/* ====== BEGIN INCLUDE SEGMENT	syscon_mseg.incl.pl1 ====================================== */



/****^  HISTORY COMMENTS:
  1) change(87-09-02,Parisek), approve(87-09-03,MECR0005),
     audit(87-09-02,GDixon), install(87-09-03,MR12.1-1098):
     Increase quit_bits from 72 bits to 504 bits so more than 72 sources
     may enable quit without error. (phx20974)
                                                   END HISTORY COMMENTS */


/* Message Coordinator message segment declaration.  Each daemon process
   enqueues its messages in a segment like this one.

   The segment consists of a header followed by many message blocks,
   each  capable  of  holding  a  message  of  132  characters  plus
   information  on  when  the  message was sent, who it's from, etc.
   These blocks are "allocated" only as needed and placed on a  free
   storage list when freed.  Blocks in use are chained together in a
   first-in-first-out queue.   */

dcl  buff_len fixed bin init (132) internal static;

dcl 1 syscon_mseg aligned based,			/* This header is of length 24 dec 30 oct words */
    2 mlock bit (36) aligned,
    2 current_process_id bit (36),
    2 ipc_el,					/* mrdim_ blocks on this list for normal reads */
      3 n fixed bin,
      3 pad fixed bin,
      3 channel fixed bin (71),
    2 proto_el,					/* mrdim_ blocks on this list for attach and detach */
      3 n fixed bin,
      3 pad fixed bin,
      3 channel fixed bin (71),
    2 flags unaligned,
      3 test_mode bit (1),				/* ON if running in test environment */
      3 receiver_woken bit (1),			/* ON if wakeup sent but not received yet */
      3 unused bit (34),
    2 first_message fixed bin,			/* index of head of message chain */
    2 last_message fixed bin,				/* index of tail of message chain */
    2 first_proto fixed bin,				/* index of head of protocol chain */
    2 last_proto fixed bin,				/* index of tail of protocol chain */
    2 first_free_buffer fixed bin,			/* head of free chain */
    2 last_assigned_buffer fixed bin,			/* high water mark of buffers ever used */
    2 no_of_streams fixed bin,
    2 quit_bits bit (504),				/* used in mc.message to mark a source waiting to be quit */
    2 locked_by_pid bit (36),				/* process id of locker */
    2 mescount fixed bin,				/* Count of unprinted messages */
    2 output_wait bit (1),				/* TRUE if in output wait - mc_wakeups resets */
    2 pad fixed bin,
    2 message (1) like message_block aligned;		/* the array of messages */

dcl 1 message_block aligned based (messp),		/* 56 dec 70 oct words */
    2 time_sent fixed bin (71),
    2 from_source char (32),
    2 from_stream char (32),
    2 source_index fixed bin,				/* index in MRT */
    2 stream_index fixed bin,				/* .. */
    2 next_message fixed bin,				/* foward pointer of message chain */
    2 flags unal,
      3 continue bit (1),				/* ON if message continued in next block */
      3 introduction bit (1),				/* ON if message is an introduction */
      3 farewell bit (1),				/* ON if message is farewell */
      3 sentinel bit (1),				/* ON if special formatting wanted */
      3 trace bit (1),				/* used only by dump_msg */
      3 unused bit (31) unal,
    2 length fixed bin,				/* number of characters in body */
    2 message_body char (132);			/* text of message */

dcl 1 debug_info based aligned,
    2 flag fixed bin (71),
    2 time fixed bin (71),
    2 last_pid bit (36),
    2 first_msg fixed bin,
    2 last_msg fixed bin,
    2 first_pro fixed bin,
    2 last_pro fixed bin,
    2 free_chain fixed bin;

/* ------ END INCLUDE SEGMENT		syscon_mseg.incl.pl1 -------------------------------------- */


*/
                                          -----------------------------------------------------------


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

*/