opendaylight/commons/protocol-framework/src/main/java/org/opendaylight/protocol/framework/ReconnectPromise.java

   1 /*
   2  * Copyright (c) 2013 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.framework;
   9
  10 import com.google.common.base.Preconditions;
  11 import io.netty.bootstrap.Bootstrap;
  12 import io.netty.channel.ChannelHandlerContext;
  13 import io.netty.channel.ChannelInboundHandlerAdapter;
  14 import io.netty.channel.socket.SocketChannel;
  15 import io.netty.util.concurrent.DefaultPromise;
  16 import io.netty.util.concurrent.EventExecutor;
  17 import io.netty.util.concurrent.Future;
  18 import io.netty.util.concurrent.Promise;
  19 import java.net.InetSocketAddress;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22
  23 final class ReconnectPromise<S extends ProtocolSession<?>, L extends SessionListener<?, ?, ?>> extends DefaultPromise<Void> {
  24     private static final Logger LOG = LoggerFactory.getLogger(ReconnectPromise.class);
  25
  26     private final AbstractDispatcher<S, L> dispatcher;
  27     private final InetSocketAddress address;
  28     private final ReconnectStrategyFactory strategyFactory;
  29     private final Bootstrap b;
  30     private final AbstractDispatcher.PipelineInitializer<S> initializer;
  31     private Future<?> pending;
  32
  33     public ReconnectPromise(final EventExecutor executor, final AbstractDispatcher<S, L> dispatcher, final InetSocketAddress address,
  34                             final ReconnectStrategyFactory connectStrategyFactory, final Bootstrap b, final AbstractDispatcher.PipelineInitializer<S> initializer) {
  35         super(executor);
  36         this.b = b;
  37         this.initializer = Preconditions.checkNotNull(initializer);
  38         this.dispatcher = Preconditions.checkNotNull(dispatcher);
  39         this.address = Preconditions.checkNotNull(address);
  40         this.strategyFactory = Preconditions.checkNotNull(connectStrategyFactory);
  41     }
  42
  43     synchronized void connect() {
  44         final ReconnectStrategy cs = this.strategyFactory.createReconnectStrategy();
  45
  46         // Set up a client with pre-configured bootstrap, but add a closed channel handler into the pipeline to support reconnect attempts
  47         pending = this.dispatcher.createClient(this.address, cs, b, new AbstractDispatcher.PipelineInitializer<S>() {
  48             @Override
  49             public void initializeChannel(final SocketChannel channel, final Promise<S> promise) {
  50                 // add closed channel handler
  51                 // This handler has to be added before initializer.initializeChannel is called
  52                 // Initializer might add some handlers using addFirst e.g. AsyncSshHandler and in that case
  53                 // closed channel handler is before the handler that invokes channel inactive event
  54                 channel.pipeline().addFirst(new ClosedChannelHandler(ReconnectPromise.this));
  55
  56                 initializer.initializeChannel(channel, promise);
  57             }
  58         });
  59     }
  60
  61     /**
  62      *
  63      * @return true if initial connection was established successfully, false if initial connection failed due to e.g. Connection refused, Negotiation failed
  64      */
  65     private boolean isInitialConnectFinished() {
  66         Preconditions.checkNotNull(pending);
  67         return pending.isDone() && pending.isSuccess();
  68     }
  69
  70     @Override
  71     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
  72         if (super.cancel(mayInterruptIfRunning)) {
  73             Preconditions.checkNotNull(pending);
  74             this.pending.cancel(mayInterruptIfRunning);
  75             return true;
  76         }
  77
  78         return false;
  79     }
  80
  81     /**
  82      * Channel handler that responds to channelInactive event and reconnects the session.
  83      * Only if the promise was not canceled.
  84      */
  85     private static final class ClosedChannelHandler extends ChannelInboundHandlerAdapter {
  86         private final ReconnectPromise<?, ?> promise;
  87
  88         public ClosedChannelHandler(final ReconnectPromise<?, ?> promise) {
  89             this.promise = promise;
  90         }
  91
  92         @Override
  93         public void channelInactive(final ChannelHandlerContext ctx) throws Exception {
  94             // Pass info about disconnect further and then reconnect
  95             super.channelInactive(ctx);
  96
  97             if (promise.isCancelled()) {
  98                 return;
  99             }
 100
 101             if (promise.isInitialConnectFinished() == false) {
 102                 LOG.debug("Connection to {} was dropped during negotiation, reattempting", promise.address);
 103             }
 104
 105             LOG.debug("Reconnecting after connection to {} was dropped", promise.address);
 106             promise.connect();
 107         }
 108     }
 109
 110 }