This crate provides allocators that are suitable for use on bare metal or with
OS allocation facilities like mmap(2)/brk(2).
The following allocator types are available:
Buddy, a binary-buddy allocator. O(log2levels) worst-case allocation and deallocation. Supports splitting and coalescing blocks by powers of 2. Good choice for periodic medium-to-large allocations.Bump, a bump allocator. O(1) allocation. Extremely fast to allocate and flexible in terms of allocation layout, but unable to deallocate individual items. Good choice for allocations that will never be deallocated or that will be deallocated en masse.Slab, a slab allocator. O(1) allocation and deallocation. All allocated blocks are the same size, making this allocator a good choice when allocating many similarly-sized objects.
All allocators provided by this crate are available in a #![no_std],
#![cfg(no_global_oom_handling)] environment. Additional functionality is
available when enabling feature flags:
| Flag | Default? | Requires nightly? | Description |
|---|---|---|---|
sptr |
Yes | No |
Uses the sptr polyfill for Strict Provenance.
|
unstable |
No | Yes |
Exposes constructors for allocators backed by implementors of the
unstable Allocator trait, and enables the internal use of
nightly-only Rust features. Obviates sptr.
|
alloc |
No | No | Exposes constructors for allocators backed by the global allocator. |
This crate includes stable-compatible polyfills for a number of unstable standard-library APIs whose implementations are reproduced verbatim here. These features are listed below along with their authors and/or maintainers:
alloc_layout_extra, by Amanieu d'Antrasint_log, by Yoshua Wuytsstrict_provenance, by Aria Beingessner (Gankra)
This crate also depends on sptr (also authored by Gankra) to reproduce
strict provenance for normal pointers on stable Rust.
If I've misattributed any of this work, or a contributor to these features is missing, please open an issue!
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.