Location of Repository

The application of scheduler agents in time-triggered embedded systems

By Lei Dong


This thesis is concerned with the monitoring of embedded systems in which timing behaviour is the key concern. The focus of this work is on the development of a “scheduler agent” (SA) which is used to monitor the temporal behaviour of embedded systems. It is assumed that the system to be monitored employs a time-triggered software architecture. \ud This thesis begins by providing a review of timing issues in embedded systems, and followed by a review of previous research on runtime monitoring techniques (including hardware, software and “hybrid” approaches). \ud The SA is then introduced. It consists of two parts: an internal monitor (IM) and an external analyzer (EA). Both of the IM and the EA have to work cooperatively in order to obtain information from the target system. The communication between them relies on a GPIO interface. However, an encoding technique is required since modern microcontrollers may not have enough GPIO port pins to represent all tasks in the target system. A simple and effective encoding technique has been introduced in this thesis to address this issue. \ud Two versions of the SA – Passive SA (PSA) and Active SA (ASA) – are implemented. PSA retrieves task information from the “instrumented” target system passively. ASA takes advantages from the TTC architecture employed by the target system, in which the monitoring process collects information from the target system at the time when a task is due to start and end. \ud We also developed a SA automation tool which can automatically generate the SA code for the external analyzer and the target system. This tool is used in the case study to generate the source code for both PSA and ASA. In the case study presented in this thesis, we confirm that the functionality of SA has in line with its requirements, since it is capable to measure task execution time and detect temporal errors in the target system. \ud Finally, the conclusions of this thesis with a discussion of the results and some suggestions for further work in this important area are presented

Publisher: University of Leicester
Year: 2011
OAI identifier: oai:lra.le.ac.uk:2381/9630

