ach Documentation

Ach is a library that provides a publish-subscribe or message-bus form of IPC based on POSIX shared memory. Ach differs from other message passing transports with regard to head of line blocking. In ach, newer messages always supersede old messsages, regardless of whether or not a subscriber has seen the old message. Old messages will never block new messages. This behavior is suited to real-time systems where a subscriber is generally interested only in the latest version of a message.

Clients may be publishers and or subscribers. Publishers they push data to channels, and subscribers can then poll or wait on the channels for data.

Ach deals only with byte arrays. Any higher level data organization (records, dictionaries, etc) must be handled in the client application.

Todo:

better networking

Author:

Neil T. Dantam, MacOSX porting: Jon Olson

Developed at the Georgia Tech Humanoid Robotics Lab

Under Direction of Professor Mike Stilman

Copyright (c) 2008-2012, Georgia Tech Research Corporation. All rights reserved.

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