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5108 :: How to implement pre-fork with async sockets?

• Tronic (orginal) [2019-08-19T17:15:36+02:00] view original

  Whenever the code gets to accept, three forked processes die with Error: unhandled exception: Bad file descriptor (code: 9) [IOSelectorsException] and only the original survives.

  var server = newAsyncSocket()
  server.setSockOpt(OptReuseAddr, true)
  server.bindAddr(Port(5000))
  server.listen()
  
  # Four processes
  discard posix.fork()
  discard posix.fork()
  
  proc serve {.async.} =
    while true:
      let client = await server.accept()
      client.setSockOpt(OptNoDelay, true)
      asyncCheck processClient(client)
  
  asyncCheck serve()
  runForever()
  Run

  I tried with net sockets instead of async and then it works as expected but I cannot figure out how to turn plain socket into async socket.

  So, how is one supposed to implement pre-fork listening on Nim?

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• dom96 (orginal) [2019-08-19T21:36:08+02:00] view original

  This isn't supported. Why not just launch a few threads instead? Why are you forking?

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• Tronic (orginal) [2019-08-20T08:44:24+02:00] view original

  Okay, how to do it with threads? I couldn't get async and threads going together, and sharing of the server socket is still a concern.

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• dom96 (orginal) [2019-08-20T21:35:24+02:00] view original

  Ideally you should avoid sharing sockets between threads, each thread will have its own event loop, all you need to do is perform IO for each threads' respective sockets there.

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