Polyphony - Easy Concurrency for Ruby

Polyphony | pəˈlɪf(ə)ni |

1. Music the style of simultaneously combining a number of parts, each forming an individual melody and harmonizing with each other.
2. Programming a Ruby gem for concurrent programming focusing on performance and developer happiness.

Polyphony is a library for building concurrent applications in Ruby. Polyphony harnesses the power of Ruby fibers to provide a cooperative, sequential coprocess-based concurrency model. Under the hood, Polyphony uses libev as a high-performance event reactor that provides timers, I/O watchers and other asynchronous event primitives.

Polyphony makes it possible to use normal Ruby built-in classes like IO, and Socket in a concurrent fashion without having to resort to threads. Polyphony takes care of context-switching automatically whenever a blocking call like Socket#accept or IO#read is issued.

Features

• Full-blown, integrated, high-performance HTTP 1 / HTTP 2 / WebSocket server with TLS/SSL termination, automatic ALPN protocol selection, and body streaming.
• Co-operative scheduling of concurrent tasks using Ruby fibers.
• High-performance event reactor for handling I/O events and timers.
• Natural, sequential programming style that makes it easy to reason about concurrent code.
• Abstractions and constructs for controlling the execution of concurrent code: coprocesses, supervisors, throttling, resource pools etc.
• Code can use native networking classes and libraries, growing support for third-party gems such as pg and redis.
• Use stdlib classes such as TCPServer and TCPSocket and Net::HTTP.
• HTTP 1 / HTTP 2 client agent with persistent connections.
• Competitive performance and scalability characteristics, in terms of both throughput and memory consumption.

Prior Art

Polyphony draws inspiration from the following, in no particular order:

• nio4r and async (Polyphony's C-extension code is largely a spinoff of nio4r's)
• EventMachine
• Trio
• Erlang supervisors (and actually, Erlang in general)

Going further

To learn more about using Polyphony to build concurrent applications, read the technical overview below, or look at the included examples. A thorough reference is forthcoming.

Contributing to Polyphony

Issues and pull requests will be gladly accepted. Please use the git repository at https://github.com/digital-fabric/polyphony as your primary point of departure for contributing.