Determining whether a Java object has been scan-missed by a garbage collector scan

摘要

A Java object is scan-missed during the mark phase of a garbage collection cycle. A list of any unscanned objects, comprising all objects of a particular object type, is created during a sweep phase of the garbage collection cycle. After the garbage collection cycle is completed, and the application resumes, for every PUTFIELD/GETFIELD operation on the object type that is part of a specific parent object, a comparison is made with the relevant information in the unscanned objects list. A scan-miss is identified by determining whether the current object being referenced by the application is a part of the unscanned object list that has been created during the sweep phase of the garbage collection cycle.