A Component Model for Separation of Control Flow from Computation in 
Component-Based Systems

Kung-Kiu Lau, Vladyslav Ukis, Perla Velasco and Zheng Wang
School of Computer Science, The University of Manchester
Manchester M13 9PL, United Kingdom
kung-kiu,vukis,velascop,zw@cs.man.ac.uk

Abstract:

Today's component models as well as architectural description languages (ADLs) 
compose components either using direct or indirect method calls. When using 
direct method calls, components carry out computation, originate control to 
and perform communication between each other. When using indirect message
calls, components are connected using connectors encapsulating communication 
between them. The components in these (ADL) systems are supposed to do 
computation only. However, in this paper we show that components in ADLs 
not only perform communication as intended but also originate control towards
connectors resulting again in a mixture of control and computation
inside components. To separate control from computation in component-based 
systems we have been developing a new component model aimed at separation of 
control from computation. In this paper we show how it can be used to
build modular and maintainable systems and argue that our component model 
has its place in Model-driven architecture.