Laboraufgaben für Kap. 3

src/pp.01.01-Inheritance/src/main/java/pp/Sensor.java

@@ -1,6 +1,7 @@
 package pp;
 
 public class Sensor extends Thread {
+
     // eigentlich abstract
 
     private final long frequency;

src/pp.01.01-Inheritance/src/main/java/pp/Thermometer.java

@@ -3,6 +3,7 @@ package pp;
 import java.util.Random;
 
 public class Thermometer extends Sensor {
+
     private final Random rand;
 
     public Thermometer(long frequency) {
@@ -12,8 +13,7 @@ public class Thermometer extends Sensor {
 
     @Override
     protected String reading() {
-        return String.format("(%04d freq.): %3d°C", getFrequency(),
+        return String.format("(%04d freq.): %3d°C", getFrequency(), this.rand.nextInt(100));
-                this.rand.nextInt(100));
     }
 
     public static void main(String... args) {

src/pp.01.01-Inheritance_solution/src/main/java/pp/Sensor.java

@@ -1,6 +1,7 @@
 package pp;
 
 public class Sensor extends Thread {
+
     // eigentlich abstract
 
     private final long frequency;

src/pp.01.01-Inheritance_solution/src/main/java/pp/Thermometer.java

@@ -3,6 +3,7 @@ package pp;
 import java.util.Random;
 
 public class Thermometer extends Sensor {
+
     private final Random rand;
 
     public Thermometer(long frequency) {
@@ -12,8 +13,7 @@ public class Thermometer extends Sensor {
 
     @Override
     protected String reading() {
-        return String.format("(%04d freq.): %3d°C", getFrequency(),
+        return String.format("(%04d freq.): %3d°C", getFrequency(), this.rand.nextInt(100));
-                this.rand.nextInt(100));
     }
 
     public static void main(String... args) {

src/pp.01.02-Runnable/src/main/java/pp/MyWorker.java

@@ -1,14 +1,14 @@
 package pp;
 
 class MyWorker implements Runnable {
-  private Thread self;
 
-  @Override
+    private Thread self;
-  public void run() {
+
-    this.self = Thread.currentThread();
+    @Override
-    while (true) {
+    public void run() {
-      System.out.println(
+        this.self = Thread.currentThread();
-          this.self.getName() + ": ID => " + this.self.threadId());
+        while (true) {
+            System.out.println(this.self.getName() + ": ID => " + this.self.threadId());
+        }
     }
-  }
 }

src/pp.01.02-Runnable/src/main/java/pp/MyWorkerCoop.java

@@ -1,15 +1,15 @@
 package pp;
 
 class MyWorkerCoop implements Runnable {
-  private Thread self;
 
-  @Override
+    private Thread self;
-  public void run() {
+
-    this.self = Thread.currentThread();
+    @Override
-    while (true) {
+    public void run() {
-      System.out.println(
+        this.self = Thread.currentThread();
-          this.self.getName() + ": ID => " + this.self.threadId());
+        while (true) {
-      Thread.yield();
+            System.out.println(this.self.getName() + ": ID => " + this.self.threadId());
+            Thread.yield();
+        }
     }
-  }
 }

src/pp.01.02-Runnable/src/main/java/pp/Starter.java

@@ -1,6 +1,7 @@
 package pp;
 
 public class Starter {
+
     static int WORKERS = 200;
 
     public static void main(String... args) {

src/pp.01.02-Runnable_solution/src/main/java/pp/MyWorker.java

@@ -1,14 +1,14 @@
 package pp;
 
 class MyWorker implements Runnable {
-  private Thread self;
 
-  @Override
+    private Thread self;
-  public void run() {
+
-    this.self = Thread.currentThread();
+    @Override
-    while (true) {
+    public void run() {
-      System.out.println(
+        this.self = Thread.currentThread();
-          this.self.getName() + ": ID => " + this.self.threadId());
+        while (true) {
+            System.out.println(this.self.getName() + ": ID => " + this.self.threadId());
+        }
     }
-  }
 }

src/pp.01.02-Runnable_solution/src/main/java/pp/MyWorkerCoop.java

@@ -1,15 +1,15 @@
 package pp;
 
 class MyWorkerCoop implements Runnable {
-  private Thread self;
 
-  @Override
+    private Thread self;
-  public void run() {
+
-    this.self = Thread.currentThread();
+    @Override
-    while (true) {
+    public void run() {
-      System.out.println(
+        this.self = Thread.currentThread();
-          this.self.getName() + ": ID => " + this.self.threadId());
+        while (true) {
-      Thread.yield();
+            System.out.println(this.self.getName() + ": ID => " + this.self.threadId());
+            Thread.yield();
+        }
     }
-  }
 }

src/pp.01.02-Runnable_solution/src/main/java/pp/Starter.java

@@ -1,12 +1,12 @@
 package pp;
 
 public class Starter {
+
     static int WORKERS = 200;
 
     public static void main(String... args) {
         for (var i = 0; i < Starter.WORKERS; i++) {
-            var t = new Thread(new MyWorkerCoop(),
+            var t = new Thread(new MyWorkerCoop(), String.format("Worker-%03d", i));
-                    String.format("Worker-%03d", i));
             t.start();
         }
     }

src/pp.01.02-Runnable_solution/src/main/java/pp/StarterInner.java

@@ -1,23 +1,26 @@
 package pp;
 
 public class StarterInner {
-  static int WORKERS = 200;
 
-  public static void main(String... args) {
+    static int WORKERS = 200;
-    for (var i = 0; i < StarterInner.WORKERS; i++) {
-      var t = new Thread(new Runnable() {
-        private Thread self;
 
