Memory leak when using mergeSources

[francisdb]

I'm quite new to Haskell but I guess this is not supposed to happen

Using the example code below when using the plain conduit source the memory usage stays constant but with mergeSources it keeps growing. Even when doing a merge with a single source.

main :: IO ()
main = do
  let
    sqrts = yieldMany [1..] .| mapC sqrt .| printC
  source <- mergeSources (replicate 2 sqrts) 16
  -- source <- return sqrts
  runConduitRes $ source .| sinkNull

[qnikst]

Thanks for the report! Indeed it looks like a problem somewhere.

A very similar program that does basically the same (except some additional actions for resource managing) has the correct behaviour:

import Control.Concurrent
import Control.Concurrent.STM.TBMChan
import Data.Conduit
import Data.Conduit.TMChan
import qualified Data.Conduit.Combinators as C
import qualified Data.Conduit.List as CL
import Control.Monad.Trans.Resource
import Control.Monad

main :: IO ()
main = do
  x <- newTBMChanIO  16
  forkIO $ runConduit $ C.yieldMany [1..] .| CL.map sqrt .| sinkTBMChan x
  forkIO $ runConduit $ C.yieldMany [1..] .| CL.map sqrt .| sinkTBMChan x
  runConduit $ sourceTBMChan x .| C.print

We will try to dig further into the problem.