# `takeaway`: High-performance task queues

`takeaway` is a Rust library providing a high-performance, work-stealing task
queue data structure.  It is perfect for task architectures where:

- There may be thousands of tasks ready to run at any time.
- Tasks are small, synchronous, and CPU-bound.
- All available CPUs should be used to maximum capacity.
- (Optional) Some tasks have a higher priority than others.
- (Optional, coming soon) Grouping certain tasks lets them be executed
  efficiently.

`takeaway` tries to provide the lowest overhead possible.  It is designed from
the ground up to process everything in batches; this amortizes synchronization
costs and makes way for interesting features like task prioritization.

## Alternatives

[`crossbeam-deque`] is a popular Rust crate which also provides work-stealing
task queues.  However, `takeaway` provides a higher-level API with more features
and comparable (if not better) performance.

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:---:|:---:|:---:
![](assets/compare-noop-4096b.svg) | ![](assets/compare-light-4096b.svg)
![](assets/batch-sizes-noop-takeaway.svg) | ![](assets/batch-sizes-noop-crossbeam-deque.svg)

These benchmarks were recorded on a 16-thread AMD Ryzen 7 7840U
(Zen 4; CPU boost disabled), and can be reproduced by [the `manual`
benchmark](benches/manual.rs). Only results up to 8 threads were recorded to
avoid contention with other system processes.

## Origin

`takeaway` was developed for [`krabby`], an experimental Rust compiler, due to
the feature limitations of [`crossbeam-deque`].  It is offered as a standalone
crate in the hope that it may prove useful for other highly-parallel and
CPU-intensive applications.

[`krabby`]: https://codeberg.org/bal-e/krabby
[`crossbeam-deque`]: https://crates.io/crates/crossbeam-deque

## License

Copyright (C) 2025 arya dradjica (<uhe8ob7m71igsl1d@bal-e.org>)

`takeaway` is available under the MIT or Apache-2.0 licenses, at your option.
Their terms are available in `LICENSES/MIT.txt` and `LICENSES/Apache-2.0.txt`
respectively.

In addition, some code from [`crossbeam-utils`] has been vendored in, under the
MIT or Apache-2.0 licenses.  See `REUSE.toml`.

[`crossbeam-utils`]: https://github.com/crossbeam-rs/crossbeam/tree/master/crossbeam-utils