-        @Override
+    public static void main(String... args) {
-        public void run() {
+        for (var i = 0; i < StarterInner.WORKERS; i++) {
-          this.self = Thread.currentThread();
+            var t = new Thread(
-          while (true) {
+                new Runnable() {
-            System.out.println(this.self.getName() + ": ID => "
+                    private Thread self;
-                + this.self.threadId());
+
-          }
+                    @Override
+                    public void run() {
+                        this.self = Thread.currentThread();
+                        while (true) {
+                            System.out.println(this.self.getName() + ": ID => " + this.self.threadId());
+                        }
+                    }
+                },
+                String.format("Worker-%03d", i)
+            );
+            t.start();
         }
-      }, String.format("Worker-%03d", i));
-      t.start();
     }
-  }
 }

src/pp.01.02-Runnable_solution/src/main/java/pp/StarterLambda.java

@@ -1,18 +1,21 @@
 package pp;
 
 public class StarterLambda {
-  static int WORKERS = 200;
 
-  public static void main(String... args) {
+    static int WORKERS = 200;
-    for (var i = 0; i < StarterLambda.WORKERS; i++) {
+
-      var t = new Thread(() -> {
+    public static void main(String... args) {
-        var self = Thread.currentThread();
+        for (var i = 0; i < StarterLambda.WORKERS; i++) {
-        while (true) {
+            var t = new Thread(
-          System.out.println(
+                () -> {
-              self.getName() + ": ID => " + self.threadId());
+                    var self = Thread.currentThread();
+                    while (true) {
+                        System.out.println(self.getName() + ": ID => " + self.threadId());
+                    }
+                },
+                String.format("Worker-%03d", i)
+            );
+            t.start();
         }
-      }, String.format("Worker-%03d", i));
-      t.start();
     }
-  }
 }

src/pp.01.03-EndThread/src/main/java/pp/Runner.java

@@ -1,15 +1,16 @@
 package pp;
 
 public class Runner {
-  public static void main(String... args) {
+
-    var task = new Task();
+    public static void main(String... args) {
-    var thread = new Thread(task);
+        var task = new Task();
-    thread.setUncaughtExceptionHandler((t, e) -> {
+        var thread = new Thread(task);
-      System.err.println("Unhandled Exception: " + e.getMessage());
+        thread.setUncaughtExceptionHandler((t, e) -> {
-      System.err.println(" Thread: " + t.threadId() + " - " + t.getName());
+            System.err.println("Unhandled Exception: " + e.getMessage());
-      System.err.println(" Thread State: " + t.getState());
+            System.err.println(" Thread: " + t.threadId() + " - " + t.getName());
-      e.printStackTrace(System.err);
+            System.err.println(" Thread State: " + t.getState());
-    });
+            e.printStackTrace(System.err);
-    thread.start();
+        });
-  }
+        thread.start();
+    }
 }

src/pp.01.03-EndThread/src/main/java/pp/Task.java

@@ -1,6 +1,7 @@
 package pp;
 
 public class Task implements Runnable {
+
     private volatile Thread self;
     private volatile boolean stopped = false;
 

src/pp.01.03-EndThread_solution/src/main/java/pp/Runner.java

@@ -1,20 +1,21 @@
 package pp;
 
 public class Runner {
-  public static void main(String... args) {
-    var task = new Task();
-    var thread = new Thread(task);
-    thread.setUncaughtExceptionHandler((t, e) -> {
-      System.err.println("Unhandled Exception: " + e.getMessage());
-      System.err.println(" Thread: " + t.threadId() + " - " + t.getName());
-      System.err.println(" Thread State: " + t.getState());
-      e.printStackTrace(System.err);
-    });
-    thread.start();
-    // falsch: thread läuft weiter:
-    // (new Thread(() -> thread.interrupt())).start();
 
-    // richtig: thread wird beendet:
+    public static void main(String... args) {
-    (new Thread(() -> task.stopRequest())).start();
+        var task = new Task();
-  }
+        var thread = new Thread(task);
+        thread.setUncaughtExceptionHandler((t, e) -> {
+            System.err.println("Unhandled Exception: " + e.getMessage());
+            System.err.println(" Thread: " + t.threadId() + " - " + t.getName());
+            System.err.println(" Thread State: " + t.getState());
+            e.printStackTrace(System.err);
+        });
+        thread.start();
+        // falsch: thread läuft weiter:
+        // (new Thread(() -> thread.interrupt())).start();
+
+        // richtig: thread wird beendet:
+        (new Thread(() -> task.stopRequest())).start();
+    }
 }

src/pp.01.03-EndThread_solution/src/main/java/pp/Task.java

@@ -1,6 +1,7 @@
 package pp;
 
 public class Task implements Runnable {
+
     private volatile Thread self;
     private volatile boolean stopped = false;
 

src/pp.02.01-MemoryBarrier/src/main/java/pp/MemoryBarrierTest.java

@@ -17,8 +17,6 @@ public class MemoryBarrierTest extends Thread {
         t.start();
         Thread.sleep(1000);
         t.stopped = true;
-        System.out.println(
+        System.out.println("Main thread set stopped on MemoryBarrierTest-Thread.");
-                "Main thread set stopped on MemoryBarrierTest-Thread.");
     }
-
 }

src/pp.02.01-MemoryBarrier_solution/src/main/java/pp/MemoryBarrierTest1.java

@@ -19,8 +19,6 @@ public class MemoryBarrierTest1 extends Thread {
         t.start();
         Thread.sleep(1000);
         t.stopped = true;
-        System.out.println(
+        System.out.println("Main thread set stopped on MemoryBarrierTest-Thread.");
-                "Main thread set stopped on MemoryBarrierTest-Thread.");
     }
-
 }

