Computer program product for a shared queue structure for data integrity

• US 5,887,168 A
• Filed: 06/02/1995
• Issued: 03/23/1999
• Est. Priority Date: 12/30/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Patterson, Betty J., Tse, Judy Y., Mansker, Janna L., Stoob, Sandra L., Vakkalagadda, Anu V., Paffendorf, Karen D., Denny, George S., Bahls, James W., Hannan, Richard G., Naylor, Bruce E.
• Primary Examiner(s): Kriess, Kevin A.
• Assistant Examiner(s): Banankhah, Majid A.
• Application Number:
  US08/460,749
• Time in Patent Office: 1,390 Days
• Field of Search: 395/250, 395/650, 395/671, 395/670, 395/672, 395/704, 395/613, 395/620, 365/221
• US Class Current: 719/314
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues

Abstract

A shared queue is provided to allow any of a plurality of systems to process messages received by clients of a data processing environment. A received message is enqueued onto the shared queue. Any of the plurality of systems having available processing capacity can retrieve the message from the shared queue and process the message. A response to the message, where appropriate, is enqueued onto the shared queue for delivery back to the client. A unique list structure is provided to implement the queue. The list structure is comprised of a plurality of sublists, or queue types. Each queue type is divided into a plurality of list headers. List entries, containing data from the received messages, are chained off of the list headers. A common queue server is used to interface to the queue and to store messages thereon. The common queue server stores message data in storage buffers, and then transfers this data to the list entries. Thus, common queue server coordinates the enqueuing of data onto the shared queue.

Claims

1. A computer program product for use with a computer system, said computer program product comprising a computer usable medium having computer readable program code means embodied in said medium for allowing one or more processing systems to process client requests, said computer readable program code means comprising:

computer readable program code means for enabling a first data processing system having a first data processing application program running thereon to submit a message for processing;

computer readable program code means for enabling one of a plurality of second data processing systems to receive said message and transmit said message for storage on a queue;

computer readable program code means for enabling one of said plurality of second data processing systems to retrieve said message from said queue and process said message via one or more data processing programs running thereon, and transmit a second message to said queue;

computer readable program code means for enabling a queue processor and shared storage device to provide communications between said plurality of second data processing systems, and to store said message in said queue in the form of a list entry, said queue comprising;

a plurality of queue types having one or more list headers, wherein said message is stored within said list entry associated with a list header associated with one of said queue types based on the type of said message,

wherein each of said one or more list headers is accessible at any given time by only one of said second data processing systems, such that said one or more list headers minimize contention for access to messages located therein.

2. The computer program product of claim 1, wherein said computer readable program code means for enabling a queue processor and shared storage device to provide communications further comprises:

computer readable program code means for enabling a list entry storage device to assign an entry key to identify said list entry and store said message in a data field thereof.

3. The computer program product of claim 2, wherein said computer readable program code means for enabling a list entry storage device to assign an entry key and store said message further comprises:

computer readable program code means for enabling chaining of said list entry to one of said list headers if there are no other list entries chained from said one of said list headers; and

computer readable program code means for enabling chaining of said list entry to a list entry having been last added to said one of said list headers if there are other list entries chained from said one of said list headers.

4. The computer program product of claim 2, wherein said computer readable program code means for enabling a list entry storage device to assign an entry key and store said message further comprises:

computer readable program code means for enabling creation of a second list entry and placement therein of a remainder of said message if said message is larger than said data field of said list entry.

5. The computer program product of claim 4, wherein said computer readable program code means for enabling a list entry storage device to assign an entry key and store said message further comprises:

computer readable program code means for enabling chaining of said second list entry from a queue type pertaining to secondary list entries.

6. The computer program product of claim 4, wherein said list entry further comprises an adjunct area for identifying said second list entry.

7. The computer program product of claim 4, further comprising:

computer readable program code means for enabling a computer to chain said second list entry from a secondary queue type list header if there are no other second list entries chained from said secondary queue type list header; and

computer readable program code means for enabling a computer to chain said second list entry from a second list entry having been last added to said secondary queue type list header if there are other second list entries chained from said secondary queue type list header.

8. The computer program product of claim 1, wherein said first data processing system is a client computer system with a processor and a RAM.

9. The computer program product of claim 1, wherein said plurality of second data processing systems are computer platforms each comprising a processor and a RAM.

10. The computer program product of claim 1, wherein said list entry comprises:

an entry key for identifying said list entry, wherein said entry key is based on a queue type assigned to said message; and

a data field for storing message data associated with said message.

11. The computer program product of claim 1, further comprising:

computer readable program code means for enabling a private queue type to lock said message if said message is being processed by one of said plurality of second data processing systems.

12. The computer program product of claim 1, further comprising:

compter readable program code means for enabling storage of said message in a plurality of buffers before thereof on said queue.