Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 158 insertions, 0 deletions

diff --git a/vendor/crossbeam/README.md b/vendor/crossbeam/README.md
new file mode 100644
index 000000000..1ed435c0a
--- /dev/null
+++ b/vendor/crossbeam/README.md
@@ -0,0 +1,158 @@
+# Crossbeam
+
+[![Build Status](https://github.com/crossbeam-rs/crossbeam/workflows/CI/badge.svg)](
+https://github.com/crossbeam-rs/crossbeam/actions)
+[![License](https://img.shields.io/badge/license-MIT_OR_Apache--2.0-blue.svg)](
+https://github.com/crossbeam-rs/crossbeam#license)
+[![Cargo](https://img.shields.io/crates/v/crossbeam.svg)](
+https://crates.io/crates/crossbeam)
+[![Documentation](https://docs.rs/crossbeam/badge.svg)](
+https://docs.rs/crossbeam)
+[![Rust 1.36+](https://img.shields.io/badge/rust-1.36+-lightgray.svg)](
+https://www.rust-lang.org)
+[![chat](https://img.shields.io/discord/569610676205781012.svg?logo=discord)](https://discord.com/invite/JXYwgWZ)
+
+This crate provides a set of tools for concurrent programming:
+
+#### Atomics
+
+* [`AtomicCell`], a thread-safe mutable memory location.<sup>(no_std)</sup>
+* [`AtomicConsume`], for reading from primitive atomic types with "consume" ordering.<sup>(no_std)</sup>
+
+#### Data structures
+
+* [`deque`], work-stealing deques for building task schedulers.
+* [`ArrayQueue`], a bounded MPMC queue that allocates a fixed-capacity buffer on construction.<sup>(alloc)</sup>
+* [`SegQueue`], an unbounded MPMC queue that allocates small buffers, segments, on demand.<sup>(alloc)</sup>
+
+#### Memory management
+
+* [`epoch`], an epoch-based garbage collector.<sup>(alloc)</sup>
+
+#### Thread synchronization
+
+* [`channel`], multi-producer multi-consumer channels for message passing.
+* [`Parker`], a thread parking primitive.
+* [`ShardedLock`], a sharded reader-writer lock with fast concurrent reads.
+* [`WaitGroup`], for synchronizing the beginning or end of some computation.
+
+#### Utilities
+
+* [`Backoff`], for exponential backoff in spin loops.<sup>(no_std)</sup>
+* [`CachePadded`], for padding and aligning a value to the length of a cache line.<sup>(no_std)</sup>
+* [`scope`], for spawning threads that borrow local variables from the stack.
+
+*Features marked with <sup>(no_std)</sup> can be used in `no_std` environments.*<br/>
+*Features marked with <sup>(alloc)</sup> can be used in `no_std` environments, but only if `alloc`
+feature is enabled.*
+
+[`AtomicCell`]: https://docs.rs/crossbeam/*/crossbeam/atomic/struct.AtomicCell.html
+[`AtomicConsume`]: https://docs.rs/crossbeam/*/crossbeam/atomic/trait.AtomicConsume.html
+[`deque`]: https://docs.rs/crossbeam/*/crossbeam/deque/index.html
+[`ArrayQueue`]: https://docs.rs/crossbeam/*/crossbeam/queue/struct.ArrayQueue.html
+[`SegQueue`]: https://docs.rs/crossbeam/*/crossbeam/queue/struct.SegQueue.html
+[`channel`]: https://docs.rs/crossbeam/*/crossbeam/channel/index.html
+[`Parker`]: https://docs.rs/crossbeam/*/crossbeam/sync/struct.Parker.html
+[`ShardedLock`]: https://docs.rs/crossbeam/*/crossbeam/sync/struct.ShardedLock.html
+[`WaitGroup`]: https://docs.rs/crossbeam/*/crossbeam/sync/struct.WaitGroup.html
+[`epoch`]: https://docs.rs/crossbeam/*/crossbeam/epoch/index.html
+[`Backoff`]: https://docs.rs/crossbeam/*/crossbeam/utils/struct.Backoff.html
+[`CachePadded`]: https://docs.rs/crossbeam/*/crossbeam/utils/struct.CachePadded.html
+[`scope`]: https://docs.rs/crossbeam/*/crossbeam/fn.scope.html
+
+## Crates
+
+The main `crossbeam` crate just [re-exports](src/lib.rs) tools from
+smaller subcrates:
+
+* [`crossbeam-channel`](crossbeam-channel)
+  provides multi-producer multi-consumer channels for message passing.