src/pp.02.01-MemoryBarrier_solution/src/main/java/pp/MemoryBarrierTest1b.java

@@ -29,8 +29,6 @@ public class MemoryBarrierTest1b extends Thread {
         t.start();
         Thread.sleep(1000);
         t.setStopped(true);
-        System.out.println(
+        System.out.println("Main thread set stopped on MemoryBarrierTest-Thread.");
-                "Main thread set stopped on MemoryBarrierTest-Thread.");
     }
-
 }

src/pp.02.01-MemoryBarrier_solution/src/main/java/pp/MemoryBarrierTest2.java

@@ -21,8 +21,6 @@ public class MemoryBarrierTest2 extends Thread {
         t.start();
         Thread.sleep(1000);
         t.stopped = true;
-        System.out.println(
+        System.out.println("Main thread set stopped on MemoryBarrierTest-Thread.");
-                "Main thread set stopped on MemoryBarrierTest-Thread.");
     }
-
 }

src/pp.02.01-MemoryBarrier_solution/src/main/java/pp/MemoryBarrierTest5.java

@@ -13,8 +13,7 @@ public class MemoryBarrierTest5 extends Thread {
                 Thread.currentThread().interrupt();
             }
             this.stopped = true;
-            System.out.println(
+            System.out.println("Stopper thread set stopped on MemoryBarrierTest-Thread.");
-                    "Stopper thread set stopped on MemoryBarrierTest-Thread.");
         });
         this.stopper.start();
     }
@@ -40,7 +39,5 @@ public class MemoryBarrierTest5 extends Thread {
     public static void main(String... args) throws InterruptedException {
         var t = new MemoryBarrierTest5();
         t.start();
-
     }
-
 }

src/pp.02.01-MemoryBarrier_solution/src/main/java/pp/MemoryBarrierTest6.java

@@ -23,8 +23,6 @@ public class MemoryBarrierTest6 extends Thread {
         t.start();
         Thread.sleep(1000);
         t.stopped = true;
-        System.out.println(
+        System.out.println("Main thread set stopped on MemoryBarrierTest-Thread.");
-                "Main thread set stopped on MemoryBarrierTest-Thread.");
     }
-
 }

src/pp.02.02-ThreadLocal_solution/src/main/java/pp/MyThreadLocalRandom0.java

@@ -3,6 +3,7 @@ package pp;
 import java.util.Random;
 
 public class MyThreadLocalRandom0 implements Runnable {
+
     public static long now = System.currentTimeMillis();
     public Random rand = new Random(now);
 

src/pp.02.02-ThreadLocal_solution/src/main/java/pp/MyThreadLocalRandom1.java

@@ -3,6 +3,7 @@ package pp;
 import java.util.Random;
 
 public class MyThreadLocalRandom1 implements Runnable {
+
     public static long now = System.currentTimeMillis();
     public ThreadLocal<Random> rand = new ThreadLocal<>() {
         @Override

src/pp.02.02-ThreadLocal_solution/src/main/java/pp/MyThreadLocalRandom2.java

@@ -3,6 +3,7 @@ package pp;
 import java.util.Random;
 
 public class MyThreadLocalRandom2 implements Runnable {
+
     public static long now = System.currentTimeMillis();
     public static ThreadLocal<Random> rand = new ThreadLocal<>() {
         @Override

src/pp.02.03-Lock/src/main/java/pp/Factory.java

@@ -21,9 +21,7 @@ public class Factory {
                 () -> {
                     Type object = Factory.getInstance();
                     System.out.println(
-                        Thread.currentThread().getName() +
+                        Thread.currentThread().getName() + ": serial of instance = " + object.getSerial()
-                        ": serial of instance = " +
-                        object.getSerial()
                     );
                 },
                 String.format("InstanceGrabber-%02d", i)

src/pp.02.03-Lock_solution/src/main/java/pp/Factory0.java

@@ -20,9 +20,7 @@ public class Factory0 {
                 () -> {
                     var object = getInstance();
                     System.out.println(
-                        Thread.currentThread().getName() +
+                        Thread.currentThread().getName() + ": serial of instance = " + object.getSerial()
-                        ": serial of instance = " +
-                        object.getSerial()
                     );
                 },
                 String.format("InstanceGrabber-%02d", i)

src/pp.02.03-Lock_solution/src/main/java/pp/Factory1.java

@@ -20,9 +20,7 @@ public class Factory1 {
                 () -> {
                     var object = getInstance();
                     System.out.println(
-                        Thread.currentThread().getName() +
+                        Thread.currentThread().getName() + ": serial of instance = " + object.getSerial()
-                        ": serial of instance = " +
-                        object.getSerial()
                     );
                 },
                 String.format("InstanceGrabber-%02d", i)

src/pp.02.03-Lock_solution/src/main/java/pp/Factory2.java

@@ -22,9 +22,7 @@ public class Factory2 {
                 () -> {
                     var object = getInstance();
                     System.out.println(
-                        Thread.currentThread().getName() +
+                        Thread.currentThread().getName() + ": serial of instance = " + object.getSerial()
-                        ": serial of instance = " +
-                        object.getSerial()
                     );
                 },
                 String.format("InstanceGrabber-%02d", i)

src/pp.02.03-Lock_solution/src/main/java/pp/Factory3.java

@@ -23,9 +23,7 @@ public class Factory3 {
                 () -> {
                     var object = Factory3.getInstance();
                     System.out.println(
-                        Thread.currentThread().getName() +
+                        Thread.currentThread().getName() + ": serial of instance = " + object.getSerial()
-                        ": serial of instance = " +
-                        object.getSerial()
                     );
                 },
                 String.format("InstanceGrabber-%02d", i)

