Writes all modified pages in an active private or global section
    back into the section file on disk. One or more I/O requests are
    queued, based on the number of pages that have been modified.

    Format

      SYS$UPDSEC  inadr ,[retadr] ,[acmode] ,[updflg] ,[efn] ,[iosb]

                  ,[astadr] ,[astprm]

    C Prototype

      int sys$updsec  (struct _va_range *inadr, struct _va_range

                      *retadr, unsigned int acmode, char updflg,

                      unsigned int efn, struct _iosb *iosb, void

                      (*astadr)(__unknown_params), int astprm);