helios::mem::FixedStackAllocator Class Reference

PMR stack allocator with fixed runtime capacity. More...

#include <fixed_stack_allocator.hpp>

Inheritance diagram for helios::mem::FixedStackAllocator:

Classes
struct	Marker
	Marker capturing the current bump offset for rewind operations. More...

Public Member Functions
	FixedStackAllocator (size_t capacity) noexcept
	Constructs fixed stack with the given backing capacity.
	FixedStackAllocator (const FixedStackAllocator &)=delete
	FixedStackAllocator (FixedStackAllocator &&other) noexcept
	Move-constructs fixed stack from another instance.
	~FixedStackAllocator () noexcept override
FixedStackAllocator &	operator= (const FixedStackAllocator &)=delete
FixedStackAllocator &	operator= (FixedStackAllocator &&other) noexcept
	Move-assigns fixed stack state from another instance.
void	RewindToMarker (Marker marker) noexcept
	Rewinds bump offset to marker.
void	Reset () noexcept
	Soft-resets bump offset and statistics.
bool	Empty () const noexcept
	Returns true when no active allocations remain.
bool	Owns (const void *ptr) const noexcept
	Checks whether pointer belongs to this stack's backing buffer.
Marker	GetMarker () const noexcept
	Returns current marker.
AllocatorStats	Stats () const noexcept
	Returns runtime statistics snapshot.
size_t	InitialCapacity () const noexcept
	Returns configured backing capacity.
size_t	TotalCapacity () const noexcept
	Returns configured backing capacity.

Detailed Description

PMR stack allocator with fixed runtime capacity.

LIFO-aware deallocation on the current top allocation uses CAS on the bump offset. Non-LIFO frees are no-ops for PMR compatibility.

Note

allocate and LIFO deallocate on the current head are lock-free.

Warning

Reset() and RewindToMarker() must not run concurrently with allocate or deallocate.

Definition at line 22 of file fixed_stack_allocator.hpp.

Constructor & Destructor Documentation

FixedStackAllocator() [1/3]

helios::mem::FixedStackAllocator::FixedStackAllocator ( size_t capacity )

inlineexplicitnoexcept

Constructs fixed stack with the given backing capacity.

Warning

Triggers assertion if capacity is too small. Triggers verification failure if backing allocation fails.

Parameters

capacity

Backing buffer size in bytes

Definition at line 138 of file fixed_stack_allocator.hpp.

FixedStackAllocator() [2/3]

helios::mem::FixedStackAllocator::FixedStackAllocator ( const FixedStackAllocator & )

delete

FixedStackAllocator() [3/3]

helios::mem::FixedStackAllocator::FixedStackAllocator ( FixedStackAllocator && other )

inlinenoexcept

Move-constructs fixed stack from another instance.

Parameters

other

Source allocator; left in empty moved-from state

Definition at line 43 of file fixed_stack_allocator.hpp.

~FixedStackAllocator()

helios::mem::FixedStackAllocator::~FixedStackAllocator ( )

inlineoverridenoexcept

Definition at line 44 of file fixed_stack_allocator.hpp.

Member Function Documentation

Empty()

bool helios::mem::FixedStackAllocator::Empty ( ) const

inlinenodiscardnoexcept

Returns true when no active allocations remain.

Returns

True if empty, false otherwise

Definition at line 73 of file fixed_stack_allocator.hpp.

GetMarker()

Marker helios::mem::FixedStackAllocator::GetMarker ( ) const

inlinenodiscardnoexcept

Returns current marker.

Returns

Marker that can later be rewound to

Definition at line 88 of file fixed_stack_allocator.hpp.

InitialCapacity()

size_t helios::mem::FixedStackAllocator::InitialCapacity ( ) const

inlinenodiscardnoexcept

Returns configured backing capacity.

Returns

Capacity in bytes

Definition at line 102 of file fixed_stack_allocator.hpp.

operator=() [1/2]

FixedStackAllocator & helios::mem::FixedStackAllocator::operator= ( const FixedStackAllocator & )

delete

operator=() [2/2]

FixedStackAllocator & helios::mem::FixedStackAllocator::operator= ( FixedStackAllocator && other )

inlinenoexcept

Move-assigns fixed stack state from another instance.

Parameters

other

Source allocator; left in empty moved-from state

Returns

Reference to this allocator

Definition at line 148 of file fixed_stack_allocator.hpp.

Owns()

bool helios::mem::FixedStackAllocator::Owns ( const void * ptr ) const

inlinenodiscardnoexcept

Checks whether pointer belongs to this stack's backing buffer.

Parameters

ptr	Pointer to test

Returns

True when owned, false otherwise

Definition at line 175 of file fixed_stack_allocator.hpp.

Reset()

void helios::mem::FixedStackAllocator::Reset ( )

inlinenoexcept

Soft-resets bump offset and statistics.

Warning

Must not be called concurrently with allocate or deallocate.

Definition at line 170 of file fixed_stack_allocator.hpp.

RewindToMarker()

void helios::mem::FixedStackAllocator::RewindToMarker ( Marker marker )

inlinenoexcept

Rewinds bump offset to marker.

Warning

Must not be called concurrently with allocate or deallocate. Triggers assertion when marker.offset exceeds the current offset.

Parameters

marker

Marker previously returned by GetMarker

Definition at line 159 of file fixed_stack_allocator.hpp.

Stats()

AllocatorStats helios::mem::FixedStackAllocator::Stats ( ) const

inlinenodiscardnoexcept

Returns runtime statistics snapshot.

Returns

Allocator stats for this stack

Definition at line 187 of file fixed_stack_allocator.hpp.

TotalCapacity()

size_t helios::mem::FixedStackAllocator::TotalCapacity ( ) const

inlinenodiscardnoexcept

Returns configured backing capacity.

Returns

Capacity in bytes

Definition at line 108 of file fixed_stack_allocator.hpp.