private async Task ConnectToDiscoveryCandidatesAsync(List <IPEndPoint> peersToDiscover)
{
await peersToDiscover.ForEachAsync(5, this.nodeLifetime.ApplicationStopping, async (endPoint, cancellation) =>
{
using (CancellationTokenSource connectTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellation))
{
this.logger.LogDebug("Attempting to discover from : '{0}'", endPoint);
connectTokenSource.CancelAfter(TimeSpan.FromSeconds(5));
INetworkPeer networkPeer = null;
// Try to connect to a peer with only the address-sharing behaviour, to learn about their peers and disconnect within 5 seconds.
try
{
NetworkPeerConnectionParameters clonedParameters = this.currentParameters.Clone();
clonedParameters.ConnectCancellation = connectTokenSource.Token;
PeerAddressManagerBehaviour addressManagerBehaviour = clonedParameters.TemplateBehaviors.OfType <PeerAddressManagerBehaviour>().FirstOrDefault();
clonedParameters.TemplateBehaviors.Clear();
clonedParameters.TemplateBehaviors.Add(addressManagerBehaviour);
networkPeer = await this.networkPeerFactory.CreateConnectedNetworkPeerAsync(endPoint, clonedParameters).ConfigureAwait(false);
await networkPeer.VersionHandshakeAsync(connectTokenSource.Token).ConfigureAwait(false);
this.peerAddressManager.PeerDiscoveredFrom(endPoint, DateTimeProvider.Default.GetUtcNow());
connectTokenSource.Token.WaitHandle.WaitOne(TimeSpan.FromSeconds(5));
}
catch
{
}
finally
{
networkPeer?.Disconnect("Discovery job done");
networkPeer?.Dispose();
}
this.logger.LogDebug("Discovery from '{0}' finished", endPoint);
}
}).ConfigureAwait(false);
}
/// <summary>
/// See <see cref="DiscoverPeers"/>
/// </summary>
private async Task DiscoverPeersAsync()
{
var peersToDiscover = new List <IPEndPoint>();
List <PeerAddress> foundPeers = this.peerAddressManager.PeerSelector.SelectPeersForDiscovery(1000).ToList();
peersToDiscover.AddRange(foundPeers.Select(p => p.Endpoint));
if (peersToDiscover.Count == 0)
{
// On normal circumstances the dns seeds are attempted only once per node lifetime.
if (this.isSeedAndDnsAttempted)
{
this.logger.LogTrace("(-)[DNS_ATTEMPTED]");
return;
}
this.AddDNSSeedNodes(peersToDiscover);
this.AddSeedNodes(peersToDiscover);
this.isSeedAndDnsAttempted = true;
if (peersToDiscover.Count == 0)
{
this.logger.LogTrace("(-)[NO_ADDRESSES]");
return;
}
peersToDiscover = peersToDiscover.OrderBy(a => RandomUtils.GetInt32()).ToList();
}
else
{
// If all attempts have failed then attempt the dns seeds again.
if (!this.isSeedAndDnsAttempted && foundPeers.All(peer => peer.Attempted))
{
peersToDiscover.Clear();
this.AddDNSSeedNodes(peersToDiscover);
this.AddSeedNodes(peersToDiscover);
this.isSeedAndDnsAttempted = true;
}
}
await peersToDiscover.ForEachAsync(5, this.nodeLifetime.ApplicationStopping, async (endPoint, cancellation) =>
{
using (CancellationTokenSource connectTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellation))
{
this.logger.LogTrace("Attempting to discover from : '{0}'", endPoint);
connectTokenSource.CancelAfter(TimeSpan.FromSeconds(5));
INetworkPeer networkPeer = null;
try
{
NetworkPeerConnectionParameters clonedParameters = this.currentParameters.Clone();
clonedParameters.ConnectCancellation = connectTokenSource.Token;
PeerAddressManagerBehaviour addressManagerBehaviour = clonedParameters.TemplateBehaviors.OfType <PeerAddressManagerBehaviour>().FirstOrDefault();
clonedParameters.TemplateBehaviors.Clear();
clonedParameters.TemplateBehaviors.Add(addressManagerBehaviour);
networkPeer = await this.networkPeerFactory.CreateConnectedNetworkPeerAsync(endPoint, clonedParameters).ConfigureAwait(false);
await networkPeer.VersionHandshakeAsync(connectTokenSource.Token).ConfigureAwait(false);
await networkPeer.SendMessageAsync(new GetAddrPayload(), connectTokenSource.Token).ConfigureAwait(false);
this.peerAddressManager.PeerDiscoveredFrom(endPoint, DateTimeProvider.Default.GetUtcNow());
connectTokenSource.Token.WaitHandle.WaitOne(TimeSpan.FromSeconds(5));
}
catch
{
}
finally
{
networkPeer?.Disconnect("Discovery job done");
networkPeer?.Dispose();
}
this.logger.LogTrace("Discovery from '{0}' finished", endPoint);
}
}).ConfigureAwait(false);
}
