Re: [Haskell-cafe] IORef memory leak

jsnow:

I'm having some trouble with excessive memory use in a program that uses a lot of IORefs. I was able to write a much simpler program which exhibits the same sort of behavior. It appears that "modifyIORef" and "writeIORef" leak memory; perhaps they keep a reference to the old value. I tried both ghc-6.8.3 and ghc-6.10.1.

Is this a known limitation, or is this a ghc bug, or am I using IORefs in the wrong way?

-jim

module Main where

import Data.IORef import Control.Monad

-- Leaks memory leakcheck1 ior = do go 1000000000 where go 0 = return () go n = do modifyIORef ior (+1) go (n-1)

It is not possible to write a modifyIORef that *doesn't* leak memory! -- Don