Implementation of HW-8 Multithreading is complete

.idea/.name

@@ -0,0 +1 @@
+Main.java

Report.md

@@ -0,0 +1,229 @@
+# Advanced Programming Assignment 8
+
+
+* Name: *Hesam Ghazi*
+* Student Number: *403222015*
+* Course: *Advanced Programming*
+
+---
+
+# Theoretical Questions
+
+## 1. `start()` vs `run()`
+
+### Question 1: What output do you get from the program? Why?
+
+The program prints something similar to the following:
+
+```
+Calling run()
+Running in: main
+Calling start()
+Running in: Thread-2
+```
+
+When `t1.run()` is called, the `run()` method executes like a normal Java method. It does **not** create a new thread, so it runs inside the current thread, which is the **main** thread.
+
+When `t2.start()` is called, the Java Virtual Machine creates a **new thread**, and that thread executes the `run()` method independently. Therefore, `Thread.currentThread().getName()` returns `"Thread-2"`.
+
+---
+
+### Question 2: What's the difference in behavior between calling `start()` and `run()`?
+
+| `start()`                                          | `run()`                                     |
+| -------------------------------------------------- | ------------------------------------------- |
+| Creates a new thread.                              | Does not create a new thread.               |
+| Executes `run()` concurrently.                     | Executes `run()` like a normal method call. |
+| The JVM schedules the new thread.                  | Runs immediately in the current thread.     |
+| Allows multiple threads to execute simultaneously. | No parallelism or concurrency occurs.       |
+
+For example:
+
+```java
+Thread thread = new Thread(new MyRunnable());
+
+thread.run();    // Executes on the current thread (main)
+thread.start();  // Executes on a new thread
+```
+
+Using `start()` is essential when we want to perform tasks concurrently.
+
+---
+
+# 2. Daemon Threads
+
+### Question 1: What output do you get from the program? Why?
+
+A typical output is:
+
+```
+Main thread ends.
+Daemon thread running...
+Daemon thread running...
+```
+
+Sometimes only the following is printed:
+
+```
+Main thread ends.
+```
+
+This happens because daemon threads are **background threads**. When the main (user) thread finishes and no other user threads remain, the JVM automatically terminates all daemon threads, even if they have not completed their work.
+
+Since the daemon thread sleeps for 500 ms in every iteration, it may be terminated before printing all twenty messages.
+
+---
+
+### Question 2: What happens if you remove `thread.setDaemon(true)`?
+
+If `thread.setDaemon(true)` is removed, the thread becomes a **user thread**.
+
+In this case, the JVM waits until the thread completes all twenty iterations before terminating the program.
+
+The output becomes similar to:
+
+```
+Main thread ends.
+Daemon thread running...
+Daemon thread running...
+...
+Daemon thread running...
+```
+
+The program will continue running for approximately **10 seconds** (20 × 500 ms).
+
+---
+
+### Question 3: What are some real-life use cases of daemon threads?
+
+Daemon threads are commonly used for background services that support the application but are not essential to its primary functionality.
+
+Examples include:
+
+* Garbage collection
+* Automatic cache cleanup
+* Logging services
+* Monitoring system resources
+* Background file synchronization
+* Session timeout checking
+* Periodic health checks
+* Scheduled maintenance tasks
+
+These tasks should stop automatically when the application exits, making daemon threads an appropriate choice.
+
+---
+
+# 3. A Shorter Way to Create Threads
+
+### Question 1: What output do you get from the program?
+
+The program prints:
+
+```
+Thread is running using a ...!
+```
+
+This message is printed by the newly created thread after `thread.start()` is called.
+
+---
+
+### Question 2: What is the `() -> { ... }` syntax called?
+
+The syntax
+
+```java
+() -> {
+    ...
+}
+```
+
+is called a **Lambda Expression**.
+
+Lambda expressions were introduced in **Java 8** as a concise way to implement functional interfaces such as `Runnable`.
+
+The previous code
+
+```java
+Thread thread = new Thread(() -> {
+    System.out.println("Thread is running using a ...!");
+});
+```
+
+is equivalent to
+
+```java
+Thread thread = new Thread(new Runnable() {
+    @Override
+    public void run() {
+        System.out.println("Thread is running using a ...!");
+    }
+});
+```
+
+---
+
+### Question 3: How is this code different from creating a class that extends `Thread` or implements `Runnable`?
+
+There are three common approaches for creating a thread.
+
+### 1. Extending `Thread`
+
+```java
+class MyThread extends Thread {
+    @Override
+    public void run() {
+        System.out.println("Running...");
+    }
+}
+```
+
+**Advantages**
+
+* Easy for simple examples.
+
+**Disadvantages**
+
+* Java supports only single inheritance.
+* The task is tightly coupled with the thread.
+
+---
+
+### 2. Implementing `Runnable`
+
+```java
+class MyRunnable implements Runnable {
+    @Override
+    public void run() {
+        System.out.println("Running...");
+    }
+}
+```
+
+**Advantages**
+
+* Better object-oriented design.
+* Allows inheritance from another class.
+* The task and the thread are separated.
+
+---
+
+### 3. Using a Lambda Expression
+
+```java
+Thread thread = new Thread(() -> {
+    System.out.println("Running...");
+});
+```
+
+**Advantages**
+
+* Very concise and readable.
+* Eliminates unnecessary boilerplate code.
+* Ideal for short tasks.
+* Still implements the `Runnable` interface internally.
+
+---
+
+## Conclusion
+
+Lambda expressions are the preferred choice for short and simple thread tasks because they produce cleaner and more maintainable code. For larger or reusable tasks, implementing `Runnable` is generally considered the best practice due to better separation of responsibilities. Extending `Thread` is the least flexible approach and is usually reserved for special cases.

