A METHOD AND APPARATUS FOR UPDATING A GRAPHICAL DISPLAY IN A DISTRIBUTED PROCESSING ENVIRONMENT

• US 20060206820A1
• Filed: 03/14/2005
• Published: 09/14/2006
• Est. Priority Date: 03/14/2005
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Opferman, Toby, Bullard, Justin, Kasik, David J.
• Granted Patent: US 8,171,169 B2
• Time in Patent Office: Days
• US Class Current: 715/733
• CPC Class Codes: H04L 67/131 Protocols for games, networked simulations or virtual reality
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC

Abstract

A system and method for updating a display unit remotely located from a computing system are described. The method includes copying display information from a video buffer of a computing device executing an application to generate a display update, calculating a size of the display update, and determining an amount of available bandwidth of a network connecting the computing device and the display unit. The method also includes calculating a time period required to communicate the display update from the computing device to the display unit, transmitting the display update to the display; and repeating the method after the time period has elapsed.

Claims

1. A method of updating a remote display unit comprising:

(a) copying display information from a video buffer of a computing device executing an application remotely located from the display unit to generate a display update;

(b) calculating a size of the display update;

(c) determining an amount of available bandwidth of a network connecting the computing device and the display unit;

(d) calculating a time period required to communicate the display update from the computing device to the display unit;

(e) transmitting the display update to the display; and

(f) repeating steps (a)-(e) after the time period has elapsed.

2. The method of claim 1 further comprising writing display information to the video buffer by the application during at least one of the steps (b)-(e).

3. The method of claim 1 further comprising generating at least one bounding rectangle indicative of a region of change of the video buffer as part of the display update.

4. The method of claim 1 further comprising tracking an amount of change to the video buffer to determine if a high update period exists.

5. The method of claim 1 further comprising applying a lossy compression algorithm to the display update during a high update period to create a lossy display update.

6. The method of claim 5 wherein the transmitting comprises transmitting the lossy display update to the display.

7. The method of claim 6 further comprising transmitting a lossless display update to replace the lossy display update after the high update period.

8. A system for updating a display unit remotely located from a computing system comprising:

a video buffer storing display data representing graphical output of an application program executing on the computer system;

a driver determining a characteristic of a network between the computing system and the remote display unit and transmitting a signal regarding network availability; and

a thread receiving the signal and creating a display update for communication to the remote display responsive to the data stored in the video buffer.

9. The system of claim 8 wherein the signal regarding network availability includes a dynamically determined time period.

10. The system of claim 8 further comprising an update region in communication with video buffer and storing bounding rectangle information.

11. The system of claim 8 further comprising an accumulator for tracking the amount of change made to the video buffer.

12. The system of claim 11 further comprising a compressor, in communication with the driver, for compressing the display update before transmitting the display update to the remote display unit when the accumulator reaches a predetermined threshold.

13. The system of claim 8 further comprising a timer module in communication with the thread for executing the dynamically determined time period and signaling the thread to copy the local video buffer.

14. A system for updating a display unit remotely located from a computing system comprising:

buffering means for storing display data representing graphical output of an application program executing on the computer system;

driving means for communicating with a network to determine a characteristic of the network and for transmitting a signal regarding network availability; and

thread means for receiving the signal and for creating a display update for communication to the remote display unit responsive to the data stored in the buffering means.

15. The system of claim 14 further comprising storage means for storing at least one bounding rectangle information and for communicating with the buffering means.

16. The system of claim 14 further comprising compressing means for applying a lossy compression algorithm during a high update period to reduce the size of the display update prior to communication of the display update to the remote display unit.

17. The system of claim 16 further comprising cache means for caching the display update before application of the lossy compression algorithm.

18. The system of claim 14 further comprising accumulation means for tracking the amount of update to the buffering means to determine if the system is in a high update period.

19. The system of claim 14 further comprising timing means executing a dynamically determined time period in response to the thread means receiving the signal.