The GASPI collectives rely on time-based blocking with a user-defined timeout. If this timeout takes the form of a mere test, the collectives perform minimal progress (e.g. completing one of the local communication phases) and then return. Hence, in order to complete the collective, the collective has to be called several times. The collectives in GASPI are thus designed to achieve a maximum of progress within the call and a minimal number of communication stages. Unless the network provides support for the collective, GASPI does not achieve progress outside of the call.
How do the asynchronous GASPI collectives work?
