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
  37     private InetSocketAddress address;
  38     private final int retryTimer;
  39     private final Bootstrap bootstrap;
  40     private final BGPPeerRegistry peerRegistry;
  41     @GuardedBy("this")
  42     private final AutoCloseable listenerRegistration;
  43     @GuardedBy("this")
  44     private ChannelFuture pending;
  45     @GuardedBy("this")
  46     private boolean peerSessionPresent;
  47     @GuardedBy("this")
  48     private boolean connectSkipped;
  49
  50
  51     public BGPProtocolSessionPromise(@Nonnull final InetSocketAddress remoteAddress, final int retryTimer,
  52         @Nonnull final Bootstrap bootstrap, @Nonnull final BGPPeerRegistry peerRegistry) {
  53         super(GlobalEventExecutor.INSTANCE);
  54         this.address = requireNonNull(remoteAddress);
  55         this.retryTimer = retryTimer;
  56         this.bootstrap = requireNonNull(bootstrap);
  57         this.peerRegistry = requireNonNull(peerRegistry);
  58         this.listenerRegistration = this.peerRegistry.registerPeerSessionListener(
  59             new PeerRegistrySessionListenerImpl(this, StrictBGPPeerRegistry.getIpAddress(this.address)));
  60     }
  61
  62     public synchronized void connect() {
  63         if (this.peerSessionPresent) {
  64             LOG.debug("Connection to {} already exists", this.address);
  65             this.connectSkipped = true;
  66             return;
  67         }
  68
  69         this.connectSkipped = false;
  70
  71         final BGPProtocolSessionPromise<?> lock = this;
  72         try {
  73             LOG.debug("Promise {} attempting connect for {}ms", lock, CONNECT_TIMEOUT);
  74             if (this.address.isUnresolved()) {
  75                 this.address = new InetSocketAddress(this.address.getHostName(), this.address.getPort());
  76             }
  77
  78             this.bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, CONNECT_TIMEOUT);
  79             this.bootstrap.remoteAddress(this.address);
  80             final ChannelFuture connectFuture = this.bootstrap.connect();
  81             connectFuture.addListener(new BootstrapConnectListener(lock));
  82             this.pending = connectFuture;
  83         } catch (final Exception e) {
  84             LOG.warn("Failed to connect to {}", this.address, e);
  85             this.setFailure(e);
  86         }
  87     }
  88
  89     public synchronized void reconnect() {
  90         if (this.retryTimer == 0) {
  91             LOG.debug("Retry timer value is 0. Reconnection will not be attempted");
  92             this.setFailure(this.pending.cause());
  93             return;
  94         }
  95
  96         final BGPProtocolSessionPromise<?> lock = this;
  97         final EventLoop loop = this.pending.channel().eventLoop();
  98         loop.schedule(() -> {
  99             synchronized (BGPProtocolSessionPromise.this) {
 100                 if (BGPProtocolSessionPromise.this.peerSessionPresent) {
 101                     LOG.debug("Connection to {} already exists", BGPProtocolSessionPromise.this.address);
 102                     BGPProtocolSessionPromise.this.connectSkipped = true;
 103                     return;
 104                 }
 105
 106                 BGPProtocolSessionPromise.this.connectSkipped = false;
 107                 LOG.debug("Attempting to connect to {}", BGPProtocolSessionPromise.this.address);
 108                 final ChannelFuture reconnectFuture = BGPProtocolSessionPromise.this.bootstrap.connect();
 109                 reconnectFuture.addListener(new BootstrapConnectListener(lock));
 110                 BGPProtocolSessionPromise.this.pending = reconnectFuture;
 111             }
 112         }, this.retryTimer, TimeUnit.SECONDS);
 113         LOG.debug("Next reconnection attempt in {}s", this.retryTimer);
 114     }
 115
 116     @Override
 117     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
 118         closePeerSessionListener();
 119         if (super.cancel(mayInterruptIfRunning)) {
 120             requireNonNull(this.pending);
 121             this.pending.cancel(mayInterruptIfRunning);
 122             return true;
 123         }
 124
 125         return false;
 126     }
 127
 128     private synchronized void closePeerSessionListener() {
 129         try {
 130             this.listenerRegistration.close();
 131         } catch (final Exception e) {
 132             LOG.debug("Exception encountered while closing peer registry session listener registration", e);
 133         }
 134     }
 135
 136     @Override
 137     public synchronized Promise<S> setSuccess(final S result) {
 138         LOG.debug("Promise {} completed", this);
 139         return super.setSuccess(result);
 140     }
 141
 142     private class BootstrapConnectListener implements ChannelFutureListener {
 143         @GuardedBy("this")
 144         private final Object lock;
 145
 146         BootstrapConnectListener(final Object lock) {
 147             this.lock = lock;
 148         }
 149
 150         @Override
 151         public void operationComplete(final ChannelFuture channelFuture) throws Exception {
 152             synchronized (this.lock) {
 153                 BGPProtocolSessionPromise.LOG.debug("Promise {} connection resolved", this.lock);
 154                 Preconditions.checkState(BGPProtocolSessionPromise.this.pending.equals(channelFuture));
 155                 if (BGPProtocolSessionPromise.this.isCancelled()) {
 156                     if (channelFuture.isSuccess()) {
 157                         BGPProtocolSessionPromise.LOG.debug("Closing channel for cancelled promise {}", this.lock);
 158                         channelFuture.channel().close();
 159                     }
 160                 } else if (channelFuture.isSuccess()) {
 161                     BGPProtocolSessionPromise.LOG.debug("Promise {} connection successful", this.lock);
 162                 } else {
 163                     BGPProtocolSessionPromise.LOG.warn("Attempt to connect to {} failed", BGPProtocolSessionPromise.this.address, channelFuture.cause());
 164                     BGPProtocolSessionPromise.this.reconnect();
 165                 }
 166             }
 167         }
 168     }
 169
 170     private class PeerRegistrySessionListenerImpl implements PeerRegistrySessionListener {
 171         @GuardedBy("this")
 172         private final Object lock;
 173         private final IpAddress peerAddress;
 174
 175         PeerRegistrySessionListenerImpl(final Object lock, final IpAddress peerAddress) {
 176             this.lock = lock;
 177             this.peerAddress = peerAddress;
 178         }
 179
 180         @Override
 181         public void onSessionCreated(@Nonnull final IpAddress ip) {
 182             if (!ip.equals(this.peerAddress)) {
 183                 return;
 184             }
 185             BGPProtocolSessionPromise.LOG.debug("Callback for session creation with peer {} received", ip);
 186             synchronized (this.lock) {
 187                 BGPProtocolSessionPromise.this.peerSessionPresent = true;
 188             }
 189         }
 190
 191         @Override
 192         public void onSessionRemoved(@Nonnull final IpAddress ip) {
 193             if (!ip.equals(this.peerAddress)) {
 194                 return;
 195             }
 196             BGPProtocolSessionPromise.LOG.debug("Callback for session removal with peer {} received", ip);
 197             synchronized (this.lock) {
 198                 BGPProtocolSessionPromise.this.peerSessionPresent = false;
 199                 if (BGPProtocolSessionPromise.this.connectSkipped) {
 200                     BGPProtocolSessionPromise.this.connect();
 201                 }
 202             }
 203         }
 204     }
 205
 206 }