ms_advice() — Apollo

MS_$ADVICE                        Domain/OS                         MS_$ADVICE


NAME
     ms_$advice - advise the system on mapped object access

SYNOPSIS (C)
     #include <apollo/base.h>
     #include <apollo/ms.h>

     void ms_$advice(
          void *&address,
          unsigned long int &length,
          ms_$access_t &access,
          ms_$advice_t &options,
          unsigned long int &record_length,
          status_$t *status)

SYNOPSIS (Pascal)
     %include '/sys/ins/base.ins.pas';
     %include '/sys/ins/ms.ins.pas';

     procedure ms_$advice(
          in address: univ_ptr;
          in length: linteger;
          in access: ms_$access_t;
          in options: ms_$advice_t;
          in record_length: linteger;
          out status: status_$t);

SYNOPSIS (FORTRAN)
     %include '/sys/ins/base.ins.ftn'
     %include '/sys/ins/ms.ins.ftn'

           integer*4 length, options, record_length, status
           integer*2 access

           integer*4 address, dummy
           pointer /address/ dummy

           call ms_$advice(address, length, access, options,
          &                record_length, status)

DESCRIPTION
     This call advises the system on how a program plans to access an object.
     Although it is not required, use ms_$advice whenever the type of access
     can be predicted in advance.  A process can call ms_$advice more than
     once to change the advice for an object mapped into its address space.

     The access advice for an object is propagated across calls to ms_$addmap
     and ms_$remap; it applies to all portions of an object mapped by the cal-
     ling process.

     address
          A pointer to the object the advice is for.

     length
          The number of bytes in the mapped portion.

     access
          The method of accessing the object.  Specify one of the following
          values:

          ms_$normal
               Advice cannot be provided.  This is the default.  If a process
               never calls ms_$advice, the assumed advice is ms_$normal.

          ms_$random
               The calling process will access the object randomly.

          ms_$sequential
               The calling process will access the object sequentially.

     options
          This argument is reserved for future use.  In Pascal, pass an empty
          set in options; in C and FORTRAN, pass 0.

     record_length
          The number of bytes in a record of the mapped object.  Specify 0 if
          the record length is unknown, or if the object is not record-
          structured.

     status
          The completion status.

SEE ALSO
     ms_$attributes.
Museum
