I'm pulling my hair out fixing a memory leak in an OpenGL program.
Don't know if this is related to OpenGL, but I've not gotten any
takers from IRC. I know the exact line of code that's causing it.
I have a draw function as follows:
draw :: Int -> State -> IO ()
draw autoexit state = do
clear [ ColorBuffer, DepthBuffer ]
-- Configure camera and scaling
loadIdentity
setView state
-- Render Cells and iterate
c <- get $ cells state
forM_ c (renderCell state)
c' <- iter c
-- ==== MEMORY LEAK LIKE A SIEVE HERE ON THIS NEXT LINE
(cells state) $=! c'
swapBuffers
-------------
The state is defined as follows:
data State = State {
frames :: IORef Int,
t0 :: IORef Int,
eyex :: IORef GLdouble,
eyey :: IORef GLdouble,
eyez :: IORef GLdouble,
sphereList :: DisplayList,
cells :: IORef Population
}
And the iter function type is as follows:
iter :: Population -> IO Population
The only reason the IO is required is there is a random component and
I'm using the random number generator in the IO space. If I comment
out the one line mentioned above, there is no memory leak. The only
other references to the cells is in the initialization which creates
the first batch.
garbett:levy-gen garbetsp$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 6.10.1
cabal list output:
* OpenGL
Latest version available: 2.2.1.1
Latest version installed: 2.2.1.1
It looks like the old data that's in the IORef is never freed. Why
would this be occurring? Is there a compile flag that would fix this?
How can I force the garbage collection to free that memory?
My alternative is to use C/C++, and I really really don't want to do
that.
Shawn Garbett