src/main/java/ConsoleUI.java

@@ -0,0 +1,158 @@
+import java.util.List;
+
+public final class ConsoleUI {
+
+    private static final int BAR_WIDTH = 40;
+
+    private ConsoleUI() {
+    }
+
+    /**
+     * Clears the console.
+     */
+    public static void clearScreen() {
+        System.out.print("\033[H\033[2J");
+        System.out.flush();
+    }
+
+    /**
+     * Prints the application header.
+     */
+    public static void printHeader(String fileName, int totalSizeMB, int chunkCount) {
+
+        System.out.println("============================================================");
+        System.out.println("              SIMULATED DOWNLOAD MANAGER");
+        System.out.println("============================================================");
+        System.out.printf("File   : %s%n", fileName);
+        System.out.printf("Size   : %d MB%n", totalSizeMB);
+        System.out.printf("Chunks : %d%n", chunkCount);
+        System.out.println("============================================================");
+        System.out.println();
+    }
+
+    /**
+     * Prints overall download statistics.
+     */
+    public static void printOverallProgress(
+            double downloaded,
+            double total,
+            double speed,
+            double etaSeconds) {
+
+        double percent = total == 0
+                ? 100
+                : downloaded * 100.0 / total;
+
+        System.out.println("Overall Progress");
+        System.out.println(buildProgressBar(percent));
+
+        System.out.printf("Downloaded : %.1f / %.1f MB%n", downloaded, total);
+        System.out.printf("Progress   : %.1f%%%n", percent);
+        System.out.printf("Speed      : %.2f MB/s%n", speed);
+        System.out.printf("ETA        : %s%n", formatTime(etaSeconds));
+
+        System.out.println();
+    }
+
+    /**
+     * Prints each chunk's progress.
+     */
+    public static void printChunks(List<ChunkStatus> chunks) {
+
+        System.out.println("Chunks");
+
+        for (ChunkStatus chunk : chunks) {
+
+            double percent = chunk.getProgressPercentage();
+
+            System.out.printf(
+                    "Chunk %-2d %s %6.1f%% %s%n",
+                    chunk.getChunkId(),
+                    buildProgressBar(percent),
+                    percent,
+                    chunk.isCompleted() ? "✓" : ""
+            );
+        }
+
+        System.out.println();
+    }
+
+    /**
+     * Prints the final report.
+     */
+    public static void printFinalReport(List<ChunkStatus> chunks) {
+
+        System.out.println();
+        System.out.println("============================================================");
+        System.out.println("                    FINAL REPORT");
+        System.out.println("============================================================");
+
+        for (ChunkStatus chunk : chunks) {
+
+            System.out.printf(
+                    "Chunk %d : %.1f / %.1f MB | %.2f sec | %s%n",
+                    chunk.getChunkId(),
+                    chunk.getDownloadedMB(),
+                    chunk.getChunkSizeMB(),
+                    chunk.getDownloadDurationMs() / 1000.0,
+                    chunk.isCompleted() ? "Completed" : "Incomplete"
+            );
+        }
+
+        System.out.println("============================================================");
+    }
+
+    /**
+     * Builds a text progress bar.
+     */
+    public static String buildProgressBar(double percent) {
+
+        percent = Math.max(0, Math.min(100, percent));
+
+        int filled = (int) Math.round((percent / 100.0) * BAR_WIDTH);
+
+        StringBuilder sb = new StringBuilder();
+
+        sb.append("[");
+
+        for (int i = 0; i < BAR_WIDTH; i++) {
+
+            if (i < filled) {
+                sb.append("█");
+            } else {
+                sb.append("░");
+            }
+
+        }
+
+        sb.append("]");
+
+        return sb.toString();
+    }
+
+    /**
+     * Formats seconds as HH:MM:SS.
+     */
+    public static String formatTime(double seconds) {
+
+        if (seconds <= 0 || Double.isInfinite(seconds) || Double.isNaN(seconds)) {
+            return "--:--:--";
+        }
+
+        int total = (int) Math.round(seconds);
+
+        int hours = total / 3600;
+        int minutes = (total % 3600) / 60;
+        int secs = total % 60;
+
+        return String.format("%02d:%02d:%02d", hours, minutes, secs);
+    }
+
+    /**
+     * Thread-safe logging method.
+     */
+    public static synchronized void log(String message) {
+        System.out.println(message);
+    }
+
+}

