cuda::experimental::stf::cached_block_allocator

Defined in include/cuda/experimental/__stf/allocators/cached_allocator.cuh

class cached_block_allocator : public cuda::experimental::stf::block_allocator_interface

Cached block allocator that implements block_allocator_interface.

This allocator uses an internal cache to reuse previously allocated memory blocks. The aim is to reduce the overhead of memory allocation.

Public Functions

inline cached_block_allocator(block_allocator_untyped root_allocator_)

This constructor takes a root allocator which performs allocations when there is a cache miss.

inline virtual void *allocate(backend_ctx_untyped &ctx, const data_place &memory_node, ::std::ptrdiff_t &s, event_list &prereqs) override

Allocates a memory block.

Attempts to allocate a memory block from the internal cache if available.

Parameters

• ctx – The backend context (unused in this implementation).

• memory_node – Memory location where the allocation should happen.

• s – Pointer to the size of memory required.

• prereqs – List of events that this allocation depends on.

Returns

void* A pointer to the allocated memory block or nullptr if allocation fails.

inline virtual void deallocate(backend_ctx_untyped&, const data_place &memory_node, event_list &prereqs, void *ptr, size_t sz) override

Deallocates a memory block.

Puts the deallocated block back into the internal cache for future reuse.

Parameters

• ctx – The backend context (unused in this implementation).

• memory_node – Memory location where the deallocation should happen.

• prereqs – List of events that this deallocation depends on.

• ptr – Pointer to the memory block to be deallocated.

• sz – Size of the memory block.

inline virtual event_list deinit(backend_ctx_untyped &ctx) override

De-initializes the allocator.

inline virtual ::std::string to_string() const override

Returns a string representation of the allocator.

Returns

std::string The string “cached_block_allocator”.

inline virtual void print_info() const override

Prints additional information about the allocator.

This function currently prints no additional information.

Protected Types

using per_place_map_t = ::std::unordered_multimap<size_t, alloc_cache_entry>

Maps sizes to cache entries for a given data_place.

Protected Attributes

block_allocator_untyped root_allocator

Underlying root allocator for base buffers.

::std::unordered_map<data_place, per_place_map_t, hash<data_place>> free_cache

Top-level cache map mapping data_place to per_place_map_t.

::std::mutex allocator_mutex

struct alloc_cache_entry

Struct representing an entry in the cache.

Holds the address of the allocated memory and a list of prerequisites for its reuse.

Public Members

void *ptr

Pointer to the allocated memory block.

event_list prereq

Prerequisites for reusing this block.