How to invoke some code once after and additional to a Thread.sleep-CodePudding

Imagine having this code running in a Thread:

while (blockingQueue.size() > 0) {
    
    AbortableCountDownLatch latch = (AbortableCountDownLatch) blockingQueue.poll();
    latch.countDown();
}
Thread.sleep(updateinterval * 1000);

How to make the while loop run after the Thread.sleep as an additional execution? As something like:

Thread.sleepAndExecute(Runnable code, sleep time);

So that the code is just executed, after the sleep has entered, not the other way around?

The blockingQueue contains some CountDownLatch, which are blocking another thread. The other thread just is allowed to continue, IF the latches are all countdown AND this thread has entered sleep/await state. Both conditions need to be true so that the other thread is allowed to continue.

CodePudding user response：

You may want to use CompletableFuture's thenApply method as a callback to supplyAsync.

As the name suggests, supplyAsync takes a Supplier<T> as an argument, while thenApply takes a Function<T,R>:

CompletableFuture<String> futureText = CompletableFuture.supplyAsync(() -> {
    try {
        TimeUnit.SECONDS.sleep(1);
    } catch (InterruptedException e) {
       throw new IllegalStateException(e);
    }
    return "waited one second";
}).thenApply(input-> {
    // run some code as an additional execution
    return "inside thenApply, "   input;
});

System.out.println(futureText.get()); // prints: inside thenApply, waited one second

CodePudding user response：

You need to add sleep in a different thread. Either you can use completeable future or Executor Service.

        ExecutorService executorService = Executors.newSingleThreadExecutor();
        executorService.submit( () -> {
            try {
                Thread.sleep(1000l);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        });

        while (blockingQueue.size() > 0) {

            AbortableCountDownLatch latch = blockingQueue.poll();
            latch.countDown();
        }
        executorService.shutdown();