com.google.common.util.concurrent.AbstractIdleService Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of aem-sdk-api Show documentation
The Adobe Experience Manager SDK
There is a newer version: 2024.11.18751.20241128T090041Z-241100
/*
 * Copyright (C) 2009 The Guava Authors
 *
 * 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 com.google.common.util.concurrent;

import com.google.common.annotations.Beta;
import com.google.common.base.Supplier;
import com.google.common.base.Throwables;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 *  Base class for services that do not need a thread while "running"
 *  but may need one during startup and shutdown. Subclasses can
 *  implement {@link #startUp} and {@link #shutDown} methods, each
 *  which run in a executor which by default uses a separate thread
 *  for each method.
 *
 *  @author Chris Nokleberg
 *  @since 1.0
 *
 * @deprecated The Google Guava Core Libraries are deprecated and will not be part of the AEM SDK after April 2023
 */
@Beta
@Deprecated(since = "2022-12-01")
public abstract class AbstractIdleService implements Service {

    /* Thread names will look like {@code "MyService STARTING"}. */
    private final Supplier threadNameSupplier = new Supplier() {

        @Override
        public String get() {
            return serviceName() + " " + state();
        }
    };

    /* use AbstractService for state management */
    private final Service delegate = new AbstractService() {

        @Override
        protected final void doStart() {
            MoreExecutors.renamingDecorator(executor(), threadNameSupplier).execute(new Runnable() {

                @Override
                public void run() {
                    try {
                        startUp();
                        notifyStarted();
                    } catch (Throwable t) {
                        notifyFailed(t);
                        throw Throwables.propagate(t);
                    }
                }
            });
        }

        @Override
        protected final void doStop() {
            MoreExecutors.renamingDecorator(executor(), threadNameSupplier).execute(new Runnable() {

                @Override
                public void run() {
                    try {
                        shutDown();
                        notifyStopped();
                    } catch (Throwable t) {
                        notifyFailed(t);
                        throw Throwables.propagate(t);
                    }
                }
            });
        }
    };

    /**
     * Constructor for use by subclasses.
     */
    protected AbstractIdleService() {
    }

    /**
     * Start the service.
     */
    protected abstract void startUp() throws Exception;

    /**
     * Stop the service.
     */
    protected abstract void shutDown() throws Exception;

    /**
     * Returns the {@link Executor} that will be used to run this service.
     * Subclasses may override this method to use a custom {@link Executor}, which
     * may configure its worker thread with a specific name, thread group or
     * priority. The returned executor's {@link Executor#execute(Runnable)
     * execute()} method is called when this service is started and stopped,
     * and should return promptly.
     */
    protected Executor executor() {
        return new Executor() {

            @Override
            public void execute(Runnable command) {
                MoreExecutors.newThread(threadNameSupplier.get(), command).start();
            }
        };
    }

    @Override
    public String toString() {
        return serviceName() + " [" + state() + "]";
    }

    // We override instead of using ForwardingService so that these can be final.
    @Deprecated
    @Override
    public final ListenableFuture start() {
        return delegate.start();
    }

    @Deprecated
    @Override
    public final State startAndWait() {
        return delegate.startAndWait();
    }

    @Override
    public final boolean isRunning() {
        return delegate.isRunning();
    }

    @Override
    public final State state() {
        return delegate.state();
    }

    @Deprecated
    @Override
    public final ListenableFuture stop() {
        return delegate.stop();
    }

    @Deprecated
    @Override
    public final State stopAndWait() {
        return delegate.stopAndWait();
    }

    /**
     * @since 13.0
     */
    @Override
    public final void addListener(Listener listener, Executor executor) {
        delegate.addListener(listener, executor);
    }

    /**
     * @since 14.0
     */
    @Override
    public final Throwable failureCause() {
        return delegate.failureCause();
    }

    /**
     * @since 15.0
     */
    @Override
    public final Service startAsync() {
        delegate.startAsync();
        return this;
    }

    /**
     * @since 15.0
     */
    @Override
    public final Service stopAsync() {
        delegate.stopAsync();
        return this;
    }

    /**
     * @since 15.0
     */
    @Override
    public final void awaitRunning() {
        delegate.awaitRunning();
    }

    /**
     * @since 15.0
     */
    @Override
    public final void awaitRunning(long timeout, TimeUnit unit) throws TimeoutException {
        delegate.awaitRunning(timeout, unit);
    }

    /**
     * @since 15.0
     */
    @Override
    public final void awaitTerminated() {
        delegate.awaitTerminated();
    }

    /**
     * @since 15.0
     */
    @Override
    public final void awaitTerminated(long timeout, TimeUnit unit) throws TimeoutException {
        delegate.awaitTerminated(timeout, unit);
    }

    /**
     * Returns the name of this service. {@link AbstractIdleService} may include the name in debugging
     * output.
     *
     * @since 14.0
     */
    protected String serviceName() {
        return getClass().getSimpleName();
    }
}