long mpiSequenceEventNotifyGet(MPISequence   sequence,
                               MPIEventMask  *eventMask,
                               void          *external) 

SequenceEventNotifyGet writes an event mask [that specifies the event types (generated by the Sequence sequence, for which host notification has been requested] to the structure pointed to by eventMask, and also writes it into the implementation-specific structure pointed to by external (if external is not NULL).

The event mask information in external is in addition to the event mask information in eventMask, i.e, the event mask information in eventMask and in external is not the same information. Note that eventMask or external can be NULL (but not both NULL).

external either points to a structure of type MEIEventMask{} or is NULL.