src/main/java/DownloadStatistics.java

@@ -0,0 +1,89 @@
+/**
+ * Utility class for calculating download statistics such as
+ * percentage, speed, and estimated remaining time (ETA).
+ */
+public final class DownloadStatistics {
+
+    private DownloadStatistics() {
+        // Utility class
+    }
+
+    /**
+     * Calculates the overall download percentage.
+     *
+     * @param downloadedMB Downloaded amount in MB
+     * @param totalMB Total file size in MB
+     * @return Percentage between 0 and 100
+     */
+    public static double calculatePercentage(double downloadedMB, double totalMB) {
+
+        if (totalMB <= 0) {
+            return 100.0;
+        }
+
+        return (downloadedMB / totalMB) * 100.0;
+    }
+
+    /**
+     * Calculates the average download speed.
+     *
+     * @param downloadedMB Downloaded amount in MB
+     * @param elapsedMillis Elapsed time in milliseconds
+     * @return Speed in MB/s
+     */
+    public static double calculateSpeed(double downloadedMB, long elapsedMillis) {
+
+        if (elapsedMillis <= 0) {
+            return 0.0;
+        }
+
+        return downloadedMB / (elapsedMillis / 1000.0);
+    }
+
+    /**
+     * Calculates the estimated remaining time.
+     *
+     * @param downloadedMB Downloaded amount
+     * @param totalMB Total size
+     * @param speedMBps Current speed
+     * @return Remaining time in seconds
+     */
+    public static double calculateETA(
+            double downloadedMB,
+            double totalMB,
+            double speedMBps) {
+
+        if (speedMBps <= 0) {
+            return Double.POSITIVE_INFINITY;
+        }
+
+        double remaining = totalMB - downloadedMB;
+
+        if (remaining <= 0) {
+            return 0;
+        }
+
+        return remaining / speedMBps;
+    }
+
+    /**
+     * Formats a duration into HH:MM:SS.
+     *
+     * @param seconds Time in seconds
+     * @return Formatted time string
+     */
+    public static String formatTime(double seconds) {
+
+        if (Double.isInfinite(seconds) || Double.isNaN(seconds)) {
+            return "--:--:--";
+        }
+
+        int totalSeconds = (int) Math.round(seconds);
+
+        int hours = totalSeconds / 3600;
+        int minutes = (totalSeconds % 3600) / 60;
+        int secs = totalSeconds % 60;
+
+        return String.format("%02d:%02d:%02d", hours, minutes, secs);
+    }
+}

src/main/java/DownloadWorker.java

@@ -3,9 +3,9 @@ import java.util.Random;
 /**
  * Simulates downloading a single chunk of a file.
  *
- * <p>This class is intentionally provided as a skeleton for students.
+ * Each DownloadWorker is responsible for exactly one ChunkStatus object.
- * The main multithreading and simulation logic should be completed
+ * Since every worker only modifies its own ChunkStatus, no explicit
- * in the run() method.</p>
+ * synchronization is required.
  */
 public class DownloadWorker implements Runnable {
 
