On 18/07/13 14:17, Ryan Newton wrote:
The "atomic-primops" library depends on symbols such as store_load_barrier and "cas", which are defined in SMP.h. Thus the result is that if the program is linked WITHOUT "-threaded", the user gets a linker error about undefined symbols.
The specific place it's used is in the 'foreign "C"' bits of this .cmm code:
https://github.com/rrnewton/haskell-lockfree-queue/blob/87e63b21b2a6c375e93c...
I'm trying to explore hacks that will enable me to pull in those functions during compile time, without duplicating a whole bunch of code from the RTS. But it's a fragile business.
It seems to me that some of these routines have general utility. In future versions of GHC, could we consider linking in those routines irrespective of "-threaded"?
We should make the non-THREADED versions EXTERN_INLINE too, so that there will be (empty) functions to call in rts/Inlines.c. Want to submit a patch? A better solution would be to make them into primops. You don't really want to be calling out to a C function to implement a memory barrier. We have this for write_barrier(), but none of the others so far. Of couse that's a larger change. Cheers, Simon