Suggested articles



  1. (2000). A Review of Worst-Case Execution-Time Analysis " doi
  2. (1999). A solution to the time jitter removal in deadline based scheduling of real-time applications.
  3. (2004). A Taxonomy and Catalog of Runtime SoftwareFault Monitoring Tools." doi
  4. (1996). Adaptive software fault tolerance policies with dynamic real-time guarantees. doi
  5. (1997). Agent-based software engineering." Software Engineering. doi
  6. (1995). An accurate worst-case timing analysis for risc processors." doi
  7. (1999). An Algorithm for Fault-Tolerant Clock State&Rate Synchronization. doi
  8. (2002). An introduction to multiagent systems, doi
  9. (1981). An Introduction to Real-Time Software Design, doi
  10. (2002). Analysis and design of real-time control systems with varying control timing constraints. Automatic Control Department, doi
  11. (2004). Analysis and synthesis of distributed real- time embedded systems, doi
  12. (2002). Difficulties in computing the WCET for processors with speculative execution. 2nd International Workshop o n Worst Case Execution Time Analysis,
  13. (1999). Digital networks in the automotive vehicle." doi
  14. (1999). Efficient and precise cache behavior prediction for real-time systems."
  15. (2008). Efficient Monitoring of Embedded RealTime Systems. Information Technology: New Generations, doi
  16. (1997). Efficient run-time monitoring of timing constraints. doi
  17. (2002). Embedded system design doi
  18. (2006). Embedded system design, doi
  19. (2003). Embedded systems dictionary, doi
  20. (2008). Embedded Systems Scheduling Monitoring. Systems, doi
  21. (2003). Execution-time clocks and Ravenscar kernels. doi
  22. (2007). Fault tolerant systems, doi
  23. (2007). Fault-tolerant time-triggered communication using CAN." doi
  24. (2002). Hard real- time computing systems predictable scheduling algorithms and applicaions, K luwer academic publisher.
  25. (1989). Hardware Monitoring of a Multiprocessor System." doi
  26. (2000). Highly Dependable Time-Triggered Operating System. doi
  27. (2003). How does control timing affect performance? Analysis and simulation of timing using J itterbug and TrueTime. doi
  28. (2003). Implement ing role-based interactions for Internet agents. Applications and the Internet, doi
  29. (2007). Improving the performance of time-triggered doi
  30. (2007). Improving the performance of timetriggered embedded systems by means of a scheduler agent, doi
  31. (2007). Improving the reliability of embedded systems using ‘scheduler agents’. Poster presentation at “Festival of Postgraduate Research,”
  32. (1995). Intelligent agents: theory and practice." doi
  33. (1996). Is it an Agent, or just a Program? A Taxonomy for Autonomous Agents. doi
  34. (2004). Jitter models for the design and test of Gbps-speed serial interconnects." doi
  35. (2002). Managing complex temporal requirements in real-time control systems. doi
  36. (2005). Measurement-Based Worst-Case Execution Time Analysis. doi
  37. (2007). Measurements or Static Analysis or Both.
  38. (2001). Minimal Invasive Monitoring. doi
  39. (2001). Monitoring and configuration in a Smart Transducer Network. doi
  40. (1992). Monitoring and debugging distributed realtime programs." doi
  41. (1995). Monitoring of Distributed Systems. doi
  42. (2007). Monitoring of Timing Constraints with Confidence Threshold Requirements." Computers, doi
  43. (1999). Multiagent Systems: A Modern Approach to Distributed Artificial Intelligence, doi
  44. (2001). On Real-Time Control Tasks Schedulability.
  45. (2004). On-Chip Monitoring for Non-Intrusive Hardware/Software Observability”.
  46. (2002). Processor Pipelines and Static Worst-Case Execution Time Analys is.
  47. (2002). Processor pipelines and their properties for static WCET analysis. doi
  48. (2006). Programming execution-time servers in ada doi
  49. (2005). Rate monotonic vs. EDF: judgment day." Real-Time Syst. doi
  50. (2004). Real Time Scheduling Theory: A Historical Perspective." Real-Time Syst. doi
  51. (1997). Real- time dystems: design principles for distributed embedded app lications,
  52. (2001). Real- time systems and software. doi
  53. (2006). Real-time in embedded systems. Embedded systems doi
  54. (2000). Real-Time Systems, doi
  55. (1997). Real-time UML: Developing efficient objects for embedded systems, doi
  56. (2002). Reliability of Computer Systems and Networks: Fault Tolerance, Analysis, and Design, doi
  57. (2001). Reliable and Precise WCET Determination for a Real-Life Processor. Embedded Software: doi
  58. (2005). Safe measurement-based WCET estimation.
  59. (1973). Scheduling algorithms for multiprogramming in a hard real-time environment." doi
  60. (1992). Software architecture for hard real- time applications: Cyclic executives vs. fixed pr iority executives." doi
  61. (2003). Task graph extraction for embedded system synthesis. doi
  62. (2006). The application of ‘scheduler agents’ in time-triggered embedded systems. Poster presentation at “Festival of Postgraduate Research,”
  63. (1989). The cyclic executive model and Ada." doi
  64. (1993). The end of line for static cyclic scheduling? Fifth Euromicro Workshop on Real-Time Systems. doi
  65. (2007). The maintenance and evolution of resourceconstrained embedded systems created using design patterns." doi
  66. (1991). The static analysis of a safety-critical avionics control system. Air Transport Safety:
  67. (2007). Time-Predictable Task Preemption for Real-Time Systems with Direct-Mapped Instruction Cache. The 10t h doi
  68. (2007). Two novel shared-clock scheduling algorithms for use with CAN-based distributed systems." doi
  69. (2001). Understanding Jitter: Getting Started, Wavecrest Corporation.
  70. (2000). Validating a worst-case execution-time analysis method for an embedded processor. doi
  71. (2000). Worst Case Execution Time Analysis for a Processor with Branch Prediction." Real-Time Systems doi
  72. (2001). Worst-Case Execution-Time Analysis for Embedded Real-Time Systems." doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.