Desktop compositor using copy-on-write semantics
US6911984B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2003 |
| Grant date | Jun 28, 2005 |
| Priority date | — |
| Expiry date | Jul 28, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/393
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Tile data for drawing and desktop buffers in a desktop compositor system is managed using “copy-on-write” semantics, in which tile data stored in a memory location is not transferred to another location until the tile data for one of the buffers is modified. For each tile in drawing buffers and desktop buffers, an association is maintained with a location in a tile memory, and the number of buffer tiles associated with each location is tracked. To copy a tile from one buffer to another, the tile association for the tile in the destination buffer is modified. New data for a tile of a buffer is written to the tile memory location associated with the buffer after ensuring that the tile memory location is not associated with any other tiles of any of the buffers. As a result, memory bandwidth can be considerably reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.