/* BEGIN INCLUDE FILE: dm_ci_header.incl.pl1 */ /* DESCRIPTION: This include file contains various structures which make up the header and trailer of a control interval. **** NOTE: The include file dm_ci.incl.pl1 is heavily dependent **** **** on this include file. When changing this include file, **** **** check dm_ci.incl.pl1 to see if it is affected. **** */ /* HISTORY: Written by Jeffrey D. Ives, 03/02/82. (Design by Andre Bensoussan and Jeffrey D. Ives) Modified: 11/02/84 by Matthew Pierret: Re-organized so that dm_ci.incl.pl1 and dm_ci_header.incl.pl1 do not duplicate structures or constants. */ /* format: style2,ind3 */ /* ci_header is the first four words of a control interval. Its contents are used to verify that a control interval is in an expected format, to identify the control interval and the file to which the control interval belongs, and to maintain information for the synchronization of disk I/O between DM file control intervals and associated before journal control intervals. The first two words are the time stamp for synchronization; the latter two identify the control interval. */ dcl ci_header_ptr ptr; dcl 1 ci_header aligned based (ci_header_ptr), 2 stamp like ci_stamp, 2 id like ci_id; /* ci_trailer is the last two words of a control interval and must match the first two words (ci_header.stamp). */ dcl ci_trailer_ptr ptr; dcl 1 ci_trailer like ci_header.stamp aligned based (ci_trailer_ptr); /* ci_stamp is a two-word date/time modified stamp, consisting of: version: a 9-bit version string for the structure bj_idx: before journal index for I/O synchronization time_modified: Multics clock time of last modification */ dcl 1 ci_stamp aligned based, 3 version bit (9) unal, 3 bj_idx fixed bin (9) uns unal, 3 time_modified fixed bin (53) unal; dcl CI_HEADER_STAMP_VERSION_1 bit (9) aligned static options (constant) init ("641"b3); /* ci_id is a two-word identification of the control interval, which rarely changes and consists of: uid: DM file unique identifier size_code: the control interval size in bytes, in an encoded form (see ci_size_code below). num: the control interval number. 0 is the number of the first control interval of a file. */ dcl 1 ci_id aligned based, 3 uid bit (36), 3 size_code bit (9) unal, 3 num fixed bin (27) uns unal; /* ci_size_code is the structure which defines the content of ci_id.size_code. The size in bytes of a control interval is equal to (2 ** ci_size_code.exponent * (64 + 8 * ci_size_code.addon)). */ dcl 1 ci_size_code aligned based, 2 exponent fixed bin (6) uns unal, 2 addon fixed bin (3) uns unal; /* ci_header_chunks is a structure which can be used to update the ci_stamp or ci_id in one memory cycle. */ dcl 1 ci_header_chunks aligned based (ci_header_ptr), 2 stamp fixed bin (71), 2 id fixed bin (71); /* ci_trailer_chunk is a structure which can e used to update the ci_trailer in one memory cycle. */ dcl 1 ci_trailer_chunk aligned based, 2 stamp fixed bin (71); /* END INCLUDE FILE: dm_ci_header.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 */