abstract interface for releasing memory. More...

Inheritance diagram for pw::Deallocator:
pw::Allocator pw::allocator::Pool pw::allocator::SynchronizedAllocator< pw::sync::Mutex > pw::allocator::TrackingAllocator< internal::AllMetrics > pw::allocator::test::AllocatorForTest< 1024 > pw::allocator::BuddyAllocator< kMinOuterSize_, kNumBuckets > pw::allocator::BumpAllocator pw::allocator::FallbackAllocator pw::allocator::LibCAllocator pw::allocator::NullAllocator pw::allocator::SynchronizedAllocator< LockType > pw::allocator::TrackingAllocator< MetricsType > pw::allocator::internal::GenericBlockAllocator pw::allocator::test::AllocatorForTest< kBufferSize, BlockType_, MetricsType > pw::allocator::test::FaultInjectingAllocator pw::allocator::AllocatorAsPool pw::allocator::AsyncPool pw::allocator::ChunkPool

Public Types

using Capabilities = allocator::Capabilities
 
using Capability = allocator::Capability
 
using Layout = allocator::Layout
 

Public Member Functions

constexpr const Capabilitiescapabilities () const
 
bool HasCapability (Capability capability) const
 Returns whether a given capability is enabled for this object.
 
void Deallocate (void *ptr)
 
void Deallocate (void *ptr, Layout layout)
 
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 Deallocator ()=default
 TODO(b/326509341): Remove when downstream consumers migrate.
 
constexpr Deallocator (const Capabilities &capabilities)
 
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)
 

Static Protected Attributes

template<typename T >
static constexpr bool is_bounded_array_v
 
template<typename T >
static constexpr bool is_unbounded_array_v
 

Detailed Description

Abstract interface for releasing memory.

Member Function Documentation

◆ Deallocate() [1/2]

void pw::Deallocator::Deallocate ( void *  ptr)
inline

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]ptrPointer to previously-allocated memory.

◆ Deallocate() [2/2]

void pw::Deallocator::Deallocate ( void *  ptr,
Layout  layout 
)
inline

Deprecated version of Deallocate that takes a Layout. Do not use this method. It will be removed. TODO(b/326509341): Remove when downstream consumers migrate.

◆ Delete()

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

Destroys the object and deallocates the associated memory.

The given pointer must have been previously obtained from a call to New using the same object; otherwise the behavior is undefined.

Warning
As with new/new[] and delete/delete[], it is an error to call a specialization of Delete other than the one that corresponds to the specialization of New that was used to allocate the object.

It is especially important to avoid passing the pointer return by a call to New<T[]> or New<T[kN] to Delete, as this will only delete the first object in the array. For this reason, it is recommended to use DeleteArray or explicitly specify the array type as a template parameter to either Delete<T[]> or Delete<T[kN]>.

Using an allocator with the kImplementsGetRequestedLayout capability and configuring the hardening level to PW_ALLOCATOR_HARDENING_DEBUG will detect such mismatches when Delete is called.

Parameters
[in]ptrPointer to previously-allocated object.

◆ DeleteArray()

template<typename ElementType >
void pw::Deallocator::DeleteArray ( ElementType *  ptr,
size_t  count 
)
inline

Destroys the array and deallocates the associated memory.

The given pointer must be to an array with count elements that was previously obtained from a call to New using the same object; otherwise the behavior is undefined.

This method MUST be used to delete arrays with deallocators that do not have the capability to recover the layout that was used to request memory, i.e. Capability::kImplementsGetRequestedLayout.

Parameters
[in]ptrPointer to previously-allocated array.
[in]countNumber of items in the array.

◆ GetCapacity()

StatusWithSize pw::Deallocator::GetCapacity ( ) const
inline

Returns the total amount of memory provided by this object.

This is an optional method. Some memory providers may not have an easily defined capacity, e.g. the system allocator. If implemented, the returned capacity may be less than the memory originally given to an allocator, e.g. if the allocator must align the region of memory, its capacity may be reduced.

◆ IsEqual()

bool pw::Deallocator::IsEqual ( const Deallocator other) const
inline

Returns whether the given object is the same as this one.

This method is used instead of operator== in keeping with std::pmr::memory_resource::is_equal. There currently is no corresponding virtual DoIsEqual, as objects that would require dynamic_cast to properly determine equality are not supported. This method will allow the interface to remain unchanged should a future need for such objects arise.

Parameters
[in]otherObject to compare with this object.

◆ WrapUnique()

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 > pw::Deallocator::WrapUnique ( ElementType *  ptr,
size_t  size 
)
inlineprotected

Wraps an array of type T in a UniquePtr

Deprecated:
Construct a UniquePtr<T> directly instead.

TODO(b/326509341): Remove when downstream consumers migrate.

Parameters
[in]ptrPointer to memory provided by this object.
[in]sizeThe size of the array.

Member Data Documentation

◆ is_bounded_array_v

template<typename T >
constexpr bool pw::Deallocator::is_bounded_array_v
staticconstexprprotected
Initial value:
=
allocator::internal::is_bounded_array_v<T>

◆ is_unbounded_array_v

template<typename T >
constexpr bool pw::Deallocator::is_unbounded_array_v
staticconstexprprotected
Initial value:
=
allocator::internal::is_unbounded_array_v<T>

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