Merge branch 'master' into BAEL-1711-move-code-snippets

libraries/src/main/java/com/baeldung/jctools/MpmcBenchmark.java

@@ -0,0 +1,73 @@
+package com.baeldung.jctools;
+
+import org.jctools.queues.MpmcArrayQueue;
+import org.jctools.queues.atomic.MpmcAtomicArrayQueue;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Control;
+
+import java.util.Queue;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.SampleTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Fork(1)
+@Warmup(iterations = 1)
+@Measurement(iterations = 3)
+@State(Scope.Group)
+public class MpmcBenchmark {
+
+    public static final String PARAM_UNSAFE = "MpmcArrayQueue";
+    public static final String PARAM_AFU = "MpmcAtomicArrayQueue";
+    public static final String PARAM_JDK = "ArrayBlockingQueue";
+
+    public static final int PRODUCER_THREADS_NUMBER = 32;
+    public static final int CONSUMER_THREADS_NUMBER = 32;
+
+    public static final String GROUP_NAME = "MyGroup";
+
+    public static final int CAPACITY = 128;
+
+    @Param({PARAM_UNSAFE, PARAM_AFU, PARAM_JDK})
+    public volatile String implementation;
+
+    public volatile Queue<Long> queue;
+
+    @Setup(Level.Trial)
+    public void setUp() {
+        switch (implementation) {
+            case PARAM_UNSAFE:
+                queue = new MpmcArrayQueue<>(CAPACITY);
+                break;
+            case PARAM_AFU:
+                queue = new MpmcAtomicArrayQueue<>(CAPACITY);
+                break;
+            case PARAM_JDK:
+                queue = new ArrayBlockingQueue<>(CAPACITY);
+                break;
+            default:
+                throw new UnsupportedOperationException("Unsupported implementation " + implementation);
+        }
+    }
+
+
+    @Benchmark
+    @Group(GROUP_NAME)
+    @GroupThreads(PRODUCER_THREADS_NUMBER)
+    public void write(Control control) {
+        //noinspection StatementWithEmptyBody
+        while (!control.stopMeasurement && !queue.offer(1L)) {
+            // Is intentionally left blank
+        }
+    }
+
+    @Benchmark
+    @Group(GROUP_NAME)
+    @GroupThreads(CONSUMER_THREADS_NUMBER)
+    public void read(Control control) {
+        //noinspection StatementWithEmptyBody
+        while (!control.stopMeasurement && queue.poll() == null) {
+            // Is intentionally left blank
+        }
+    }
+}

libraries/src/main/java/com/baeldung/jctools/README.md

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+## How to build and run the JMH benchmark
+
+Execute the following from the project's root:  
+```bash
+mvn clean install
+java -jar ./target/benchmarks.jar MpmcBenchmark -si true
+```