org.jboss.netty.channel.socket.nio.AbstractNioBossPool Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of netty Show documentation

The Netty project is an effort to provide an asynchronous event-driven network application framework and tools for rapid development of maintainable high performance and high scalability protocol servers and clients. In other words, Netty is a NIO client server framework which enables quick and easy development of network applications such as protocol servers and clients. It greatly simplifies and streamlines network programming such as TCP and UDP socket server.

There is a newer version: 4.0.0.Alpha8

Show newest version

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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 org.jboss.netty.channel.socket.nio;

import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
import org.jboss.netty.util.ExternalResourceReleasable;
import org.jboss.netty.util.internal.ExecutorUtil;

import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

public abstract class AbstractNioBossPool
        implements BossPool, ExternalResourceReleasable {

    /**
     * The boss pool raises an exception unless all boss threads start and run within this timeout (in seconds.)
     */
    private static final int INITIALIZATION_TIMEOUT = 10;

    private static final InternalLogger logger = InternalLoggerFactory.getInstance(AbstractNioBossPool.class);

    private final Boss[] bosses;
    private final AtomicInteger bossIndex = new AtomicInteger();
    private final Executor bossExecutor;
    private volatile boolean initialized;

    /**
     * Create a new instance
     *
     * @param bossExecutor the {@link Executor} to use for the {@link Boss}'s
     * @param bossCount the count of {@link Boss}'s to create
     */
    AbstractNioBossPool(Executor bossExecutor, int bossCount) {
        this(bossExecutor, bossCount, true);
    }

    AbstractNioBossPool(Executor bossExecutor, int bossCount, boolean autoInit) {
        if (bossExecutor == null) {
            throw new NullPointerException("bossExecutor");
        }
        if (bossCount <= 0) {
            throw new IllegalArgumentException(
                    "bossCount (" + bossCount + ") " +
                            "must be a positive integer.");
        }
        bosses = new Boss[bossCount];
        this.bossExecutor = bossExecutor;
        if (autoInit) {
            init();
        }
    }

    protected void init() {
        if (initialized) {
            throw new IllegalStateException("initialized already");
        }
        initialized = true;

        for (int i = 0; i < bosses.length; i++) {
            bosses[i] = newBoss(bossExecutor);
        }

        waitForBossThreads();
    }

    private void waitForBossThreads() {
        long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(INITIALIZATION_TIMEOUT);
        boolean warn = false;
        for (Boss boss: bosses) {
            if (!(boss instanceof AbstractNioSelector)) {
                continue;
            }

            AbstractNioSelector selector = (AbstractNioSelector) boss;
            long waitTime = deadline - System.nanoTime();
            try {
                if (waitTime <= 0) {
                    if (selector.thread == null) {
                        warn = true;
                        break;
                    }
                } else if (!selector.startupLatch.await(waitTime, TimeUnit.NANOSECONDS)) {
                    warn = true;
                    break;
                }
            } catch (InterruptedException ignore) {
                // Stop waiting for the boss threads and let someone else take care of the interruption.
                Thread.currentThread().interrupt();
                break;
            }
        }

        if (warn) {
            logger.warn(
                    "Failed to get all boss threads ready within " + INITIALIZATION_TIMEOUT + " second(s). " +
                    "Make sure to specify the executor which has more threads than the requested bossCount. " +
                    "If unsure, use Executors.newCachedThreadPool().");
        }
    }

    /**
     * Create a new {@link Boss} which uses the given {@link Executor} to service IO
     *
     *
     * @param executor the {@link Executor} to use
     * @return worker the new {@link Boss}
     */
    protected abstract E newBoss(Executor executor);

    @SuppressWarnings("unchecked")
    public E nextBoss() {
        return (E) bosses[Math.abs(bossIndex.getAndIncrement() % bosses.length)];
    }

    public void rebuildSelectors() {
        for (Boss boss: bosses) {
            boss.rebuildSelector();
        }
    }

    public void releaseExternalResources() {
        shutdown();
        ExecutorUtil.shutdownNow(bossExecutor);
    }

    public void shutdown() {
        for (Boss boss: bosses) {
            boss.shutdown();
        }
    }
}