Distributed computer system providing simultaneous access to a plurality of users

• US 5,687,317 A
• Filed: 06/05/1996
• Issued: 11/11/1997
• Est. Priority Date: 10/28/1992
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Hughes, Philip Thomas, Plant, Tony
• Primary Examiner(s): Geckil, Mehmet B.
• Application Number:
  US08/658,706
• Time in Patent Office: 524 Days
• Field of Search: 395/200.2, 395/726, 395/200.03, 395/200.04, 395/200.19, 395/200.11, 395/53, 395/331
• US Class Current: 709/205
• CPC Class Codes: G06F 11/3006 where the computing system is distributed, e.g. networked systems, clusters, multiprocessor systems multiprogramming arrangements G06F9/46; allocation of resources G06F9/50
• CPC Class Codes: G06F 11/3055 Monitoring arrangements for monitoring the status of the computing system or of the computing system component, e.g. monitoring if the computing system is on, off, available, not available error or fault processing without redundancy G06F11/0703; error detection or correction by redundancy in data representation G06F11/08; error detection or correction by redundancy in operation G06F11/14; error detection or correction by redundancy in hardware G06F11/16
• CPC Class Codes: G06F 9/451 Execution arrangements for user interfaces
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A distributed computer system is provided with a listener system interposed between the application server and the surface interfaces of the system. The listener system supervises processing of user entered commands and provides substantially simultaneous feedback of system status and progress of the system response to a command to all users. This allows system users to work simultaneously on a common document.

Claims

1. A distributed computer system adapted to provide simultaneous interactive access by a plurality of users, the system including a first computer, an application server associated with the first computer, a plurality of further computers each in communication with the first computer whereby to access the application server via the first computer and each having means including a user interface whereby to provide user access to the system so as to permit simultaneous access by more than one user to a document, and a listener system responsive to user generated events interposed between the application server and each said user interface, wherein the listener system comprises an application listener associated with the application server and a plurality of surface listeners one associated with each said user interface, wherein the application listener and surface listeners each have a first free condition and a second busy condition, wherein each said listener is responsive to both application and user events in its free condition, wherein each said surface listener has first processor means responsive to an application event or a user event at that surface listener for relaying that event to the application listener, wherein the application listener has switch means responsive to a said relayed event for switching the application listener from its free condition to its busy condition, wherein the application listener has signalling means responsive to the switching to its busy condition for sending a signal to all said surface listeners so as to cause each said surface listener to enter its busy condition and to provide to the respective further computer a message indicative of the change in condition and of the nature and origin of the event causing change in condition, wherein the application listener has second processor means responsive to the switching from its free condition to its busy condition for relaying the corresponding event to the application server for processing, for relaying the result of said processing to the originating surface listener and for resetting all surface listeners to their free condition, and wherein each said surface listener has means responsive to the change from its busy condition. to its free condition for notifying its respective further computer that said processing is completed whereby to provide substantially simultaneous indication to all system users of the status and progress of the system response to user interaction with the system and to permit a number of said users to work together on a single document and ensure that each user of said number of users is made aware of actions performed by others of said number of users.

2. A distributed computer system as claimed in claim 1, wherein the application listener has means for resetting from its busy to its free condition after a predetermined time period.

3. A distributed computer system as claimed in claim 2 and comprising a computer aided design (CAD) system.