02/08/84  define_area_


Entry points in define_area_:
   (List is generated by the help command)


:Entry: define_area_: 02/08/84  define_area_

Function: initializes a region of storage as an area and enables
special area management features.  The region being initialized may or
may not consist of an entire segment or may not even be specified at
all, in which case a segment is acquired (from the free pool of
temporary segments) for the caller.

See the release_area_ subroutine for a description of how to free up
segments acquired via this interface.


Syntax:
declare define_area_ entry (ptr, fixed bin(35));
call define_area_ (info_ptr, code);


Arguments:
info_ptr
   points to the standard area_info structure used by the various area
   management routines and is declared in area_info.incl.pl1.  (Input)
code
   is a system status code.  (Output)


Notes:  The define_area_ subroutine gives the user more control over an
area than is defined in the PL/I language.  The PL/I empty built-in
function cannot empty a define_area_ area; the release_area_ subroutine
must be used instead.  PL/I offset values and PL/I area assignment
cannot be used with extensible areas.  In PL/I, an area variable is
always initialized.  Consequently, if a based area is overlayed upon
arbitrary storage instead of being allocated with a PL/I allocate
statement, then the define_area_ subroutine must be used to turn the
contents of the based area into a PL/I area value.


                                          -----------------------------------------------------------


Historical Background

This edition of the Multics software materials and documentation is provided and donated
to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. 
as a contribution to computer science knowledge.  
This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology,
Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL
and BULL HN Information Systems Inc. to the development of this operating system. 
Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970),
renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership
of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture 
for managing computer hardware properly and for executing programs. Many subsequent operating systems 
incorporated Multics principles.
Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., 
as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. .

                                          -----------------------------------------------------------

Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without
fee is hereby granted,provided that the below copyright notice and historical background appear in all copies
and that both the copyright notice and historical background and this permission notice appear in supporting
documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining
to distribution of the programs without specific prior written permission.
    Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc.
    Copyright 2006 by BULL HN Information Systems Inc.
    Copyright 2006 by Bull SAS
    All Rights Reserved