1 / 12

Cheddar – Real Time Simulator

Cheddar – Real Time Simulator. Scheduling with task dependencies. Task Dependencies. Meaning…… resources shared by several tasks (ex : semaphores) precedencies relationship between several tasks (like constraints between the end of a task and the start of another one). Types Of Tools.

maeve
Download Presentation

Cheddar – Real Time Simulator

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cheddar – Real Time Simulator Scheduling with task dependencies

  2. Task Dependencies • Meaning…… • resources shared by several tasks (ex : semaphores) • precedencies relationship between several tasks (like constraints between the end of a task and the start of another one).

  3. Types Of Tools • Shared resources analysis tools • Task precedencies analysis tools • Buffer analysis tools

  4. Task precedencies analysis tools • With Cheddar, dependencies are links between at least two tasks • Three different types of dependencies • Precedencies • Message and • Buffer dependencies

  5. Types Of Dependencies • Precendencies express order constraints between end or begin of task execution. • Message dependencies expressed relationship between a sender and a receiver task of a given message. • Buffer dependencies expressed relationship between producer and consumer of data in a given buffer.

  6. Precedencies Graph • Tasks -> circles. • Messages -> rectangles. • Buffers -> envelopes.

  7. Typical Precedencies Graph

  8. An Example • Different Parameters • Periodic Tasks - T1(4,1), T2(5,2), T3(5,1) • Aperiodic Task – T4(10,2) • EDF Scheduler • Preemptive • Precedence: T3  T2

  9. Precedence Graph

  10. Simulation Result

  11. Some Limitations… • Capacity Is Integer Only. • Aperiodic Job Cannot Be Done On Rate Monotonic Scheduler. • For Task Precedencies, Tasks Must Have Equal Periods…

  12. Project Files • Information stored during a simulation can be saved into Project Files • A project file is a XML file • Correct structure of the Project Files can be checked by the tool dump_sys • dump_sys just read, parses and displays to the screen the content of a XML Cheddar project file.

More Related