Java Thread - 如何从ReentrantReadWriteLock安全获取写锁...

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

public class Main {
  static int SEQ_THRESHOLD;

  public static void main(String[] args) throws Exception {
    int size = 100000;
    int[] v1 = new int[size];
    for (int i = 0; i < size; i++) {
      v1[i] = i;
    }
    for (SEQ_THRESHOLD = 10; SEQ_THRESHOLD < size; SEQ_THRESHOLD += 50) {
      double avgTime = 0.0;
      int samples = 5;
      for (int i = 0; i < samples; i++) {
        long startTime = System.nanoTime();
        ForkJoinPool fjp = new ForkJoinPool();
        fjp.invoke(new MyAction(0, size, v1));
        long endTime = System.nanoTime();
        double secsTaken = (endTime - startTime) / 1.0e9;
        avgTime += secsTaken;
      }
      System.out.println(SEQ_THRESHOLD + " " + (avgTime / samples));
    }
  }
}

class MyAction extends RecursiveAction {
  int[] v1;
  int start, end;

  MyAction(int start, int end, int[] v1) {
    this.start = start;
    this.end = end;
    this.v1 = v1;
  }

  int SEQ_THRESHOLD = Main.SEQ_THRESHOLD;

  @Override
  protected void compute() {
    if (end - start < SEQ_THRESHOLD) {
      for (int i = start; i < end; i++) {
        v1[i] = v1[i] + i * i;
      }
    } else {
      int mid = (start + end) / 2;
      invokeAll(new MyAction(start, mid, v1), new MyAction(mid, end, v1));
    }
  }
}