Alexander -Are you wondering about why only acquire semantics?
Yes. I need release and all sort of other msync semantics. And also "naked" (no msync) atomic stuff, to begin with. In my book, op.acquire is "equivalent" to op.(hoist_load+hoist_store) and release is nothing but op.(sinkt_load+sink_store). I need less constrained atomic "op"-stuff as well. See http://tinyurl.com/xky8 and http://tinyurl.com/xky9.