1# Crossbeam Utils
2
3[![Build Status](https://github.com/crossbeam-rs/crossbeam/workflows/CI/badge.svg)](
4https://github.com/crossbeam-rs/crossbeam/actions)
5[![License](https://img.shields.io/badge/license-MIT_OR_Apache--2.0-blue.svg)](
6https://github.com/crossbeam-rs/crossbeam/tree/master/crossbeam-utils#license)
7[![Cargo](https://img.shields.io/crates/v/crossbeam-utils.svg)](
8https://crates.io/crates/crossbeam-utils)
9[![Documentation](https://docs.rs/crossbeam-utils/badge.svg)](
10https://docs.rs/crossbeam-utils)
11[![Rust 1.36+](https://img.shields.io/badge/rust-1.36+-lightgray.svg)](
12https://www.rust-lang.org)
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14
15This crate provides miscellaneous tools for concurrent programming:
16
17#### Atomics
18
19* [`AtomicCell`], a thread-safe mutable memory location.<sup>(no_std)</sup>
20* [`AtomicConsume`], for reading from primitive atomic types with "consume" ordering.<sup>(no_std)</sup>
21
22#### Thread synchronization
23
24* [`Parker`], a thread parking primitive.
25* [`ShardedLock`], a sharded reader-writer lock with fast concurrent reads.
26* [`WaitGroup`], for synchronizing the beginning or end of some computation.
27
28#### Utilities
29
30* [`Backoff`], for exponential backoff in spin loops.<sup>(no_std)</sup>
31* [`CachePadded`], for padding and aligning a value to the length of a cache line.<sup>(no_std)</sup>
32* [`scope`], for spawning threads that borrow local variables from the stack.
33
34*Features marked with <sup>(no_std)</sup> can be used in `no_std` environments.*<br/>
35
36[`AtomicCell`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/atomic/struct.AtomicCell.html
37[`AtomicConsume`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/atomic/trait.AtomicConsume.html
38[`Parker`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/sync/struct.Parker.html
39[`ShardedLock`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/sync/struct.ShardedLock.html
40[`WaitGroup`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/sync/struct.WaitGroup.html
41[`Backoff`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/struct.Backoff.html
42[`CachePadded`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/struct.CachePadded.html
43[`scope`]: https://docs.rs/crossbeam-utils/*/crossbeam_utils/thread/fn.scope.html
44
45## Usage
46
47Add this to your `Cargo.toml`:
48
49```toml
50[dependencies]
51crossbeam-utils = "0.8"
52```
53
54## Compatibility
55
56Crossbeam Utils supports stable Rust releases going back at least six months,
57and every time the minimum supported Rust version is increased, a new minor
58version is released. Currently, the minimum supported Rust version is 1.36.
59
60## License
61
62Licensed under either of
63
64 * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
65 * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
66
67at your option.
68
69#### Contribution
70
71Unless you explicitly state otherwise, any contribution intentionally submitted
72for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
73dual licensed as above, without any additional terms or conditions.
74