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Refactor ProcessDetails and PreemptivePriorityScheduling (#5448)

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* Refactor ProcessDetails and PreemptivePriorityScheduling for consistency

* fix formatting

* fix formatting

* Improve test readability and maintainability
This commit is contained in:
doxxx
2024-09-11 21:49:36 +09:00
committed by GitHub
parent 65e32641fc
commit 648572a8c5
3 changed files with 55 additions and 46 deletions
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12
src/main/java/com/thealgorithms/devutils/entities/ProcessDetails.java
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@ -6,6 +6,14 @@ public class ProcessDetails {
private int burstTime;
private int waitingTime;
private int turnAroundTime;
private int priority;
public ProcessDetails(final String processId, final int arrivalTime, final int burstTime, int priority) {
this.processId = processId;
this.arrivalTime = arrivalTime;
this.burstTime = burstTime;
this.priority = priority;
}
public ProcessDetails(final String processId, final int arrivalTime, final int burstTime) {
this.processId = processId;
@ -33,6 +41,10 @@ public class ProcessDetails {
return turnAroundTime;
}
public int getPriority() {
return priority;
}
public void setProcessId(final String processId) {
this.processId = processId;
}

54
src/main/java/com/thealgorithms/scheduling/PreemptivePriorityScheduling.java
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@ -1,5 +1,6 @@
package com.thealgorithms.scheduling;
import com.thealgorithms.devutils.entities.ProcessDetails;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
@ -7,44 +8,35 @@ import java.util.PriorityQueue;
/**
* Preemptive Priority Scheduling Algorithm
*
* @author [Bama Charan Chhandogi](https://www.github.com/BamaCharanChhandogi)
*/
public class PreemptivePriorityScheduling {
protected final List<ProcessDetails> processes;
protected final List<String> ganttChart;
class Process {
String name;
int arrivalTime;
int burstTime;
int priority;
Process(String name, int arrivalTime, int burstTime, int priority) {
this.name = name;
this.arrivalTime = arrivalTime;
this.burstTime = burstTime;
this.priority = priority;
public PreemptivePriorityScheduling(List<ProcessDetails> processes) {
this.processes = new ArrayList<>(processes);
this.ganttChart = new ArrayList<>();
}
}
public final class PreemptivePriorityScheduling {
private PreemptivePriorityScheduling() {
}
public static List<String> preemptivePriorityScheduling(List<Process> processes) {
List<String> ganttChart = new ArrayList<>();
PriorityQueue<Process> readyQueue = new PriorityQueue<>(Comparator.comparingInt(p -> - p.priority));
public void scheduleProcesses() {
PriorityQueue<ProcessDetails> readyQueue = new PriorityQueue<>(Comparator.comparingInt(ProcessDetails::getPriority).reversed().thenComparingInt(ProcessDetails::getArrivalTime));
int currentTime = 0;
List<ProcessDetails> arrivedProcesses = new ArrayList<>();
while (!processes.isEmpty() || !readyQueue.isEmpty()) {
while (!processes.isEmpty() && processes.get(0).arrivalTime <= currentTime) {
readyQueue.add(processes.remove(0));
}
updateArrivedProcesses(currentTime, arrivedProcesses);
readyQueue.addAll(arrivedProcesses);
arrivedProcesses.clear();
if (!readyQueue.isEmpty()) {
Process currentProcess = readyQueue.poll();
ProcessDetails currentProcess = readyQueue.poll();
ganttChart.add(currentProcess.getProcessId());
currentProcess.setBurstTime(currentProcess.getBurstTime() - 1);
ganttChart.add(currentProcess.name);
currentProcess.burstTime--;
if (currentProcess.burstTime > 0) {
if (currentProcess.getBurstTime() > 0) {
readyQueue.add(currentProcess);
}
} else {
@ -53,7 +45,15 @@ public final class PreemptivePriorityScheduling {
currentTime++;
}
}
return ganttChart;
private void updateArrivedProcesses(int currentTime, List<ProcessDetails> arrivedProcesses) {
processes.removeIf(process -> {
if (process.getArrivalTime() <= currentTime) {
arrivedProcesses.add(process);
return true;
}
return false;
});
}
}