Browse Prior Art Database

Coordinating Changes to the Contents of a Collection of Objects

IP.com Disclosure Number: IPCOM000112784D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Cole, G: AUTHOR [+3]

Abstract

Disclosed is a program that coordinates changes to a collection of objects. The collection is built and maintained by a system service program. The contents can change at any time. Applications which perform services for each object in the collection must be able to determine when changes have occurred.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Coordinating Changes to the Contents of a Collection of Objects

      Disclosed is a program that coordinates changes to a collection
of objects.  The collection is built and maintained by a system
service program.  The contents can change at any time.  Applications
which perform services for each object in the collection must be able
to determine when changes have occurred.

      In this program, an application may request a list of the
objects in the collection.  When the list is delivered by the system
service, it is tagged with a revision level.  When changes occur to
the contents of the collection, the system service communicates the
changes to applications by calling an application function and
passing the change list and the revision number of the contents list
to which the change applies.

      When an application receives a change list, it compares the
revision number of the affected contents list with the last contents
list of which it was aware.  If they do not match, the application
can request a new contents list.  If they do match, then the
application can simply apply the changes to any internal contents
list which it maintains and increment its internal contents list
revision number.  In this manner, an application may determine if it
has failed to process a change to the contents of the collection of
objects.