@@ -21,23 +21,80 @@ public class DownloadWorker implements Runnable {
 
     @Override
     public void run() {
-        // TODO: Record the chunk start time in chunkStatus.
+
+        // Record start time
+        chunkStatus.setStartTimeMs(System.currentTimeMillis());
+
         double downloaded = 0.0;
 
-        // TODO: Print a message that this chunk has started downloading.
+        System.out.printf(
+                "[%s] Chunk %d started (%.1f MB)%n",
+                Thread.currentThread().getName(),
+                chunkStatus.getChunkId(),
+                chunkStatus.getChunkSizeMB()
+        );
 
         while (downloaded < chunkStatus.getChunkSizeMB()) {
-            // TODO: Generate a random sleep delay between min and max delay.
+
-            // TODO: Sleep for that delay.
+            try {
-            // TODO: Generate a random download amount for this step.
+                // Random delay
-            // TODO: Increase downloaded, but do not go beyond chunk size.
+                int delay = random.nextInt(
-            // TODO: Save the updated downloaded value into chunkStatus.
+                        config.getMaxStepDelayMs() - config.getMinStepDelayMs() + 1
-            // TODO: Optionally print step-by-step progress.
+                ) + config.getMinStepDelayMs();
+
+                Thread.sleep(delay);
+
+            } catch (InterruptedException e) {
+
+                System.out.printf(
+                        "[%s] Chunk %d interrupted.%n",
+                        Thread.currentThread().getName(),
+                        chunkStatus.getChunkId()
+                );
+
+                Thread.currentThread().interrupt();
+                return;
+            }
+
+            // Random download amount
+            double step =
+                    config.getMinStepDownloadMB()
+                            + random.nextDouble()
+                            * (config.getMaxStepDownloadMB()
+                            - config.getMinStepDownloadMB());
+
+            downloaded += step;
+
+            // Prevent downloading beyond chunk size
+            if (downloaded > chunkStatus.getChunkSizeMB()) {
+                downloaded = chunkStatus.getChunkSizeMB();
+            }
+
+            // Save progress
+            chunkStatus.setDownloadedMB(downloaded);
+
+            // Optional step-by-step debug output
+            System.out.printf(
+                    "[%s] Chunk %d: %.1f/%.1f MB (%.1f%%)%n",
+                    Thread.currentThread().getName(),
+                    chunkStatus.getChunkId(),
+                    chunkStatus.getDownloadedMB(),
+                    chunkStatus.getChunkSizeMB(),
+                    chunkStatus.getProgressPercentage()
+            );
         }
 
-        // TODO: Mark the chunk as completed.
+        // Mark completed
-        // TODO: Record the chunk end time in chunkStatus.
+        chunkStatus.setCompleted(true);
-        // TODO: Print a message that this chunk has finished downloading.
-    }
 
-}
+        // Record finish time
+        chunkStatus.setEndTimeMs(System.currentTimeMillis());
+
+        System.out.printf(
+                "[%s] Chunk %d completed in %.2f seconds.%n",
+                Thread.currentThread().getName(),
+                chunkStatus.getChunkId(),
+                chunkStatus.getDownloadDurationMs() / 1000.0
+        );
+    }
+}

src/main/java/Main.java

@@ -2,11 +2,16 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class Main {
+
     public static void main(String[] args) {
-        System.out.println("=== Simulated Download Manager ===");
+
+        System.out.println("=================================================");
+        System.out.println("         SIMULATED DOWNLOAD MANAGER");
+        System.out.println("=================================================");
 
         // 1. Read config
         DownloadConfig config;
+
         try {
             config = ConfigReader.readConfig("download_config.txt");
         } catch (Exception e) {
@@ -14,94 +19,150 @@ public class Main {
             return;
         }
 
