31 Jul
2012
31 Jul
'12
1:18 p.m.
On Tue, Jul 31, 2012 at 7:37 AM, Bertram Felgenhauer < bertram.felgenhauer@googlemail.com> wrote:
Note that MVar# itself cannot be unpacked -- the StgMVar record will always be a separate heap object.
One could imagine a couple of techniques to unpack the MVar# itself, and was curious if GHC might employ one of them. So, really, unpacking the MVar does not eliminate a layer of indirection, it just eliminates the need to check a pointer tag (and possibly execute a thunk or follow some redirects if you don't have a pointer to an MVar#). I think this is what I was ultimately after. Best, Leon