org.glowroot.agent.init.NettyInit.java Source code

Introduction

Here is the source code for org.glowroot.agent.init.NettyInit.java

Source

/*
 * Copyright 2015-2019 the original author or 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 org.glowroot.agent.init;

import io.netty.buffer.PooledByteBufAllocator;
import io.netty.util.internal.PlatformDependent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.glowroot.agent.util.JavaVersion;

public class NettyInit {

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

    private NettyInit() {
    }

    public static void run() {
        if (JavaVersion.isJ9Jvm()) {
            // WebSphere crashes on startup without this workaround (at least when pointing to
            // glowroot central and using WebSphere 8.5.5.11)
            String prior = System.getProperty("io.netty.noUnsafe");
            System.setProperty("io.netty.noUnsafe", "true");
            try {
                if (PlatformDependent.hasUnsafe()) {
                    throw new IllegalStateException("Netty property to disable usage of UNSAFE was"
                            + " not set early enough, please report to the Glowroot project");
                }
            } finally {
                if (prior == null) {
                    System.clearProperty("io.netty.noUnsafe");
                } else {
                    System.setProperty("io.netty.noUnsafe", prior);
                }
            }
        }
        String prior = System.getProperty("io.netty.allocator.maxOrder");
        // check that the property has not been explicitly set at the command line
        // e.g. -Dorg.glowroot.agent.shaded.io.netty.allocator.maxOrder=9
        if (prior == null || prior.isEmpty()) {
            // maxOrder 11 ==> default PoolChunk size 16mb (this is Netty's default)
            // maxOrder 10 ==> default PoolChunk size 8mb (making this Glowroot's default)
            // maxOrder 9 ==> default PoolChunk size 4mb (can be set at the command line)
            // maxOrder 8 ==> default PoolChunk size 2mb (can be set at the command line)
            System.setProperty("io.netty.allocator.maxOrder", "10");
            try {
                // the call to PooledByteBufAllocator.defaultMaxOrder() forces it to initialize
                // only logging warning if shaded, since this is always too late to initialize Netty
                // when running unshaded tests (which initialize Netty early via GrpcServerWrapper)
                if (PooledByteBufAllocator.defaultMaxOrder() != 10 && isShaded()) {
                    logger.warn("Netty property to reduce the default pool chunk size was not set"
                            + " early enough, please report to the Glowroot project");
                }
            } finally {
                if (prior == null) {
                    System.clearProperty("io.netty.allocator.maxOrder");
                } else {
                    System.setProperty("io.netty.allocator.maxOrder", prior);
                }
            }
        }
    }

    private static boolean isShaded() {
        try {
            Class.forName("org.glowroot.agent.shaded.org.slf4j.Logger");
            return true;
        } catch (ClassNotFoundException e) {
            // log exception at trace level
            logger.trace(e.getMessage(), e);
            return false;
        }
    }
}