package com.juick.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;

/**
 * Created by aalexeev on 11/11/16.
 */
public class ThreadHelper {
    private ThreadHelper() {
        throw new IllegalStateException();
    }

    private static Logger logger = LoggerFactory.getLogger(ThreadHelper.class);

    public static void shutdownAndAwaitTermination(ExecutorService pool) {
        pool.shutdown(); // Disable new tasks from being submitted
        try {
            // Wait a while for existing tasks to terminate
            if (!pool.awaitTermination(5, TimeUnit.SECONDS)) {
                logger.info("Calls shutDownNow for pool");
                pool.shutdownNow(); // Cancel currently executing tasks
                // Wait a while for tasks to respond to being cancelled
                if (!pool.awaitTermination(5, TimeUnit.SECONDS))
                    logger.error("Pool did not terminate");
            }
        } catch (InterruptedException ie) {
            // (Re-)Cancel if current thread also interrupted
            pool.shutdownNow();
            // Preserve interrupt status
            Thread.currentThread().interrupt();
        }
    }
}