Browse Prior Art Database

Logical Full Duplex CLOSE

IP.com Disclosure Number: IPCOM000061285D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 5 page(s) / 97K

Publishing Venue

IBM

Related People

Heidt, DD: AUTHOR [+4]

Abstract

A Full Duplex Close of a connection in a computing system between two processors may be initiated by either process using the connection. There are no restrictions concerning which side may initiate the close. When a close is initiated, the connection is driven through a series of states on each side of the connection that insures: . once the close is initiated, no further work requests may be started by the processes on either side of the connection, and . all work in progress (at the time the close is initiated) is completed, either normally or abnormally, before shutting down the connection. A Connection Manager is defined and exists on both sides of the full duplex connection. Its role is to drive the connection through the series of close states.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 30% of the total text.

Page 1 of 5

Logical Full Duplex CLOSE

A Full Duplex Close of a connection in a computing system between two processors may be initiated by either process using the connection. There are no restrictions concerning which side may initiate the close. When a close is initiated, the connection is driven through a series of states on each side of the connection that insures: . once the close is initiated, no further work requests may be started by the processes on either side of the connection, and
. all work in progress (at the time the close is initiated) is completed, either normally or abnormally, before shutting down the connection. A Connection Manager is defined and exists on both sides of the full duplex connection. Its role is to drive the connection through the series of close states. A sequence of flows on a "management" connection between the Connection Managers provides the inputs that result in state changes. These flows are defined as work requests and responses to those work requests. Fig. 1 portrays the procedure for effecting a full duplex close: 1. Process Px issues "close" to initiate the takedown of connection Z. 2. A sequence of Connection Manager work requests and responses flow on the management connection to effect the close. 3. The sequence of flows are the inputs that drive the connection through the close states. 4. A "Close Notification" indication is presented by the Connection Manager to the process that is the target of the close. Process Py is the target of the close. "Close Notification" tells the target process that the takedown of the connection is in progress. No further work is permitted on the connection. 5. A "Close Complete" indication is presented to both the source and target processes.

"Close Complete" tells both processes that the takedown of the connection is completed. Work requests and responses for closing a connection are sent between the Connection Managers on the management connection: CONNECTION MANAGEMENT WORK REQUESTS AND RESPONSES FOR
CLOSE . Close Notification Request Sent from the source Connection Manager to the target Connection Manager when a close is issued for a connection. Indicates to the target Connection Manager that a close is being initiated and identifies the connection being closed. .

Close Notification Response Sent from the target Connection Manager to the source Connection Manager; indicates confirmation of the arrival of the close notification request. . Close Complete Request Sent from the source Connection manager to the source Connection manager when no work requests from Py to Px are outstanding on the connection being closed. Sent in response to the Close Complete Request. Indicates confirmation of the arrival of the Close Complete Request. CLOSE CONNECTION STATES In the descriptions of the states below, the following terms are used: . Source Connection Manager - The connection management function at the source of the close being issued. . Target Connection Manager - The...