Struct Allocator

pub struct Allocator { /* private fields */ }

A super-simple soft-realtime allocator for managing an external pool of memory

Implementations

impl Allocator

pub fn new(capacity: u32) -> Self

Create a new allocator to manage a pool of memory

Panics:

• Panics if capacity == 0

pub fn alloc(&mut self, size: u32) -> Option<Allocation>

Try to allocate a region with the provided size

Uses a best-fit strategy, and returns Allocations with arbitrary alignment.

Returns None if:

• size == 0, or
• size + 1 overflows.

pub fn alloc_with_align(&mut self, size: u32, align: u32) -> Option<Allocation>

Try to allocate a region with the provided size & alignment

Implements the following strategy (not quite best-fit):

• Search for a region with at least size + align - 1, and then truncate the start of the region such that alignment is reached.

This is more prone to causing fragmentation compared to an unaligned alloc.

Returns None if:

• there are no free-regions with size + align - 1 available space, or
• size == 0, or
• align == 0, or
• size + align overflows.

pub fn free(&mut self, alloc: Allocation)

Free the given allocation

Panics

• May panic if the allocation’s location gets freed twice, without first being re-allocated.

  Note: This panic will not catch all double frees.

pub fn reset(&mut self)

Free all allocations

pub fn capacity(&self) -> u32

Get the total capacity of the pool

pub fn total_available(&self) -> u32

Get the total available memory in this pool

Note: The memory may be fragmented, so it may not be possible to allocate an object of this size.

pub fn largest_available(&self) -> u32

Get the size of the largest available memory region in this pool

pub fn is_empty(&self) -> bool

Returns true if there are no allocations

Trait Implementations

impl Clone for Allocator

fn clone(&self) -> Allocator

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Allocator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.