Abstract
Next generation real-time systems will require greater flexibility and predictability than is commonly found in today's systems. These future systems include the space station, integrated vision/robotics/AI systems, collections of humans/robots coordinating to achieve common objectives (usually in hazardous environments such as undersea exploration or chemical plants), and various command and control applications. The complexity of such systems due to timing constraints, concurrency, and distribution is high. It is accepted that the synchronization, failure atomicity, and permanence properties of transactions aid in the development of distributed systems. However, little work has been done in exploiting transactions in a real-time context. We have been attempting to categorize real-time data into classes depending on their time, synchronization, atomicity, and permanence properties. Then, using the semantics of the data and the applications, we are developing special, tailored, real-time transactions that only supply the minimal properties necessary for that class. This reduces the system overhead in supporting access to various types of data. The eventual goal is to verify that timing requirements can be met.
- {1} Biyabani, S., "Criticalness Considerations in Task Allocation in Hard Real-Time Systems," Masters Thesis, Univ. of Mass, in preparation.Google Scholar
- {2} Blazewicz, J., "Deadline Scheduling of Tasks with Ready Times and Resource Constraints", Information Processing Letters, Vol. 8, No. 2, February 1979.Google ScholarCross Ref
- {3} Leinbaugh, D., "Guaranteed Response Times in a Hard Real-Time Environment," IEEE Trans on Soft Eng., Vol. SE-6, January 1980.Google ScholarDigital Library
- {4} M. L. Molle and Lenonard Kleinrock, "Virtual Time CSMA: Why Two Clocks are Better than One", IEEE transactions on Communications, Vol. COM-33, No. 9, September 1985.Google Scholar
- {5} Ramamritham, K.: and J. Stankovic, "Dynamic Task Scheduling in Distributed Hard Real-Time Systems," IEEE Software, Vol. 1, No. 3, July 1984.Google Scholar
- {6} Stankovic, J. and K. Ramamritham, "The Design of the Spring Kernel," Proc 1987 Real Time Systems Symposium, 1987.Google Scholar
- {7} Stankovic, J., and L. Sha, "The Principle of Segmentation," Technical Report, 1987.Google Scholar
- {8} Zhao, W., Ramamritham, K., and J. Stankovic, "Scheduling Tasks with Resource Requirements in Hard Real-Time Systems," IEEE Transactions on Software Engineering, May 1987. Google ScholarDigital Library
- {9} W. Zhao, and K. Ramamritham "Virtual Time CSMA Protocols for Hard Real-Time Communication", IEEE Transactions on Software Engineering, Vol. SE- 13, No. 8, August 1987. Google ScholarDigital Library
Index Terms
- On real-time transactions
Recommendations
Concurrency Control for Mixed Transactions in Real-Time Databases
Many recent studies have suggested that the optimistic concurrency control (OCC) protocols outperform the locking-based protocols in real-time database systems (RTDBS). However, the OCC protocols suffer from the problem of unnecessary transaction ...
Concurrency control for real-time database systems with mixed transactions
RTCSA '97: Proceedings of the 4th International Workshop on Real-Time Computing Systems and ApplicationsThis paper proposes a real-time concurrency control protocol called Reduced Ceiling Protocol (RCP) for database systems consisting of hard and soft real-time transactions. In the RCP, the schedulability of hard real-time transactions is guaranteed by ...
Comments