-        System.out.println("File name: " + config.getFileName());
+        System.out.println("File Name  : " + config.getFileName());
-        System.out.println("Total size (MB): " + config.getTotalSizeMB());
+        System.out.println("File Size  : " + config.getTotalSizeMB() + " MB");
-        System.out.println("Chunk count: " + config.getChunkCount());
+        System.out.println("Chunk Count: " + config.getChunkCount());
+        System.out.println("Delay Range: "
+                + config.getMinStepDelayMs()
+                + " - "
+                + config.getMaxStepDelayMs()
+                + " ms");
+        System.out.println("Step Range : "
+                + config.getMinStepDownloadMB()
+                + " - "
+                + config.getMaxStepDownloadMB()
+                + " MB");
         System.out.println();
 
+        long simulationStart = System.currentTimeMillis();
+
         // 2. Create chunks
         List<ChunkStatus> chunks = ChunkUtils.createChunks(
                 config.getTotalSizeMB(),
                 config.getChunkCount()
         );
 
+        System.out.println("Created Chunks:");
+
+        for (ChunkStatus chunk : chunks) {
+            System.out.printf(
+                    "  Chunk %d -> %.1f MB%n",
+                    chunk.getChunkId(),
+                    chunk.getChunkSizeMB()
+            );
+        }
+
+        System.out.println();
+
         // 3. Create worker threads
         List<Thread> workerThreads = new ArrayList<>();
 
         for (ChunkStatus chunk : chunks) {
+
             DownloadWorker worker = new DownloadWorker(chunk, config);
-            Thread workerThread = new Thread(worker, "Worker-" + chunk.getChunkId());
+
+            Thread workerThread = new Thread(
+                    worker,
+                    "Worker-" + chunk.getChunkId()
+            );
 
             workerThreads.add(workerThread);
 
-            // TODO:
+            System.out.printf(
-            // Students may print helpful debug information here,
+                    "Assigned Chunk %d to %s%n",
-            // for example which chunk is assigned to which worker thread.
+                    chunk.getChunkId(),
+                    workerThread.getName()
+            );
         }
 
+        System.out.println();
+
         // 4. Create and start monitor thread
         ProgressMonitor monitor = new ProgressMonitor(config, chunks);
-        Thread monitorThread = new Thread(monitor, "Progress-Monitor");
 
-        // TODO:
+        Thread monitorThread = new Thread(
-        // Start the monitor thread before starting the workers
+                monitor,
-        // so that progress can be displayed while downloading happens.
+                "Progress-Monitor"
-        //
+        );
-        // Example idea:
+
-        // monitorThread.start();
+        System.out.println("Starting monitor thread...");
+        monitorThread.start();
 
         // 5. Start worker threads
-        // TODO:
+        System.out.println("Starting worker threads...");
-        // Start each worker thread in workerThreads.
+
-        // Use a loop and call start() on each thread.
+        for (Thread workerThread : workerThreads) {
+            workerThread.start();
+        }
 
         // 6. Wait for workers to finish
-        // TODO:
+        try {
-        // Wait for all worker threads to complete by calling join().
-        // This should be done inside a try-catch block for InterruptedException.
-        //
-        // Hint:
-        // for (Thread thread : workerThreads) {
-        //     thread.join();
-        // }
 
-        // TODO:
+            for (Thread workerThread : workerThreads) {
-        // After all workers finish, the monitor thread may also need to stop.
+                workerThread.join();
-        // Depending on how ProgressMonitor is implemented, students may:
+            }
-        // - wait for it to finish on its own, or
-        // - add a stopping mechanism in ProgressMonitor later.
-        //
-        // If your monitor finishes automatically, you may join it here.
 
-        // NOTE:
+            // Wait for monitor to finish automatically
-        // this final report may show 0 progress because no worker has actually run yet.
+            monitorThread.join();
-        // Until students complete the thread start/join TODOs above,
+
+        } catch (InterruptedException e) {
+
+            System.out.println("Main thread interrupted.");
+
+            Thread.currentThread().interrupt();
+            return;
+        }
+
+        long simulationEnd = System.currentTimeMillis();
 
         // 7. Print final report
         System.out.println();
-        System.out.println("=== Final Report ===");
+        System.out.println("=================================================");
+        System.out.println("                 FINAL REPORT");
+        System.out.println("=================================================");
 
         int completedChunks = 0;
         double downloadedMB = 0.0;
 
         for (ChunkStatus chunk : chunks) {
+
             downloadedMB += chunk.getDownloadedMB();
 
             if (chunk.isCompleted()) {
                 completedChunks++;
             }
 
-            System.out.println(
+            System.out.printf(
-                    "Chunk " + chunk.getChunkId()
+                    "Chunk %-2d | Downloaded: %6.1f / %6.1f MB | %-10s | Duration: %.2f sec%n",
-                            + ": " + chunk.getDownloadedMB()
+                    chunk.getChunkId(),
-                            + "/" + chunk.getChunkSizeMB()
+                    chunk.getDownloadedMB(),
-                            + " MB"
+                    chunk.getChunkSizeMB(),
+                    chunk.isCompleted() ? "Completed" : "Incomplete",
+                    chunk.getDownloadDurationMs() / 1000.0
             );
         }
 
