Java通过Fork/Join优化并行计算

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));    }  }}