US 5,390,328 AGranted

Data processing system and method for providing notification in a central processor of state changes for shared data structure on external storage

AssigneeInternational Business Machines Corporation

InventorsJeffrey A. Frey, Audrey A. Helffrich, Jeffrey M. Nick, Michael D. Swanson

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Abstract

Two or more user applications executing on one or more processors, each controlled by an operating system, share use of a list structure within a Structured External Storage (SES) facility to which each processor is connected. One of the applications registers interest in particular state transitions affecting one or more lists within the list structure, causing a process within the SES to notify the appropriate processor when a list operation causes the particular state transition, without interrupting processing on the processor. The application receives notice of the state transition by periodically polling a vector within the processor, or by receiving control when a test by the operating system of a summary indicator for the vector causes an application exit to be driven.

Claims22

Dependent claims

An apparatus for managing one or more list data structures each comprising one or more list entries, within a Structured External Storage (SES) facility in a data processing system, said apparatus comprising,

(a) one or more Central Processor Complexes (CPC's) each comprising a processing unit and main storage, each said CPC capable of executing one or more user processes;
(b) said Structured External Storage (SES) facility coupled to each of the one or more CPC's;
(c) communication means for communicating List Function requests by one or more user processes between one of said one or more CPC's and said SES;
(d) detection means in said SES, responsive to said list function requests, for detecting a state change for one of said one or more list data structures Caused by performance of said list function requests;
(e) registration means in said SES for registering interest of one of said user processes, executing on a particular one of said one or more CPC's, in said state change for a set of said one or more list data structures by associating an identifier of of a first process of said one or more user processes with a notification field with each list data structure in said set and transmitting a registration message comprising a process identified, a list identifier , and a vector means entry identifier to a registration process in said SES;
(f) means in said SES utilizing Said registration message for communicating said state change notification from said SES to said particular one of said one or more CPC's over said communication means, and means in said particular one of said one or more CPC's receiving said state change notification for directly updating said notification field to indicate that said state change has occurred.

3 more elements

A computer implemented method for notification of a first data processing (DP) system, on which a first process is executing, that a list, comprising one or more list entries, in a list structure in a structured external storage (SES) unit has undergone s state transition because of performance of a list function on said list at request of a second process in a second DP system, said method comprising the steps of:

(a) said first process registering interest in said state transition for said list in said SES by causing the association of an identifier of a said first user process with a notification field, within said first DP system, with said list;
and transmitting a registration message comprising a process identified, a list identifier, and a vector means entry identifier to a registration process in said SES;
(b) said second process initiating said list function on said list;
(c) detection means in said SES, initiate by said list function, detecting said state change caused by performance of said list function, utilizing said registration message for identifying said first process as having registered interest, and sending a notification to said first DP system;
(d) notification vector means in said first DP system receiving said notification from said detection means by updating said notification field by a direct update of said notification field to indicate said state change occurred.

2 more elements

Dependencies are inferred from the claim text.