Dear SevenThunders (if that is how you like to addressed) Thanks for extracting a small program that exhibits the leak; that is really helpful. We'll look into it. Would you like to create a Trac bug and attach your files? Simon | -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] | On Behalf Of SevenThunders | Sent: 03 November 2006 02:54 | To: glasgow-haskell-users@haskell.org | Subject: Memory leak in FFI callback: GHC 6.6 | | | I'm not sure if this is a bug, but it sure seems that way to me. When using | the "wrapper" technique for creating a Haskell callback function it seems | that freeHaskellFunPtr is not properly freeing the resource. | | Here is an example program | | module Main where | import Foreign | import Foreign.Ptr | import Foreign.Storable | | -- | A convenient type synonym for storable arrays | type Darr = Ptr (Double) | -- | Function type for mapping doubles to doubles | type Dfunc = Double -> Double | -- | A convenient type synonym for monad containing storable arrays | type IODarr = IO (Darr) | | | foreign import ccall "wrapper" mkDfunc :: Dfunc -> IO (FunPtr Dfunc) | foreign import ccall "cleaky.h cfunc" cfunc :: (FunPtr Dfunc) -> IO ( Double | ) | | | dadd :: Dfunc | dadd x = x + 1.0 | | getleaky :: Dfunc -> IO () | getleaky cf = do | pcf <- mkDfunc cf | -- pd <- cfunc pcf | print pcf | freeHaskellFunPtr pcf | | | main = sequence_ [getleaky dadd | q <- [1..500000]] | | | It's compiled with | ghc -fglasgow-exts -fffi -prof -auto -I. --make leaky.hs cleaky.o | | A possible cleaky.c and cleaky.h are | #include | #include | #include "cleaky.h" | | | double state = 1.0 ; | | double cfunc(DFptr fptr) | { | // printf("In cfunc, fptr: %p\n", fptr) ; | state = (*fptr) (state) ; | // printf("state: %g\n", state) ; | return(state) ; | } | | typedef double (*DFptr) (double) ; | double cfunc(DFptr) ; | | though they are not used. | | leaky.exe grows the heap linearly without bound on windows XP 64. The | profiler never reports this correctly either. | calling | leaky +RTS -hc -RTS | does not show the increase in the memory usage. | | -- | View this message in context: http://www.nabble.com/Memory-leak-in-FFI-callback%3A-GHC-6.6- | tf2565446.html#a7150757 | Sent from the Haskell - Glasgow-haskell-users mailing list archive at Nabble.com. | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users