Cooperating Resource Managers

Operating System designers currently face two major challenges. One is the coexistence of time-sharing and dynamic real-time components on a single machine and even in the same application. The other is that many acceleration techniques (e.g. caches) used in modern hardware architectures work very well for the average case, but not for the worst case which counts for real-time systems. This scenario is addressed by DROPS, the Dresden Realtime OPerating System. DROPS uses resource managers which have been and still are being built in an ad hoc manner and that allow the reservation of resources, the enforcement of the reservations and the usage of unreserved or reserved but unused resources for other, non-real-time applications. While these resource managers have been built and work very well and are well published (see e.g. [5, 9, 3]), they all have their own, unique ad hoc interface. This paper describes a more unified, systematic approach that is applicable at various system levels and allows a systematic construction of applications using cooperating resource managers.