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 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     private final AutoCloseable listenerRegistration;
  40     @GuardedBy("this")
  41     private ChannelFuture pending;
  42     @GuardedBy("this")
  43     private boolean peerSessionPresent;
  44     @GuardedBy("this")
  45     private boolean connectSkipped;
  46
  47
  48     public BGPProtocolSessionPromise(InetSocketAddress remoteAddress, int retryTimer, Bootstrap bootstrap, BGPPeerRegistry peerRegistry) {
  49         super(GlobalEventExecutor.INSTANCE);
  50         this.address = Preconditions.checkNotNull(remoteAddress);
  51         this.retryTimer = retryTimer;
  52         this.bootstrap = Preconditions.checkNotNull(bootstrap);
  53         this.peerRegistry = Preconditions.checkNotNull(peerRegistry);
  54         this.listenerRegistration = this.peerRegistry
  55                 .registerPeerSessionListener(new BGPProtocolSessionPromise.PeerRegistrySessionListenerImpl(this,
  56                         StrictBGPPeerRegistry.getIpAddress(this.address)));
  57     }
  58
  59     public synchronized void connect() {
  60         if (this.peerSessionPresent) {
  61             LOG.debug("Connection to {} already exists", this.address);
  62             this.connectSkipped = true;
  63             return;
  64         } else {
  65             this.connectSkipped = false;
  66         }
  67
  68         final BGPProtocolSessionPromise lock = this;
  69         try {
  70             LOG.debug("Promise {} attempting connect for {}ms", lock, Integer.valueOf(CONNECT_TIMEOUT));
  71             if (this.address.isUnresolved()) {
  72                 this.address = new InetSocketAddress(this.address.getHostName(), this.address.getPort());
  73             }
  74
  75             this.bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, CONNECT_TIMEOUT);
  76             this.bootstrap.remoteAddress(this.address);
  77             final ChannelFuture connectFuture = this.bootstrap.connect();
  78             connectFuture.addListener(new BGPProtocolSessionPromise.BootstrapConnectListener(lock));
  79             this.pending = connectFuture;
  80         } catch (Exception e) {
  81             LOG.info("Failed to connect to {}", this.address, e);
  82             this.setFailure(e);
  83         }
  84     }
  85
  86     public synchronized void reconnect() {
  87         if (this.retryTimer == 0) {
  88             LOG.debug("Retry timer value is 0. Reconnection will not be attempted");
  89             this.setFailure(this.pending.cause());
  90             return;
  91         }
  92
  93         final BGPProtocolSessionPromise lock = this;
  94         final EventLoop loop = this.pending.channel().eventLoop();
  95         loop.schedule(new Runnable() {
  96             @Override
  97             public void run() {
  98                 if (BGPProtocolSessionPromise.this.peerSessionPresent) {
  99                     LOG.debug("Connection to {} already exists", BGPProtocolSessionPromise.this.address);
 100                     BGPProtocolSessionPromise.this.connectSkipped = true;
 101                     return;
 102                 } else {
 103                     BGPProtocolSessionPromise.this.connectSkipped = false;
 104                 }
 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         } else {
 122             return false;
 123         }
 124     }
 125
 126     private 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         private final Object lock;
 142
 143         public BootstrapConnectListener(final Object lock) {
 144             this.lock = lock;
 145         }
 146
 147         @Override
 148         public void operationComplete(final ChannelFuture channelFuture) throws Exception {
 149             synchronized (this.lock) {
 150                 BGPProtocolSessionPromise.LOG.debug("Promise {} connection resolved", this.lock);
 151                 Preconditions.checkState(BGPProtocolSessionPromise.this.pending.equals(channelFuture));
 152                 if (BGPProtocolSessionPromise.this.isCancelled()) {
 153                     if (channelFuture.isSuccess()) {
 154                         BGPProtocolSessionPromise.LOG.debug("Closing channel for cancelled promise {}", this.lock);
 155                         channelFuture.channel().close();
 156                     }
 157                 } else if (channelFuture.isSuccess()) {
 158                     BGPProtocolSessionPromise.LOG.debug("Promise {} connection successful", this.lock);
 159                 } else {
 160                     BGPProtocolSessionPromise.LOG.debug("Attempt to connect to {} failed", BGPProtocolSessionPromise.this.address, channelFuture.cause());
 161                     BGPProtocolSessionPromise.this.reconnect();
 162                 }
 163             }
 164         }
 165     }
 166
 167     private class PeerRegistrySessionListenerImpl implements PeerRegistrySessionListener {
 168         private final Object lock;
 169         private final IpAddress peerAddress;
 170
 171         PeerRegistrySessionListenerImpl(final Object lock, final IpAddress peerAddress) {
 172             this.lock = lock;
 173             this.peerAddress = peerAddress;
 174         }
 175
 176         @Override
 177         public void onSessionCreated(@Nonnull final IpAddress ip) {
 178             if (!ip.equals(this.peerAddress)) {
 179                 return;
 180             }
 181             BGPProtocolSessionPromise.LOG.debug("Callback for session creation with peer {} received", ip);
 182             synchronized (this.lock) {
 183                 BGPProtocolSessionPromise.this.peerSessionPresent = true;
 184             }
 185         }
 186
 187         @Override
 188         public void onSessionRemoved(@Nonnull final IpAddress ip) {
 189             if (!ip.equals(this.peerAddress)) {
 190                 return;
 191             }
 192             BGPProtocolSessionPromise.LOG.debug("Callback for session removal with peer {} received", ip);
 193             synchronized (this.lock) {
 194                 BGPProtocolSessionPromise.this.peerSessionPresent = false;
 195                 if (BGPProtocolSessionPromise.this.connectSkipped) {
 196                     BGPProtocolSessionPromise.this.connect();
 197                 }
 198             }
 199         }
 200     }
 201
 202 }