uk.gov.gchq.gaffer.commonutil.ExecutorService Maven / Gradle / Ivy

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/*
 * Copyright 2019 Crown Copyright
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package uk.gov.gchq.gaffer.commonutil;

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

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;

/**
 * An {@code ExecutorService} that can schedule commands to run after a given
 * delay, or to execute periodically.
 * 
 * @see java.util.concurrent.ScheduledExecutorService
 **/
public final class ExecutorService {

    private static final Logger LOGGER = LoggerFactory.getLogger(ExecutorService.class);
    private static ScheduledExecutorService service;

    private ExecutorService() {
        // private constructor to prevent instantiation
    }

    public static void initialise(final int jobExecutorThreadCount) {
        LOGGER.debug("Initialising ExecutorService with " + jobExecutorThreadCount + " threads");
        service = Executors.newScheduledThreadPool(jobExecutorThreadCount, runnable -> {
            final Thread thread = new Thread(runnable);
            thread.setDaemon(true);
            return thread;
        });
    }

    public static ScheduledExecutorService getService() {
        return service;
    }

    public static boolean isEnabled() {
        return null != service;
    }

    public static void shutdown() {
        if (null != service) {
            service.shutdown();
        }
        service = null;
    }
}