A device_memory_resource which allocates memory blocks of a single fixed size. More...

#include <fixed_size_memory_resource.hpp>

Inheritance diagram for rmm::mr::fixed_size_memory_resource< Upstream >:

Collaboration diagram for rmm::mr::fixed_size_memory_resource< Upstream >:

Public Member Functions
	fixed_size_memory_resource (Upstream *upstream_mr, std::size_t block_size=default_block_size, std::size_t blocks_to_preallocate=default_blocks_to_preallocate)
	Construct a new `fixed_size_memory_resource` that allocates memory from `upstream_resource`. More...

	~fixed_size_memory_resource () override
	Destroy the `fixed_size_memory_resource` and free all memory allocated from upstream.

	fixed_size_memory_resource (fixed_size_memory_resource const &)=delete

	fixed_size_memory_resource (fixed_size_memory_resource &&)=delete

fixed_size_memory_resource &	operator= (fixed_size_memory_resource const &)=delete

fixed_size_memory_resource &	operator= (fixed_size_memory_resource &&)=delete

bool	supports_streams () const noexcept override
	Query whether the resource supports use of non-null streams for allocation/deallocation. More...

bool	supports_get_mem_info () const noexcept override
	Query whether the resource supports the get_mem_info API. More...

Upstream *	get_upstream () const noexcept
	Get the upstream memory_resource object. More...

std::size_t	get_block_size () const noexcept
	Get the size of blocks allocated by this memory resource. More...

Static Public Attributes
static constexpr std::size_t	default_block_size = 1 << 20
	Default allocation block size.

static constexpr std::size_t	default_blocks_to_preallocate = 128

Protected Types
using	free_list = detail::fixed_size_free_list
	The free list type.

using	block_type = free_list::block_type
	The type of block managed by the free list.

using	lock_guard = std::lock_guard< std::mutex >
	Type of lock used to synchronize access.

Protected Member Functions
std::size_t	get_maximum_allocation_size () const
	Get the (fixed) size of allocations supported by this memory resource. More...

block_type	expand_pool (std::size_t size, free_list &blocks, cuda_stream_view stream)
	Allocate a block from upstream to supply the suballocation pool. More...

free_list	blocks_from_upstream (cuda_stream_view stream)
	Allocate blocks from upstream to expand the suballocation pool. More...

split_block	allocate_from_block (block_type const &block, std::size_t size)
	Splits block if necessary to return a pointer to memory of `size` bytes. More...

block_type	free_block (void *ptr, std::size_t size) noexcept
	Finds, frees and returns the block associated with pointer. More...

std::pair< std::size_t, std::size_t >	do_get_mem_info ([[maybe_unused]] cuda_stream_view stream) const override
	Get free and available memory for memory resource. More...

void	release ()
	free all memory allocated using the upstream resource.

std::pair< std::size_t, std::size_t >	free_list_summary (free_list const &blocks)
	Get the largest available block size and total free size in the specified free list. More...

Friends
class	detail::stream_ordered_memory_resource< fixed_size_memory_resource< Upstream >, detail::fixed_size_free_list >

Detailed Description

template<typename Upstream>
class rmm::mr::fixed_size_memory_resource< Upstream >

A device_memory_resource which allocates memory blocks of a single fixed size.

Supports only allocations of size smaller than the configured block_size.

Constructor & Destructor Documentation

◆ fixed_size_memory_resource()

template<typename Upstream >

rmm::mr::fixed_size_memory_resource< Upstream >::fixed_size_memory_resource	(	Upstream *	upstream_mr,
		std::size_t	block_size = `default_block_size`,
		std::size_t	blocks_to_preallocate = `default_blocks_to_preallocate`
	)

inlineexplicit

Construct a new fixed_size_memory_resource that allocates memory from upstream_resource.

When the pool of blocks is all allocated, grows the pool by allocating blocks_to_preallocate more blocks from upstream_mr.

Parameters

upstream_mr	The memory_resource from which to allocate blocks for the pool.
block_size	The size of blocks to allocate.
blocks_to_preallocate	The number of blocks to allocate to initialize the pool.

Member Function Documentation

◆ allocate_from_block()

template<typename Upstream >

split_block rmm::mr::fixed_size_memory_resource< Upstream >::allocate_from_block	(	block_type const &	block,
		std::size_t	size
	)

inlineprotected

Splits block if necessary to return a pointer to memory of size bytes.

If the block is split, the remainder is returned to the pool.

Parameters

block	The block to allocate from.
size	The size in bytes of the requested allocation.

Returns: A pair comprising the allocated pointer and any unallocated remainder of the input block.

