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Earliest Deadline First (EDF) - Example

There are Four Tasks T1,T2,T3 and T4 with its release time, execution time and absolute Deadlines
T1(0,4,15)
T2(0,3,12)
T3(2,5,9)
T4(5,2,8)

At time 0, Task T1 and T2 are ready; T2 is having earlier deadline, so T2 is having higher priority
At time 2, T3 releases; and it preempts T2
at time 5, T4 releases; and it preempts T3 and completes it execution
at time 7, T3 resumes and completes;
at time 9, T2 resumes and completes;
at time 10, T1 starts and completes;

The following Diagram represents this


Comments

  1. Hi;
    I would like to use the Earliest Deadline First (EDF) Scheduling scheme for real time flow for network packet, but I have difficulty to implement the EDF using simulator ns-2.
    I'de like to know:
    1) How to add the information of absolute deadline in the packet (under ns-2)
    2) How to conceive a queue that will sort all the packets according
    to their absolute deadlines when a new packet arrive (undr ns-2).
    can you help me?
    Regards,
    Rabie

    ReplyDelete
  2. comment realiser un programme EDF et qulle structure de donnée etuliser

    ReplyDelete
  3. Can u provide me EDF code...

    ReplyDelete

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