Event Models in Distributed Event Based Systems

Applications are regularly developed by composing functionality encapsulated in units of computation. Depending on the type of system these units of computation, components for short, include modules, classes, and programs. The functionality provided by components can be composed by procedural abstraction and implicit invocation (Garlan & Shaw, 1994; Dingel et al., 1998; Notkin et al., 1993). When composing functionality by procedural abstraction, also referred to as explicit invocation, names that identify a component are statically bound to the component implementing the functionality. This is the case of a function in one module invoking another function in another module, or a program in one computer using a Remote Procedure Call (RPC) to invoke functionality implemented by a different program on another computer. In contrast, when composing functionality by implicit invocation, a component announces an event. This event announcement triggers the invocation of functionality implemented by another component. The component announcing the event may or may not be required to know the name nor location of the component triggered by the event. aBsTRaCT