aaec95a74b5886150c8d0bc4bb7d11a1a1570dbf
[controller.git] / 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                 initializer.initializeChannel(channel, promise);
51                 // add closed channel handler
52                 // This handler has to be added as last channel handler and the channel inactive event has to be caught by it
53                 // Handlers in front of it can react to channelInactive event, but have to forward the event or the reconnect will not work
54                 // 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
55                 channel.pipeline().addLast(new ClosedChannelHandler(ReconnectPromise.this));
56             }
57         });
58     }
59
60     /**
61      *
62      * @return true if initial connection was established successfully, false if initial connection failed due to e.g. Connection refused, Negotiation failed
63      */
64     private boolean isInitialConnectFinished() {
65         Preconditions.checkNotNull(pending);
66         return pending.isDone() && pending.isSuccess();
67     }
68
69     @Override
70     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
71         if (super.cancel(mayInterruptIfRunning)) {
72             Preconditions.checkNotNull(pending);
73             this.pending.cancel(mayInterruptIfRunning);
74             return true;
75         }
76
77         return false;
78     }
79
80     /**
81      * Channel handler that responds to channelInactive event and reconnects the session.
82      * Only if the promise was not canceled.
83      */
84     private static final class ClosedChannelHandler extends ChannelInboundHandlerAdapter {
85         private final ReconnectPromise<?, ?> promise;
86
87         public ClosedChannelHandler(final ReconnectPromise<?, ?> promise) {
88             this.promise = promise;
89         }
90
91         @Override
92         public void channelInactive(final ChannelHandlerContext ctx) throws Exception {
93             // This is the ultimate channel inactive handler, not forwarding
94             if (promise.isCancelled()) {
95                 return;
96             }
97
98             if (promise.isInitialConnectFinished() == false) {
99                 LOG.debug("Connection to {} was dropped during negotiation, reattempting", promise.address);
100             }
101
102             LOG.debug("Reconnecting after connection to {} was dropped", promise.address);
103             promise.connect();
104         }
105     }
106
107 }

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