Unhandled exception at Grapevine.Interfaces.Server.HttpResponse.SendResponse

Question

I have a server which listens to HTTP POSTs that several client make sending information. I use Grapevine as http server because methods are really simple and didn't need the complexity of ASP.

Sometimes I get this random

error:

2017-12-12 15:39:25.5642|ERROR|Omnibox_Server.Modelo.HttpServer.Controllers.OpenALPRController|System.Net.HttpListenerException (0x80004005): The I/O operation has been aborted because of either a thread exit or an application request
   at System.Net.HttpRequestStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.IO.StreamReader.ReadBuffer()
   at System.IO.StreamReader.ReadToEnd()
   at Grapevine.Interfaces.Server.HttpRequest.get_Payload()
   at Omnibox_Server.Modelo.HttpServer.Controllers.OpenALPRController.PostPatente(IHttpContext context)

This is the

class/method:

namespace Omnibox_Server.Modelo.HttpServer.Controllers
{
    [RestResource(BasePath = "/openalpr")]
    public class OpenALPRController
    {
        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
        [RestRoute(HttpMethod = HttpMethod.POST, PathInfo = "/patente")]
        public IHttpContext PostPatente(IHttpContext context)
        {
            try
            {
                context.Response.StatusCode = HttpStatusCode.Ok;
                context.Response.ContentType = ContentType.JSON;
                context.Response.ContentEncoding = Encoding.UTF8;
                var fotoOpenAlpr = JsonConvert.DeserializeObject<FotoOpenALPR>(context.Request.Payload); //<--- exception occurs here? shouldn't try/catch work?
                var ip = context.Request.RemoteEndPoint;
                if (fotoOpenAlpr.agent_uid != null)
                    Task.Run(async () =>
                    {
                        if (fotoOpenAlpr.is_parked) return;
                        await fotoOpenAlpr.ObtenerFoto(ip.Address);
                        try
                        {
                            var foto = new Foto(fotoOpenAlpr);
                            if (foto.IdOmnibox == 0) Logger.Info("Omnibox sin ID con IP " + ip.Address);
                            await foto.Procesar();
                        }
                        catch (Exception e)
                        {
                        }
                    });
                context.Response.SendResponse(HttpStatusCode.Ok); //or maybe exception triggers here?
            }
            catch (Exception e)
            {
                Logger.Error(e);
            }
            return context;
        }
    }
}

An event is generated in the

windows log:

Application: Omnibox Server.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Net.HttpListenerException
   at System.Net.HttpResponseStream.Write(Byte[], Int32, Int32)
   at Grapevine.Interfaces.Server.HttpResponse.SendResponse(Byte[])
   at Grapevine.Server.HttpResponseExtensions.SendResponse(Grapevine.Interfaces.Server.IHttpResponse, System.String)
   at Grapevine.Server.Router.Route(System.Object)
   at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(System.Object)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

Both exception log and windows log in the event viewer have the same timestamp.

Answer 1

From the OP:

I fixed the issue by moving the line context.Response.SendResponse(HttpStatusCode.Ok); below the try/catch. I think what happened was that sometimes TCP pipe breaks and payload is corrupt/incomplete, therefore an exception is thrown when trying to get it, and because I didn't SendResponse(OK) another exception is thrown outside the try/catch, breaking my server.