src/pp.02.03-Lock_solution/src/main/java/pp/Factory4.java

@@ -24,9 +24,7 @@ public class Factory4 {
                 () -> {
                     var object = getInstance();
                     System.out.println(
-                        Thread.currentThread().getName() +
+                        Thread.currentThread().getName() + ": serial of instance = " + object.getSerial()
-                        ": serial of instance = " +
-                        object.getSerial()
                     );
                 },
                 String.format("InstanceGrabber-%02d", i)

src/pp.03.01-SynchPhilosopher/README.md

@@ -0,0 +1,7 @@
+# Laboraufgabe "Dinnierende Philosoph:innen"
+- [Aufgabenstellung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-01-SynchPhilosopher.html)
+- [Musterlösung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-Solutions.html#laboraufgabe-dinierende-philosophinnen)
+
+# Materialien
+- [Folien](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/slides/03-steuerung.html)
+- [Skript](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/notes/03-steuerung.html)

src/pp.03.01-SynchPhilosopher/justfile

@@ -0,0 +1,12 @@
+default:
+    mvn clean compile exec:java
+exec args:
+    mvn exec:java -Dexec.args={{args}}
+clean:
+    mvn clean
+compile:
+    mvn compile
+test:
+    mvn test
+javadoc:
+    mvn javadoc:javadoc

src/pp.03.01-SynchPhilosopher/pom.xml

@@ -0,0 +1,61 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>pp</groupId>
+  <artifactId>pp.03.01-SynchPhilosopher</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <properties>	
+    <exec.mainClass>pp.PhilosopherExperiment</exec.mainClass>
+    <maven.compiler.release>19</maven.compiler.release>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+  <dependencies>
+    <dependency><!-- für Unit-Tests -->
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>5.10.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency><!-- für Lombok -->
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.30</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency><!-- für net.jcip Annotationen -->
+      <groupId>net.jcip</groupId>
+      <artifactId>jcip-annotations</artifactId>
+      <version>1.0</version>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin><!-- für Unit-Tests [mvn test] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.0.0</version>
+      </plugin>
+      <plugin><!-- [mvn compile] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.9.0</version>
+      </plugin>
+      <plugin><!-- [mvn exec:java] -->
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>3.1.0</version>
+      </plugin>
+      <plugin><!-- [mvn javadoc:javadoc] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <version>3.5.0</version>
+        <configuration>
+          <show>private</show>
+          <locale>en_US</locale>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/pp.03.01-SynchPhilosopher/src/main/java/pp/Chopstick.java

@@ -0,0 +1,3 @@
+package pp;
+
+public class Chopstick {}

src/pp.03.01-SynchPhilosopher/src/main/java/pp/Philosopher.java

@@ -0,0 +1,77 @@
+package pp;
+
+import java.util.Random;
+
+public class Philosopher extends Thread {
+
+    static final int MAX_THINKING_DURATION_MS = 1000;
+    static final int MAX_EATING_DURATION_MS = 3000;
+    static final int MAX_TAKING_TIME_MS = 1000;
+
+    private final Chopstick left;
+    private final Chopstick right;
+    private final Random random;
+    private int eaten;
+    private final int seat;
+
+    private volatile boolean stop;
+
+    private void log(String message) {
+        synchronized (Philosopher.class) {
+            for (var i = 1; i <= this.seat; i++) {
+                System.out.print("                         ");
+            }
+            System.out.println(threadId() + " " + message);
+        }
+    }
+
+    public void stopPhilosopher() {
+        log("stopping");
+        this.stop = true;
+        interrupt();
+    }
+
+    public Philosopher(int seat, Chopstick left, Chopstick right) {
+        this.stop = false;
+        this.seat = seat;
+        this.left = left;
+        this.right = right;
+        this.random = new Random();
+        this.eaten = 0;
+    }
+
+    @Override
+    public void run() {
+        log("starting");
+        try {
+            while (!this.stop) {
+                think();
+                eat();
+            }
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
+        log("stopped; eaten=" + this.eaten);
+    }
+
+    private void think() throws InterruptedException {
+        Thread.sleep(this.random.nextInt(MAX_THINKING_DURATION_MS));
+    }
+
+    private void eat() throws InterruptedException {
+        log("try taking left");
+        synchronized (this.left) {
+            log("left acquired");
+            Thread.sleep(this.random.nextInt(MAX_TAKING_TIME_MS));
+            log("try taking right");
+            synchronized (this.right) {
+                log("right acquired");
+                log("eating");
+                this.eaten++;
+                Thread.sleep(this.random.nextInt(MAX_EATING_DURATION_MS));
+            }
+            log("right released");
+        }
+        log("left released");
+    }
+}

src/pp.03.01-SynchPhilosopher/src/main/java/pp/PhilosopherExperiment.java

@@ -0,0 +1,25 @@
+package pp;
+
+public class PhilosopherExperiment {
+
+    static final int PHILOSOPHER_NUM = 5;
+    static final int EXP_DURATION_MS = 20000;
+
+    public static void main(String... args) throws InterruptedException {
+        var chopsticks = new Chopstick[PHILOSOPHER_NUM];
+        var philosophers = new Philosopher[PHILOSOPHER_NUM];
+        for (var i = 0; i < PHILOSOPHER_NUM; i++) {
+            chopsticks[i] = new Chopstick();
+        }
+        for (var i = 0; i < PHILOSOPHER_NUM; i++) {
+            philosophers[i] = new Philosopher(i, chopsticks[i], chopsticks[(i + 1) % PHILOSOPHER_NUM]);
+        }
+        for (var i = 0; i < PHILOSOPHER_NUM; i++) {
+            philosophers[i].start();
+        }
+        Thread.sleep(EXP_DURATION_MS);
+        for (var i = 0; i < PHILOSOPHER_NUM; i++) {
+            philosophers[i].stopPhilosopher();
+        }
+    }
+}

