01/24/83  compute_common_aim_ceiling_


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


:Entry: compute_common_aim_ceiling_: 01/19/83  compute_common_aim_ceiling_


Function: computes the maximum authorization or access class which is
in common between two Multics systems given the definitions of their
AIM attributes.


Syntax:
declare compute_common_aim_ceiling_ entry (ptr, bit(72) aligned, ptr,
     bit(72) aligned, fixed bin(35));
call compute_common_aim_ceiling_ (aim_attributes_1_ptr,
     common_ceiling_1, aim_attributes_2_ptr, common_ceiling_2, code);


Arguments:
aim_attributes_1_ptr
   is a pointer to the aim_attributes structure defining the AIM
   attributes of the first system.  (Input) This structure is declared
   in aim_attributes.incl.pl1.
common_ceiling_1
   is set to the maximum authorization or access class in common
   between the two systems in terms of the AIM attributes of the first
   system.  (Output)
aim_attributes_2_ptr
   is a pointer to the aim_attributes structure defining the AIM
   attributes of the second system.  (Input)


common_ceiling_1
   is set to the maximum authorization or access class in common
   between the two systems in terms of the AIM attributes of the second
   system.  (Output)
code
   is a standard system status code.  (Output) It can be one of the
   following:
   0
      the common access ceiling was successfully computed.
   error_table_$unimplemented_version
      one of the aim_attributes structures supplied by the caller was
      of a version not supported by this procedure.
   error_table_$ai_no_common_max
      there is no set of AIM attributes in common between the two
      systems.


Notes: See the description of the get_system_aim_attributes_
subroutine for a definition of the aim_attributes structure.

See the Programmers' Reference Manual for a definition of common access
ceiling.


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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. .

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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