使用 Haskell 和 Thrift 进行 Ping Pong 时遇到困难

Question

我正在尝试使用 Haskell 和 Thrift 做一个简单的 Ping Pong。然而，它只重复一次，然后就卡住了。我认为问题在于 Thrift 的（不）正确使用，而不是 Haskell。可能有些东西没有正确冲洗。有没有具有 Thrift 经验的人可以帮助我对如何解决这个问题做出有根据的猜测？

服务器：

echorequest :: TXT
echorequest = TXT {
    f_TXT_anytxt = Just "Ping"
    }

echoreply :: TXT
echoreply = TXT {
    f_TXT_anytxt = Just "Pong"
    }

serverFunc :: a -> (BinaryProtocol Handle, BinaryProtocol Handle)
              -> IO Bool
serverFunc a (h1,h2) = do
  let t1 = getTransport h1
  dat <- read_TXT h1
-- the following two lines are only for debugging
  putStrLn "Recieved data:"
  print dat
  write_TXT h1 echoreply
  tFlush t1
-- the following line is for debugging
  putStrLn "Data written"

  return False


main :: IO ()
main = do
   runBasicServer () serverFunc 4390
   putStrLn "Server stopped"

客户端：

main :: IO ()
main = do
  h <- connectTo "127.0.0.1" $ PortNumber 4390
  let proto = BinaryProtocol h
  putStrLn "Client started"
  let tryOnePing c i = do
      write_TXT proto echorequest
      putStrLn "ping sent"
      tFlush h
      w <- read_TXT proto
      putStrLn "pong received"
      return $ if w == echoreply then c+1 else c
  c <- foldM tryOnePing 0 [0 .. 1000]
  tClose h
  print (c, 10000 - c)

Answer 1

您的问题是您从 serverFunc 返回 False。 Haskell 将循环直到您返回 false （通过您的代码，仅一次）

http://hackage.haskell.org/packages/archive/thrift/0.6.0/doc/html/src/Thrift-Server.html#line-65