JUnit tests

mutex/src/main/java/com/iluwatar/mutex/App.java

@@ -40,7 +40,7 @@ public class App {
    */
   public static void main(String[] args) {
     Mutex mutex = new Mutex();
-    Jar jar = new Jar(mutex);
+    Jar jar = new Jar(1000, mutex);
     Thief peter = new Thief("Peter", jar);
     Thief john = new Thief("John", jar);
     peter.start();

mutex/src/main/java/com/iluwatar/mutex/Jar.java

@@ -37,16 +37,17 @@ public class Jar {
   /**
    * The resource within the jar.
    */
-  private int beans = 1000;
+  private int beans;
 
-  public Jar(Lock lock) {
+  public Jar(int beans, Lock lock) {
+    this.beans = beans;
     this.lock = lock;
   }
 
   /**
    * Method for a thief to take a bean.
    */
-  public boolean takeBean(Thief thief) {
+  public boolean takeBean() {
     boolean success = false;
     try {
       lock.acquire();

mutex/src/main/java/com/iluwatar/mutex/Mutex.java

@@ -32,6 +32,13 @@ public class Mutex implements Lock {
    */
   private Object owner;
 
+  /**
+   * Returns the current owner of the Mutex, or null if available
+   */
+  public Object getOwner() {
+    return owner;
+  }
+  
   /**
    * Method called by a thread to acquire the lock. If the lock has already
    * been acquired this will wait until the lock has been released to 
@@ -51,8 +58,10 @@ public class Mutex implements Lock {
    */
   @Override
   public synchronized void release() {
-    owner = null;
-    notify();
+    if (Thread.currentThread() == owner) {
+      owner = null;
+      notify();
+    }
   }
 
 }

mutex/src/main/java/com/iluwatar/mutex/Thief.java

@@ -51,7 +51,7 @@ public class Thief extends Thread {
   public void run() {
     int beans = 0;
 
-    while (jar.takeBean(this)) {
+    while (jar.takeBean()) {
       beans = beans + 1;
       System.out.println(name + " took a bean.");
     }

mutex/src/test/java/com/iluwatar/mutex/JarTest.java

@@ -0,0 +1,43 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.mutex;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ * Test case for taking beans from a Jar
+ */
+public class JarTest {
+
+  @Test
+  public void testTakeBeans() {
+    Mutex mutex = new Mutex();
+    Jar jar = new Jar(10, mutex);
+    for (int i = 0; i < 10; i++) {
+      assertTrue(jar.takeBean());
+    }
+    assertFalse(jar.takeBean());
+  }
+
+}

mutex/src/test/java/com/iluwatar/mutex/MutexTest.java

@@ -0,0 +1,47 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.mutex;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ * Test case for acquiring and releasing a Mutex
+ */
+public class MutexTest {
+
+  @Test
+  public void acquireReleaseTest() {
+    Mutex mutex = new Mutex();
+    assertNull(mutex.getOwner());
+    try {
+      mutex.acquire();
+      assertEquals(mutex.getOwner(), Thread.currentThread());
+    } catch (InterruptedException e) {
+      fail(e.toString());
+    }
+    mutex.release();
+    assertNull(mutex.getOwner());
+  }
+
+}

semaphore/src/main/java/com/iluwatar/semaphore/Semaphore.java

@@ -27,13 +27,29 @@ package com.iluwatar.semaphore;
  */
 public class Semaphore implements Lock {
 
+  private final int licenses;
   /**
    * The number of concurrent resource accesses which are allowed.
    */
   private int counter;
     
-  public Semaphore(int counter) {
-    this.counter = counter;    
+  public Semaphore(int licenses) {
+    this.licenses = licenses;
+    this.counter = licenses;    
+  }
+  
+  /**
+   * Returns the number of licenses managed by the Semaphore
+   */
+  public int getNumLicenses() {
+    return licenses;
+  }
+  
+  /**
+   * Returns the number of available licenses
+   */
+  public int getAvailableLicenses() {
+    return counter; 
   }
   
   /**
@@ -52,8 +68,10 @@ public class Semaphore implements Lock {
    * Method called by a thread to release the lock.
    */
   public synchronized void release() {
-    counter = counter + 1;
-    notify();
+    if (counter < licenses) {
+      counter = counter + 1;
+      notify();
+    }
   }
 
 }

semaphore/src/test/java/com/iluwatar/semaphore/FruitBowlTest.java

@@ -0,0 +1,51 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.semaphore;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ * Test taking from and putting Fruit into a FruitBowl
+ */
+public class FruitBowlTest {
+
+  @Test
+  public void fruitBowlTest() {
+    FruitBowl fbowl = new FruitBowl();
+    
+    assertEquals(fbowl.countFruit(), 0);
+    
+    for (int i = 1; i <= 10; i++) {
+      fbowl.put(new Fruit(Fruit.FruitType.LEMON));
+      assertEquals(fbowl.countFruit(), i);
+    }
+
+    for (int i = 9; i >= 0; i--) {
+      assertNotNull(fbowl.take());
+      assertEquals(fbowl.countFruit(), i);
+    }
+
+    assertNull(fbowl.take());
+  }
+}

semaphore/src/test/java/com/iluwatar/semaphore/SemaphoreTest.java

@@ -0,0 +1,56 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.semaphore;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ * Test case for acquiring and releasing a Semaphore
+ */
+public class SemaphoreTest {
+
+  @Test
+  public void acquireReleaseTest() {
+    Semaphore sphore = new Semaphore(3);
+
+    assertEquals(sphore.getAvailableLicenses(), 3);
+
+    for (int i = 2; i >= 0; i--) {
+      try {
+        sphore.acquire();
+        assertEquals(sphore.getAvailableLicenses(), i);
+      } catch (InterruptedException e) {
+        fail(e.toString());
+      }
+    }
+  
+    for (int i = 1; i <= 3; i++) {
+      sphore.release();
+      assertEquals(sphore.getAvailableLicenses(), i);
+    }
+
+    sphore.release();
+    assertEquals(sphore.getAvailableLicenses(), 3);
+  }
+}