CODEWITHSUNDEEP
javascheduledexecutorservice
expoter
expoter

Reputation: 1640

Is it safe to reschedule a task before it done when using ScheduledExecutorService?

I want to do some timing tasks using ScheduledExecutorService, but time intervals are changeable. I try to reschedule a task before it finished:

import java.io.IOException;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class Test {
    public static ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(1);
    public static int interval = 1;

    public static void main(String[] args) throws IOException {
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                System.out.println(System.currentTimeMillis() / 1000);
                interval += 1;
                scheduledExecutorService.schedule(this, interval, TimeUnit.SECONDS);
            }
        };
        scheduledExecutorService.schedule(runnable, interval, TimeUnit.SECONDS);
    }
}

But, I never found anyone do timing tasks using ScheduledExecutorService like this, I wonder whether it's safe.

Upvotes: 2

Views: 499

Answers (1)

Nicolas Filotto
Nicolas Filotto

Reputation: 44965

As long as you use the method schedule that executes the task only once, there is nothing wrong with this approach, it will only re-schedule at each iteration the same task with a different delay. For the scheduler it will be seen as a new task scheduled at each iteration, nothing more.

Upvotes: 2

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