Architecture and Mechanisms of the Multi-Change Control Layer (MCCL)
Final Report Abstract
The A1 project was engaged in developing the basic (software) architecture and the mechanisms for CCC to control changes of application and platform components. In this central role, A1 provided a networked run-time environment (RTE) for the C projects. This RTE was based on the Genode OS Framework that strictly applies the concepts of component-based operating systems and serviceoriented interfaces. Furthermore, A1 developed the MCC core models and algorithm for applying the methods developed in the B projects. In this regard, an overarching and modular framework for automated model-based integration was developed. There were three major scientific results that not only contributed to the MCC automation concept but are also relevant far beyond the application of CCC. A first accurate timing model was developed in order to enable worst-case response-time analysis for service-based architectures. Those architectures are receiving an increasing interest for shifting from statically configured systems to a dynamic/adaptive system configuration in which software components provide services to which other components can connect at runtime. Prominent examples for this are the robot operating system (ROS2) and Adaptive AUTOSAR. In conjunction with microkernels, a strong separation is possible on component-level, which is required for mixed-criticality systems. From a timing perspective, these systems substantially differ from the classical periodically executed task set used by the real-time research community. A major result was the task-chain model and analysis that accurately reflects the service-oriented communication by incorporating the particular precedence and blocking effects. An automated software configuration environment that is controlled by constraints on multiple design layers that builds the core MCC framework. This framework incrementally refines a platformand implementation-independent specification to a specific system configuration by automating design parameter decisions. Constraints are checked by admission tests. A backtracking algorithm allows an iterative design-space exploration if an admission test fails by revising the responsible decisions. Although parameter decisions and admission tests are assisted by constraint solving methods, we found that these methods cannot be efficiently applied for solving the configuration problem holistically. A self-aware monitoring environment to enforce multi-viewpoint contracts. A first technical contribution for closing the model-implementation gap by platform-centric self-awareness was done within A1 w.r.t. scheduling. We provide temporal isolation and enforcement by budget-based scheduling in the presence of uncertainty of required budgets (from software components) and scheduling overhead (from OS/kernel). By monitoring scheduling overheads and execution budgets, a long-term adaptation of models to the actual (observed) platform behaviour was enabled. CCC work on self-awareness influenced research far beyond the research group. Several related papers and special sessions in top journals and events, organized and authored with external partners, were strongly influenced by the results of A1. One major collaborative result of A1 was the demonstrations of the D1 and D2 showcases at the “Autonomous System Design” workshop and exhibition at the DATE19 conference in Florence, Italy. In both cases, A1 provided the software platform.
Publications
- A communication framework for distributed access control in microkernel-based systems. 12th Annual Workshop on Operating Systems Platforms for Embedded Real-Time Applications (OSPERT16), Toulouse, France, July 2016
M. Hamad, J. Schlatow, V. Prevelakis, and R. Ernst
(See online at https://doi.org/10.24355/dbbs.084-201806251501-3) - Response-Time Analysis for Task Chains in Communicating Threads. 22nd IEEE Real-Time Embedded Technology & Applications Symposium (RTAS 2016), Vienna, Austria, April 2016
J. Schlatow and R. Ernst
(See online at https://doi.org/10.1109/RTAS.2016.7461359) - Response-Time Analysis for Task Chains with Complex Precedence and Blocking Relations. International Conference on Embedded Software (EMSOFT), ACM Transactions on Embedded Computing Systems ESWEEK Special Issue, vol. 16, No. 5s, pp. 172:1-172:19, September 2017
J. Schlatow and R. Ernst
(See online at https://doi.org/10.1145/3126505) - Self-awareness in autonomous automotive systems. Proc. of the Conference on Design, Automation and Test in Europe (DATE), Lausanne, Switzerland, March 2017
J. Schlatow, M. Möstl, R. Ernst, M. Nolte, I. Jatzkowski, M. Maurer, C. Herber, and A. Herkersdorf
(See online at https://doi.org/10.23919/DATE.2017.7927145) - Towards model-based integration of component-based automotive software systems. Annual Conference of the IEEE Industrial Electronics Society (IECON17), Beijing, China, October 2017
J. Schlatow, M. Nolte, M. Möstl, I. Jatzkowski, R. Ernst, and M. Maurer
(See online at https://doi.org/10.1109/IECON.2017.8217479) - Data-Age Analysis and Optimisation for Cause-Effect Chains in Automotive Control Systems. IEEE Symposium on Industrial Embedded Systems (SIES), Graz, Austria, June 2018
J. Schlatow, M. Möstl, S. Tobuschat, T. Ishigooka, and R. Ernst
(See online at https://doi.org/10.1109/SIES.2018.8442077) - Hardware and Software Task Scheduling for ARM-FPGA Platforms. NASA/ESA Conference on Adaptive Hardware and Systems (AHS), Edinburgh, UK, August 2018
A. Dörflinger, M. Albers, J. Schlatow, B. Fiethe, H. Michalik, P. Keldenich, and S. P. Fekete
(See online at https://doi.org/10.1109/AHS.2018.8541481) - Platform-centric self-awareness as a key enabler for controlling changes. Proc. of the IEEE, vol. 106, no. 9, pp. 1543-1567, September 2018
M. Möstl, J. Schlatow, R. Ernst, N. Dutt, A. Nassar, A. Rahmani, F. Kurdahi, T. Wild, A. Sadighi, and A. Herkersdorf
(See online at https://doi.org/10.1109/JPROC.2018.2858023) - Synthesis of Monitors for Networked Systems With Heterogeneous Safety Requirements. IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, vol. 37, No. 11, pp. 2824-2834, November 2018
M. Möstl, J. Schlatow, and R. Ernst
(See online at https://doi.org/10.1109/TCAD.2018.2862458) - Controlling Concurrent Change - A Multiview Approach Toward Updatable Vehicle Automation Systems. Workshop on Autonomous Systems Design (ASD 2019) (Selma Saidi and Rolf Ernst and Dirk Ziegenbein, Ed.), vol. 68 of series OpenAccess Series in Informatics (OASIcs), Florence, Italy, March 2019
M. Möstl, M. Nolte, J. Schlatow, and R. Ernst
(See online at https://doi.org/10.4230/OASIcs.ASD.2019.4) - Demonstrating Controlled Change for Autonomous Space Vehicles. NASA/ESA Conference on Adaptive Hardware and Systems (AHS), Colchester, UK, July 2019
A. Dörflinger, M. Albers, B. Fiethe, H. Michalik, M. Möstl, J. Schlatow, and R. Ernst
(See online at https://doi.org/10.1109/AHS.2019.00010) - Self-aware scheduling for mixed-criticality component-based systems. Real-Time and Embedded Technology and Applications Symposium (RTAS), Montreal, Canada, April 2019
J. Schlatow, M. Möstl, and R. Ernst
(See online at https://doi.org/10.1109/RTAS.2019.00030)
