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 com.google.common.base.Preconditions.checkState;
  11 import static java.util.Objects.requireNonNull;
  12
  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 org.checkerframework.checker.lock.qual.GuardedBy;
  24 import org.eclipse.jdt.annotation.NonNull;
  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.IpAddressNoZone;
  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(final @NonNull InetSocketAddress remoteAddress, final int retryTimer,
  51             final @NonNull Bootstrap bootstrap, final @NonNull 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     @SuppressWarnings("checkstyle:illegalCatch")
  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         }
  67
  68         this.connectSkipped = false;
  69
  70         final BGPProtocolSessionPromise<?> lock = this;
  71         try {
  72             LOG.debug("Promise {} attempting connect for {}ms", lock, 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 BootstrapConnectListener());
  81             this.pending = connectFuture;
  82         } catch (final Exception e) {
  83             LOG.warn("Failed to connect to {}", this.address, e);
  84             this.setFailure(e);
  85         }
  86     }
  87
  88     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 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());
 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             requireNonNull(this.pending);
 119             this.pending.cancel(mayInterruptIfRunning);
 120             return true;
 121         }
 122
 123         return false;
 124     }
 125
 126     @SuppressWarnings("checkstyle:illegalCatch")
 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         @Override
 143         public void operationComplete(final ChannelFuture channelFuture) throws Exception {
 144             synchronized (BGPProtocolSessionPromise.this) {
 145                 LOG.debug("Promise {} connection resolved", BGPProtocolSessionPromise.this);
 146                 checkState(BGPProtocolSessionPromise.this.pending.equals(channelFuture), "Unexpected promise %s",
 147                     channelFuture);
 148                 if (BGPProtocolSessionPromise.this.isCancelled()) {
 149                     if (channelFuture.isSuccess()) {
 150                         LOG.debug("Closing channel for cancelled promise {}", BGPProtocolSessionPromise.this);
 151                         channelFuture.channel().close();
 152                     }
 153                 } else if (channelFuture.isSuccess()) {
 154                     LOG.debug("Promise {} connection successful", BGPProtocolSessionPromise.this);
 155                 } else {
 156                     LOG.warn("Attempt to connect to {} failed", BGPProtocolSessionPromise.this.address,
 157                         channelFuture.cause());
 158                     BGPProtocolSessionPromise.this.reconnect();
 159                 }
 160             }
 161         }
 162     }
 163
 164     private class PeerRegistrySessionListenerImpl implements PeerRegistrySessionListener {
 165         private final IpAddressNoZone peerAddress;
 166
 167         PeerRegistrySessionListenerImpl(final IpAddressNoZone peerAddress) {
 168             this.peerAddress = peerAddress;
 169         }
 170
 171         @Override
 172         public void onSessionCreated(final IpAddressNoZone ip) {
 173             if (ip.equals(this.peerAddress)) {
 174                 LOG.debug("Callback for session creation with peer {} received", ip);
 175                 synchronized (BGPProtocolSessionPromise.this) {
 176                     BGPProtocolSessionPromise.this.peerSessionPresent = true;
 177                 }
 178             }
 179         }
 180
 181         @Override
 182         public void onSessionRemoved(final IpAddressNoZone ip) {
 183             if (ip.equals(this.peerAddress)) {
 184                 LOG.debug("Callback for session removal with peer {} received", ip);
 185                 synchronized (BGPProtocolSessionPromise.this) {
 186                     BGPProtocolSessionPromise.this.peerSessionPresent = false;
 187                     if (BGPProtocolSessionPromise.this.connectSkipped) {
 188                         BGPProtocolSessionPromise.this.connect();
 189                     }
 190                 }
 191             }
 192         }
 193     }
 194 }