FLinearBlockAllocator

Provides Malloc operation that reduces per-malloc and per-free overhead by allocating in blocks, and not allowing individual calls to free.

API > API/Runtime > API/Runtime/Core

Provides Malloc operation that reduces per-malloc and per-free overhead by allocating in blocks, and not allowing individual calls to free. Does not free any malloc'd memory until the allocator goes out of scope. Intended use is dynamically allocated scratch data, or long-lived global allocations that never need to free data. Allocations at the end of each block waste memory: when the next requested allocation is too big for the current block, the remaining memory goes unused. To avoid large amounts of waste, allocations should be relatively small compared to blocksize.

Memory for the blocks is allocated from InnerMalloc->Malloc. If InnerMalloc is nullptr, GMalloc is used.

The LinearBlockAllocator must be destroyed before its InnerMalloc is destroyed; the InnerMalloc pointer is not reference counted.

   
Name FLinearBlockAllocator
Type class
Header File /Engine/Source/Runtime/Core/Public/Memory/LinearAllocator.h
Include Path #include "Memory/LinearAllocator.h"

Syntax

class FLinearBlockAllocator : public FNoncopyable

Inheritance Hierarchy

Constructors

Name Remarks Include Path Unreal Specifiers
  Memory/LinearAllocator.h  

FLinearBlockAllocator ( FMalloc* InInnerMalloc,
uint32 InBlockSize,
ESPMode InThreadMode
)

 Constructor. Memory/LinearAllocator.h  

Destructors

Name Remarks Include Path Unreal Specifiers

~FLinearBlockAllocator()

   Memory/LinearAllocator.h  

Structs

Name Remarks
FBlock  

Constants

Name Type Remarks Include Path
MinBlockSize uint32   Memory/LinearAllocator.h

Functions

Public

Name Remarks Include Path Unreal Specifiers

SIZE_T GetAllocatedMemorySize()

 Returns the size of allocated blocks, which is >= size of pointers returned from Malloc calls. Memory/LinearAllocator.h  

void * Malloc ( SIZE_T Size,
uint32 Alignment
)

   Memory/LinearAllocator.h  

Protected

Name Remarks Include Path Unreal Specifiers

FBlock * AddCustomBlock ( SIZE_T UserSize,
uint32 UserAlignment
)

   Memory/LinearAllocator.h  

FBlock * AddDefaultBlock()

   Memory/LinearAllocator.h  

FBlock * AllocateBlock ( uint32 BlockSize,
uint32 BlockAlignment
)

   Memory/LinearAllocator.h  

bool IsThreadSafe()

   Memory/LinearAllocator.h  

bool RequiresCustomAllocation ( SIZE_T Size,
uint32 Alignment
) const

   Memory/LinearAllocator.h  

void * TryAllocateFromBlock ( SIZE_T Size,
uint32 Alignment,
FBlock* BlockHeader
)

   Memory/LinearAllocator.h  

Operators

Name Remarks Include Path Unreal Specifiers
  Memory/LinearAllocator.h  

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