rm-sim

Rate-Monotonic Scheduler simulation

Link

• https://github.com/ereeq/rm-sim

Task details

• Thread T1 has a period of 1 unit
• Thread T2 has a period of 2 units
• Thread T3 has a period of 4 units
• Thread T4 has a period of 16 units
• Each thread will execute the same doWork method but run it a different number of times:
  • Thread T1 executes doWork 100 times
  • Thread T2 executes doWork 200 times
  • Thread T3 executes doWork 400 times
  • Thread T4 executes doWork 1600 times

Scheduler details

• Scheduler has a major frame of 16 frames.
• as a Rate-monotonic scheduler, T1 has the highest priority, as T4, lowest.
• Scheduler needs to be woken up by a periodic source (signal/timer/etc) and it shall schedule the threads
• The program shall run for 10 periods and then terminate, but not before printing out how many times each thread ran
• The scheduler takes and releases semaphores so that each thread may run at its assigned time, according to its priority
• The thread then releases a flag only if the "doWork" function is completed, which marks the completion
• If the next thread must run and the flag is not up, semaphore is taken and overrun count is +1

Results

References

• https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ScheduledExecutorService.html
• https://www.mkyong.com/java/java-scheduledexecutorservice-examples/