adding the STM module.

Network/Socket.hs

@@ -382,6 +382,12 @@ module Network.Socket (
 
     -- * Special constants
     maxListenQueue,
+
+    -- * STM to check read and write
+    waitReadSocketSTM,
+    waitAndCancelReadSocketSTM,
+    waitWriteSocketSTM,
+    waitAndCancelWriteSocketSTM,
 ) where
 
 import Network.Socket.Buffer hiding (
@@ -399,6 +405,7 @@ import Network.Socket.Info
 import Network.Socket.Internal
 import Network.Socket.Name hiding (getPeerName, getSocketName)
 import Network.Socket.Options
+import Network.Socket.STM
 import Network.Socket.Shutdown
 import Network.Socket.SockAddr
 import Network.Socket.Syscall hiding (accept, bind, connect)

Network/Socket/STM.hs

@@ -0,0 +1,24 @@
+module Network.Socket.STM where
+
+import Control.Concurrent
+import Control.Concurrent.STM
+import Network.Socket.Types
+import System.Posix.Types
+
+-- | STM action to wait until the socket is ready for reading.
+waitReadSocketSTM :: Socket -> IO (STM ())
+waitReadSocketSTM s = fst <$> waitAndCancelReadSocketSTM s
+
+-- | STM action to wait until the socket is ready for reading and STM
+--   action to cancel the waiting.
+waitAndCancelReadSocketSTM :: Socket -> IO (STM (), IO ())
+waitAndCancelReadSocketSTM s = withFdSocket s $ threadWaitReadSTM . Fd
+
+-- | STM action to wait until the socket is ready for writing.
+waitWriteSocketSTM :: Socket -> IO (STM ())
+waitWriteSocketSTM s = fst <$> waitAndCancelWriteSocketSTM s
+
+-- | STM action to wait until the socket is ready for writing and STM
+--   action to cancel the waiting.
+waitAndCancelWriteSocketSTM :: Socket -> IO (STM (), IO ())
+waitAndCancelWriteSocketSTM s = withFdSocket s $ threadWaitWriteSTM . Fd

network.cabal

@@ -115,6 +115,7 @@ library
         Network.Socket.Name
         Network.Socket.Options
         Network.Socket.ReadShow
+        Network.Socket.STM
         Network.Socket.Shutdown
         Network.Socket.SockAddr
         Network.Socket.Syscall
@@ -132,7 +133,8 @@ library
         base >=4.9 && <5,
         bytestring >=0.10,
         deepseq,
-        directory
+        directory,
+        stm
 
     if !os(windows)
         other-modules: