+
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 Perl library (aka Ivy-Perl or ivy-perl) is a Perl library that allows you to connect +applications to an Ivy bus. You can use it to write applications in Perl or any +other language that supports Perl extensions (Perl/Tk for instance). This guide documents how you can do +that. +
The Ivy Perl library is known to compile and work in WindowsNT and Linux +environments. It should be easy to use on most Posix environments. +
The Ivy Perl library was originally developed by Alexandre Bustico at CENA. It +is maintained by the CENA-Toulouse team. +
+