Michal Sojka, Czech Technical University
Pavel Pisa, Czech Technical University
Martin Molnar, Czech Technical University

Component-based development of distributed real-time applications is a challenging task since satisfying timing requirements of individual components after system integration requires support from the component middleware which is not common today. This paper presents a software architecture of a contract-based on-line resource reservation framework which can be used as a basis for a real-time component-based middleware. The architecture was developed within EU project FRESCOR and its main contribution is the modularity which enables the framework to support many different resources such as CPUs, networks, disks etc. The basis of the middleware is the contract between the application and the middleware.  Application specifies in the contract its timing requirements and the framework guaranties the availability of the resources to application so that the requirements can be fulfilled.

To manage the CPU resource, the framework uses cgroups subsystem of Linux. We have conducted several experiments in which we measure the overhead and other properties of the framework. We also discuss and measure how the framework operates in a distributed system with multiple nodes connected by Ethernet. Finally, we conclude with current limitations of the framework and with future development directions.