ForkJoinTest

whatsmars-common/src/test/java/org/hongxi/java/util/concurrent/ForkJoinTest.java

+package org.hongxi.java.util.concurrent;
+
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.RecursiveTask;
+
+/**
+ * @author shenhongxi 2019/8/11
+ */
+public class ForkJoinTest {
+
+    public static void main(String[] args) {
+        ForkJoinPool forkJoinPool = new ForkJoinPool(Runtime.getRuntime().availableProcessors() * 2);
+        int sum = forkJoinPool.invoke(new AccumulationTask(1, 60000));
+        System.out.println(sum);
+    }
+
+    static class AccumulationTask extends RecursiveTask<Integer> {
+        private int start;
+        private int end;
+
+        AccumulationTask(int start, int end) {
+            super();
+            this.start = start;
+            this.end = end;
+        }
+
+        @Override
+        protected Integer compute() {
+            int result = 0;
+            if (end - start <= 2) {
+                for (int i = start; i <= end; i++) {
+                    result += i;
+                }
+            } else {
+                int middle = (start + end) / 2;
+                AccumulationTask left = new AccumulationTask(start, middle);
+                AccumulationTask right = new AccumulationTask(middle + 1, end);
+                left.fork();
+                right.fork();
+                result = left.join() + right.join();
+            }
+            return result;
+        }
+    }
+}