3.3.1.1.2 Implementation

A plug-in is a dynamic library written in C code. The library implements the methods specified by the interface. The Oracle Tuxedo plug-in framework supports multiple implementations (interceptors) for one interface.

Oracle Tuxedo supports two types of interceptors: Fan-out interceptors and Stack interceptors. The Oracle TSAM Plus Agent uses the Fan-out interceptors. The following figure displays the Oracle TSAM Plus Agent plug-in architecture.

Figure 3-1 Oracle TSAM Plus Agent Plug-in Architecture

When the Oracle Tuxedo infrastructure invokes plug-in A method X, plug-in A invokes method X of the intercepting plug-ins in the order specified by the InterceptionSeq attribute as follows:

• Plug-in 1 method is invoked
• Plug-in 1 method X is returned
• Plug-in 2 method X is invoked
• Plug-in 2 method X is returned
• Plug-in n method X is invoked
• Plug-in n method X of is returned

All plug-ins involved in the interceptor implement the same interface. Multiple occurrences of the same plug-in are not allowed in an interception sequence.

Oracle TSAM Plus Agent provides the Fan-out plug-in which allows you to write/create an interceptor plug-in.