Semaphore_Sync

.gitignore

+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
\ No newline at end of file

.idea/encodings.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding">
+    <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
+  </component>
+</project>
\ No newline at end of file

.idea/misc.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="MavenProjectsManager">
+    <option name="originalFiles">
+      <list>
+        <option value="$PROJECT_DIR$/pom.xml" />
+      </list>
+    </option>
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>
\ No newline at end of file

.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file

.idea/workspace.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="AutoImportSettings">
+    <option name="autoReloadType" value="SELECTIVE" />
+  </component>
+  <component name="ChangeListManager">
+    <list default="true" id="f14d66a1-1dc3-4666-9147-5cc7b3e41171" name="Changes" comment="">
+      <change afterPath="$PROJECT_DIR$/.gitignore" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/encodings.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/misc.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/vcs.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/Input/input.txt" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/pom.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/main/java/org/example/Consumer.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/main/java/org/example/Producer.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/main/java/org/example/Writer.java" afterDir="false" />
+    </list>
+    <option name="SHOW_DIALOG" value="false" />
+    <option name="HIGHLIGHT_CONFLICTS" value="true" />
+    <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
+    <option name="LAST_RESOLUTION" value="IGNORE" />
+  </component>
+  <component name="Git.Settings">
+    <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
+  </component>
+  <component name="MarkdownSettingsMigration">
+    <option name="stateVersion" value="1" />
+  </component>
+  <component name="ProjectId" id="2YjyaLFXx8wHOKZZXlc0MNVcTqc" />
+  <component name="ProjectLevelVcsManager" settingsEditedManually="true" />
+  <component name="ProjectViewState">
+    <option name="hideEmptyMiddlePackages" value="true" />
+    <option name="showLibraryContents" value="true" />
+  </component>
+  <component name="PropertiesComponent"><![CDATA[{
+  "keyToString": {
+    "RunOnceActivity.OpenProjectViewOnStart": "true",
+    "RunOnceActivity.ShowReadmeOnStart": "true",
+    "SHARE_PROJECT_CONFIGURATION_FILES": "true",
+    "last_opened_file_path": "C:/Users/Abdullah/Desktop/Producer_Consumer"
+  }
+}]]></component>
+  <component name="RecentsManager">
+    <key name="CopyFile.RECENT_KEYS">
+      <recent name="C:\Users\Abdullah\Desktop\Producer_Consumer2" />
+      <recent name="C:\Users\Abdullah\Desktop\Producer_Consumer2\src\main\java\org\example" />
+    </key>
+  </component>
+  <component name="SpellCheckerSettings" RuntimeDictionaries="0" Folders="0" CustomDictionaries="0" DefaultDictionary="application-level" UseSingleDictionary="true" transferred="true" />
+  <component name="TaskManager">
+    <task active="true" id="Default" summary="Default task">
+      <changelist id="f14d66a1-1dc3-4666-9147-5cc7b3e41171" name="Changes" comment="" />
+      <created>1701053373612</created>
+      <option name="number" value="Default" />
+      <option name="presentableId" value="Default" />
+      <updated>1701053373612</updated>
+    </task>
+    <servers />
+  </component>
+  <component name="Vcs.Log.Tabs.Properties">
+    <option name="TAB_STATES">
+      <map>
+        <entry key="MAIN">
+          <value>
+            <State />
+          </value>
+        </entry>
+      </map>
+    </option>
+  </component>
+</project>
\ No newline at end of file

pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.example</groupId>
+    <artifactId>Producer_Consumer2</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+</project>
\ No newline at end of file

