Java tutorial
package org.apache.helix.ipc.netty; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF 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. */ import io.netty.buffer.ByteBuf; import io.netty.channel.Channel; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import org.apache.log4j.Logger; public class NettyHelixIPCBackPressureHandler extends SimpleChannelInboundHandler<ByteBuf> { private static final Logger LOG = Logger.getLogger(NettyHelixIPCBackPressureHandler.class); private final Object sync = new Object(); public NettyHelixIPCBackPressureHandler() { super(false); } @Override protected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg) throws Exception { ctx.fireChannelRead(msg); } public void waitUntilWritable(Channel channel) throws InterruptedException { synchronized (sync) { while (channel.isOpen() && !channel.isWritable()) { LOG.warn(channel + " is not writable, waiting until it is"); sync.wait(); } } } @Override public void channelWritabilityChanged(ChannelHandlerContext ctx) { synchronized (sync) { if (ctx.channel().isWritable()) { sync.notifyAll(); } } } }