Priority Scheduler Simulator
A priority scheduler always selects a ready process from the highest non-empty priority queue. Processes with the same priority follow FIFO order. This simulator uses three levels—High, Medium, and Low—and can optionally use aging to reduce starvation.
Selection orderHigh → Medium → Low
Same priorityFIFO
Preemption unitConfigurable quantum
Starvation controlOptional aging
Scheduler controls
Priority Queues
High PriorityFRONT → REAR
Medium PriorityFRONT → REAR
Low PriorityFRONT → REAR
Current Process
Add a process or load the example workload.
Current time0
Ready processes0
Completed0
Promotions0
Process metrics
| Process | Priority | Burst | Remaining | Arrival | Completion | Turnaround | Waiting |
|---|
Execution log
Priority scheduling concepts
Strict priority
A lower-priority queue is ignored whenever a higher-priority queue contains ready work.
FIFO tie breaking
Processes at the same priority level are served in arrival order. Unfinished work returns to the rear.
Starvation
A continuous stream of high-priority work can delay lower-priority processes for a very long time.
Aging
When aging is enabled, waiting processes can be promoted to a higher priority after reaching the threshold.
Algorithm summary
| Step | Action |
|---|---|
| 1 | Select the front process from the highest non-empty priority queue. |
| 2 | Run it for min(quantum, remaining time). |
| 3 | Complete it or return it to the rear of its current priority queue. |
| 4 | Promote waiting processes whose aging threshold has been reached. |