Eliminating synchronization between sweep and allocate in a concurrent garbage collector

摘要

A computer-implemented method for eliminating synchronization between sweep and allocate in respect of a newly created object in a concurrent garbage collector for a heap implemented in shared memory having mark and sweep phases. In a first collection cycle, a first attribute is associated with objects believed to be reachable and a second attribute is associated with objects believed to be unreachable, whilst for each successive collection cycle, the roles of the first and second attributes are exchanged. In accordance with conventional mark-sweep garbage collectors, the attribute is a colour: usually Black and White for objects which are believed to be reachable and unreachable, respectively. Exchanging the colours for each collection cycle eliminates the overhead in synchronising the colour marking of a new object depending on whether it is located in an area of the heap that has already been swept or has yet to be swept.