Methods and apparatus for avoidance of remote display packet buffer overflow

• US 20040042476A1
• Filed: 08/30/2002
• Published: 03/04/2004
• Est. Priority Date: 08/30/2002
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Peacock, John Kent
• Granted Patent: US 7,269,136 B2
• Time in Patent Office: Days
• US Class Current: 370/412
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/16 Threshold monitoring

Abstract

The present invention manages memory buffers in a computer network system. In one embodiment, a managing system on a thin client unit modifies an amount of central processing unit (CPU) resource on the thin client unit that is granted to a server application (e.g., a X server application). The modification is based on a function of how many network information packets are in a packet queue of the thin client unit. By dropping the amount of CPU resource granted lower and lower as the queue gets more and more full, the server application reduces the rate at which it sends commands, thus giving the thin client unit the opportunity to catch up in processing the commands already in the queue. When the number of packets in the queue passes a high critical threshold, the granted CPU resource is dropped to zero, effectively shutting off the server application. Accordingly, the above embodiment makes sure that the thin client unit is kept as busy as possible because the throttling of the granted CPU resource occurs only when there is an overabundance of work waiting to be done, and the embodiment avoids packet queue overflow by slowing down and eventually stopping the flow of packets from the server application to the thin client unit.

Claims

1. A computer network system for managing memory buffers comprising:

a network;

a first module for receiving a data packet from said network;

a second module for transmitting said data packet to said first module over said network;

a processor connected with said first module and having an amount of resource for processing said data packet;

a memory device associated with said first module and having an amount of space available for storing data packets before processing by said processor;

a managing system associated with said memory device;

wherein said managing system allocates said amount of resource for processing said data packet.

2. The computer network system of claim 1, wherein said managing system determines said amount of resource for processing said data packet by monitoring said amount of space available for storing data packets.

3. The computer network system of claim 1, wherein said managing system allocates said amount of resource for processing said data packet in proportion to said amount of space available for storing data packets.

4. The computer network system of claim 1, wherein said managing system uses a plurality of predetermined threshold levels on said amount of space available for storing data packets to determine said amount of resource for processing said data packet.

5. The computer network system of claim 1, wherein said amount of resource for processing said data packet is measured in percentage and wherein said amount of resource for processing said data packet is approximately zero percent when said amount of space available for storing data packets is greater than approximately {fraction (15/16)}^th full.

6. The computer network system of claim 1, wherein said amount of resource for processing said data packet is measured in percentage and wherein said amount of resource for processing said data packet is approximately 100 percent when said amount of space available for storing data packets is not greater than approximately ½

^th full.

7. The computer network system of claim 1, wherein said amount of resource for processing said data packet allocated by said managing system is below a fair share of resource available on said processor for processing said data packet.

8. The computer network system of claim 1, wherein said management system comprises a computer firmware located with said first module.

9. The computer network system of claim 1, wherein said first module comprises a thin client computer and wherein said second module comprises a server computer.

10. The computer network system of claim 1, wherein said second module comprises a sever application for generating said data packet.

11. The computer network system of claim 10, wherein said data packet comprises a graphics primitive.

12. The computer network system of claim 11, wherein said second module further comprises a client application, wherein said client application sends a protocol command to said server application, and wherein said graphics primitive is generated from said protocol command.

13. The computer network system of claim 12, wherein said protocol command comprises an X protocol command.

14. The computer network system of claim 12, wherein said second module further comprises a first server computer and a second server computer, wherein said client application is running on said first server computer, and wherein said server application is running on said second server computer.

15. The computer network system of claim 11, wherein said first module comprises a graphics device and wherein said graphics primitive is in a format suitable for said graphics device.

16. A method for managing memory buffers in a computer network system comprising:

monitoring an amount of storage space available on a first module;

allocating a percentage of available resource on said first module for processing graphics information from a second module based on said monitored amount of storage space;

transmitting said allocated percentage to said second module over a network; and

limiting an amount of graphics information sent from said second module over said network to said first module based on said allocated percentage.

17. The method of claim 16, wherein said allocating a percentage of available resource on said first module comprises:

allocating a first percent of available resource on said first module for processing graphics information from said second module, if said amount of storage space available is greater than a first predetermined value full; and

allocating a second percent of available resource on said first module for processing graphics information from said second module, if said amount of storage available is not greater than a second predetermined value full;

wherein said first predetermined value is greater than said second predetermined value; and

wherein said first percent is less than said second percent.

18. The method of claim 17, wherein said first predetermined value is approximately {fraction (15/16)}^th and said second predetermined value is approximately ½

^th.

19. The method of claim 18, wherein said first percent is approximately zero and wherein second percent is approximately 100.

20. The method of claim 19, wherein said allocating a percentage of available resource on said first module further comprises:

allocating approximately 25 percent of available resource on said first module for processing graphics information from said second module, if said amount of storage space available is not greater than approximately {fraction (15/16)}^th full and is greater than approximately ⅞

^th full;

allocating approximately 50 percent of available resource on said first module for processing graphics information from said second module, if said amount of storage available is not greater than approximately ⅞

^th full and is greater than ¾

^th full; and

allocating approximately 75 percent of available resource on said first module for processing graphics information from said second module, if said amount of storage available is not greater than approximately ¾

^th full and is greater than ½

^th full.

21. A computer network system for managing memory buffers comprising:

a network;

a first module for receiving graphics information from said network;

a second module for transmitting said graphics information to said first module over said network;

a processor connected with said first module and having an amount of resource for processing said graphics information; and

a managing system associated with said first module;

wherein said managing system allocates said amount of resource for processing said graphics information; and

wherein second module determines an amount of graphics information to be transmitted to said first module based on said amount of resource for processing said graphics information.

22. The computer network system of claim 21, wherein said first module also comprises an amount of space for storing said graphics information before processing by said processor and wherein said amount of resource for processing said graphics information is based on said amount of space for storing said graphics information.