Class DynamicPoolMap

Inheritance Relationships

Base Type

Class Documentation

class DynamicPoolMap : public umpire::strategy::AllocationStrategy

Simple dynamic pool for allocations.

This AllocationStrategy uses Simpool to provide pooling for allocations of any size. The behavior of the pool can be controlled by two parameters: the initial allocation size, and the minimum allocation size.

The initial size controls how large the first piece of memory allocated is, and the minimum size controls the lower bound on all future chunk allocations.

Public Types

using Pointer = void *
using CoalesceHeuristic = std::function<bool(const strategy::DynamicPoolMap&)>

Callback heuristic to trigger coalesce of free blocks in pool.

The registered heuristic callback function will be called immediately after a deallocation() has completed from the pool.

Public Functions

DynamicPoolMap(const std::string &name, int id, Allocator allocator, const std::size_t initial_alloc_size = (512 * 1024 * 1024), const std::size_t min_alloc_size = (1 * 1024 * 1024), const std::size_t align_bytes = 16, CoalesceHeuristic coalesce_heuristic = heuristic_percent_releasable(100))

Construct a new DynamicPoolMap.

Parameters

  • name: Name of this instance of the DynamicPoolMap

  • id: Unique identifier for this instance

  • initial_alloc_bytes: Size the pool initially allocates

  • min_alloc_bytes: The minimum size of all future allocations

  • coalesce_heuristic: Heuristic callback function

  • align_bytes: Number of bytes with which to align allocation sizes

~DynamicPoolMap()

Destructs the DynamicPoolMap.

DynamicPoolMap(const DynamicPoolMap&)
void *allocate(std::size_t bytes)

Allocate bytes of memory.

Return

Pointer to start of allocated bytes.

Parameters

  • bytes: Number of bytes to allocate.

void deallocate(void *ptr)

Free the memory at ptr.

Parameters

  • ptr: Pointer to free.

void release()

Release any and all unused memory held by this AllocationStrategy.

std::size_t getCurrentSize() const

Get current (total) size of the allocated memory.

This is the total size of all allocation currently ‘live’ that have been made by this AllocationStrategy object.

Return

Current total size of allocations.

std::size_t getActualSize() const

Get the current amount of memory allocated by this allocator.

Note that this can be larger than getCurrentSize(), particularly if the AllocationStrategy implements some kind of pooling.

Return

The total size of all the memory this object has allocated.

std::size_t getHighWatermark() const

Get the high watermark of the total allocated size.

This is equivalent to the highest observed value of getCurrentSize.

Return

High watermark allocation size.

Platform getPlatform()

Get the platform associated with this AllocationStrategy.

The Platform distinguishes the appropriate place to execute operations on memory allocated by this AllocationStrategy.

Return

The platform associated with this AllocationStrategy.

std::size_t getReleasableSize() const

Returns the number of bytes of unallocated data held by this pool that could be immediately released back to the resource.

A memory pool has a set of blocks that are not leased out to the application as allocations. Allocations from the resource begin as a single chunk, but these could be split, and only the first chunk can be deallocated back to the resource immediately.

Return

The total number of bytes that are immediately releasable.

std::size_t getFreeBlocks() const

Return the number of free memory blocks that the pools holds.

std::size_t getInUseBlocks() const

Return the number of used memory blocks that the pools holds.

std::size_t getBlocksInPool() const

Return the number of memory blocks both leased to application and internal free memory that the pool holds.

std::size_t getLargestAvailableBlock()

Get the largest allocatable number of bytes from pool before the pool will grow.

return The largest number of bytes that may be allocated without causing pool growth

void coalesce()

Merge as many free records as possible, release all possible free blocks, then reallocate a chunk to keep the actual size the same.

const std::string &getName()

Get the name of this AllocationStrategy.

Return

The name of this AllocationStrategy.

int getId()

Get the id of this AllocationStrategy.

Return

The id of this AllocationStrategy.

Protected Attributes

std::string m_name
int m_id