+* [`crossbeam-deque`](crossbeam-deque)
+  provides work-stealing deques, which are primarily intended for building task schedulers.
+* [`crossbeam-epoch`](crossbeam-epoch)
+  provides epoch-based garbage collection for building concurrent data structures.
+* [`crossbeam-queue`](crossbeam-queue)
+  provides concurrent queues that can be shared among threads.
+* [`crossbeam-utils`](crossbeam-utils)
+  provides atomics, synchronization primitives, scoped threads, and other utilities.
+
+There is one more experimental subcrate that is not yet included in `crossbeam`:
+
+* [`crossbeam-skiplist`](crossbeam-skiplist)
+  provides concurrent maps and sets based on lock-free skip lists.
+
+## Usage
+
+Add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+crossbeam = "0.8"
+```
+
+## Compatibility
+
+Crossbeam supports stable Rust releases going back at least six months,
+and every time the minimum supported Rust version is increased, a new minor
+version is released. Currently, the minimum supported Rust version is 1.36.
+
+## Contributing
+
+Crossbeam welcomes contribution from everyone in the form of suggestions, bug reports,
+pull requests, and feedback. 💛
+
+If you need ideas for contribution, there are several ways to get started:
+
+* Found a bug or have a feature request?
+  [Submit an issue](https://github.com/crossbeam-rs/crossbeam/issues/new)!
+* Issues and PRs labeled with
+  [feedback wanted](https://github.com/crossbeam-rs/crossbeam/issues?utf8=%E2%9C%93&q=is%3Aopen+sort%3Aupdated-desc+label%3A%22feedback+wanted%22+)
+  need feedback from users and contributors.
+* Issues labeled with
+  [good first issue](https://github.com/crossbeam-rs/crossbeam/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc+label%3A%22good+first+issue%22)
+  are relatively easy starter issues.
+
+#### RFCs
+
+We also have the [RFCs](https://github.com/crossbeam-rs/rfcs) repository for more
+high-level discussion, which is the place where we brainstorm ideas and propose
+substantial changes to Crossbeam.
+
+You are welcome to participate in any open
+[issues](https://github.com/crossbeam-rs/rfcs/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc)
+or
+[pull requests](https://github.com/crossbeam-rs/rfcs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-desc).
+
+#### Learning resources
+
+If you'd like to learn more about concurrency and non-blocking data structures, there's a
+list of learning resources in our [wiki](https://github.com/crossbeam-rs/rfcs/wiki),
+which includes relevant blog posts, papers, videos, and other similar projects.
+
+Another good place to visit is [merged RFCs](https://github.com/crossbeam-rs/rfcs/tree/master/text).
+They contain elaborate descriptions and rationale for features we've introduced to
+Crossbeam, but keep in mind that some of the written information is now out of date.
+
+#### Conduct
+
+The Crossbeam project adheres to the
+[Rust Code of Conduct](https://github.com/rust-lang/rust/blob/master/CODE_OF_CONDUCT.md).
+This describes the minimum behavior expected from all contributors.
+
+## License
+
+Licensed under either of
+
+ * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+Some Crossbeam subcrates have additional licensing notices.
+Take a look at other readme files in this repository for more information.
+
+#### Contribution
+
+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.