Implement unsafeUSend.

facundominguez · facundominguez · commit 222beb5f7e71 · 2015-11-27T15:57:43.000-03:00
diff --git a/src/Control/Distributed/Process.hs b/src/Control/Distributed/Process.hs
@@ -40,6 +40,7 @@ module Control.Distributed.Process
   , mergePortsRR
     -- * Unsafe messaging variants
   , unsafeSend
+  , unsafeUSend
   , unsafeSendChan
   , unsafeNSend
   , unsafeWrapMessage
@@ -212,6 +213,7 @@ import Control.Distributed.Process.Internal.Primitives
   , mergePortsBiased
   , mergePortsRR
   , unsafeSend
+  , unsafeUSend
   , unsafeSendChan
   , unsafeNSend
     -- Advanced messaging
diff --git a/src/Control/Distributed/Process/Internal/Primitives.hs b/src/Control/Distributed/Process/Internal/Primitives.hs
@@ -23,6 +23,7 @@ module Control.Distributed.Process.Internal.Primitives
   , mergePortsRR
     -- * Unsafe messaging variants
   , unsafeSend
+  , unsafeUSend
   , unsafeSendChan
   , unsafeNSend
     -- * Advanced messaging
@@ -279,6 +280,13 @@ usend them msg = do
       else sendCtrlMsg (Just there) $ UnreliableSend (processLocalId them)
                                                      (createMessage msg)
 
+-- | /Unsafe/ variant of 'usend'. This function makes /no/ attempt to serialize
+-- the message when the destination process resides on the same local
+-- node. Therefore, a local receiver would need to be prepared to cope with any
+-- errors resulting from evaluation of the message.
+unsafeUSend :: Serializable a => ProcessId -> a -> Process ()
+unsafeUSend = Unsafe.usend
+
 -- | Wait for a message of a specific type
 expect :: forall a. Serializable a => Process a
 expect = receiveWait [match return]
diff --git a/src/Control/Distributed/Process/UnsafePrimitives.hs b/src/Control/Distributed/Process/UnsafePrimitives.hs
@@ -45,6 +45,7 @@ module Control.Distributed.Process.UnsafePrimitives
     send
   , sendChan
   , nsend
+  , usend
   , wrapMessage
   ) where
 
@@ -65,6 +66,7 @@ import Control.Distributed.Process.Internal.Types
   , ImplicitReconnect(..)
   , SendPortId(..)
   , Message
+  , createMessage
   , sendPortProcessId
   , unsafeCreateUnencodedMessage
   )
@@ -96,6 +98,25 @@ send them msg = do
     unsafeSendLocal pid msg' =
       sendCtrlMsg Nothing $ LocalSend pid (unsafeCreateUnencodedMessage msg')
 
+-- | Send a message unreliably.
+--
+-- Unlike 'send', this function is insensitive to 'reconnect'. It will
+-- try to send the message regardless of the history of connection failures
+-- between the nodes.
+--
+-- Message passing with 'usend' is ordered for a given sender and receiver
+-- if the messages arrive at all.
+--
+usend :: Serializable a => ProcessId -> a -> Process ()
+usend them msg = do
+    proc <- ask
+    let there = processNodeId them
+    if localNodeId (processNode proc) == there
+      then sendCtrlMsg Nothing $
+             LocalSend them (unsafeCreateUnencodedMessage msg)
+      else sendCtrlMsg (Just there) $ UnreliableSend (processLocalId them)
+                                                     (createMessage msg)
+
 -- | Send a message on a typed channel
 sendChan :: Serializable a => SendPort a -> a -> Process ()
 sendChan (SendPort cid) msg = do
