membar

plural membars

1. systems programmingA memory barrier (an instruction that enforces an ordering constraint on memory operations issued before and after it).

   The crucial thing to remember about memory visibility is that the perceived *sequence* of two operations is not guaranteed to be the same as seen from two different threads unless membars are used to guarantee it.

   2003 September 25, Mike Mowbray, “Threads and initialization only once”, in comp.programming.threads (Usenet)