An event loop interface for interoperability.

v0.5.0 2017-01-05 10:19 UTC


The purpose of this specification is to provide a common interface for event loop implementations. This allows libraries and components from different vendors to operate in an event driven architecture, sharing a common event loop.

Current Status

This project is currently on hold and to be seen as failed for now. It might be reconsidered at a later point in time. The specification in its current state has been merged into Amp. Interoperability between ReactPHP and Amp will be solved via adapters instead of a common interface. Icicle has been deprecated and parts of it been merged into Amp libraries.

Why Bother?

Some programming languages, such as Javascript, have an event loop that is native to the execution environment. This allows package vendors to easily create asynchronous software that uses this native event loop. Although PHP is historically a synchronous programming environment, it is still possible to use asynchronous programming techniques. Using these techniques, package vendors have created event loop implementations that have seen success.

However, as these event loop implementations are from package vendors, it is not yet possible to create event driven software components that are independent of the underlying event loop implementation. By creating a common interface for an event loop, interoperability of this nature will be possible.


The functionality exposed by this interface should include the ability to:

  • Watch input streams for available data
  • Watch output streams for the ability to perform non-blocking write operations
  • Run single and periodic timers
  • Listen for signals
  • Defer the execution of callables


You can find available implementations on Packagist.

Compatible Packages

You can find compatible packages on Packagist.