From bc8360faf51a058f3c1dd90145d4b87506e2ddfe Mon Sep 17 00:00:00 2001
From: joe <joe@jerkface.net>
Date: Wed, 13 Jun 2018 16:11:11 -0400
Subject: tox: Associate a state with each connection management thread.

---
 Connection/Tox.hs | 74 +++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 64 insertions(+), 10 deletions(-)

(limited to 'Connection/Tox.hs')

diff --git a/Connection/Tox.hs b/Connection/Tox.hs
index c8ce9a53..f6f15f3c 100644
--- a/Connection/Tox.hs
+++ b/Connection/Tox.hs
@@ -19,6 +19,8 @@ import Control.Concurrent.Lifted.Instrument
 import Control.Concurrent.Lifted
 import GHC.Conc                  (labelThread)
 #endif
+import GHC.Conc (threadStatus,ThreadStatus(..))
+
 
 
 
@@ -35,7 +37,7 @@ data Key = Key NodeId{-me-} NodeId{-them-}
 
 instance Show Key where show = show . showKey_
 
-
+{-
 -- | A conneciton status that is tagged with a state type that is specific to
 -- the status.
 data Transient a where
@@ -56,21 +58,48 @@ untag (IsAcquiringCookie       :=> _) = G.InProgress AcquiringCookie
 untag (IsAwaitingHandshake     :=> _) = G.InProgress AwaitingHandshake
 untag (IsAwaitingSessionPacket :=> _) = G.InProgress AwaitingSessionPacket
 untag (IsEstablished           :=> _) = G.Established
+-}
+
+data StatefulTask st = StatefulTask
+    { taskThread :: ThreadId
+    , taskState  :: TVar st
+    }
+
+launch :: String -> st -> ((st -> STM ()) -> IO ()) -> IO (StatefulTask st)
+launch lbl st f = do
+    stvar <- newTVarIO st
+    tid <- forkIO (f $ writeTVar stvar)
+    labelThread tid lbl
+    return $ StatefulTask tid stvar
 
 
+data SessionTasks = SessionTasks
+    { accepting  :: StatefulTask (G.Status ToxProgress)
+    , persuing   :: StatefulTask (G.Status ToxProgress)
+    , refreshing :: StatefulTask (G.Status ToxProgress)
+    }
+
 data SessionState = SessionState
-    { transient     :: TVar (DSum Transient Identity)
-    , connPolicy    :: TVar Policy
+    { connPolicy    :: TVar Policy
     , connPingLogic :: PingMachine
+    , sessionTasks  :: TVar SessionTasks
+    -- , transient     :: TVar (DSum Transient Identity)
     }
 
 sessionStatus :: SessionState -> G.Connection ToxProgress
 sessionStatus st = G.Connection
-    { G.connStatus    = untag <$> readTVar (transient st)
+    { G.connStatus    = combinedStatus =<< readTVar (sessionTasks st)
     , G.connPolicy    = readTVar (connPolicy st)
     , G.connPingLogic = connPingLogic st
     }
 
+combinedStatus :: SessionTasks -> STM (G.Status ToxProgress)
+combinedStatus tasks = do
+    a <- readTVar (taskState $ accepting tasks)
+    p <- readTVar (taskState $ persuing tasks)
+    r <- readTVar (taskState $ refreshing tasks)
+    return $ maximum [a,p,r]
+
 lookupForPolicyChange :: TVar (Map.Map Key SessionState)
                          -> Key -> Policy -> IO (Maybe SessionState)
 lookupForPolicyChange conmap k policy = atomically $ do
@@ -93,22 +122,47 @@ setToxPolicy params conmap k policy = case policy of
         mst <- lookupForPolicyChange conmap k policy
         forM_ mst $ \st -> do
             let getPolicy = readTVar $ connPolicy st
-            --TODO accept_thread may already be started if policy was OpenToConnect
-            accept_thread  <- forkIO $ acceptContact  getPolicy _accept_methods
-            persue_thread  <- forkIO $ persueContact  getPolicy _get_status _persue_methods
-            freshen_thread <- forkIO $ freshenContact getPolicy _get_status _freshen_methods
+            tasks <- atomically $ readTVar (sessionTasks st)
+            --TODO This check to determine whether to launch the accepting thread
+            --is probably racey.
+            astat <- threadStatus (taskThread $ accepting tasks)
+            accepting <- if astat /= ThreadRunning
+                          then launch ("accept:"++show k)
+                                (G.InProgress $ toEnum 0)
+                                $ acceptContact  getPolicy _accept_methods
+                          else return $ accepting tasks
+            persuing <- launch ("persue:"++show k)
+                                (G.InProgress $ toEnum 0)
+                               $ persueContact  getPolicy _get_status _persue_methods
+            refreshing <- launch ("refresh:"++show k)
+                                (G.InProgress $ toEnum 0)
+                               $ freshenContact getPolicy _get_status _freshen_methods
+            atomically $ writeTVar (sessionTasks st)
+                       $ SessionTasks accepting persuing refreshing
             return ()
         return ()
     RefusingToConnect -> do -- disconnect or cancel any pending connection
         mst <- lookupForPolicyChange conmap k policy
         -- Since the 3 connection threads poll the current policy, they should
         -- all terminate on their own.
-        return ()
+        --
+        -- Here we block until they finish.
+        forM_ mst $ \st -> do
+            atomically $ do
+                tasks <- readTVar (sessionTasks st)
+                a <- readTVar $ taskState (accepting tasks)
+                p <- readTVar $ taskState (persuing tasks)
+                r <- readTVar $ taskState (refreshing tasks)
+                case (a,p,r) of
+                    (G.Dormant,G.Dormant,G.Dormant) -> return ()
+                    _                               -> retry
     OpenToConnect -> do -- passively accept connections if they initiate.
         mst <- lookupForPolicyChange conmap k policy
         forM_ mst $ \st -> do
             let getPolicy = readTVar $ connPolicy st
-            accept_thread  <- forkIO $ acceptContact  getPolicy _accept_methods
+            accept_thread  <- launch ("accept:"++show k)
+                                     (G.InProgress $ toEnum 0)
+                                     $ acceptContact  getPolicy _accept_methods
             return ()
 
 
-- 
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