mattmassicotte/queue

A queue for Swift concurrency

Integration

dependencies: [
    .package(url: "https://github.com/mattmassicotte/Queue", from: "0.2.0")
]

Usage

let queue = AsyncQueue()

queue.addOperation {
    await asyncFunction()
    await anotherAsyncFunction()
}

// This can can also return the underlying Task,
// so you can cancel, or await a value
let task = queue.addOperation {
    return await makeValue()
}

let value = try await task.value

By default, AsyncQueue will only run one operation at a time. But, it can be configured as a concurrent queue.

let queue = AsyncQueue(attributes: [.concurrent])

// these two may run concurrently
queue.addOperation { await asyncFunction() }
queue.addOperation { await asyncFunction() }

// This will only run once existing operations are complete, and will
// prevent new operations from starting until done
queue.addBarrierOperation {
    await asyncFunction()
}

The AsyncQueue type has an errorSequence property, which can be used to detect uncaught errors out of band.

let queue = AsyncQueue(attributes: [.publishErrors])

Task {
    for await error in queue.errorSequence {
        print(error)
    }
}

This package was inspired by [Semaphore][semaphore], which is another concurrency-related synchronization system that I've found very useful.

Alternatives

swift-async-queue

Contributing and Collaboration

I would love to hear from you! Issues or pull requests work great. Both a [Matrix space][matrix] and [Discord][discord] are available for live help, but I have a strong bias towards answering in the form of documentation. You can also find me here.

I prefer collaboration, and would love to find ways to work together if you have a similar project.

I prefer indentation with tabs for improved accessibility. But, I'd rather you use the system you want and make a PR than hesitate because of whitespace.

By participating in this project you agree to abide by the Contributor Code of Conduct.

[build status]: https://github.com/mattmassicotte/Queue/actions [build status badge]: https://github.com/mattmassicotte/Queue/workflows/CI/badge.svg [platforms]: https://swiftpackageindex.com/mattmassicotte/Queue [platforms badge]: https://img.shields.io/endpoint?url=https%3A%2F%2Fswiftpackageindex.com%2Fapi%2Fpackages%2Fmattmassicotte%2FQueue%2Fbadge%3Ftype%3Dplatforms [documentation]: https://swiftpackageindex.com/mattmassicotte/Queue/main/documentation [documentation badge]: https://img.shields.io/badge/Documentation-DocC-blue [matrix]: https://matrix.to/#/%23chimehq%3Amatrix.org [matrix badge]: https://img.shields.io/matrix/chimehq%3Amatrix.org?label=Matrix [discord]: https://discord.gg/esFpX6sErJ [semaphore]: https://github.com/groue/Semaphore

Package Metadata

Repository: mattmassicotte/queue

Default branch: main

README: README.md