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 com.google.common.base.Preconditions;
  11 import io.netty.bootstrap.Bootstrap;
  12 import io.netty.channel.ChannelFuture;
  13 import io.netty.channel.ChannelFutureListener;
  14 import io.netty.channel.ChannelOption;
  15 import io.netty.channel.EventLoop;
  16 import io.netty.util.concurrent.DefaultPromise;
  17 import io.netty.util.concurrent.GlobalEventExecutor;
  18 import io.netty.util.concurrent.Promise;
  19 import java.net.InetSocketAddress;
  20 import java.util.concurrent.TimeUnit;
  21 import javax.annotation.Nonnull;
  22 import javax.annotation.concurrent.GuardedBy;
  23 import org.opendaylight.protocol.bgp.rib.impl.StrictBGPPeerRegistry;
  24 import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
  25 import org.opendaylight.protocol.bgp.rib.impl.spi.PeerRegistrySessionListener;
  26 import org.opendaylight.protocol.bgp.rib.spi.BGPSession;
  27 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
  28 import org.slf4j.Logger;
  29 import org.slf4j.LoggerFactory;
  30
  31 public final class BGPProtocolSessionPromise<S extends BGPSession> extends DefaultPromise<S> {
  32     private static final Logger LOG = LoggerFactory.getLogger(BGPProtocolSessionPromise.class);
  33     private static final int CONNECT_TIMEOUT = 5000;
  34
  35     private InetSocketAddress address;
  36     private final int retryTimer;
  37     private final Bootstrap bootstrap;
  38     private final BGPPeerRegistry peerRegistry;
  39     @GuardedBy("this")
  40     private final AutoCloseable listenerRegistration;
  41     @GuardedBy("this")
  42     private ChannelFuture pending;
  43     @GuardedBy("this")
  44     private boolean peerSessionPresent;
  45     @GuardedBy("this")
  46     private boolean connectSkipped;
  47
  48
  49     public BGPProtocolSessionPromise(@Nonnull final InetSocketAddress remoteAddress, final int retryTimer,
  50         @Nonnull final Bootstrap bootstrap, @Nonnull final BGPPeerRegistry peerRegistry) {
  51         super(GlobalEventExecutor.INSTANCE);
  52         this.address = Preconditions.checkNotNull(remoteAddress);
  53         this.retryTimer = retryTimer;
  54         this.bootstrap = Preconditions.checkNotNull(bootstrap);
  55         this.peerRegistry = Preconditions.checkNotNull(peerRegistry);
  56         this.listenerRegistration = this.peerRegistry.registerPeerSessionListener(
  57             new PeerRegistrySessionListenerImpl(this, 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, Integer.valueOf(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(lock));
  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     public 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 BGPProtocolSessionPromise<?> lock = this;
  95         final EventLoop loop = this.pending.channel().eventLoop();
  96         loop.schedule(() -> {
  97             synchronized (BGPProtocolSessionPromise.this) {
  98                 if (BGPProtocolSessionPromise.this.peerSessionPresent) {
  99                     LOG.debug("Connection to {} already exists", BGPProtocolSessionPromise.this.address);
 100                     BGPProtocolSessionPromise.this.connectSkipped = true;
 101                     return;
 102                 }
 103
 104                 BGPProtocolSessionPromise.this.connectSkipped = false;
 105                 LOG.debug("Attempting to connect to {}", BGPProtocolSessionPromise.this.address);
 106                 final ChannelFuture reconnectFuture = BGPProtocolSessionPromise.this.bootstrap.connect();
 107                 reconnectFuture.addListener(new BootstrapConnectListener(lock));
 108                 BGPProtocolSessionPromise.this.pending = reconnectFuture;
 109             }
 110         }, this.retryTimer, TimeUnit.SECONDS);
 111         LOG.debug("Next reconnection attempt in {}s", this.retryTimer);
 112     }
 113
 114     @Override
 115     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
 116         closePeerSessionListener();
 117         if (super.cancel(mayInterruptIfRunning)) {
 118             Preconditions.checkNotNull(this.pending);
 119             this.pending.cancel(mayInterruptIfRunning);
 120             return true;
 121         }
 122
 123         return false;
 124     }
 125
 126     private synchronized void closePeerSessionListener() {
 127         try {
 128             this.listenerRegistration.close();
 129         } catch (final Exception e) {
 130             LOG.debug("Exception encountered while closing peer registry session listener registration", e);
 131         }
 132     }
 133
 134     @Override
 135     public synchronized Promise<S> setSuccess(final S result) {
 136         LOG.debug("Promise {} completed", this);
 137         return super.setSuccess(result);
 138     }
 139
 140     private class BootstrapConnectListener implements ChannelFutureListener {
 141         @GuardedBy("this")
 142         private final Object lock;
 143
 144         BootstrapConnectListener(final Object lock) {
 145             this.lock = lock;
 146         }
 147
 148         @Override
 149         public void operationComplete(final ChannelFuture channelFuture) throws Exception {
 150             synchronized (this.lock) {
 151                 BGPProtocolSessionPromise.LOG.debug("Promise {} connection resolved", this.lock);
 152                 Preconditions.checkState(BGPProtocolSessionPromise.this.pending.equals(channelFuture));
 153                 if (BGPProtocolSessionPromise.this.isCancelled()) {
 154                     if (channelFuture.isSuccess()) {
 155                         BGPProtocolSessionPromise.LOG.debug("Closing channel for cancelled promise {}", this.lock);
 156                         channelFuture.channel().close();
 157                     }
 158                 } else if (channelFuture.isSuccess()) {
 159                     BGPProtocolSessionPromise.LOG.debug("Promise {} connection successful", this.lock);
 160                 } else {
 161                     BGPProtocolSessionPromise.LOG.warn("Attempt to connect to {} failed", BGPProtocolSessionPromise.this.address, channelFuture.cause());
 162                     BGPProtocolSessionPromise.this.reconnect();
 163                 }
 164             }
 165         }
 166     }
 167
 168     private class PeerRegistrySessionListenerImpl implements PeerRegistrySessionListener {
 169         @GuardedBy("this")
 170         private final Object lock;
 171         private final IpAddress peerAddress;
 172
 173         PeerRegistrySessionListenerImpl(final Object lock, final IpAddress peerAddress) {
 174             this.lock = lock;
 175             this.peerAddress = peerAddress;
 176         }
 177
 178         @Override
 179         public void onSessionCreated(@Nonnull final IpAddress ip) {
 180             if (!ip.equals(this.peerAddress)) {
 181                 return;
 182             }
 183             BGPProtocolSessionPromise.LOG.debug("Callback for session creation with peer {} received", ip);
 184             synchronized (this.lock) {
 185                 BGPProtocolSessionPromise.this.peerSessionPresent = true;
 186             }
 187         }
 188
 189         @Override
 190         public void onSessionRemoved(@Nonnull final IpAddress ip) {
 191             if (!ip.equals(this.peerAddress)) {
 192                 return;
 193             }
 194             BGPProtocolSessionPromise.LOG.debug("Callback for session removal with peer {} received", ip);
 195             synchronized (this.lock) {
 196                 BGPProtocolSessionPromise.this.peerSessionPresent = false;
 197                 if (BGPProtocolSessionPromise.this.connectSkipped) {
 198                     BGPProtocolSessionPromise.this.connect();
 199                 }
 200             }
 201         }
 202     }
 203
 204 }