"lost device memory reference" when using accessing size of array when reshaping

[meric]

test2 - when reshaping the array and finding size of array at the same time, fails with "lost device memory reference" error.

test2 is successful when using Data.Array.Accelerate.Interpreter instead.

module Test where
import Data.Array.Accelerate as Acc
import Data.Array.Accelerate.CUDA
import Debug.Trace

-- Exp a -> a
fromExp :: (Elt a) => Exp a -> a
fromExp x = (toList(run $ unit $ x))!!0

arr = use$fromList(fromExp (index1 4)) ([1, 3, 5, 7]::[Int])

first len = fromExp $ (reshape (index1 len) arr) ! (index1 0)

test0 = 4 == (fromExp $ size arr) -- Success, returns True
test1 = first (4::Exp Int) -- Success, returns 1
test2 = first (size arr::Exp Int) -- Failure, "lost device memory reference", expected return 1
test3 = first (lift $ fromExp $ size arr::Exp Int) -- Success, returns 1

[tmcdonell]

Hi meric,

I'm currently overseas, but will look into it once I get back. This problem has come up before in other contexts, but hopefully this will help me narrow down the problem. Thanks a lot for the minimal test case!!

-T

[tmcdonell]

so this is actually fixed now, since I have switched to using finalisers for memory management instead of explicit reference counting. but... this work hasn't been merged from my fork into the main repo yet, so I'll leave this open until we get a new hackage release out.

[mchakravarty]

Since we merged @tmcdonell and my branch, this issue should now be resolved.