BrokerClient: handle timeout

src/ATrade/Broker/Client.hs

@@ -15,9 +15,11 @@ import Control.Concurrent.BoundedChan
 import Control.Concurrent.MVar
 import Control.Exception
 import Control.Monad
+import Control.Monad.Loops
 import Data.Aeson
 import Data.Int
 import Data.IORef
+import Data.Maybe
 import Data.List.NonEmpty
 import qualified Data.Text as T
 import qualified Data.ByteString.Lazy as BL
@@ -28,6 +30,7 @@ import System.Log.Logger
 data BrokerClientHandle = BrokerClientHandle {
   tid :: ThreadId,
   completionMvar :: MVar (),
+  killMvar :: MVar (),
   submitOrder :: Order -> IO (Either T.Text OrderId),
   cancelOrder :: OrderId -> IO (Either T.Text ()),
   getNotifications :: IO (Either T.Text [Notification]),
@@ -35,32 +38,41 @@ data BrokerClientHandle = BrokerClientHandle {
   respVar :: MVar BrokerServerResponse
 }
 
-brokerClientThread ctx ep cmd resp comp = do
+brokerClientThread :: Context -> T.Text -> MVar BrokerServerRequest -> MVar BrokerServerResponse -> MVar () -> MVar () -> IO ()
+brokerClientThread ctx ep cmd resp comp killMv = finally brokerClientThread' cleanup
+  where
+    cleanup = putMVar comp ()
+    brokerClientThread' = whileM_ (isNothing <$> tryReadMVar killMv) $ do
       sock <- socket ctx Req
       connect sock $ T.unpack ep
-  finally (brokerClientThread' sock) (cleanup sock)
+      setReceiveTimeout (restrict 1000) sock
-  where
+      finally (brokerClientThread'' sock) (close sock)
-    cleanup sock = close sock >> putMVar comp ()
+    brokerClientThread'' sock = whileM_ (isNothing <$> tryReadMVar killMv) $ do
-    brokerClientThread' sock = do
-      forever $ do
         request <- takeMVar cmd
         send sock [] (BL.toStrict $ encode request)
+        events <- poll 1000 [Sock sock [In] Nothing]
+        if (not . null) events
+          then do
             maybeResponse <- decode . BL.fromStrict <$> receive sock
             case maybeResponse of
               Just response -> putMVar resp response
               Nothing -> putMVar resp (ResponseError "Unable to decode response")
+          else
+            putMVar resp (ResponseError "Response timeout")
 
 startBrokerClient :: Context -> T.Text -> IO BrokerClientHandle
 startBrokerClient ctx endpoint = do
   idCounter <- newIORef 1
   compMv <- newEmptyMVar
+  killMv <- newEmptyMVar
   cmdVar <- newEmptyMVar :: IO (MVar BrokerServerRequest)
   respVar <- newEmptyMVar :: IO (MVar BrokerServerResponse)
-  tid <- forkIO (brokerClientThread ctx endpoint cmdVar respVar compMv)
+  tid <- forkIO (brokerClientThread ctx endpoint cmdVar respVar compMv killMv)
 
   return BrokerClientHandle {
     tid = tid,
     completionMvar = compMv,
+    killMvar = killMv,
     submitOrder = bcSubmitOrder idCounter cmdVar respVar,
     cancelOrder = bcCancelOrder idCounter cmdVar respVar,
     getNotifications = bcGetNotifications idCounter cmdVar respVar,
@@ -69,7 +81,7 @@ startBrokerClient ctx endpoint = do
   }
 
 stopBrokerClient :: BrokerClientHandle -> IO ()
-stopBrokerClient handle = yield >> killThread (tid handle) >> readMVar (completionMvar handle)
+stopBrokerClient handle = putMVar (killMvar handle) () >> yield >> killThread (tid handle) >> readMVar (completionMvar handle)
 
 nextId cnt = atomicModifyIORef' cnt (\v -> (v + 1, v))