Process Management Exercise
Given the following data, prepare a Gantt Chart to a system based on priority andinterrupts ("preemptive"), where priority 1 is the highest and 3 is the lowest.
Process Priority Burst Time Tiempo de Llegada
P1 3 2 0
P2 1 3 0
P3 2 2 0
P4 2 5 4
P5 1 3 4
P6 2 2 8
P1 3 2 0
P2 1 3 0
P3 2 2 0
P4 2 5 4
P5 1 3 4
P6 2 2 8
Queue: P2/P3/P1 (in order of priority)
Time 0
P2 runs
Queue: -/P3/P1
Time 3: P2 ends
run P3
Queue: -/-/P1
Time 4: 2 new jobs
Queue: P5/P4/P1
P3 swapped out
P5 runs
Queue: -/P4,P3/P1
P5 runs
Time 7: P5 ends
P4 runs
Queue: -/P3/P1
Time 8: P6 arrives
Queue: -/P3,P6/P1
P4 continues to run
Time 12: P4 terminates
P3 runs
Queue: -/P6/P1
Time 13: P3 terminates
P6 runs
Queue -/-/P1
Time 15: P6 terminates
P1 runs
Time 17: P1 terminates
no more jobs in queue
This is just one scenario. Many parameters depend on the algorithm. Some have promotion (like the P1 job), some would run till the time slice is up before switching, even if a higher priority job is waiting, etc.
Check the above scheduling against your detailed algorithm (time slice, promotion, etc.) and make necessary adjustments.
To prepare a Gantt Chart for the given system based on priority and interrupts, follow these steps:
1. Sort the processes based on their priority in descending order:
Priority 1 - P2, P5
Priority 2 - P3, P4, P6
Priority 3 - P1
2. Determine the total execution time by summing up the burst times of all processes:
Total execution time = 2 + 3 + 2 + 5 + 3 + 2 = 17
3. Create the Gantt Chart by representing time intervals and the processes running during those intervals. Start from time 0 and assign processes according to their priority. For the preemptive approach, if a process with higher priority arrives during the execution of a lower priority process, it will preempt the lower priority process and start executing.
Here is the Gantt Chart:
| Time | Process |
|---------|---------|
| 0 | P2 |
| 3 | P5 |
| 6 | P3 |
| 8 | P4 |
| 10 | P1 |
| 11 | P6 |
Explanation:
- At time 0, P2 starts executing as it has the highest priority.
- At time 3, P2 finishes executing, and P5 starts executing as it has the second-highest priority.
- At time 6, P5 finishes executing, and P3 starts executing as it has the next highest priority.
- At time 8, P3 is preempted by P4 as it has a higher priority.
- At time 10, P4 is preempted by P1 as it has the highest priority.
- At time 11, P1 finishes executing, and P6 starts executing as it has the next highest priority.
Note: The time column represents the time intervals, and the process column represents the respective process running during that interval.
This Gantt Chart represents the execution order of processes based on their priority and interrupts ("preemptive").