Abstract: Clustering related objects in a region-based garbage collector is solved by associating one or more regions with each cluster, and allocating objects from a region belonging to the primary cluster for the object. Relatedness may refer to, e.g., proximity to a cluster center (such as topic) in a persistent knowledge base or a home node in a distributed object system. The cluster for an object may be determined, e.g., from reachability from particular roots or objects during global tracing. For new objects, the initial cluster may be guessed based on history of where objects allocated in that call site have recently been clustered (possibly several stack frames deep).

Abstract: A method of efficiently allocating space for copied objects during garbage collection by grouping many objects together, and after determining which objects belong to a group, allocating space for them in one unit and copying the objects to the allocated space (possibly in parallel).

Abstract: A method for exactly tracking the amount of free space in an independently collectable memory region is described. This enables more accurate decisions about the utility of collecting each individual region. The method uses zombie multiobjects (special multiobject descriptors denoting inaccessible space) to track which inaccessible areas have already been added to a region's free space counters.

Abstract: Attached and detached subordinate multiobjects provide a means for managing references to within multiobjects in multiobject-based garbage collection (multiobjects are basically linearized trees of objects that are treated as a single unit in various garbage collection operations). Attached subordinate multiobjects provide an efficient means for dealing with transient references from registers, local variables and short-lived data structures, and detached subordinate multiobjects are created when the link connecting an attached subordinate multiobject to its containing multiobject is severed by a write to the data structure.

Abstract: A fast data compression method approximating dynamic Huffman coding for applications with exteremely large data sets is disclosed. The method includes periodic regeneration of the Huffman coding tables and use of precomputed information to speed up encoding and decoding.

Abstract: A configurable object graph traversal component with redirection capability for use in garbage collectors and other related applications. The component may be implemented in either hardware or in software, and provides an interface that allows reuse of the same component for the various traversal tasks performed during garbage collection. The interface supports redirecting traversal to new copies of moved objects, updating referring cells, performing cycle detection efficiently, and in some embodiments also supports selecting the direction of traversal, handling exits from the traversed memory region specially, and providing access to the old address of copied cells.

Abstract: Parallel garbage collection, tracing, copying, and/or serialization of source memory areas is achieved without per-object synchronization instructions by dividing a source memory area into non-overlapping partitions, accessing each partition by only one thread at a time, and using a combination of global and thread-local data structures to minimize synchronization overhead and maximize achievable parallelism, while providing a full solution for handling pointers that cross partition boundaries.

Abstract: A method of encoding data structures using compressed object encodings during serialization. A compressed representation of the data is generated directly while encoding. Serialization means converting a data structure to a string of bytes for external storage or communication.

Abstract: A method for serializing cyclic or shared data structures using information from the garbage collector to determine that some objects in the data structure being serialized cannot have more than one reference.

Abstract: A fast data compression method approximating dynamic Huffman coding for applications with exteremely large data sets is disclosed. The method includes periodic regeneration of the Huffman coding tables and use of precomputed information to speed up encoding and decoding.

Abstract: A method and computer system for determining the memory address range of a subtree of a linearized tree of objects or the original version of such tree when the tree has been modified or is concurrently being modified by other threads. The primary application of the method is in garbage collection for multiprocessor shared memory computers with very large memories, but it is also relevant for a number of other applications.

Abstract: Computer system, method and article of manufacture for garbage collection in computer systems that combines individual objects into linearized trees called multiobjects and thereafter utilizes multiobjects to implement most memory management operations such as detection of dead objects and compaction without the need to inspect individual objects, thereby improving performance and reducing power consumption.

Abstract: Copying or compacting performance in garbage collection is improved by copying a first memory area (preferably comprising multiple objects) to a second memory area without traversing individual objects in the copied memory area and adjusting all copied memory locations identified as pointers in a metadata data structure. An entire linearized subgraph of the object graph can be copied at a time.