src/pp.03.01-SynchPhilosopher_solution/README.md

@@ -0,0 +1,7 @@
+# Laboraufgabe "Dinnierende Philosoph:innen"
+- [Aufgabenstellung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-01-SynchPhilosopher.html)
+- [Musterlösung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-Solutions.html#laboraufgabe-dinierende-philosophinnen)
+
+# Materialien
+- [Folien](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/slides/03-steuerung.html)
+- [Skript](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/notes/03-steuerung.html)

src/pp.03.01-SynchPhilosopher_solution/justfile

@@ -0,0 +1,12 @@
+default:
+    mvn clean compile exec:java
+exec args:
+    mvn exec:java -Dexec.args={{args}}
+clean:
+    mvn clean
+compile:
+    mvn compile
+test:
+    mvn test
+javadoc:
+    mvn javadoc:javadoc

src/pp.03.01-SynchPhilosopher_solution/pom.xml

@@ -0,0 +1,61 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>pp</groupId>
+  <artifactId>pp.03.01-SynchPhilosopher_solution</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <properties>	
+    <exec.mainClass>pp.PhilosopherExperiment</exec.mainClass>
+    <maven.compiler.release>19</maven.compiler.release>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+  <dependencies>
+    <dependency><!-- für Unit-Tests -->
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>5.10.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency><!-- für Lombok -->
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.30</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency><!-- für net.jcip Annotationen -->
+      <groupId>net.jcip</groupId>
+      <artifactId>jcip-annotations</artifactId>
+      <version>1.0</version>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin><!-- für Unit-Tests [mvn test] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.0.0</version>
+      </plugin>
+      <plugin><!-- [mvn compile] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.9.0</version>
+      </plugin>
+      <plugin><!-- [mvn exec:java] -->
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>3.1.0</version>
+      </plugin>
+      <plugin><!-- [mvn javadoc:javadoc] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <version>3.5.0</version>
+        <configuration>
+          <show>private</show>
+          <locale>en_US</locale>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/pp.03.01-SynchPhilosopher_solution/src/main/java/pp/Chopstick.java

@@ -0,0 +1,3 @@
+package pp;
+
+public class Chopstick {}

src/pp.03.01-SynchPhilosopher_solution/src/main/java/pp/Philosopher.java

@@ -0,0 +1,77 @@
+package pp;
+
+import java.util.Random;
+
+public class Philosopher extends Thread {
+
+    static final int MAX_THINKING_DURATION_MS = 1000;
+    static final int MAX_EATING_DURATION_MS = 3000;
+    static final int MAX_TAKING_TIME_MS = 1000;
+
+    private final Chopstick left;
+    private final Chopstick right;
+    private final Random random;
+    private int eaten;
+    private final int seat;
+
+    private volatile boolean stop;
+
+    private void log(String message) {
+        synchronized (Philosopher.class) {
+            for (var i = 1; i <= this.seat; i++) {
+                System.out.print("                         ");
+            }
+            System.out.println(threadId() + " " + message);
+        }
+    }
+
+    public void stopPhilosopher() {
+        log("stopping");
+        this.stop = true;
+        interrupt();
+    }
+
+    public Philosopher(int seat, Chopstick left, Chopstick right) {
+        this.stop = false;
+        this.seat = seat;
+        this.left = left;
+        this.right = right;
+        this.random = new Random();
+        this.eaten = 0;
+    }
+
+    @Override
+    public void run() {
+        log("starting");
+        try {
+            while (!this.stop) {
+                think();
+                eat();
+            }
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
+        log("stopped; eaten=" + this.eaten);
+    }
+
+    private void think() throws InterruptedException {
+        Thread.sleep(this.random.nextInt(MAX_THINKING_DURATION_MS));
+    }
+
+    private void eat() throws InterruptedException {
+        log("try taking left");
+        synchronized (this.left) {
+            log("left acquired");
+            Thread.sleep(this.random.nextInt(MAX_TAKING_TIME_MS));
+            log("try taking right");
+            synchronized (this.right) {
+                log("right acquired");
+                log("eating");
+                this.eaten++;
+                Thread.sleep(this.random.nextInt(MAX_EATING_DURATION_MS));
+            }
+            log("right released");
+        }
+        log("left released");
+    }
+}

src/pp.03.01-SynchPhilosopher_solution/src/main/java/pp/PhilosopherExperiment.java

@@ -0,0 +1,32 @@
+package pp;
+
+public class PhilosopherExperiment {
+
+    static final int PHILOSOPHER_NUM = 5;
+    static final int EXP_DURATION_MS = 20000;
+
+    public static void main(String... args) throws InterruptedException {
+        var chopsticks = new Chopstick[PHILOSOPHER_NUM];
+        var philosophers = new Philosopher[PHILOSOPHER_NUM];
+        for (int i = 0; i < PHILOSOPHER_NUM; i++) {
+            chopsticks[i] = new Chopstick();
+        }
+        // first n-1 philosophers
+        for (var i = 0; i < (PHILOSOPHER_NUM - 1); i++) {
+            philosophers[i] = new Philosopher(i, chopsticks[i], chopsticks[(i + 1)]);
+        }
+        // nth philosophers: initialize with right+left instead of left+right
+        philosophers[PHILOSOPHER_NUM - 1] = new Philosopher(
+            PHILOSOPHER_NUM - 1,
+            chopsticks[0],
+            chopsticks[PHILOSOPHER_NUM - 1]
+        );
+        for (var i = 0; i < PHILOSOPHER_NUM; i++) {
+            philosophers[i].start();
+        }
+        Thread.sleep(EXP_DURATION_MS);
+        for (var i = 0; i < PHILOSOPHER_NUM; i++) {
+            philosophers[i].stopPhilosopher();
+        }
+    }
+}

