Add LongAdder example

Author: winterbe

src/com/winterbe/java8/samples/concurrent/LongAdder1.java

@@ -0,0 +1,43 @@
+package com.winterbe.java8.samples.concurrent;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.LongAdder;
+import java.util.stream.IntStream;
+
+/**
+ * @author Benjamin Winterberg
+ */
+public class LongAdder1 {
+
+ private static final int NUM_INCREMENTS = 10000;
+
+ private static LongAdder adder = new LongAdder();
+
+ public static void main(String[] args) {
+ testIncrement();
+ testAdd();
+ }
+
+ private static void testAdd() {
+ ExecutorService executor = Executors.newFixedThreadPool(2);
+
+ IntStream.range(0, NUM_INCREMENTS)
+ .forEach(i -> executor.submit(() -> adder.add(2)));
+
+ ConcurrentUtils.stop(executor);
+
+ System.out.format("Add: %d\n", adder.sumThenReset());
+ }
+
+ private static void testIncrement() {
+ ExecutorService executor = Executors.newFixedThreadPool(2);
+
+ IntStream.range(0, NUM_INCREMENTS)
+ .forEach(i -> executor.submit(adder::increment));
+
+ ConcurrentUtils.stop(executor);
+
+ System.out.format("Increment: Expected=%d; Is=%d\n", NUM_INCREMENTS, adder.sumThenReset());
+ }
+}