async

Async is a composable asynchronous I/O framework for Ruby based on io-event.

"Lately I've been looking into async, as one of my projects – tus-ruby-server – would really benefit from non-blocking I/O. It's really beautifully designed." – janko

Features

• Scalable event-driven I/O for Ruby. Thousands of clients per process!
• Light weight fiber-based concurrency. No need for callbacks!
• Multi-thread/process containers for parallelism.
• Growing eco-system of event-driven components.

Usage

Please see the project documentation for more details.

• Getting Started - This guide shows how to add async to your project and run code asynchronously.

• Scheduler - This guide gives an overview of how the scheduler is implemented.

• Tasks - This guide explains how asynchronous tasks work and how to use them.

• Best Practices - This guide gives an overview of best practices for using Async.

• Debugging - This guide explains how to debug issues with programs that use Async.

• Thread safety - This guide explains thread safety in Ruby, focusing on fibers and threads, common pitfalls, and best practices to avoid problems like data corruption, race conditions, and deadlocks.

Releases

Please see the project releases for all releases.

v2.27.4

• Suppress excessive warning in Async::Scheduler#async.

v2.27.3

• Ensure trace attributes are strings, fixes integration with OpenTelemetry.

v2.27.2

• Fix context/index.yaml schema.

v2.27.1

• Updated documentation and agent context.

v2.27.0

• Async::Task#stop supports an optional cause: argument (that defaults to $!), which allows you to specify the cause (exception) for stopping the task.
• Add thread-safety agent context.

v2.26.0

• Async::Notification#signal now returns true if a task was signaled, false otherwise, providing better feedback for notification operations.
• require "async/limited_queue" is required to use Async::LimitedQueue without a deprecation warning. Async::LimitedQueue is not deprecated, but it's usage via async/queue is deprecated.
• Async::Task#sleep is deprecated with no replacement.
• Async::Task.yield is deprecated with no replacement.
• Async::Scheduler#async is deprecated, use Async{}, Sync{} or Async::Task#async instead.
• Agent context is now available, via the agent-context gem.
• Async::Barrier Improvements
• Introduce Async::Queue#close

v2.25.0

• Added support for io_select hook in the fiber scheduler, allowing non-blocking IO.select operations. This enables better integration with code that uses IO.select for multiplexing IO operations.
• Use IO::Event::WorkerPool for Blocking Operations
• Better handling of IO#close using fiber_interrupt

v2.24.0

• Ruby v3.1 support is dropped.
• Async::Wrapper which was previously deprecated, is now removed.
• Flexible Timeouts

v2.23.0

• Rename ASYNC_SCHEDULER_DEFAULT_WORKER_POOL to ASYNC_SCHEDULER_WORKER_POOL.
• Fiber Stall Profiler

v2.21.1

• Worker Pool

See Also

• async-http — Asynchronous HTTP client/server.
• async-websocket — Asynchronous client and server websockets.
• async-dns — Asynchronous DNS resolver and server.
• falcon — A rack compatible server built on top of async-http.
• rubydns — An easy to use Ruby DNS server.
• slack-ruby-bot — A client for making slack bots.

Contributing

We welcome contributions to this project.

• Fork it.
• Create your feature branch (git checkout -b my-new-feature).
• Commit your changes (git commit -am 'Add some feature').
• Push to the branch (git push origin my-new-feature).
• Create new Pull Request.

Developer Certificate of Origin

In order to protect users of this project, we require all contributors to comply with the Developer Certificate of Origin. This ensures that all contributions are properly licensed and attributed.

Community Guidelines

This project is best served by a collaborative and respectful environment. Treat each other professionally, respect differing viewpoints, and engage constructively. Harassment, discrimination, or harmful behavior is not tolerated. Communicate clearly, listen actively, and support one another. If any issues arise, please inform the project maintainers.