helios::mem::StackAllocator Class Reference

PMR stack allocator with LIFO-aware deallocation. More...

#include <stack_allocator.hpp>

Inheritance diagram for helios::mem::StackAllocator:

Classes
struct	Marker
	Marker for rewind operations. More...

Public Member Functions
	StackAllocator (StackAllocatorOptions options) noexcept
	Constructs stack allocator from options.
	StackAllocator (size_t initial_capacity) noexcept
	Constructs stack allocator with geometric growth.
	StackAllocator (const StackAllocator &)=delete
	StackAllocator (StackAllocator &&other) noexcept
	Move-constructs stack allocator from another instance.
	~StackAllocator () noexcept override
StackAllocator &	operator= (const StackAllocator &)=delete
StackAllocator &	operator= (StackAllocator &&other) noexcept
	Move-assigns stack state from another instance.
void	RewindToMarker (Marker marker) noexcept
	Rewinds allocator to marker.
void	Reset () noexcept
	Resets allocator to a fresh single initial block.
bool	Empty () const noexcept
	Returns true when no active allocations remain.
Marker	GetMarker () const noexcept
	Returns current marker.
AllocatorStats	Stats () const noexcept
	Returns runtime statistics.
size_t	InitialCapacity () const noexcept
	Returns initial block capacity.
size_t	TotalCapacity () const noexcept
	Returns total capacity across block chain.
size_t	BlockCount () const noexcept
	Returns current number of blocks.
GrowthPolicy	Growth () const noexcept
	Returns growth policy.

Detailed Description

PMR stack allocator with LIFO-aware deallocation.

Uses block-chained bump allocation with per-allocation headers.

Allocation path is lock-free with atomic CAS on head block offset. Deallocate tries LIFO rewind when possible. Non-LIFO deallocation is treated as no-op, which keeps PMR compatibility for containers that may free out of order.

Note

allocate and LIFO deallocate on the current head are lock-free. Reset, GetMarker, and RewindToMarker require external synchronization. Marker.block is internal and invalid after growth.

Definition at line 35 of file stack_allocator.hpp.

Constructor & Destructor Documentation

StackAllocator() [1/4]

helios::mem::StackAllocator::StackAllocator ( StackAllocatorOptions options )

inlineexplicitnoexcept

Constructs stack allocator from options.

Warning

Triggers assertion if options.initial_capacity == 0 or options.growth.max_capacity < options.initial_capacity.

Parameters

options

Stack allocator options

Definition at line 203 of file stack_allocator.hpp.

StackAllocator() [2/4]

helios::mem::StackAllocator::StackAllocator ( size_t initial_capacity )

inlineexplicitnoexcept

Constructs stack allocator with geometric growth.

Warning

Triggers assertion if initial_capacity == 0.

Parameters

initial_capacity

Initial block capacity

Definition at line 58 of file stack_allocator.hpp.

StackAllocator() [3/4]

helios::mem::StackAllocator::StackAllocator ( const StackAllocator & )

delete

StackAllocator() [4/4]

helios::mem::StackAllocator::StackAllocator ( StackAllocator && other )

inlinenoexcept

Move-constructs stack allocator from another instance.

Parameters

other

Source allocator; left in empty moved-from state

Definition at line 69 of file stack_allocator.hpp.

~StackAllocator()

helios::mem::StackAllocator::~StackAllocator ( )

inlineoverridenoexcept

Definition at line 70 of file stack_allocator.hpp.

Member Function Documentation

BlockCount()

size_t helios::mem::StackAllocator::BlockCount ( ) const

inlinenodiscardnoexcept

Returns current number of blocks.

Returns

Block count

Definition at line 137 of file stack_allocator.hpp.

Empty()

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

inlinenodiscardnoexcept

Returns true when no active allocations remain.

Returns

True if empty, false otherwise.

Definition at line 101 of file stack_allocator.hpp.

GetMarker()

auto helios::mem::StackAllocator::GetMarker ( ) const

inlinenodiscardnoexcept

Returns current marker.

Returns

Marker that can later be rewound to

Definition at line 229 of file stack_allocator.hpp.

Growth()

GrowthPolicy helios::mem::StackAllocator::Growth ( ) const

inlinenodiscardnoexcept

Returns growth policy.

Returns

Growth policy

Definition at line 145 of file stack_allocator.hpp.

InitialCapacity()

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

inlinenodiscardnoexcept

Returns initial block capacity.

Returns

Capacity in bytes

Definition at line 121 of file stack_allocator.hpp.

operator=() [1/2]

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

delete

operator=() [2/2]

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

inlinenoexcept

Move-assigns stack state from another instance.

Parameters

other

Source allocator; left in empty moved-from state

Returns

Reference to this allocator

Definition at line 218 of file stack_allocator.hpp.

Reset()

void helios::mem::StackAllocator::Reset ( )

noexcept

Resets allocator to a fresh single initial block.

Warning

Must not be called concurrently with allocation/deallocation.

Definition at line 20 of file stack_allocator.cpp.

RewindToMarker()

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

noexcept

Rewinds allocator to marker.

Warning

Must not be called concurrently with allocation/deallocation. Triggers assertion if marker does not belong to this allocator.

Parameters

marker

Marker previously returned by GetMarker

Definition at line 42 of file stack_allocator.cpp.

Stats()

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

inlinenodiscardnoexcept

Returns runtime statistics.

Returns

Allocator stats snapshot

Definition at line 241 of file stack_allocator.hpp.

TotalCapacity()

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

inlinenodiscardnoexcept

Returns total capacity across block chain.

Returns

Capacity in bytes

Definition at line 129 of file stack_allocator.hpp.