wpi::memory::iteration_allocator< N, BlockOrRawAllocator > Class Template Reference

A stateful RawAllocator that is designed for allocations in a loop. More...

#include <wpi/memory/iteration_allocator.hpp>

Public Types
using	allocator_type = detail::iteration_block_allocator<BlockOrRawAllocator>

Public Member Functions
template<typename... Args>
	iteration_allocator (std::size_t block_size, Args &&... args)
	iteration_allocator (iteration_allocator &&other) noexcept
	~iteration_allocator () noexcept
iteration_allocator &	operator= (iteration_allocator &&other) noexcept
void *	allocate (std::size_t size, std::size_t alignment)
void *	try_allocate (std::size_t size, std::size_t alignment) noexcept
void	next_iteration () noexcept
std::size_t	cur_iteration () const noexcept
allocator_type &	get_allocator () noexcept
std::size_t	capacity_left (std::size_t i) const noexcept
std::size_t	capacity_left () const noexcept

Static Public Member Functions
static std::size_t	max_iterations () noexcept

Detailed Description

template<std::size_t N, class BlockOrRawAllocator = default_allocator>
class wpi::memory::iteration_allocator< N, BlockOrRawAllocator >

A stateful RawAllocator that is designed for allocations in a loop.

It uses N stacks for the allocation, one of them is always active. Allocation uses the currently active stack. Calling iteration_allocator::next_iteration() at the end of the loop, will make the next stack active for allocation, effectively releasing all of its memory. Any memory allocated will thus be usable for N iterations of the loop. This type of allocator is a generalization of the double frame allocator.

Member Typedef Documentation

allocator_type

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

using wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::allocator_type = detail::iteration_block_allocator<BlockOrRawAllocator>

Constructor & Destructor Documentation

iteration_allocator() [1/2]

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

template<typename... Args>

wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::iteration_allocator ( std::size_t block_size, Args &&... args )

inlineexplicit

Effects:

Creates it with a given initial block size and and other constructor arguments for the BlockAllocator. It will allocate the first (and only) block and evenly divide it on all the stacks it uses.

iteration_allocator() [2/2]

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::iteration_allocator ( iteration_allocator< N, BlockOrRawAllocator > && other )

inlinenoexcept

~iteration_allocator()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::~iteration_allocator ( )

inlinenoexcept

Member Function Documentation

allocate()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

void * wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::allocate ( std::size_t size, std::size_t alignment )

inline

Effects:

Allocates a memory block of given size and alignment. It simply moves the top marker of the currently active stack.

Returns:

A node with given size and alignment.

Throws:

out_of_fixed_memory if the current stack does not have any memory left.

Requires:

size and alignment must be valid.

capacity_left() [1/2]

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

std::size_t wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::capacity_left ( ) const

inlinenoexcept

Returns:

The amount of memory remaining in the currently active stack.

capacity_left() [2/2]

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

std::size_t wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::capacity_left ( std::size_t i ) const

inlinenoexcept

Returns:

The amount of memory remaining in the stack with the given index. This is the number of bytes that are available for allocation.

cur_iteration()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

std::size_t wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::cur_iteration ( ) const

inlinenoexcept

Returns:

The index of the current iteration. This is modulo max_iterations().

get_allocator()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

allocator_type & wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::get_allocator ( )

inlinenoexcept

Returns:

A reference to the BlockAllocator used for managing the memory.

Requires:

It is undefined behavior to move this allocator out into another object.

max_iterations()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

static std::size_t wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::max_iterations ( )

inlinestaticnoexcept

Returns:

The number of iteration each allocation will live. This is the template parameter N.

next_iteration()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

void wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::next_iteration ( )

inlinenoexcept

Effects:

Goes to the next internal stack. This will clear the stack whose max_iterations() lifetime has reached, and use it for all allocations in this iteration.

Note

This function should be called at the end of the loop.

operator=()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

iteration_allocator & wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::operator= ( iteration_allocator< N, BlockOrRawAllocator > && other )

inlinenoexcept

try_allocate()

template<std::size_t N, class BlockOrRawAllocator = default_allocator>

void * wpi::memory::iteration_allocator< N, BlockOrRawAllocator >::try_allocate ( std::size_t size, std::size_t alignment )

inlinenoexcept

Effects:

Allocates a memory block of given size and alignment similar to allocate().

Returns:

A node with given size and alignment or nullptr if the current stack does not have any memory left.

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

• wpi/memory/iteration_allocator.hpp