Multi-Algorithm Process Scheduling Simulator in Java

Understanding the Java Process Scheduling Simulator

This Java program, serving as a process scheduling simulator, utilizes various algorithms like FCFS, SPN, PP, and PRR to manage the execution of processes. It reads input from a file, initializes processes, and employs modular scheduling algorithms to simulate their execution. The design allows for easy expansion or modification of scheduling strategies. For students seeking assistance with Java assignment, this code provides a practical illustration of process scheduling principles and algorithms. Through comprehensive metric calculations and a summary overview, users gain insights into the comparative performance of different scheduling methodologies. This resource can be invaluable for understanding and implementing process management concepts to enhance Java programming skills.

Block 1: Imports and Class Declarations

import java.util.*;
import javax.imageio.plugins.tiff.TIFFDirectory;
import java.io.File;
import java.io.FileNotFoundException;
class Summary { ... }
class Process { ... }
public class A1 { ... }

Discussion: This block includes the necessary Java imports and class declarations. Summary and Process are used to store summary and process information, respectively. The main class is A1, which contains the main method for the program.

Block 2: Class Process Implementation

class Process {
String id;
int arrivalTime;
int serviceTime;
int priority;
int turnAroundTime;
int waitTime;
int endTime;
Process() { }
Process(String id, int arrivalTime, int serviceTime, int priority) { ... }
public void resetTimes() { ... }
}

Discussion: This block defines the Process class, representing a process with attributes like id, arrival time, service time, priority, etc. It includes a parameterized constructor and a method resetTimes to reset turnaround time, wait time, and end time.

Block 3: Class A1 and Main Method


public class A1 {
static int dispatcherTime;
static Summary fcfsSummary;
static Summary spnSummary;
static Summary ppnSummary;
public static void main(String[] args) { ... }
static void runSchedulingAlgorithms(List

processes) { ... }
static void fcfsAlgorithm(List

processes) { ... }
static void spnAlgorithm(List

processes) { ... }
static void ppAlgorithm(List

processes) { ... }
static void prrAlgorithm(List

processes) { ... }
static void calculateAndPrintMetrics(List

processes) { ... }
static Summary calculateSummaryMetrics(List

processes) { ... }
static void resetProcessTimes(List

processes) { ... }
static void printSummary(List
 processes) { ... }
}

Discussion: This block defines the main class A1 and its static methods. The class contains static variables for dispatcher time and summary metrics. The main method reads input, initializes a list of processes, and then calls the scheduling algorithms and prints the summary.

Block 4: Input Processing in Main Method

if (args.length != 1) { ... }
String inputFilePath = args[0];
try { ... }

Discussion: This block checks if the correct number of command-line arguments is provided. It then reads the input file, initializes a scanner, and processes the input file to extract process information and dispatcher time.

Block 5: Scheduling Algorithm Runner


static void runSchedulingAlgorithms(List
 processes) { ... }

Discussion: This block sorts the list of processes by arrival time and then calls each scheduling algorithm (FCFS, SPN, PP, PRR) with a copy of the processes list.

Block 6: Scheduling Algorithms (FCFS, SPN, PP, PRR)


static void fcfsAlgorithm(List

processes) { ... }
static void spnAlgorithm(List

processes) { ... }
static void ppAlgorithm(List

processes) { ... }
static void prrAlgorithm(List
 processes) { ... }

Discussion: These blocks implement the FCFS, SPN, PP, and PRR scheduling algorithms. Each algorithm prints the sequence of processes executed, updates metrics, and finally calculates and prints summary metrics.

Block 7: Metrics Calculation and Printing


static void calculateAndPrintMetrics(List
 processes) { ... }

Discussion: This block calculates and prints the turnaround time and waiting time for each process.

Block 8: Summary Metrics Calculation


static void calculateAndPrintMetrics(List

processes) {
// ... (calculating and printing metrics)
}
static Summary calculateSummaryMetrics(List
 processes) {
// ... (calculating summary metrics)
}

Discussion: These methods calculate and print process metrics and summary metrics.

Block 9: Process Times Reset


static void resetProcessTimes(List
 processes) {
// ... (resetting process times)
}

Discussion: This block resets the turnaround time, wait time, and end time for each process in the given list.

Block 10: Summary Printing


static void printSummary(List
 processes) {
// ... (printing the summary metrics for each algorithm)
}

Discussion: Prints the summary metrics for each scheduling algorithm.

Conclusion

In conclusion, this Java process scheduling simulator offers a valuable resource for comprehending and implementing diverse scheduling algorithms. Through its modular design and comprehensive metric calculations, it not only aids in understanding core principles of process management but also serves as a practical tool for students grappling with Java assignments. The simulator's flexibility allows users to explore and experiment with various scheduling strategies, fostering a deeper insight into their comparative performances. As an educational resource, it strikes a balance between theoretical understanding and hands-on application, making it an excellent companion for those aiming to enhance their proficiency in Java programming and grasp the intricacies of process scheduling in a practical context.

Java Process Scheduling Simulator with Multiple Algorithms