bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/protocol/BGPReconnectPromise.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.protocol.bgp.rib.impl.protocol;
   9
  10 import com.google.common.base.Preconditions;
  11 import io.netty.bootstrap.Bootstrap;
  12 import io.netty.channel.ChannelHandler;
  13 import io.netty.channel.ChannelHandlerContext;
  14 import io.netty.channel.ChannelInboundHandlerAdapter;
  15 import io.netty.channel.ChannelInitializer;
  16 import io.netty.channel.socket.SocketChannel;
  17 import io.netty.util.concurrent.DefaultPromise;
  18 import io.netty.util.concurrent.EventExecutor;
  19 import io.netty.util.concurrent.Future;
  20 import io.netty.util.concurrent.GenericFutureListener;
  21 import io.netty.util.concurrent.Promise;
  22 import java.net.InetSocketAddress;
  23 import org.opendaylight.protocol.bgp.rib.impl.spi.ChannelPipelineInitializer;
  24 import org.opendaylight.protocol.bgp.rib.spi.BGPSession;
  25 import org.opendaylight.protocol.framework.ReconnectStrategy;
  26 import org.opendaylight.protocol.framework.ReconnectStrategyFactory;
  27 import org.slf4j.Logger;
  28 import org.slf4j.LoggerFactory;
  29
  30 public class BGPReconnectPromise<S extends BGPSession> extends DefaultPromise<Void> {
  31     private static final Logger LOG = LoggerFactory.getLogger(BGPReconnectPromise.class);
  32
  33     private final InetSocketAddress address;
  34     private final ReconnectStrategyFactory strategyFactory;
  35     private final Bootstrap bootstrap;
  36     private final ChannelPipelineInitializer initializer;
  37     private Future<S> pending;
  38
  39     public BGPReconnectPromise(final EventExecutor executor, final InetSocketAddress address,
  40                                final ReconnectStrategyFactory connectStrategyFactory, final Bootstrap bootstrap,
  41                                final ChannelPipelineInitializer initializer) {
  42         super(executor);
  43         this.bootstrap = bootstrap;
  44         this.initializer = Preconditions.checkNotNull(initializer);
  45         this.address = Preconditions.checkNotNull(address);
  46         this.strategyFactory = Preconditions.checkNotNull(connectStrategyFactory);
  47     }
  48
  49     public synchronized void connect() {
  50         final ReconnectStrategy reconnectStrategy = this.strategyFactory.createReconnectStrategy();
  51
  52         // Set up a client with pre-configured bootstrap, but add a closed channel handler into the pipeline to support reconnect attempts
  53         this.pending = connectSessionPromise(this.address, reconnectStrategy, this.bootstrap, new ChannelPipelineInitializer<S>() {
  54             @Override
  55             public void initializeChannel(final SocketChannel channel, final Promise<S> promise) {
  56                 BGPReconnectPromise.this.initializer.initializeChannel(channel, promise);
  57                 // add closed channel handler
  58                 // This handler has to be added as last channel handler and the channel inactive event has to be caught by it
  59                 // Handlers in front of it can react to channelInactive event, but have to forward the event or the reconnect will not work
  60                 // This handler is last so all handlers in front of it can handle channel inactive (to e.g. resource cleanup) before a new connection is started
  61                 channel.pipeline().addLast(new ClosedChannelHandler(BGPReconnectPromise.this));
  62             }
  63         });
  64
  65         this.pending.addListener(new GenericFutureListener<Future<Object>>() {
  66             @Override
  67             public void operationComplete(final Future<Object> future) throws Exception {
  68                 if (!future.isSuccess()) {
  69                     BGPReconnectPromise.this.setFailure(future.cause());
  70                 }
  71             }
  72         });
  73     }
  74
  75     public Future<S> connectSessionPromise(final InetSocketAddress address, final ReconnectStrategy strategy, final Bootstrap bootstrap,
  76                                   final ChannelPipelineInitializer initializer) {
  77         final BGPProtocolSessionPromise sessionPromise = new BGPProtocolSessionPromise(address, strategy, bootstrap);
  78         final ChannelHandler chInit = new ChannelInitializer<SocketChannel>() {
  79             @Override
  80             protected void initChannel(final SocketChannel channel) {
  81                 initializer.initializeChannel(channel, sessionPromise);
  82             }
  83         };
  84
  85         bootstrap.handler(chInit);
  86         sessionPromise.connect();
  87         LOG.debug("Client created.");
  88         return sessionPromise;
  89     }
  90
  91     /**
  92      * @return true if initial connection was established successfully, false if initial connection failed due to e.g. Connection refused, Negotiation failed
  93      */
  94     private boolean isInitialConnectFinished() {
  95         Preconditions.checkNotNull(this.pending);
  96         return this.pending.isDone() && this.pending.isSuccess();
  97     }
  98
  99     @Override
 100     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
 101         if (super.cancel(mayInterruptIfRunning)) {
 102             Preconditions.checkNotNull(this.pending);
 103             this.pending.cancel(mayInterruptIfRunning);
 104             return true;
 105         }
 106         return false;
 107     }
 108
 109     /**
 110      * Channel handler that responds to channelInactive event and reconnects the session.
 111      * Only if the promise was not canceled.
 112      */
 113     private static final class ClosedChannelHandler extends ChannelInboundHandlerAdapter {
 114         private final BGPReconnectPromise promise;
 115
 116         public ClosedChannelHandler(final BGPReconnectPromise promise) {
 117             this.promise = promise;
 118         }
 119
 120         @Override
 121         public void channelInactive(final ChannelHandlerContext ctx) throws Exception {
 122             // This is the ultimate channel inactive handler, not forwarding
 123             if (this.promise.isCancelled()) {
 124                 return;
 125             }
 126
 127             if (!this.promise.isInitialConnectFinished()) {
 128                 LOG.debug("Connection to {} was dropped during negotiation", this.promise.address);
 129                 return;
 130             }
 131
 132             LOG.debug("Reconnecting after connection to {} was dropped", this.promise.address);
 133             this.promise.connect();
 134         }
 135     }
 136 }