bgp/rib-impl/src/main/java/org/opendaylight/protocol/bgp/rib/impl/protocol/BGPProtocolSessionPromise.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 static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.base.Preconditions;
  13 import io.netty.bootstrap.Bootstrap;
  14 import io.netty.channel.ChannelFuture;
  15 import io.netty.channel.ChannelFutureListener;
  16 import io.netty.channel.ChannelOption;
  17 import io.netty.channel.EventLoop;
  18 import io.netty.util.concurrent.DefaultPromise;
  19 import io.netty.util.concurrent.GlobalEventExecutor;
  20 import io.netty.util.concurrent.Promise;
  21 import java.net.InetSocketAddress;
  22 import java.util.concurrent.TimeUnit;
  23 import javax.annotation.Nonnull;
  24 import javax.annotation.concurrent.GuardedBy;
  25 import org.opendaylight.protocol.bgp.rib.impl.StrictBGPPeerRegistry;
  26 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
  27 import org.opendaylight.protocol.bgp.rib.impl.spi.PeerRegistrySessionListener;
  28 import org.opendaylight.protocol.bgp.rib.spi.BGPSession;
  29 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 public final class BGPProtocolSessionPromise<S extends BGPSession> extends DefaultPromise<S> {
  34     private static final Logger LOG = LoggerFactory.getLogger(BGPProtocolSessionPromise.class);
  35     private static final int CONNECT_TIMEOUT = 5000;
  36     private final int retryTimer;
  37     private final Bootstrap bootstrap;
  38     @GuardedBy("this")
  39     private final AutoCloseable listenerRegistration;
  40     @GuardedBy("this")
  41     private InetSocketAddress address;
  42     @GuardedBy("this")
  43     private ChannelFuture pending;
  44     @GuardedBy("this")
  45     private boolean peerSessionPresent;
  46     @GuardedBy("this")
  47     private boolean connectSkipped;
  48
  49
  50     public BGPProtocolSessionPromise(@Nonnull final InetSocketAddress remoteAddress, final int retryTimer,
  51             @Nonnull final Bootstrap bootstrap, @Nonnull final BGPPeerRegistry peerRegistry) {
  52         super(GlobalEventExecutor.INSTANCE);
  53         this.address = requireNonNull(remoteAddress);
  54         this.retryTimer = retryTimer;
  55         this.bootstrap = requireNonNull(bootstrap);
  56         this.listenerRegistration = requireNonNull(peerRegistry).registerPeerSessionListener(
  57                 new PeerRegistrySessionListenerImpl(StrictBGPPeerRegistry.getIpAddress(this.address)));
  58     }
  59
  60     public synchronized void connect() {
  61         if (this.peerSessionPresent) {
  62             LOG.debug("Connection to {} already exists", this.address);
  63             this.connectSkipped = true;
  64             return;
  65         }
  66
  67         this.connectSkipped = false;
  68
  69         final BGPProtocolSessionPromise<?> lock = this;
  70         try {
  71             LOG.debug("Promise {} attempting connect for {}ms", lock, CONNECT_TIMEOUT);
  72             if (this.address.isUnresolved()) {
  73                 this.address = new InetSocketAddress(this.address.getHostName(), this.address.getPort());
  74             }
  75
  76             this.bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, CONNECT_TIMEOUT);
  77             this.bootstrap.remoteAddress(this.address);
  78             final ChannelFuture connectFuture = this.bootstrap.connect();
  79             connectFuture.addListener(new BootstrapConnectListener());
  80             this.pending = connectFuture;
  81         } catch (final Exception e) {
  82             LOG.warn("Failed to connect to {}", this.address, e);
  83             this.setFailure(e);
  84         }
  85     }
  86
  87     synchronized void reconnect() {
  88         if (this.retryTimer == 0) {
  89             LOG.debug("Retry timer value is 0. Reconnection will not be attempted");
  90             this.setFailure(this.pending.cause());
  91             return;
  92         }
  93
  94         final EventLoop loop = this.pending.channel().eventLoop();
  95         loop.schedule(() -> {
  96             synchronized (BGPProtocolSessionPromise.this) {
  97                 if (BGPProtocolSessionPromise.this.peerSessionPresent) {
  98                     LOG.debug("Connection to {} already exists", BGPProtocolSessionPromise.this.address);
  99                     BGPProtocolSessionPromise.this.connectSkipped = true;
 100                     return;
 101                 }
 102
