1 files changed, 21 insertions, 0 deletions

diff --git a/Presence/Control/Concurrent/STM/Util.hs b/Presence/Control/Concurrent/STM/Util.hs
new file mode 100644
index 00000000..4be3cff5
--- /dev/null
+++ b/Presence/Control/Concurrent/STM/Util.hs
@@ -0,0 +1,21 @@
+module Control.Concurrent.STM.Util where
+
+import Control.Monad.IO.Class
+import Control.Concurrent.STM
+
+chanContents :: TChan x -> IO [x]
+chanContents ch = do
+        x  <- atomically $ do
+            bempty <- isEmptyTChan ch
+            if bempty
+                then return Nothing
+                else fmap Just $ readTChan ch
+        maybe (return [])
+              (\x -> do
+                xs <- chanContents ch
+                return (x:xs))
+              x
+
+ioWriteChan :: MonadIO m => TChan a -> a -> m ()
+ioWriteChan c v = liftIO . atomically $ writeTChan c v
+