Struct RewindableAllocator

An allocator that is fast like a linear allocator, is threadsafe, and automatically invalidates all allocations made from it, when "rewound" by the user.

Namespace: Unity.Collections
Syntax
[BurstCompile]
public struct RewindableAllocator : AllocatorManager.IAllocator, IDisposable

Properties

BlocksAllocated

Retrieves the number of memory blocks that the allocator has requested from the system.

Declaration
public readonly int BlocksAllocated { get; }
Property Value
Type Description
Int32

EnableBlockFree

Property to get and set enable block free flag, a flag indicating whether the allocator should enable individual block to be freed.

Declaration
public bool EnableBlockFree { get; set; }
Property Value
Type Description
Boolean

Function

All allocators must implement this property, in order to be installed in the custom allocator table.

Declaration
[ExcludeFromBurstCompatTesting("Uses managed delegate")]
public readonly AllocatorManager.TryFunction Function { get; }
Property Value
Type Description
AllocatorManager.TryFunction
Implements

Handle

Retrieve the AllocatorHandle associated with this allocator. The handle is used as an index into a global table, for times when a reference to the allocator object isn't available.

Declaration
public AllocatorManager.AllocatorHandle Handle { get; set; }
Property Value
Type Description
AllocatorManager.AllocatorHandle

The AllocatorHandle retrieved.
Implements

InitialSizeInBytes

Retrieves the size of the initial memory block, as requested in the Initialize function.

Declaration
public readonly int InitialSizeInBytes { get; }
Property Value
Type Description
Int32

IsCustomAllocator

Check whether this AllocatorHandle is a custom allocator.

Declaration
public readonly bool IsCustomAllocator { get; }
Property Value
Type Description
Boolean

True if this AllocatorHandle is a custom allocator.
Implements

ToAllocator

Retrieve the Allocator associated with this allocator.

Declaration
public readonly Allocator ToAllocator { get; }
Property Value
Type Description
Allocator

The Allocator retrieved.
Implements

Methods

AllocateNativeArray<T>(Int32)

Allocate a NativeArray of type T from memory that is guaranteed to remain valid until the end of the next Update of this World. There is no need to Dispose the NativeArray so allocated. It is not possible to free the memory by Disposing it - it is automatically freed after the end of the next Update for this World.

Declaration
public NativeArray<T> AllocateNativeArray<T>(int length)
    where T : struct
Parameters
Type Name Description
Int32 length

The length of the NativeArray to allocate, measured in elements.
Returns
Type Description
NativeArray<T>

The NativeArray allocated by this function.
Type Parameters
Name Description
T

The element type of the NativeArray to allocate.

AllocateNativeList<T>(Int32)

Allocate a NativeList of type T from memory that is guaranteed to remain valid until the end of the next Update of this World. There is no need to Dispose the NativeList so allocated. It is not possible to free the memory by Disposing it - it is automatically freed after the end of the next Update for this World. The NativeList must be initialized with its maximum capacity; if it were to dynamically resize, up to 1/2 of the total final capacity would be wasted, because the memory can't be dynamically freed.

Declaration
public NativeList<T> AllocateNativeList<T>(int capacity)
    where T : struct
Parameters
Type Name Description
Int32 capacity

The capacity of the NativeList to allocate, measured in elements.
Returns
Type Description
NativeList<T>

The NativeList allocated by this function.
Type Parameters
Name Description
T

The element type of the NativeList to allocate.

Dispose()

Dispose the allocator. This must be called to free the memory blocks that were allocated from the system.

Declaration
public void Dispose()

Initialize(Int32, Boolean)

Initializes the allocator. Must be called before first use.

Declaration
public void Initialize(int initialSizeInBytes, bool enableBlockFree = false)
Parameters
Type Name Description
Int32 initialSizeInBytes

The initial capacity of the allocator, in bytes
Boolean enableBlockFree

A flag indicating if allocator enables individual block free

Rewind()

Rewind the allocator; invalidate all allocations made from it, and potentially also free memory blocks it has allocated from the system.

Declaration
public void Rewind()

Try(ref AllocatorManager.Block)

Try to allocate, free, or reallocate a block of memory. This is an internal function, and is not generally called by the user.

Declaration
public int Try(ref AllocatorManager.Block block)
Parameters
Type Name Description
AllocatorManager.Block block

The memory block to allocate, free, or reallocate
Returns
Type Description
Int32

0 if successful. Otherwise, returns the error code from the allocator function.
Implements

Extension Methods