Add a TraceDrainingThePipe event

Author: Niols

ouroboros-consensus-diffusion/test/consensus-test/Test/Consensus/PeerSimulator/Trace.hs

@@ -419,6 +419,8 @@ traceChainSyncClientEventTestBlockWith pid tracer = \case
       trace "Waiting for next instruction from the jumping governor"
     TraceJumpingInstructionIs instr ->
       trace $ "Received instruction: " ++ showInstr instr
+    TraceDrainingThePipe n ->
+      trace $ "Draining the pipe, remaining messages: " ++ show n
   where
     trace = traceUnitWith tracer ("ChainSyncClient " ++ condense pid)
 

ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/MiniProtocol/ChainSync/Client.hs

@@ -917,7 +917,9 @@ chainSyncClient cfgEnv dynEnv =
                Nat n'
             -> s
             -> m (Consensus (ClientPipelinedStIdle n') blk m)
-          go n s = case n of
+          go n s = do
+            traceWith tracer $ TraceDrainingThePipe n
+            case n of
               Zero    -> continueWithState s m
               Succ n' -> return $ CollectResponse Nothing $ ClientStNext {
                   recvMsgRollForward  = \_hdr _tip -> go n' s
@@ -2334,12 +2336,8 @@ data TraceChainSyncClientEvent blk =
   |
     TraceJumpingInstructionIs (Jumping.Instruction blk)
     -- ^ ChainSync Jumping -- the ChainSync client got its next instruction.
-
-deriving instance
-  ( BlockSupportsProtocol blk
-  , Eq (Header blk)
-  )
-  => Eq (TraceChainSyncClientEvent blk)
+  |
+    forall n. TraceDrainingThePipe (Nat n)
 
 deriving instance
   ( BlockSupportsProtocol blk