re-structure convergenceSampleThread to work on a RealNode and iterate over all joined vservers

contributes to #34

src/Hash2Pub/FediChord.hs

@@ -133,7 +133,7 @@ fediChordInit initConf serviceRunner = do
         putStrLn $ err <> " Error joining, start listening for incoming requests anyways"
         -- launch thread attempting to join on new cache entries
         _ <- forkIO $ joinOnNewEntriesThread firstVSSTM
-        async (fediMainThreads serverSock firstVSSTM)
+        async (fediMainThreads serverSock realNodeSTM)
            )
            (\joinedNS -> do
         -- launch main eventloop with successfully joined state
@@ -195,33 +195,36 @@ fediChordBootstrapJoin nsSTM bootstrapNode = do
 
 -- Periodically lookup own ID through a random bootstrapping node to discover and merge separated DHT clusters.
 -- Unjoined try joining instead.
-convergenceSampleThread :: Service s (RealNodeSTM s) => LocalNodeStateSTM s -> IO ()
-convergenceSampleThread nsSTM = forever $ do
-    nsSnap <- readTVarIO nsSTM
-    parentNode <- readTVarIO $ parentRealNode nsSnap
-    if isJoined nsSnap
-       then
-        runExceptT (do
-            -- joined node: choose random node, do queryIDLoop, compare result with own responsibility
-            let bss = bootstrapNodes parentNode
-            randIndex <- liftIO $ randomRIO (0, length bss - 1)
-            chosenNode <- maybe (throwError "invalid bootstrapping node index") pure $ atMay bss randIndex
-            lookupResult <- liftIO $ bootstrapQueryId nsSTM chosenNode (getNid nsSnap)
-            currentlyResponsible <- liftEither lookupResult
-            if getNid currentlyResponsible /= getNid nsSnap
-               -- if mismatch, stabilise on the result, else do nothing
-               then do
-                   stabResult <- liftIO $ requestStabilise nsSnap currentlyResponsible
-                   (preds, succs) <- liftEither stabResult
-                   -- TODO: verify neighbours before adding, see #55
-                   liftIO . atomically $ do
-                       ns <- readTVar nsSTM
-                       writeTVar nsSTM $ addPredecessors preds ns
-               else pure ()
-                   ) >> pure ()
-    -- unjoined node: try joining through all bootstrapping nodes
-    else tryBootstrapJoining nsSTM >> pure ()
-    let delaySecs = confBootstrapSamplingInterval . nodeConfig $ parentNode
+convergenceSampleThread :: Service s (RealNodeSTM s) => RealNodeSTM s -> IO ()
+convergenceSampleThread nodeSTM = forever $ do
+    node <- readTVarIO nodeSTM
+    forM_ (vservers node) $ \nsSTM -> do
+        nsSnap <- readTVarIO nsSTM
+        parentNode <- readTVarIO $ parentRealNode nsSnap
+        if isJoined nsSnap
+           then
+            runExceptT (do
+                -- joined node: choose random node, do queryIDLoop, compare result with own responsibility
+                let bss = bootstrapNodes parentNode
+                randIndex <- liftIO $ randomRIO (0, length bss - 1)
+                chosenNode <- maybe (throwError "invalid bootstrapping node index") pure $ atMay bss randIndex
+                lookupResult <- liftIO $ bootstrapQueryId nsSTM chosenNode (getNid nsSnap)
+                currentlyResponsible <- liftEither lookupResult
+                if getNid currentlyResponsible /= getNid nsSnap
+                   -- if mismatch, stabilise on the result, else do nothing
+                   then do
+                       stabResult <- liftIO $ requestStabilise nsSnap currentlyResponsible
+                       (preds, succs) <- liftEither stabResult
+                       -- TODO: verify neighbours before adding, see #55
+                       liftIO . atomically $ do
+                           ns <- readTVar nsSTM
+                           writeTVar nsSTM $ addPredecessors preds ns
+                   else pure ()
+                       ) >> pure ()
+        -- unjoined node: try joining through all bootstrapping nodes
+        else tryBootstrapJoining nsSTM >> pure ()
+
+    let delaySecs = confBootstrapSamplingInterval . nodeConfig $ node
     threadDelay delaySecs
 
 
@@ -657,7 +660,7 @@ fediMainThreads sock nodeSTM = do
         -- choose option 2 for the sake of limiting concurrency in simulation scenario
         concurrently_ (stabiliseThread nodeSTM) $
             concurrently_ (nodeCacheVerifyThread nodeSTM) $
-                concurrently_ (convergenceSampleThread nsSTM) $
+                concurrently_ (convergenceSampleThread nodeSTM) $
                     concurrently_ (lookupCacheCleanup $ parentRealNode ns) $
                         concurrently_
                             (sendThread sock sendQ)