src/pp.03.02-BoundedQueueWaitNotify/README.md

@@ -0,0 +1,7 @@
+# Laboraufgabe "``wait``/``notifyAll`` für Ringpuffer"
+- [Aufgabenstellung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-02-BoundedQueueWaitNotify.html)
+- [Musterlösung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-Solutions.html#laboraufgabe-waitnotifyall-für-ringpuffer)
+
+# Materialien
+- [Folien](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/slides/03-steuerung.html)
+- [Skript](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/notes/03-steuerung.html)

src/pp.03.02-BoundedQueueWaitNotify/justfile

@@ -0,0 +1,12 @@
+default:
+    mvn clean compile exec:java
+exec args:
+    mvn exec:java -Dexec.args={{args}}
+clean:
+    mvn clean
+compile:
+    mvn compile
+test:
+    mvn test
+javadoc:
+    mvn javadoc:javadoc

src/pp.03.02-BoundedQueueWaitNotify/pom.xml

@@ -0,0 +1,61 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>pp</groupId>
+  <artifactId>pp.03.02-BoundedQueueWaitNotify</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <properties>	
+    <exec.mainClass>pp.BoundedBuffer</exec.mainClass>
+    <maven.compiler.release>10</maven.compiler.release>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+  <dependencies>
+    <dependency><!-- für Unit-Tests -->
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>5.10.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency><!-- für Lombok -->
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.30</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency><!-- für net.jcip Annotationen -->
+      <groupId>net.jcip</groupId>
+      <artifactId>jcip-annotations</artifactId>
+      <version>1.0</version>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin><!-- für Unit-Tests [mvn test] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.0.0</version>
+      </plugin>
+      <plugin><!-- [mvn compile] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.9.0</version>
+      </plugin>
+      <plugin><!-- [mvn exec:java] -->
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>3.1.0</version>
+      </plugin>
+      <plugin><!-- [mvn javadoc:javadoc] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <version>3.5.0</version>
+        <configuration>
+          <show>private</show>
+          <locale>en_US</locale>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/pp.03.02-BoundedQueueWaitNotify/src/main/java/pp/BoundedBuffer.java

@@ -0,0 +1,82 @@
+package pp;
+
+public class BoundedBuffer<T> {
+
+    final Object[] items = new Object[8];
+    int putptr, takeptr, count;
+
+    public void put(T x) throws InterruptedException {
+        // solange der Speicher voll ist, warten
+        this.items[this.putptr] = x;
+        if (++this.putptr == this.items.length) {
+            this.putptr = 0;
+        }
+        ++this.count;
+        // nun ist etwas neues im Speicher: Alle wartenden Threads
+        // benachrichtigen
+    }
+
+    public T take() throws InterruptedException {
+        // solange der Speicher leer ist, warten
+        @SuppressWarnings("unchecked")
+        var x = (T) this.items[this.takeptr];
+        if (++this.takeptr == this.items.length) {
+            this.takeptr = 0;
+        }
+        --this.count;
+        // nun ist etwas Platz im Speicher: Alle wartenden Threads
+        // benachrichtigen
+        return x;
+    }
+
+    public static void main(String... args) throws InterruptedException {
+        var mem = new BoundedBuffer<Integer>();
+        var p1 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 10; j++) {
+                        mem.put(j);
+                        System.out.println(Thread.currentThread().getName() + ": put=" + j);
+                        Thread.sleep(1000);
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Producer-1"
+        );
+        var p2 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 10; j++) {
+                        mem.put(j);
+                        System.out.println(Thread.currentThread().getName() + ": put=" + j);
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Producer-2"
+        );
+        var c1 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 20; j++) {
+                        System.out.println(Thread.currentThread().getName() + ": taken=" + mem.take());
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Consumer-1"
+        );
+        var now = System.currentTimeMillis();
+        p1.start();
+        p2.start();
+        c1.start();
+        p1.join();
+        p2.join();
+        c1.join();
+        System.out.println("Runtime: " + (System.currentTimeMillis() - now) + "ms");
+    }
+}

src/pp.03.02-BoundedQueueWaitNotify_solution/README.md

@@ -0,0 +1,7 @@
+# Laboraufgabe "``wait``/``notifyAll`` für Ringpuffer"
+- [Aufgabenstellung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-02-BoundedQueueWaitNotify.html)
+- [Musterlösung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-Solutions.html#laboraufgabe-waitnotifyall-für-ringpuffer)
+
+# Materialien
+- [Folien](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/slides/03-steuerung.html)
+- [Skript](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/notes/03-steuerung.html)

src/pp.03.02-BoundedQueueWaitNotify_solution/justfile

@@ -0,0 +1,12 @@
+default:
+    mvn clean compile exec:java
+exec args:
+    mvn exec:java -Dexec.args={{args}}
+clean:
+    mvn clean
+compile:
+    mvn compile
+test:
+    mvn test
+javadoc:
+    mvn javadoc:javadoc

src/pp.03.02-BoundedQueueWaitNotify_solution/pom.xml

@@ -0,0 +1,61 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>pp</groupId>
+  <artifactId>pp.03.02-BoundedQueueWaitNotify_solution</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <properties>	
+    <exec.mainClass>pp.BoundedBuffer</exec.mainClass>
+    <maven.compiler.release>10</maven.compiler.release>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+  <dependencies>
+    <dependency><!-- für Unit-Tests -->
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>5.10.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency><!-- für Lombok -->
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.30</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency><!-- für net.jcip Annotationen -->
+      <groupId>net.jcip</groupId>
+      <artifactId>jcip-annotations</artifactId>
+      <version>1.0</version>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin><!-- für Unit-Tests [mvn test] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.0.0</version>
+      </plugin>
+      <plugin><!-- [mvn compile] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.9.0</version>
+      </plugin>
+      <plugin><!-- [mvn exec:java] -->
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>3.1.0</version>
+      </plugin>
+      <plugin><!-- [mvn javadoc:javadoc] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <version>3.5.0</version>
+        <configuration>
+          <show>private</show>
+          <locale>en_US</locale>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/pp.03.02-BoundedQueueWaitNotify_solution/src/main/java/pp/BoundedBuffer.java