         System.out.println();
-        System.out.println("Completed chunks: " + completedChunks + "/" + chunks.size());
+
-        System.out.println("Downloaded total: " + downloadedMB + "/" + config.getTotalSizeMB() + " MB");
+        System.out.println(
+                "Completed Chunks: "
+                        + completedChunks
+                        + "/"
+                        + chunks.size()
+        );
+
+        System.out.printf(
+                "Downloaded Total: %.1f / %d MB%n",
+                downloadedMB,
+                config.getTotalSizeMB()
+        );
+
+        System.out.printf(
+                "Execution Time  : %.2f seconds%n",
+                (simulationEnd - simulationStart) / 1000.0
+        );
+
+        System.out.println();
         System.out.println("Simulation finished.");
     }
-}
+}

src/main/java/ProgressMonitor.java

@@ -16,18 +16,11 @@ public class ProgressMonitor implements Runnable {
 
     @Override
     public void run() {
-        // TODO:
-        // Repeatedly check chunk progress until all chunks are completed.
-        // In each loop:
-        // 1. Read the downloaded size from every chunk
-        // 2. Add all downloaded amounts to totalDownloadedMB
-        // 3. Count completed chunks
-        // 4. Print a progress message
-        // 5. If completedChunks == chunks.size(), print a final monitor message and stop
-        // 6. Otherwise sleep for monitorDelayMs and continue
 
+        long startTime = System.currentTimeMillis();
 
         while (true) {
+
             double totalDownloadedMB = 0.0;
             int completedChunks = 0;
 
@@ -39,31 +32,68 @@ public class ProgressMonitor implements Runnable {
                 }
             }
 
-            double percent = 0.0;
-            if (totalSizeMB > 0) {
-                percent = (totalDownloadedMB * 100.0) / totalSizeMB;
-            }
 
-            System.out.printf(
+
-                    "Progress for %s: %.1f/%.1f MB (%.2f%%), completed chunks: %d/%d%n",
+            long elapsedMillis = System.currentTimeMillis() - startTime;
-                    fileName,
+            double elapsedSeconds = elapsedMillis / 1000.0;
+
+
+
+            double remainingMB = totalSizeMB - totalDownloadedMB;
+
+            double percent = DownloadStatistics.calculatePercentage(
                     totalDownloadedMB,
-                    (double) totalSizeMB,
+                    totalSizeMB
-                    percent,
+            );
-                    completedChunks,
+
+            double speed = DownloadStatistics.calculateSpeed(
+                    totalDownloadedMB,
+                    elapsedMillis
+            );
+
+            double eta = DownloadStatistics.calculateETA(
+                    totalDownloadedMB,
+                    totalSizeMB,
+                    speed
+            );
+
+            // Refresh console
+            ConsoleUI.clearScreen();
+
+            ConsoleUI.printHeader(
+                    fileName,
+                    totalSizeMB,
                     chunks.size()
             );
 
+            ConsoleUI.printOverallProgress(
+                    totalDownloadedMB,
+                    totalSizeMB,
+                    speed,
+                    eta
+            );
 
-            // TODO:
+            ConsoleUI.printChunks(chunks);
-            // If all chunks are completed, print a final message and exit the loop
+
+            // Finished?
+            if (completedChunks == chunks.size()) {
+
+                System.out.println("Download completed successfully!");
+                System.out.printf(
+                        "Total download time: %.2f seconds%n",
+                        elapsedSeconds
+                );
+
+                ConsoleUI.printFinalReport(chunks);
+                return;
+            }
 
             try {
                 Thread.sleep(monitorDelayMs);
             } catch (InterruptedException e) {
-                System.out.println("Progress monitor interrupted.");
+                Thread.currentThread().interrupt();
                 return;
             }
         }
     }
-}
+}