The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 18, 2005
Filed:
Aug. 13, 2002
Samuel David Borman, Southsea, GB;
Andrew Dean Wharmby, Romsey, GB;
Samuel David Borman, Southsea, GB;
Andrew Dean Wharmby, Romsey, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A computer system has a heap for storing objects and a card table for tracking updates to objects on the heap, typically for garbage collection purposes. In particular, the heap is divided into segments, each corresponding to a card in the card table, and any update to a segment in the heap triggers a write barrier to mark the corresponding card in the card table. It is important that this write barrier is as efficient as possible to optimize system performance. In some circumstances an object update may be made to an address outside the heap. To ensure that this still properly maps to a card in the card table, the entire memory space is folded cyclically, so that any given memory address corresponds to one, and only one card, in the card table.