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