src/main/java/org/example/Consumer.java

+package org.example;
+
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.Semaphore;
+
+public class Consumer implements Runnable {
+
+    // Object for synchronization when incrementing numLines
+    private Object synchronizationObject = new Object();
+
+    // Queue of lines before processing them
+    private Queue<String> linesQueue;
+
+    // Queue of lines after processing them
+    private ConcurrentLinkedQueue<String> processedLines;
+
+    // Semaphore for controlling access to the  linesQueue
+    private Semaphore linesQueueSemaphore;
+
+    // Volatile variable to track the number of processed lines
+    private volatile static long numLines = 0;
+
+    // Getter for numLines
+    public static long getNumLines() {
+        return numLines;
+    }
+
+    // Constructor
+    public Consumer(LinkedList<String> linesQueue, ConcurrentLinkedQueue<String> processedLines, Semaphore linesQueueSemaphore) {
+        this.linesQueue = linesQueue;
+        this.processedLines = processedLines;
+        this.linesQueueSemaphore = linesQueueSemaphore;
+    }
+
+    // Run method to be executed when the thread starts
+    @Override
+    public void run() {
+        try {
+            // Infinite loop for continuous processing
+            while (true) {
+                try {
+                    // Acquire the semaphore to process the lines
+                    linesQueueSemaphore.acquire();
+                } catch (InterruptedException i) {
+                    // just for Handle InterruptedException
+                }
+
+                // Print the name of the current thread for debugging purposes
+                System.out.println(Thread.currentThread().getName());
+
+                // Increment the numLines variable in a synchronized block for thread safety
+                synchronized (synchronizationObject) {
+                    numLines++;
+                }
+
+                // Retrieve a line from the linesQueue
+                String line = linesQueue.poll();
+
+                if (line == null) {
+                    break; // Exit the loop if no more lines
+                }
+
+                // Convert each lowercase letter to uppercase and vice versa
+                StringBuilder swappedString = new StringBuilder();
+                for (char c : line.toCharArray()) {
+                    if (Character.isUpperCase(c)) {
+                        swappedString.append(Character.toLowerCase(c));
+                    } else if (Character.isLowerCase(c)) {
+                        swappedString.append(Character.toUpperCase(c));
+                    } else {
+                        swappedString.append(c);
+                    }
+                }
+
+                // Offer the processed line to the processedLines queue
+                processedLines.offer(swappedString.toString());
+            }
+        } catch (Exception e) {
+            // Print the exception stack trace for debugging purposes
+            e.printStackTrace();
+        }
+    }
+}

src/main/java/org/example/Producer.java

+package org.example;
+
+import java.io.*;
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.concurrent.Semaphore;
+
+public class Producer implements Runnable {
+
+    // Static variable to keep track of the total number of lines produced
+    private static long numLines = 0;
+
+    // File to read lines from
+    private String file;
+
+    // Queue to store lines read from the file
+    private Queue<String> linesQueue;
+
+    // Semaphore to control access to the linesQueue
+    private Semaphore linesQueueSemaphore;
+
+    // Getter for numLines
+    public static long getNumLines() {
+        return numLines;
+    }
+
+    // Constructor
+    public Producer(String file, LinkedList<String> linesQueue) {
+        this.file = file;
+        this.linesQueue = linesQueue;
+        this.linesQueueSemaphore = new Semaphore(0);
+    }
+
+
+    // Getter for the linesQueueSemaphore
+    public Semaphore getSemaphore() {
+        return linesQueueSemaphore;
+    }
+
+    // Run method to be executed when the thread starts
+    @Override
+    public void run() {
+        try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
+            String line;
+
+            // Read lines from the file until the end is reached
+            while ((line = reader.readLine()) != null) {
+                // Offer the line to the linesQueue
+                linesQueue.offer(line);
+
+                // Increment the numLines variable
+                numLines++;
+
+                // Release the semaphore to signal that a new line is available for consumption
+                linesQueueSemaphore.release();
+            }
+        } catch (IOException e) {
+            // Print the exception stack trace for debugging purposes
+            e.printStackTrace();
+        }
+    }
+}

src/main/java/org/example/Writer.java

+package org.example;
+
+import java.io.BufferedWriter;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.LinkedList;
+import java.util.concurrent.*;
+
+public class Writer {
+    public static void main(String[] args) {
+        // File paths
+        String inputFile = "Input/input.txt";
+        String outputFile = "Output/output.txt";
+
+        // Determine the number of consumer threads
+        int numConsumers = Runtime.getRuntime().availableProcessors();
+
+        // Create a queue to hold the lines read from the file
+        LinkedList<String> linesQueue = new LinkedList<>();
+
+        // Create a concurrent queue to store the processed results for each consumer
+        ConcurrentLinkedQueue<String> processedResults = new ConcurrentLinkedQueue<>();
+
+        // Create a producer thread to read lines from the file and put them into the linesQueue
+        Producer producer = new Producer(inputFile, linesQueue);
+        Thread producerThread = new Thread(producer);
+        producerThread.start();
+
+        // Create a thread pool with the specified number of consumers
+        ExecutorService executor = Executors.newFixedThreadPool(numConsumers);
+
+        // Submit consumer tasks to the thread pool
+        for (int i = 0; i < numConsumers; i++) {
+            Consumer consumer = new Consumer(linesQueue, processedResults, producer.getSemaphore());
+            executor.submit(consumer);
+        }
+
+        // Wait for the producer to finish
+        try {
+            producerThread.join();
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // Wait until all consumers finish processing the lines then shutdown the executor
+        while (true) {
+            if ( Producer.getNumLines() == Consumer.getNumLines()) {
+                executor.shutdownNow();
+                break;
+            }
+        }
+
+        // Write the processed results to the output file
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(outputFile))) {
+            for (String result : processedResults) {
+                writer.write(result);
+                writer.newLine();
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}