async Task HandleFailedConnectedPeerAsync(Exception e, MessageRelayConnection connection)
{
if (connection == null) // there was no connection available
{
return;
}
if (e == null) // explicit disconnect
{
Debug.Assert(connection.ConnectionState.HasFlag(ConnectedPeer.State.Disconnecting));
Debug.Assert(connection.ConnectionState.HasFlag(ConnectedPeer.State.Disposed));
}
else
{
Debug.Assert(connection.ConnectionState.HasFlag(ConnectedPeer.State.Failed));
Debug.Assert(connection.ConnectionState.HasFlag(ConnectedPeer.State.Disposed));
}
if (PeerManager.ShouldRecordError(e, !this.cancellation.Token.IsCancellationRequested, connection.ToString(), this.logger))
{
// set these properties on the loaded connection instance and not only in the repository, so that we can
// use the cached collection of Peer objects
connection.MessageRelayRecord.LastErrorUtc = DateTime.UtcNow;
await this.messageRelayRecords.UpdatePeerLastError(connection.MessageRelayRecord.Id,
connection.MessageRelayRecord.LastErrorUtc);
}
this.connections.TryRemove(connection.MessageRelayRecord.Id, out _);
}
public async Task <MessageRelayConnection> SelectNextConnectionAsync()
{
IReadOnlyList <MessageRelayRecord> allRecords = await this.messageRelayRecords.GetAllMessageRelayRecordsAsync();
if (allRecords.Count == 0)
{
this.logger.LogWarning("No relay addresses in the store - can't select a connection candidate!");
return(null);
}
// peers, shortest success ago first
var hottestRecords = allRecords
.Where(x => !IsExcluded(x)) // e.g. if we are already connected, or the last error is less than a certain time ago
.OrderBy(x => DateTimeOffset.UtcNow - x.LastSeenUtc) // then, try the best candidates first
.ThenByDescending(x => DateTimeOffset.UtcNow - x.LastErrorUtc) // then, try the candidates where the last error is longest ago
.ToList();
if (hottestRecords.Count == 0)
{
this.logger.LogDebug("After applying the filtering rules, no connection candidates remain for selection.");
return(null);
}
MessageRelayRecord messageRelayRecord = hottestRecords[0];
this.logger.LogDebug($"Selected connection candidate {messageRelayRecord}, last seen {DateTimeOffset.UtcNow - messageRelayRecord.LastSeenUtc} ago, last error {DateTimeOffset.UtcNow - messageRelayRecord.LastErrorUtc} ago.");
var messageRelayConnection = new MessageRelayConnection(messageRelayRecord, this.cancellation.Token);
bool addSuccess = this.connections.TryAdd(messageRelayRecord.Id, messageRelayConnection);
Debug.Assert(addSuccess, $"Bug: Peer {messageRelayRecord} was already in the ConnectedPeers dictionary - that should not happen.");
return(messageRelayConnection);
}
async Task ConnectAndRunAsync(MessageRelayConnection createdInstance)
{
var connectedInstance = await CreateConnectedPeerBlockingOrThrowAsync(createdInstance);
if (connectedInstance != null)
{
this.logger.LogInformation($"Successfully created connected peer {createdInstance}, loading off to new thread.");
//await RunNetworkPeer(createdInstance);
}
}
async Task <MessageRelayConnection> CreateConnectedPeerBlockingOrThrowAsync(MessageRelayConnection connection)
{
try
{
connection.ConnectionState |= ConnectedPeer.State.Connecting;
await connection.ConnectAsync();
connection.ConnectionState &= ~ConnectedPeer.State.Connecting;
connection.ConnectionState |= ConnectedPeer.State.Connected;
return(connection);
}
catch (Exception e)
{
await HandleFailedConnectedPeerAsync(e, connection);
return(null);
}
}
public async Task <List <IEnvelope> > SendRequestAsync(byte[] request)
{
var response = new List <IEnvelope>();
MessageRelayConnection currentConnection = null;
try
{
await this.semaphore.WaitAsync(); // this definitely deadlocks sometimes
currentConnection = GetRandomConnection();
if (currentConnection == null)
{
throw new MessageRelayConnectionException("No connection(s) available, please retry later.", null)
{
NoConnectionAvailable = true
}
}
;
await currentConnection.SendAsync(request);
response.AddRange(await currentConnection.ReceiveAsync());
}
catch (Exception e)
{
await HandleFailedConnectedPeerAsync(e, currentConnection);
throw;
}
finally
{
this.semaphore.Release();
}
return(response);
}