一個關於CountDownLatch的併發需求

需求

A，B，C可併發運行，全部成功纔算成功，一個失敗全員回滾。

思考

使用CountDownLatch，可以保證三個線程結束後，才進行提交成功狀態。但是怎麼才能判斷某個任務失敗了呢？

1. 捕獲子線程異常？
2. await(long timeout, TimeUnit unit)?

陷入了沉思

加一個原子變量判斷子線程異常的次數不就OK嘛（分佈式用分佈式鎖，單機用原子類）

    @GetMapping("/{id}")
    String test(@PathVariable("id") String id) {

        ThreadPoolExecutor threadPoolExecutor = ExecutorFactory.newCustomerThreadExecutor(3, 3, 1000, new NameThreadFactory("畫像表"));

        // 失敗線程數
        LongAdder failThreadNum = new LongAdder();

        int threadSize = 2;
        CountDownLatch cdl = new CountDownLatch(threadSize);


        Thread t1 = new Thread(() -> {
            try {
                System.out.println(Thread.currentThread().getName());
                if (Objects.equals(id, "1")) {
                    throw new RuntimeException();
                }
            } catch (Exception e) {
                failThreadNum.increment();
            } finally {
                cdl.countDown();
            }
        });

        Thread t2 = new Thread(() -> {
            try {
                System.out.println(Thread.currentThread().getName());
            } catch (Exception e) {
                failThreadNum.increment();
            } finally {
                cdl.countDown();
            }
        });

        threadPoolExecutor.submit(t1);
        threadPoolExecutor.submit(t2);

        try {
            cdl.await();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        if (failThreadNum.intValue() != 0) {
            System.out.println("回滾");
        } else {
            System.out.println("Main over");
        }
        threadPoolExecutor.shutdown();
        return "success";
    }