02/13/84 ring_zero_peek_ The ring_zero_peek_ subroutine is used to copy information out of an inner ring segment. The user must have access to either the phcs_ gate or the metering_ring_zero_peek_ gate in order to use any of the entry points in this subroutine. The phcs_ gate allows unrestricted access to all inner ring segments; metering_ring_zero_peek_ allows the user to examine specifically those data bases that are useful for metering the system. The program chooses the appropriate gate depending on the user's access and the segments being examined. Entry points in ring_zero_peek_: (List is generated by the help command) :Entry: ring_zero_peek_: 02/13/84 ring_zero_peek_ Function: copies information out of a segment in the Multics supervisor, given a pointer to it. Syntax: declare ring_zero_peek_ entry (ptr, ptr, fixed bin(19), fixed bin(35)); call ring_zero_peek_ (ptr0, ptr_user, nwords, code); Arguments: ptr0 is a pointer to the data in ring 0 that is to be copied out. (Input) ptr_user is a pointer to the region in the user's address space where the data is to be copied. (Input) nwords is the number of words to be copied. (Input) code is the standard status code that is nonzero if the user did not have access to the requested data. (Output) :Entry: by_definition: 02/13/84 ring_zero_peek_$by_definition Function: copies information out of a named segment in the Multics supervisor, starting at a named symbol. It is like ring_zero_peek_$by_name, except that the copying is done from the specified definition, rather than from the base of the segment. Syntax: declare ring_zero_peek_$by_definition entry (char(*), char(*), fixed bin(18), pointer, fixed bin(19), fixed bin(35)); call ring_zero_peek_$by_definition (segment_name, symbol_name, offset, ptr_user, word_count, code); Arguments: segment_name is the name of the supervisor segment from which words are to be copied. (Input). It cannot be a pathname. symbol_name is the name of the external symbol in the specified segment at which copying is to start. (Input) offset is the offset from the specified definition at which copying is to start. (Input). It can be specified as zero to cause copying to start at the specified definition. ptr_user is a pointer to the area in the outer ring where the data is to be copied. (Input) word_count is the number of words to be copied. (Input) code is a standard status code. (Output). It is nonzero if the segment cannot be found, if the specified external symbol does not exist or is ambiguous, or if the user does not have sufficient access to copy the requested data. Notes: This entry point can be used to avoid a call to ring0_get_. For examining segments in the supervisor, this entry point and the by_name entry point are recommended because they are much simpler to use than ring0_get_, and they are only minimally less efficient. Generally, it is nearly as efficient to use this entry point as it is to save static pointers to inner ring objects. :Entry: by_name: 02/13/84 ring_zero_peek_$by_name Function: copies information out of a named segment in the Multics supervisor. It is like ring_zero_peek_, except that the name of the ring zero segment is provided, rather than a pointer to it. Syntax: declare ring_zero_peek_$by_name entry (char(*), fixed bin(18), pointer, fixed bin(19), fixed bin(35)); call ring_zero_peek_$by_name (segment_name, offset, copy_ptr, word_count, code); Arguments: segment_name is the name of the supervisor segment from which data is to be copied. It cannot be a pathname. (Input) offset is the offset from the beginning of the segment at which copying is to start. (Input). It can be specified as zero to cause copying to start from the base of the segment. copy_ptr is a pointer to the area in the outer ring where the data is to be copied. (Input) word_count is the number of words to be copied. (Input) code is a standard status code. (Output). It is nonzero if the segment cannot be found, or if the user does not have sufficient access to copy the requested data from it. Notes: This entry point can be used to avoid a call to ring0_get_. For examining segments in the supervisor, this entry point and the by_definition entry point are recommended because they are much simpler to use than ring0_get_, and they are only minimally less efficient. Generally, it is nearly as efficient to use this entry point as it is to save static pointers to inner ring objects. :Entry: get_max_length: 02/13/84 ring_zero_peek_$get_max_length Function: determines the maximum length of a named ring zero segment. Syntax: declare ring_zero_peek_$get_max_length entry (char(*), fixed bin(19), fixed bin(35)); call ring_zero_peek_$get_max_length (seg_name, max_length, code); Arguments: seg_name is the name of the ring zero segment. (Input) max_length is the maximum length (in words) of the segment. (Output) code is a standard status code. (Output). It is nonzero if the user does not have sufficient access to copy the requested data, or if the segment does not exist. :Entry: get_max_length_ptr: 02/13/84 ring_zero_peek_$get_max_length_ptr Function: determines the maximum length of a specified segment by examining its SDW. The user must have sufficient access to examine the SDW for the segment. Syntax: declare ring_zero_peek_$get_max_length_ptr entry (pointer, fixed bin(19), fixed bin(35)); call ring_zero_peek_$get_max_length_ptr (seg_ptr, max_length, code); Arguments: seg_ptr is a pointer to the segment for which the max length is to be returned. (Input). If the segment is not active at the time of the call, the user must have sufficient access to reference the segment, and this reference causes a segment fault. max_length is the maximum length (in words) of the segment. (Output) code is a standard status code. (Output). It is nonzero if the user does not have sufficient access to copy the requested data, or if the segment does not exist. ----------------------------------------------------------- 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