Separation of processing and coordination in computer systems

Systems are built for a purpose. The purpose transacted is usually handled by the processing part of a system and is observed and adjusted by coordination parts. In principle, these two kinds of system parts share the same target resource; the thing that is controlled by processing and indirectly by coordination subsystems. This leads to mutual influences, which can result in timing and priorities violations as well as performance degradations. The presented pattern, SEPARATION OF PROCESSING AND COORDINATION, provides an architectural solution which shows how processing subsystems can be observed and adjusted by coordination subsystems. We show this pattern in the context of self-adaptive software systems, industrial control devices, a real-time operating system, and a hardware architecture for wireless embedded platforms.