@@ -0,0 +1,84 @@
+package pp;
+
+public class BoundedBuffer<T> {
+
+    final Object[] items = new Object[8];
+    int putptr, takeptr, count;
+
+    public synchronized void put(T x) throws InterruptedException {
+        while (this.count == this.items.length) {
+            wait();
+        }
+        this.items[this.putptr] = x;
+        if (++this.putptr == this.items.length) {
+            this.putptr = 0;
+        }
+        ++this.count;
+        notifyAll();
+    }
+
+    public synchronized T take() throws InterruptedException {
+        while (this.count == 0) {
+            wait();
+        }
+        @SuppressWarnings("unchecked")
+        var x = (T) this.items[this.takeptr];
+        if (++this.takeptr == this.items.length) {
+            this.takeptr = 0;
+        }
+        --this.count;
+        notifyAll();
+        return x;
+    }
+
+    public static void main(String... args) throws InterruptedException {
+        var mem = new BoundedBuffer<Integer>();
+        var p1 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 10; j++) {
+                        mem.put(j);
+                        System.out.println(Thread.currentThread().getName() + ": put=" + j);
+                        Thread.sleep(1000);
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Producer-1"
+        );
+        var p2 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 10; j++) {
+                        mem.put(j);
+                        System.out.println(Thread.currentThread().getName() + ": put=" + j);
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Producer-2"
+        );
+        var c1 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 20; j++) {
+                        System.out.println(Thread.currentThread().getName() + ": taken=" + mem.take());
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Consumer-1"
+        );
+        var now = System.currentTimeMillis();
+        p1.start();
+        p2.start();
+        c1.start();
+        p1.join();
+        p2.join();
+        c1.join();
+        System.out.println("Runtime: " + (System.currentTimeMillis() - now) + "ms");
+    }
+}

src/pp.03.03-BoundedQueueAwaitSignal/README.md

@@ -0,0 +1,7 @@
+# Laboraufgabe "``await``/``signal`` für Ringpuffer”
+- [Aufgabenstellung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-03-BoundedQueueAwaitSignal.html)
+- [Musterlösung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-Solutions.html#laboraufgabe-awaitsignal-für-ringpuffer)
+
+# Materialien
+- [Folien](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/slides/03-steuerung.html)
+- [Skript](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/notes/03-steuerung.html)

src/pp.03.03-BoundedQueueAwaitSignal/justfile

@@ -0,0 +1,12 @@
+default:
+    mvn clean compile exec:java
+exec args:
+    mvn exec:java -Dexec.args={{args}}
+clean:
+    mvn clean
+compile:
+    mvn compile
+test:
+    mvn test
+javadoc:
+    mvn javadoc:javadoc

src/pp.03.03-BoundedQueueAwaitSignal/pom.xml

@@ -0,0 +1,61 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>pp</groupId>
+  <artifactId>pp.03.03-BoundedQueueAwaitSignal</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <properties>	
+    <exec.mainClass>pp.BoundedBuffer</exec.mainClass>
+    <maven.compiler.release>10</maven.compiler.release>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+  <dependencies>
+    <dependency><!-- für Unit-Tests -->
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>5.10.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency><!-- für Lombok -->
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.30</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency><!-- für net.jcip Annotationen -->
+      <groupId>net.jcip</groupId>
+      <artifactId>jcip-annotations</artifactId>
+      <version>1.0</version>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin><!-- für Unit-Tests [mvn test] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.0.0</version>
+      </plugin>
+      <plugin><!-- [mvn compile] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.9.0</version>
+      </plugin>
+      <plugin><!-- [mvn exec:java] -->
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>3.1.0</version>
+      </plugin>
+      <plugin><!-- [mvn javadoc:javadoc] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <version>3.5.0</version>
+        <configuration>
+          <show>private</show>
+          <locale>en_US</locale>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/pp.03.03-BoundedQueueAwaitSignal/src/main/java/pp/BoundedBuffer.java

@@ -0,0 +1,92 @@
+package pp;
+
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+public class BoundedBuffer<T> {
+
+    final Lock lock = new ReentrantLock();
+    final Condition notFull = this.lock.newCondition();
+    final Condition notEmpty = this.lock.newCondition();
+
+    final Object[] items = new Object[8];
+    int putptr, takeptr, count;
+
+    public void put(T x) throws InterruptedException {
+        // solange der Speicher voll ist, warten
+        this.items[this.putptr] = x;
+        if (++this.putptr == this.items.length) {
+            this.putptr = 0;
+        }
+        ++this.count;
+        // nun ist etwas neues im Speicher: Alle wartenden Threads
+        // benachrichtigen
+    }
+
+    public T take() throws InterruptedException {
+        // solange der Speicher leer ist, mit der Bedingungsvariablen notEmpty
+        // warten
+        @SuppressWarnings("unchecked")
+        var x = (T) this.items[this.takeptr];
+        if (++this.takeptr == this.items.length) {
+            this.takeptr = 0;
+        }
+        --this.count;
+        // nun ist etwas Platz im Speicher: Alle für notFull wartenden Threads
+        // benachrichtigen
+        return x;
+    }
+
+    public static void main(String... args) throws InterruptedException {
+        var mem = new BoundedBuffer<Integer>();
+        var p1 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 10; j++) {
+                        mem.put(j);
+                        System.out.println(Thread.currentThread().getName() + ": put=" + j);
+                        Thread.sleep(1000);
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Producer-1"
+        );
+        var p2 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 10; j++) {
+                        mem.put(j);
+                        System.out.println(Thread.currentThread().getName() + ": put=" + j);
+                        Thread.sleep(1000);
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Producer-2"
+        );
+        var c1 = new Thread(
+            () -> {
+                try {
+                    for (var j = 1; j <= 20; j++) {
+                        System.out.println(Thread.currentThread().getName() + ": taken=" + mem.take());
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                }
+            },
+            "Consumer-1"
+        );
+        var now = System.currentTimeMillis();
+        p1.start();
+        p2.start();
+        c1.start();
+        p1.join();
+        p2.join();
+        c1.join();
+        System.out.println("Runtime: " + (System.currentTimeMillis() - now) + "ms");
+    }
+}

