Patent · US Expired

Asynchronous garbage collection

US5355483A · kind A · utility

95Cited by
18References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 18, 1991
Grant dateOct 11, 1994
Priority date
Expiry dateJul 18, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2212/702
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

The present invention consists of a new type of garbage collector, one that runs in a different process being scanned. With this method, the process being collected communicates its memory state ("a memory snapshot") to a garbage collecting process (GC), and the GC process scans the memory and sends back the information about garbage. As a result, the present invention permits garbage collection to be performed asynchronously. The process being scanned for garbage is interrupted only briefly, to obtain the memory snapshot. The process then runs without interruption while the garbage collection is being performed. The present invention makes the assumption that if an object is garbage at the time of the memory snapshot it remains garbage any time later, since new pointers to that object cannot be created during asynchronous collection. The method further considers the case where the results of a cache computation is a collectable object itself. The method includes keeping a list while a collection is in progress of all the objects being given away from the cache. When an object is received as garbage from the GC, it is only freed if it is not on the list. The garbage collecting proc…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.