+ * Implementation is based on GuardedQueue, which has two methods: get and put, + * the condition is that we cannot get from empty queue so when thread attempt + * to break the condition we invoke Object's wait method on him and when other thread put an element + * to the queue he notify the waiting one that now he can get from queue. + */ +package com.iluwatar.guarded.suspension; + +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.TimeUnit; + +/** + * Created by robertt240 on 1/26/17. + */ +public class App { + /** + * Example pattern execution + * + * @param args - command line args + */ + public static void main(String[] args) { + GuardedQueue guardedQueue = new GuardedQueue(); + ExecutorService executorService = Executors.newFixedThreadPool(3); + + //here we create first thread which is supposed to get from guardedQueue + executorService.execute(() -> { + guardedQueue.get(); + } + ); + + //here we wait two seconds to show that the thread which is trying to get from guardedQueue will be waiting + try { + Thread.sleep(2000); + } catch (InterruptedException e) { + e.printStackTrace(); + } + //now we execute second thread which will put number to guardedQueue and notify first thread that it could get + executorService.execute(() -> { + guardedQueue.put(20); + } + ); + executorService.shutdown(); + try { + executorService.awaitTermination(30, TimeUnit.SECONDS); + } catch (InterruptedException e) { + e.printStackTrace(); + } + } + +} diff --git a/guarded-suspension/src/main/java/com/iluwatar/guarded/suspension/GuardedQueue.java b/guarded-suspension/src/main/java/com/iluwatar/guarded/suspension/GuardedQueue.java new file mode 100644 index 000000000..89b330bfb --- /dev/null +++ b/guarded-suspension/src/main/java/com/iluwatar/guarded/suspension/GuardedQueue.java @@ -0,0 +1,65 @@ +/** + * 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.guarded.suspension;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+
+public class GuardedQueue {
+ private static final Logger LOGGER = LoggerFactory.getLogger(GuardedQueue.class);
+ private final Queue
+ * 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.guarded.suspension;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+public class GuardedQueueTest {
+ private volatile Integer value;
+
+ @Test
+ public void testGet() {
+ GuardedQueue g = new GuardedQueue();
+ ExecutorService executorService = Executors.newFixedThreadPool(2);
+ executorService.submit(() -> value = g.get());
+ executorService.submit(() -> g.put(Integer.valueOf(10)));
+ executorService.shutdown();
+ try {
+ executorService.awaitTermination(30, TimeUnit.SECONDS);
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ Assert.assertEquals(Integer.valueOf(10), value);
+ }
+
+ @Test
+ public void testPut() {
+ GuardedQueue g = new GuardedQueue();
+ g.put(12);
+ Assert.assertEquals(Integer.valueOf(12), g.get());
+
+ }
+
+}
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index 5ddd3bf98..d2ea715a7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -121,7 +121,7 @@