src/pp.03.03-BoundedQueueAwaitSignal_solution/README.md

@@ -0,0 +1,7 @@
+# Laboraufgabe "``await``/``signal`` für Ringpuffer”
+- [Aufgabenstellung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-03-BoundedQueueAwaitSignal.html)
+- [Musterlösung](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/labs/03-Solutions.html#laboraufgabe-awaitsignal-für-ringpuffer)
+
+# Materialien
+- [Folien](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/slides/03-steuerung.html)
+- [Skript](https://services.informatik.hs-mannheim.de/~s.leuchter/pp/notes/03-steuerung.html)

src/pp.03.03-BoundedQueueAwaitSignal_solution/justfile

@@ -0,0 +1,12 @@
+default:
+    mvn clean compile exec:java
+exec args:
+    mvn exec:java -Dexec.args={{args}}
+clean:
+    mvn clean
+compile:
+    mvn compile
+test:
+    mvn test
+javadoc:
+    mvn javadoc:javadoc

src/pp.03.03-BoundedQueueAwaitSignal_solution/pom.xml

@@ -0,0 +1,61 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>pp</groupId>
+  <artifactId>pp.03.03-BoundedQueueAwaitSignal_solution</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <properties>	
+    <exec.mainClass>pp.BoundedBuffer</exec.mainClass>
+    <maven.compiler.release>10</maven.compiler.release>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+  <dependencies>
+    <dependency><!-- für Unit-Tests -->
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>5.10.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency><!-- für Lombok -->
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <version>1.18.30</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency><!-- für net.jcip Annotationen -->
+      <groupId>net.jcip</groupId>
+      <artifactId>jcip-annotations</artifactId>
+      <version>1.0</version>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+  <build>
+    <plugins>
+      <plugin><!-- für Unit-Tests [mvn test] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.0.0</version>
+      </plugin>
+      <plugin><!-- [mvn compile] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.9.0</version>
+      </plugin>
+      <plugin><!-- [mvn exec:java] -->
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>3.1.0</version>
+      </plugin>
+      <plugin><!-- [mvn javadoc:javadoc] -->
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-javadoc-plugin</artifactId>
+        <version>3.5.0</version>
+        <configuration>
+          <show>private</show>
+          <locale>en_US</locale>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/pp.03.03-BoundedQueueAwaitSignal_solution/src/main/java/pp/BoundedBuffer.java

@@ -0,0 +1,96 @@
+package pp;
+
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+public class BoundedBuffer<T> {
+    final Lock lock = new ReentrantLock();
+    final Condition notFull = this.lock.newCondition();
+    final Condition notEmpty = this.lock.newCondition();
+
+    final Object[] items = new Object[8];
+    int putptr, takeptr, count;
+
+    public void put(T x) throws InterruptedException {
+        this.lock.lock();
+        try {
+            while (this.count == this.items.length) {
+                this.notFull.await(); // unlock falls Bedingung
+            }
+            this.items[this.putptr] = x;
+            if (++this.putptr == this.items.length) {
+                this.putptr = 0;
+            }
+            ++this.count;
+            this.notEmpty.signal();
+        } finally {
+            this.lock.unlock();
+        }
+    }
+
+    public T take() throws InterruptedException {
+        this.lock.lock();
+        try {
+            while (this.count == 0) {
+                this.notEmpty.await();
+            }
+            @SuppressWarnings("unchecked")
+            var x = (T) this.items[this.takeptr];
+            if (++this.takeptr == this.items.length) {
+                this.takeptr = 0;
+            }
+            --this.count;
+            this.notFull.signal();
+            return x;
+        } finally {
+            this.lock.unlock();
+        }
+    }
+
+    public static void main(String... args) throws InterruptedException {
+        var mem = new BoundedBuffer<Integer>();
+        var p1 = new Thread(() -> {
+            try {
+                for (var j = 1; j <= 10; j++) {
+                    mem.put(j);
+                    System.out.println(
+                            Thread.currentThread().getName() + ": put=" + j);
+                    Thread.sleep(1000);
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }, "Producer-1");
+        var p2 = new Thread(() -> {
+            try {
+                for (var j = 1; j <= 10; j++) {
+                    mem.put(j);
+                    System.out.println(
+                            Thread.currentThread().getName() + ": put=" + j);
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }, "Producer-2");
+        var c1 = new Thread(() -> {
+            try {
+                for (var j = 1; j <= 20; j++) {
+                    System.out.println(Thread.currentThread().getName()
+                            + ": taken=" + mem.take());
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }, "Consumer-1");
+        var now = System.currentTimeMillis();
+        p1.start();
+        p2.start();
+        c1.start();
+        p1.join();
+        p2.join();
+        c1.join();
+        System.out.println(
+                "Runtime: " + (System.currentTimeMillis() - now) + "ms");
+    }
+}