Question

i’m looking to connect to a WCF service from w/in the same .exe from which it is hosted. I host the service in a WPF application as:

        ServiceHost svc = new ServiceHost(typeof("Namespace.Service"));
        svc.Open();

and config file of

  <service name="Namespace.Service" >
    <endpoint address="Contract/tcp"
              binding="netTcpBinding"
              contract="Namespace.IContract"/>
    <host>
      <baseAddresses>
        <add baseAddress="net.tcp://localhost:9002"/>
      </baseAddresses>
    </host>
  </service>

This allows me to fire up a separate VS instance, create a console app and perform the following successfully:

        IChannelFactory<IContract> facContract = new ChannelFactory<IContract>(new NetTcpBinding());
        IContract contract = facContract.CreateChannel(new EndpointAddress("net.tcp://localhost:9002/Contract/tcp"));

        string x = contract.GetProperty; //returns value I would expect

However if I amend my original WPF ServiceHost code to the following, a timeout exception is thrown when I access the service (NOTE: That if I do the same thing in the Console App Service host, I do not get the timeout…):

        ServiceHost svc = new ServiceHost(typeof("Namespace.Service"));
        svc.Open();

        IChannelFactory<IContract> facContract = new ChannelFactory<IContract>(new NetTcpBinding());
        IContract contract = facContract.CreateChannel(new EndpointAddress("net.tcp://localhost:9002/Contract/tcp"));

        string x = contract.GetProperty; //<-!!WCF Timeout exception thrown..

WCF Tracing doesn’t provide add’l details (just confirms that a timeout exception is thrown). Any thoughts? {this isn’t a question about WCF Exception management best practices; I’m looking to access a service from within the service host & am blocked by this curious timeout exception}

EDIT:
This timeout occurs when the service host is a WPF application (perhaps others); but console app as a service host behaves as I would expect (e.g. can access a self-hosted service). I’ve updated the title and tags to reflect this new info…

Thanks in advance,
T

Answer 1

This was because WPF servicehost was hosting service on same thread as consuming service. Problem is defined here: http://social.msdn.microsoft.com/Forums/en/wcf/thread/74bc9d15-c458-4f1f-81a0-ebded46b68c4. Resolution is detailed here: http://msdn.microsoft.com/en-us/library/ms752260.aspx

Resolution was to start service host endpoint on a separate thread ala:

    private void StartHostThread()
    {
        // Before opening host, add endpoints...
        host.AddServiceEndpoint(typeof(IContract)),
                                new NetTcpBinding(), 
                                "Contract/tcp"); //Assumes base address of net.tcp://localhost:9002/

        //For hosting on its own thread, be sure to mark service attribute 
        //  as UseSyncContext == false
        ServiceBehaviorAttribute behavior = host.Description.Behaviors.Find<ServiceBehaviorAttribute>();
        behavior.UseSynchronizationContext = false; 

        host.Open();
    }

once host is opened on thread, then can consume service on main UI thread ala:

        EndpointAddress epoint = new EndpointAddress("net.tcp://localhost:9002/Contract/tcp");
        IContract proxy = ChannelFactory<IContract>.CreateChannel(new NetTcpBinding(), epoint);
        string xyz;
        using (proxy as IDisposable)
        {
            xyz = proxy.GetProperty;
        }