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:
Aug. 08, 2000
Filed:
Apr. 23, 1997
Ole Agesen, Franklin, MA (US);
Steve Heller, Chelmsford, MA (US);
Michael O'Connor, Union City, CA (US);
Guy Steele, Lexington, MA (US);
Marc Tremblay, Palo Alto, CA (US);
Sun Microsystems, Inc., Palo Alto, CA (US);
Abstract
In computer systems which do not inherently distinguish between references and primitive values within a program stack a method and apparatus to assist exact garbage collection techniques utilizes a stack tag cache which operates in conjunction with a program stack and supplies a tag item for every entry in the process stack. The value of a tag item indicates whether the stack entry is either a reference to another memory location or a primitive value, i.e. integer or floating point number. The arrangements and values of the tag items are correlated with changes to the program stack. The stack tag cache includes facilities for swapping the contents of the cache in the event of a trap or context switch, as well as means for redundantly verifying the tag value with intended instruction operand types.