Java通过Fork/Join优化并行计算

本文实例为大家分享了Java通过Fork/Join优化并行计算的具体代码，供大家参考，具体内容如下

Java代码：

package Threads;

import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.RecursiveAction;

/**
* Created by Frank
*/
public class RecursiveActionDemo extends RecursiveAction {

static int[] raw = {19, 3, 0, -1, 57, 24, 65, Integer.MAX_VALUE, 42, 0, 3, 5};
 static int[] sorted = null;
 int[] source;
 int[] dest;
 int length;
 int start;
 final static int THRESHOLD = 4;

public static void main(String[] args) {
   sorted = new int[raw.length];

ForkJoinPool pool = new ForkJoinPool();
   pool.invoke(new RecursiveActionDemo(raw, 0, raw.length, sorted));

System.out.println('[');
   for (int i : sorted) {
     System.out.println(i + ",");
   }
   System.out.println(']');
 }

public RecursiveActionDemo(int[] source, int start, int length, int[] dest) {
   this.source = source;
   this.dest = dest;
   this.length = length;
   this.start = start;
 }

@Override
 protected void compute() {
   System.out.println("ForkJoinDemo.compute()");
   if (length < THRESHOLD) {  // 直接计算
     for (int i = start; i < start + length; i++) {
       dest[i] = source[i] * source[i];
     }
   } else { // 分而治之
     int split = length / 2;
     /**
      * invokeAll反复调用fork和join直到完成。
      */
     invokeAll(new RecursiveActionDemo(source, start, split, dest), new RecursiveActionDemo(source, start + split, length - split, dest));
   }
 }
}