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Ivy is a software bus designed at CENA (France). A software bus is a system -that allows software applications to exchange information with the illusion of -broadcasting that information, selection being performed by the receiving -applications. Using a software bus is very similar to dealing with events in a -graphical toolkit: on one side, messages are emitted without caring about who -will handle them, and on the other side, one decide to handle the messages that -have a certain type or follow a certain pattern. Software buses are mainly aimed -at facilitating the rapid development of new agents, and at managing a dynamic -collection of agents on the bus: agents show up, emit messages and receive some, -then leave the bus without blocking the others. -
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As opposed to other software buses, Ivy does not depend on a centralised -server. Actually, Ivy is mostly a communication convention between processes, -implemented through a collection of libraries in several languages. -
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From the programmer's point of view, Ivy is an information broadcasting -channel. The main functions are: -
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Ivy's -decentralised connection scheme probably incurs limitations in terms of how many -applications can be connected to an Ivy bus, but this simplifies management a -lot. Basically, an Ivy bus is just a set of applications that decide to -communicate together. The only conventions between these applications are: -
The messages are exchanged in text format, and bindings are based on regular
-expressions with captures. If an application subscribes to
-HELLO (.*) and if another application emits the message HELLO WORLD, a
-callback will be called in the first application with WORLD as an argument.
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You can use Ivy through applications that have been provided to you. This is the
-case for ivyprobe, an Ivy agent that allows you to examine the messages
-exchanged on a given bus and to send messages on that bus. You can refer to the
-web site http: for a list of available agents. However, what you will
-usually want to do is to develop your own applications. In order to do that you
-can use an Ivy connection kit, that is a library that implements Ivy.
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Libraries that implement Ivy are available in the following environments: -
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Connecting your application to an Ivy bus just consists in choosing the -appropriate library, add the appropriate message emission and reception calls to -your code, use the main loop provided in the library or make the necessary -integrations, and get your code running! -
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The Ivy C library (aka Ivy-C or ivy-c) is a C library that allows you to connect -applications to an Ivy bus. You can use it to write applications in C or any -other language that supports C extensions. This guide documents how you can do -that. -
The Ivy C library is known to compile and work in WindowsNT and Linux -environments. It should be easy to use on most Posix environments. -
The Ivy C library was originally developed by François-Régis Colin at CENA. It -is maintained by the CENA-Toulouse team. -
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