 103                 BGPProtocolSessionPromise.this.connectSkipped = false;
 104                 LOG.debug("Attempting to connect to {}", BGPProtocolSessionPromise.this.address);
 105                 final ChannelFuture reconnectFuture = BGPProtocolSessionPromise.this.bootstrap.connect();
 106                 reconnectFuture.addListener(new BootstrapConnectListener());
 107                 BGPProtocolSessionPromise.this.pending = reconnectFuture;
 108             }
 109         }, this.retryTimer, TimeUnit.SECONDS);
 110         LOG.debug("Next reconnection attempt in {}s", this.retryTimer);
 111     }
 112
 113     @Override
 114     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
 115         closePeerSessionListener();
 116         if (super.cancel(mayInterruptIfRunning)) {
 117             requireNonNull(this.pending);
 118             this.pending.cancel(mayInterruptIfRunning);
 119             return true;
 120         }
 121
 122         return false;
 123     }
 124
 125     private synchronized void closePeerSessionListener() {
 126         try {
 127             this.listenerRegistration.close();
 128         } catch (final Exception e) {
 129             LOG.debug("Exception encountered while closing peer registry session listener registration", e);
 130         }
 131     }
 132
 133     @Override
 134     public synchronized Promise<S> setSuccess(final S result) {
 135         LOG.debug("Promise {} completed", this);
 136         return super.setSuccess(result);
 137     }
 138
 139     private class BootstrapConnectListener implements ChannelFutureListener {
 140         @Override
 141         public void operationComplete(final ChannelFuture channelFuture) throws Exception {
 142             synchronized (BGPProtocolSessionPromise.this) {
 143                 BGPProtocolSessionPromise.LOG.debug("Promise {} connection resolved", BGPProtocolSessionPromise.this);
 144                 Preconditions.checkState(BGPProtocolSessionPromise.this.pending.equals(channelFuture));
 145                 if (BGPProtocolSessionPromise.this.isCancelled()) {
 146                     if (channelFuture.isSuccess()) {
 147                         BGPProtocolSessionPromise.LOG.debug("Closing channel for cancelled promise {}",
 148                                 BGPProtocolSessionPromise.this);
 149                         channelFuture.channel().close();
 150                     }
 151                 } else if (channelFuture.isSuccess()) {
 152                     BGPProtocolSessionPromise.LOG.debug("Promise {} connection successful",
 153                             BGPProtocolSessionPromise.this);
 154                 } else {
 155                     BGPProtocolSessionPromise.LOG.warn("Attempt to connect to {} failed",
 156                             BGPProtocolSessionPromise.this.address, channelFuture.cause());
 157                     BGPProtocolSessionPromise.this.reconnect();
 158                 }
 159             }
 160         }
 161     }
 162
 163     private class PeerRegistrySessionListenerImpl implements PeerRegistrySessionListener {
 164         private final IpAddress peerAddress;
 165
 166         PeerRegistrySessionListenerImpl(final IpAddress peerAddress) {
 167             this.peerAddress = peerAddress;
 168         }
 169
 170         @Override
 171         public void onSessionCreated(@Nonnull final IpAddress ip) {
 172             if (!ip.equals(this.peerAddress)) {
 173                 return;
 174             }
 175             BGPProtocolSessionPromise.LOG.debug("Callback for session creation with peer {} received", ip);
 176             synchronized (BGPProtocolSessionPromise.this) {
 177                 BGPProtocolSessionPromise.this.peerSessionPresent = true;
 178             }
 179         }
 180
 181         @Override
 182         public void onSessionRemoved(@Nonnull final IpAddress ip) {
 183             if (!ip.equals(this.peerAddress)) {
 184                 return;
 185             }
 186             BGPProtocolSessionPromise.LOG.debug("Callback for session removal with peer {} received", ip);
 187             synchronized (BGPProtocolSessionPromise.this) {
 188                 BGPProtocolSessionPromise.this.peerSessionPresent = false;
 189                 if (BGPProtocolSessionPromise.this.connectSkipped) {
 190                     BGPProtocolSessionPromise.this.connect();
 191                 }
 192             }
 193         }
 194     }
 195
 196 }