Abstract
Real-time multiprocessor systems are being used extensively in industrial applications. Ada provides ample support for such systems, including a complete tasking model providing time predictability, especially when restricted by the Ravenscar profile. A fundamental element of this tasking model is inter-task communication by means of protected objects. The definition of resource locking policies with bounded priority inversion is a fundamental aspect of protected objects, which has received considerable attention, with some interesting results that can be used in multiprocessor real-time systems. However, there is another important subject, the service policy for protected entries, that has received less attention in the research community and is also important in order to guarantee a predictable time behaviour. The impact of the service model on the response time analysis of multiprocessor real-time systems is evaluated in the paper for the self-service model and the proxy model, and their relation to the MSRP and the MrsP locking policies is discussed. Extensions to response time analysis for the proxy model with both locking policies are also contributed.
This work has been partially funded by the Spanish National R&D&I plan (project M2C2, TIN2014-56158-C4-3-P).
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
For this bound to be effective it must be assumed that the task set is static, or at least that there is a bound on the number of caller tasks for the resource.
- 2.
Following Ada convention, a higher value indicates a higher priority.
References
Ada Reference Manual, ISO/IEC 8652:2012(E) with COR.1:2016 (2016). http://www.ada-auth.org/arm.html
Baker, T.P.: A stack-based resource allocation policy for realtime processes. In: 1990 Proceedings of the 11th Real-Time Systems Symposium, pp. 191–200, December 1990
Baker, T.P.: Stack-based scheduling for realtime processes. Real-Time Syst. 3(1), 67–99 (1991)
Barnes, J.: Programming in Ada 2012. Cambridge University Press, Cambridge (2014)
Brandenburg, B.B.: Scheduling and locking in multiprocessor real-time operating systems. Ph.D. thesis, The University of North Carolina at Chapel Hill (2011)
Burns, A., Wellings, A.J.: Locking policies for multiprocessor Ada. Ada Lett. 33(2), 59–65 (2013)
Burns, A., Wellings, A.: Analysable Real-Time Systems: Programmed in Ada. CreateSpace Independent Publishing Platform (2016)
Burns, A., Wellings, A.J.: A schedulability compatible multiprocessor resource sharing protocol-MrsP. In: 2013 25th Euromicro Conference on Real-Time Systems (ECRTS), pp. 282–291. IEEE (2013)
Chouteau, F., Ruiz, J.F.: Design and implementation of a Ravenscar extension for multiprocessors. In: Romanovsky, A., Vardanega, T. (eds.) Ada-Europe 2011. LNCS, vol. 6652, pp. 31–45. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-21338-0_3
Davis, R.I., Burns, A.: A survey of hard real-time scheduling for multiprocessor systems. ACM Comput. Surv. 43(4), 35:1–35:44 (2011). http://doi.acm.org/10.1145/1978802.1978814
Gai, P., Lipari, G., Natale, M.D.: Minimizing memory utilization of real-time task sets in single and multi-processor systems-on-a-chip. In: Proceedings of the 22nd IEEE Real-Time Systems Symposium. IEEE Computer Society (2001)
Garrido, J., Zamorano, J., Alonso, A., de la Puente, J.A.: Evaluating MSRP and MrsP with the multiprocessor Ravenscar profile. In: Blieberger, J., Bader, M. (eds.) Ada-Europe 2017. LNCS, vol. 10300, pp. 3–17. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-60588-3_1
Garrido, J., Zhao, S., Burns, A., Wellings, A.: Supporting nested resources in MrsP. In: Blieberger, J., Bader, M. (eds.) Ada-Europe 2017. LNCS, vol. 10300, pp. 73–86. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-60588-3_5
Giering, E.W., Baker, T.P.: The GNU Ada Runtime Library (GNARL): design and implementation. In: WADAS 1994: Proceedings of the Eleventh Annual Washington Ada Symposium & Summer ACM SIGAda Meeting on Ada, pp. 97–107. ACM Press, New York (1994)
Giering, E.W., Mueller, F., Baker, T.P.: Implementing ada 9x features using posix threads: design issues. In: Proceedings of the Conference on TRI-Ada 1993, TRI-Ada 1993, pp. 214–228. ACM, New York (1993). http://doi.acm.org/10.1145/170657.170736
Lin, S., Wellings, A.J., Burns, A.: Ada 2012: resource sharing and multiprocessors. Ada Lett. 33(1), 32–44 (2013)
Miranda, J.: A detailed description of the GNU Ada run time (2003). http://www.iuma.ulpgc.es/users/jmiranda/gnat-rts/
Sha, L., Rajkumar, R., Lehoczky, J.P.: Priority inheritance protocols: an approach to real-time synchronization. IEEE Trans. Comput. 39(9), 1175–1185 (1990)
Wieder, A., Brandenburg, B.B.: On spin locks in AUTOSAR: blocking analysis of FIFO, unordered, and priority-ordered spin locks. In: Proceedings of the IEEE 34th Real-Time Systems Symposium, RTSS 2013, Vancouver, BC, Canada, 3–6 December 2013, pp. 45–56 (2013). https://doi.org/10.1109/RTSS.2013.13
Zhao, S., Garrido, J., Burns, A., Wellings, A.: New schedulability analysis for MrsP. In: 2017 IEEE 23rd International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA), pp. 1–10. IEEE (2017)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer International Publishing AG, part of Springer Nature
About this paper
Cite this paper
Garrido, J., Zamorano, J., Alonso, A., de la Puente, J.A. (2018). On the Effect of Protected Entry Servicing Policies on the Response Time of Ada Tasks. In: Casimiro, A., Ferreira, P. (eds) Reliable Software Technologies – Ada-Europe 2018. Ada-Europe 2018. Lecture Notes in Computer Science(), vol 10873. Springer, Cham. https://doi.org/10.1007/978-3-319-92432-8_5
Download citation
DOI: https://doi.org/10.1007/978-3-319-92432-8_5
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-92431-1
Online ISBN: 978-3-319-92432-8
eBook Packages: Computer ScienceComputer Science (R0)