On 08 December 2005 11:52, Claus Reinke wrote:

is every MVar access is a synchronisation point (in terms of memory update propagation between threads, not just in terms of thread interaction)?

Yes, it is. On a multiprocessor every MVar operation performs a full memory barrier internally. Incedentally, GHC hasn't actually supported multiprocessors until very recently, and it's still only in CVS and very experimental. Cheers, Simon