Returns information about the local system or about other
    systems in an OpenVMS Cluster system. The $GETSYI service
    completes asynchronously; for synchronous completion, use the
    Get Systemwide Information and Wait ($GETSYIW) service.

    For additional information about system service completion, see
    the Synchronize ($SYNCH) service.

    On Alpha and Integrity server systems, this service accepts 64-
    bit addresses.

    Format

      SYS$GETSYI  [efn] ,[csidadr] ,[nodename] ,itmlst [,iosb]

                  [,astadr] [,astprm]

    C Prototype

      int sys$getsyi  (unsigned int efn, unsigned int *csidadr, void

                      *nodename, void *itmlst, struct _iosb *iosb,

                      void (*astadr)(__unknown_params), unsigned

                      __int64 astprm);