Arjan van IJzendoorn wrote:
I couldn't get finalisers to work either with the newForeignPtr from this module. I didn't know how to create a proper FunPtr. In Foreign.Concurrent there is a newForeignPtr that is easier to use: [deleted]
I seem to remeber running in to this problem a couple of years ago, and if I remember correctly, I came to the conclusion that finalizers do run at the end of the program, but *after* standard input is closed. However, I don't remember anymore how I came to this conclusion :) I did manage to find some evidence in favour of this though. The following is your program with a finalizer that is observable in other means than printing to standard output. It simply prints somethig to a file. {-# OPTIONS -fglasgow-exts #-} module Main where import Foreign.Ptr import Foreign.ForeignPtr hiding (newForeignPtr) import Foreign.Marshal.Alloc import Foreign.Concurrent import System.Mem myFinalizer = do writeFile "apa" "fisk" putStrLn "My finalizer" subproc = do (ptr :: Ptr Int) <- malloc finptr <- newForeignPtr ptr myFinalizer putStrLn "End of subproc" main = do subproc putStrLn "End of program" This is what happens: nik@csmisc79:~/tmp> ghc --make final.hs -o final Chasing modules from: final.hs Compiling Main ( final.hs, ./final.o ) Linking ... nik@csmisc79:~/tmp> ls final final.hs final.o Main.hi nik@csmisc79:~/tmp> ./final End of subproc End of program nik@csmisc79:~/tmp> ls apa final final.hs final.o Main.hi We can see that the finalizer was run because the file was created, but nothing was printed to the screen. BTW, I'm using ghc 6.0.1 /Niklas