Browse Prior Art Database

Message Bracketing

IP.com Disclosure Number: IPCOM000120395D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Arndt, RL: AUTHOR [+3]

Abstract

Disclosed is a mechanism for allowing a computer system input or output (I/O) device to denote multiple individual variable length messages within a receive buffer. The mechanism involves placing a data structure, called a bracket, at the end of each individual message. This bracket allows the computer system software to determine the starting point and length of the message in the buffer. The bracket further points back to previous brackets (and thereby messages) in the buffer so that all messages are thereby chained. A hardware register points to the last bracket in the buffer, allowing the computer system software to find all messages that the I/O device has placed into the buffer. (Image Omitted)

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Message Bracketing

      Disclosed is a mechanism for allowing a computer system
input or output (I/O) device to denote multiple individual variable
length messages within a receive buffer.  The mechanism involves
placing a data structure, called a bracket, at the end of each
individual message.  This bracket allows the computer system software
to determine the starting point and length of the message in the
buffer.  The bracket further points back to previous brackets (and
thereby messages) in the buffer so that all messages are thereby
chained.  A hardware register points to the last bracket in the
buffer, allowing the computer system software to find all messages
that the I/O device has placed into the buffer.

                            (Image Omitted)

      There are several possible formats for brackets.  The simplest
bracket contains just a back pointer to the previous bracket.  This
would indicate to the software that the message start immediately
after the previous bracket and fills all the intervening space.  In
many computer systems it is convenient to have the bracket start on a
specific byte boundary; in these cases, the starting point of the
bracket does not indicate the end of the message, so a message length
field is added to the bracket to perform this function.  Lastly, it
may be convenient to have the message start on a specific byte
boundary; in these cases, a fixed length reserved field is added to
the message...