07/07/75  Static Handlers

A new feature has been added to the system which improves the system's
performance with respect to its handling of certain user-ring system
conditions. The user-interface change externally visible is in the signalling
of certain system events. In particular, "alrm" and "cput" are no longer
signalled, but are rather handled directly by system code. Similarly, there is
a change in the signalling of "no_write_permission" and "not_in_write_bracket"
such that these, also are not signalled IF THE SEGMENT CAUSING THE CONDITION TO
BE RAISED HAS ITS COPY SWITCH ON (type "help copy_on_write").
  Handlers for "cput" and "alrm" used to be established in the process overseer
of a process. This reuqired users wishing to write their own process overseer
to know that this was necessary. This strategy has changed such that the
"real_init_admin" program for a process takes on this task thereby relieving
writers of process overseer programs from knowing about this special process
(ring) initialization requirement.
  Process overseers that establish timer_manager_ as the handler for "cput" and
"alrm" will continue to work although this effort is no longer necessary and
indeed ignored. If a process overseer establishes any other procedure as the
handler for these conditions, this no longer works in the same fashion.


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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