[Haskell-cafe] Compiled program using OpenGL fails to trigger GPU switch on Mac, but works in GHCi

[Albert Y. C. Lai]

On 13-03-18 09:19 AM, Jesper Särnesjö wrote:
> Interestingly, running the program in GHCi with the -fno-ghci-sandbox
> flag, causes it to misbehave in the same way as when compiled:

Then perhaps to mimic default ghci in hope of getting good results:

- compile with -threaded (more candidly, link with -threaded, it does 
not change code generation)

- in the program, deliberately move the work to a forkIO-thread

(I suggest forkIO instead of forkOS because I have just tried:

$ ghci
GHCi, version 7.4.2: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> Control.Concurrent.isCurrentThreadBound
False

$ ghci -fno-ghci-sandbox
GHCi, version 7.4.2: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> Control.Concurrent.isCurrentThreadBound
True

Although, perhaps it doesn't matter.)