io.druid.java.util.common.concurrent.Execs.java Source code

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Here is the source code for io.druid.java.util.common.concurrent.Execs.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets licenses this file
 * to you 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 io.druid.java.util.common.concurrent;

import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import com.google.common.util.concurrent.ThreadFactoryBuilder;

import javax.annotation.Nullable;
import javax.validation.constraints.NotNull;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 */
public class Execs {
    /**
     * Returns an ExecutorService which is terminated and shutdown from the beginning and not able to accept any tasks.
     */
    public static ExecutorService dummy() {
        return DummyExecutorService.INSTANCE;
    }

    public static ExecutorService singleThreaded(@NotNull String nameFormat) {
        return singleThreaded(nameFormat, null);
    }

    public static ExecutorService singleThreaded(@NotNull String nameFormat, @Nullable Integer priority) {
        return Executors.newSingleThreadExecutor(makeThreadFactory(nameFormat, priority));
    }

    public static ExecutorService multiThreaded(int threads, @NotNull String nameFormat) {
        return multiThreaded(threads, nameFormat, null);
    }

    public static ExecutorService multiThreaded(int threads, @NotNull String nameFormat,
            @Nullable Integer priority) {
        return Executors.newFixedThreadPool(threads, makeThreadFactory(nameFormat, priority));
    }

    public static ScheduledExecutorService scheduledSingleThreaded(@NotNull String nameFormat) {
        return scheduledSingleThreaded(nameFormat, null);
    }

    public static ScheduledExecutorService scheduledSingleThreaded(@NotNull String nameFormat,
            @Nullable Integer priority) {
        return Executors.newSingleThreadScheduledExecutor(makeThreadFactory(nameFormat, priority));
    }

    public static ThreadFactory makeThreadFactory(@NotNull String nameFormat) {
        return makeThreadFactory(nameFormat, null);
    }

    public static ThreadFactory makeThreadFactory(@NotNull String nameFormat, @Nullable Integer priority) {
        final ThreadFactoryBuilder builder = new ThreadFactoryBuilder().setDaemon(true).setNameFormat(nameFormat);
        if (priority != null) {
            builder.setPriority(priority);
        }

        return builder.build();
    }

    public static Thread makeThread(String name, Runnable runnable, boolean isDaemon) {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(name), "name null/empty");
        Preconditions.checkNotNull(runnable, "null runnable");

        Thread t = new Thread(runnable);
        t.setName(name);
        t.setDaemon(isDaemon);
        return t;
    }

    /**
     * @param nameFormat nameformat for threadFactory
     * @param capacity   maximum capacity after which the executorService will block on accepting new tasks
     *
     * @return ExecutorService which blocks accepting new tasks when the capacity reached
     */
    public static ExecutorService newBlockingSingleThreaded(final String nameFormat, final int capacity) {
        return newBlockingSingleThreaded(nameFormat, capacity, null);
    }

    public static ExecutorService newBlockingSingleThreaded(final String nameFormat, final int capacity,
            final Integer priority) {
        final BlockingQueue<Runnable> queue;
        if (capacity > 0) {
            queue = new ArrayBlockingQueue<>(capacity);
        } else {
            queue = new SynchronousQueue<>();
        }
        return new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS, queue,
                makeThreadFactory(nameFormat, priority), new RejectedExecutionHandler() {
                    @Override
                    public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
                        try {
                            executor.getQueue().put(r);
                        } catch (InterruptedException e) {
                            throw new RejectedExecutionException("Got Interrupted while adding to the Queue", e);
                        }
                    }
                });
    }
}