Java tutorial
/* * Copyright 2015-present Open Networking Foundation * * 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.onosproject.openflow.controller.impl; import static org.slf4j.LoggerFactory.getLogger; import java.util.concurrent.TimeUnit; import org.slf4j.Logger; import io.netty.channel.ChannelDuplexHandler; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelPromise; /** * Trigger a timeout if a switch fails to complete handshake soon enough. */ public class HandshakeTimeoutHandler extends ChannelDuplexHandler { private static final Logger log = getLogger(HandshakeTimeoutHandler.class); final OFChannelHandler channelHandler; final long timeoutMillis; volatile long deadline; public HandshakeTimeoutHandler(OFChannelHandler channelHandler, long timeoutSeconds) { super(); this.channelHandler = channelHandler; this.timeoutMillis = TimeUnit.SECONDS.toMillis(timeoutSeconds); this.deadline = System.currentTimeMillis() + timeoutMillis; } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { if (timeoutMillis > 0) { // set Handshake deadline deadline = System.currentTimeMillis() + timeoutMillis; } super.channelActive(ctx); } @Override public void read(ChannelHandlerContext ctx) throws Exception { checkTimeout(ctx); super.read(ctx); } @Override public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception { checkTimeout(ctx); super.write(ctx, msg, promise); } @Override public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception { // expecting idle event checkTimeout(ctx); super.userEventTriggered(ctx, evt); } void checkTimeout(ChannelHandlerContext ctx) { if (channelHandler.isHandshakeComplete()) { // handshake complete, Handshake monitoring timeout no-longer needed ctx.channel().pipeline().remove(this); return; } if (!ctx.channel().isActive()) { return; } if (System.currentTimeMillis() > deadline) { log.info("Handshake time out {}", channelHandler); ctx.fireExceptionCaught(new HandshakeTimeoutException()); } } }