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3146 :: Killing an AsyncHttpServer

• def_pri_pub (orginal) [2017-09-05T06:04:26+02:00] view original

  So I've got some code like this:

  import asyncDispatch
  import asynchttpserver
  
  # Create the server object and state data
  var
    server = newAsyncHttpServer()
  let port = 8000
  
  # ...
  
  proc handleRequest(req: Request) {.async.}=
    ## Handle an incomming connection
    var killServer = false
    
    # ...
    
    if killServer:
      server.close()
    
    # Write a response
    var headers = newHttpHeaders()
    headers.add("Content-Type", "text/html")
    await req.respond(Http200, mkPage(pageViews, killServer), headers)
  
  
  # Handle requests
  echo("Listening for connections on http://localhost:" & $port & "/")
  waitFor server.serve(Port(port), handleRequest)
  Run

  If I try to call server.close() I keep on getting this error:

  
  Server.nim(74, 15) Error: type mismatch: got (AsyncHttpServer, Port, proc (req: Request): Future[system.void]{.locks: <unknown>.})
  but expected one of:
  proc serve(server: AsyncHttpServer; port: Port;
            callback: proc (request: Request): Future[void]; address = ""): Future[void]
  Run

  I've tried creating a wrapper async function around the close call, that didn't work. I tried using an event callback, that didn't work either. Both other produced the same compilation errors. What's going on here?

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• Tiberium (orginal) [2017-09-05T06:14:34+02:00] view original

  Try to add gcsafe pragma to your proc

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• def_pri_pub (orginal) [2017-09-06T02:10:29+02:00] view original

  It now compiles successfully, but it doesn't seem to be killing the server when I trip that killServer block. It will run over the line and continue on with execution.

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• enthus1ast (orginal) [2017-09-06T18:20:09+02:00] view original

  try returning after server.close

  Edit: also this is this bug https://github.com/nim-lang/Nim/issues/6186

  Edit2: do you set killServer = true in your code?

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• def_pri_pub (orginal) [2017-09-09T05:25:31+02:00] view original

  Yeah, I have the killServer = true in a block somewhere.

  Adding return after server.close() does work, but I need to mark server with {.threadsafe.}. It also causes an issue with the HTTP Request (on the browser side) doesn't get finished and just hangs. Interestingly enough this doesn't actually stop the application then and there. It's if I try to send a request after killServer = true that it will end the program with this output:

  
  Traceback (most recent call last)
  Server.nim(76)           Server
  asyncdispatch.nim(1010)  waitFor
  asyncdispatch.nim(1013)  poll
  Error: unhandled exception: No handles or timers registered in dispatcher. [ValueError]
  Run

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