◆ blocks_from_upstream()

template<typename Upstream >

free_list rmm::mr::fixed_size_memory_resource< Upstream >::blocks_from_upstream ( cuda_stream_view stream )

inlineprotected

Allocate blocks from upstream to expand the suballocation pool.

Parameters

stream The stream on which the memory is to be used.

Returns: block_type The allocated block

◆ do_get_mem_info()

template<typename Upstream >

std::pair<std::size_t, std::size_t> rmm::mr::fixed_size_memory_resource< Upstream >::do_get_mem_info ( [[maybe_unused] ] cuda_stream_view stream ) const

inlineoverrideprotected

Get free and available memory for memory resource.

Exceptions

std::runtime_error if we could not get free / total memory

Parameters

stream the stream being executed on

Returns: std::pair with available and free memory for resource

◆ expand_pool()

template<typename Upstream >

block_type rmm::mr::fixed_size_memory_resource< Upstream >::expand_pool	(	std::size_t	size,
		free_list &	blocks,
		cuda_stream_view	stream
	)

inlineprotected

Allocate a block from upstream to supply the suballocation pool.

Note typically the allocated size will be larger than requested, and is based on the growth strategy (see size_to_grow()).

Parameters

size	The minimum size to allocate
blocks	The set of blocks from which to allocate
stream	The stream on which the memory is to be used.

Returns: block_type The allocated block

◆ free_block()

template<typename Upstream >

block_type rmm::mr::fixed_size_memory_resource< Upstream >::free_block	(	void *	ptr,
		std::size_t	size
	)

inlineprotectednoexcept

Finds, frees and returns the block associated with pointer.

Parameters

ptr	The pointer to the memory to free.
size	The size of the memory to free. Must be equal to the original allocation size.

Returns: The (now freed) block associated with p. The caller is expected to return the block to the pool.

◆ free_list_summary()

template<typename Upstream >

std::pair<std::size_t, std::size_t> rmm::mr::fixed_size_memory_resource< Upstream >::free_list_summary ( free_list const & blocks )

inlineprotected

Get the largest available block size and total free size in the specified free list.

This is intended only for debugging

Parameters

blocks The free list from which to return the summary

Returns: std::pair<std::size_t, std::size_t> Pair of largest available block, total free size

◆ get_block_size()

template<typename Upstream >

std::size_t rmm::mr::fixed_size_memory_resource< Upstream >::get_block_size ( ) const

inlinenoexcept

Get the size of blocks allocated by this memory resource.

Returns: std::size_t size in bytes of allocated blocks.

◆ get_maximum_allocation_size()

template<typename Upstream >

std::size_t rmm::mr::fixed_size_memory_resource< Upstream >::get_maximum_allocation_size ( ) const

inlineprotected

Get the (fixed) size of allocations supported by this memory resource.

Returns: std::size_t The (fixed) maximum size of a single allocation supported by this memory resource

◆ get_upstream()

template<typename Upstream >

Upstream* rmm::mr::fixed_size_memory_resource< Upstream >::get_upstream ( ) const

inlinenoexcept

Get the upstream memory_resource object.

Returns: UpstreamResource* the upstream memory resource.

◆ supports_get_mem_info()

template<typename Upstream >

bool rmm::mr::fixed_size_memory_resource< Upstream >::supports_get_mem_info ( ) const

inlineoverridenoexcept

Query whether the resource supports the get_mem_info API.

Returns: false

◆ supports_streams()

template<typename Upstream >

bool rmm::mr::fixed_size_memory_resource< Upstream >::supports_streams ( ) const

inlineoverridenoexcept

Query whether the resource supports use of non-null streams for allocation/deallocation.

Returns: true

Member Data Documentation

◆ default_blocks_to_preallocate

template<typename Upstream >

constexpr std::size_t rmm::mr::fixed_size_memory_resource< Upstream >::default_blocks_to_preallocate = 128

staticconstexpr

The number of blocks that the pool starts out with, and also the number of blocks by which the pool grows when all of its current blocks are allocated

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

fixed_size_memory_resource.hpp

Public Member Functions

Static Public Attributes

Protected Types

Protected Member Functions

Friends

Detailed Description

template<typename Upstream> class rmm::mr::fixed_size_memory_resource< Upstream >

Constructor & Destructor Documentation

◆ fixed_size_memory_resource()

Member Function Documentation

◆ allocate_from_block()

◆ blocks_from_upstream()

◆ do_get_mem_info()

◆ expand_pool()

◆ free_block()

◆ free_list_summary()

◆ get_block_size()

◆ get_maximum_allocation_size()

◆ get_upstream()

◆ supports_get_mem_info()

◆ supports_streams()

Member Data Documentation

◆ default_blocks_to_preallocate

template<typename Upstream>
class rmm::mr::fixed_size_memory_resource< Upstream >