ASSERTIONS ABOUT PAST AND FUTURE IN HIGHWAYS - GLOBAL FLUSH BROADCAST AND FLUSH-VECTOR-TIME

Highways is a high-performance distributed-programming toolkit. The suite of broadcast primitives implemented in Highways, called Global-Flush Broadcast Primitives (GFBCASTs), is an alternative to the CBCAST primitive of ISIS. GFBCASTs permit making an assertion about messages broadcasted in the past of broadcasting m, in the future of broadcasting m, about both, or neither. In this paper, we define GFBCASTs. We also define flush-vector time, which is preferable to vector time because it has additional applications, e.g. in implementing GFBCASTs. Using flush-vector time, we give a simple implementation of GFBCASTs at costs comparable to the most lightweight implementation of CBCAST.