private void MakeBrokerConnection(IBrokerInfo brokerDetail)
{
try
{
_stateManager = new AMQStateManager();
_protocolListener = new AMQProtocolListener(this, _stateManager);
_protocolListener.AddFrameListener(_stateManager);
/*
* // Currently there is only one transport option - BlockingSocket.
* String assemblyName = "Apache.Qpid.Client.Transport.Socket.Blocking.dll";
* String transportType = "Apache.Qpid.Client.Transport.Socket.Blocking.BlockingSocketTransport";
*
* // Load the transport assembly dynamically.
* _transport = LoadTransportFromAssembly(brokerDetail.getHost(), brokerDetail.getPort(), assemblyName, transportType);
*/
_transport = new BlockingSocketTransport();
// Connect.
_transport.Connect(brokerDetail, this);
_protocolWriter = new ProtocolWriter(_transport.ProtocolWriter, _protocolListener);
_protocolSession = new AMQProtocolSession(_transport.ProtocolWriter, _transport, this);
_protocolListener.ProtocolSession = _protocolSession;
// Now start the connection "handshake".
_transport.ProtocolWriter.Write(new ProtocolInitiation());
// Blocks until the connection has been opened.
_stateManager.AttainState(AMQState.CONNECTION_OPEN);
_failoverPolicy.attainedConnection();
// XXX: Again this should be changed to a suitable notify.
_connected = true;
}
catch (AMQException e)
{
_lastAMQException = e;
throw; // rethrow
}
}
public void Run()
{
if (Thread.CurrentThread.IsBackground)
{
throw new InvalidOperationException("FailoverHandler must Run on a non-background thread.");
}
AMQProtocolListener pl = _connection.ProtocolListener;
pl.FailoverLatch = new ManualResetEvent(false);
// We wake up listeners. If they can handle failover, they will extend the
// FailoverSupport class and will in turn block on the latch until failover
// has completed before retrying the operation
_connection.ProtocolListener.PropagateExceptionToWaiters(new FailoverException("Failing over about to start"));
// Since failover impacts several structures we protect them all with a single mutex. These structures
// are also in child objects of the connection. This allows us to manipulate them without affecting
// client code which runs in a separate thread.
lock (_connection.FailoverMutex)
{
_log.Info("Starting failover process");
// We switch in a new state manager temporarily so that the interaction to get to the "connection open"
// state works, without us having to terminate any existing "state waiters". We could theoretically
// have a state waiter waiting until the connection is closed for some reason. Or in future we may have
// a slightly more complex state model therefore I felt it was worthwhile doing this.
AMQStateManager existingStateManager = _connection.ProtocolListener.StateManager;
_connection.ProtocolListener.StateManager = new AMQStateManager();
if (!_connection.FirePreFailover(_host != null))
{
_connection.ProtocolListener.StateManager = existingStateManager;
if (_host != null)
{
_connection.ExceptionReceived(new AMQDisconnectedException("Redirect was vetoed by client"));
}
else
{
_connection.ExceptionReceived(new AMQDisconnectedException("Failover was vetoed by client"));
}
pl.FailoverLatch.Set();
pl.FailoverLatch = null;
return;
}
bool failoverSucceeded;
// when host is non null we have a specified failover host otherwise we all the client to cycle through
// all specified hosts
// if _host has value then we are performing a redirect.
if (_host != null)
{
// todo: fix SSL support!
failoverSucceeded = _connection.AttemptReconnection(_host, _port, null);
}
else
{
failoverSucceeded = _connection.AttemptReconnection();
}
// XXX: at this point it appears that we are going to set StateManager to existingStateManager in
// XXX: both paths of control.
if (!failoverSucceeded)
{
_connection.ProtocolListener.StateManager = existingStateManager;
_connection.ExceptionReceived(
new AMQDisconnectedException("Server closed connection and no failover " +
"was successful"));
}
else
{
_connection.ProtocolListener.StateManager = existingStateManager;
try
{
if (_connection.FirePreResubscribe())
{
_log.Info("Resubscribing on new connection");
_connection.ResubscribeChannels();
}
else
{
_log.Info("Client vetoed automatic resubscription");
}
_connection.FireFailoverComplete();
_connection.ProtocolListener.FailoverState = FailoverState.NOT_STARTED;
_log.Info("Connection failover completed successfully");
}
catch (Exception e)
{
_log.Info("Failover process failed - exception being propagated by protocol handler");
_connection.ProtocolListener.FailoverState = FailoverState.FAILED;
try
{
_connection.ProtocolListener.OnException(e);
}
catch (Exception ex)
{
_log.Error("Error notifying protocol session of error: " + ex, ex);
}
}
}
}
pl.FailoverLatch.Set();
}
