Abstract: A computer-implementable method, system and apparatus. The frequency of reference to an object, also known as “hotness,” can be collected as a part of a profiling phase during a runtime operation of data-processing system by permitting each reference to the object during the runtime operation to randomly guess a predetermined value associated with the object, such that a correct guess thereof implies that the object is referenced frequently. Thereafter, the frequency of reference to the object can be validated by identifying a particular value in a header associated with the object, in response to collecting the frequency of reference to the object during the profiling phase, thereby increasing the scalability and efficiency of the runtime operation while permitting data associated with the frequency of reference to the object to other applications for immediate use.

Abstract: An illustrative embodiment of a computer-implemented process for dynamic measurement and adaptation of a parallel copying garbage collector initializes values and data structures, receives an evacuate set, determines whether a new copy block is required and responsive to a determination that a new copy block is required, calculates a size of the new copy block. The computer-implemented process further selects a survivor region from a list of survivor regions to form a selected survivor region, places a lock on the selected survivor region, identifies a number of threads enqueued on the selected survivor region, responsive to a determination that a contention value exceeds a predetermined value, increases a size of the list of survivor regions, evacuates blocks to the selected survivor region and responsive to a determination that more evacuate blocks do not exist, terminates.

Abstract: An operating system or virtual machine of an information handling system (IHS) initializes a garbage collector to provide object memory compaction during application execution. The operating system or virtual machine performs move and fixup management within heap or object memory stores. The garbage collector identifies holes or unused portions of heap memory and moves one or more objects during compaction operations. After the garbage collector moves the object, a fixup cache tool fixes up the object pointers within the object. The fixup cache tool maintains a fixup cache that includes pointer information corresponding to the objects that the garbage collector moves. The fixup cache tool employs the pointer information within the fixup cache to update or otherwise fixup the objects within the heap that the garbage collector moves during compaction operations. The fixup cache may provide predictive pointer update information during fixup operations for each object move within the heap.

Abstract: A technique for incrementally unloading classes using a region-based garbage collector is described. One aspect of such a technique includes maintaining a remembered set for a class set. The remembered set indicates whether instances of the class set are contained in one or more regions in memory, and in which regions the instances are contained. Upon performing an incremental garbage collection process for a subset of the regions in memory, the technique examines the remembered set to determine whether the class set includes instances in regions outside of the subset. If the remembered set indicates that the class set includes instances outside of the subset of regions, the technique identifies the class set as “live.” This will preclude unloading the class set from the subset of regions.

Abstract: A technique for incrementally unloading classes using a region-based garbage collector is described. One aspect of such a technique includes maintaining a remembered set for a class set. The remembered set indicates whether instances of the class set are contained in one or more regions in memory, and in which regions the instances are contained. Upon performing an incremental garbage collection process for a subset of the regions in memory, the technique examines the remembered set to determine whether the class set includes instances in regions outside of the subset. If the remembered set indicates that the class set includes instances outside of the subset of regions, the technique identifies the class set as “live.” This will preclude unloading the class set from the subset of regions.

Abstract: A technique for incrementally unloading classes using a region-based garbage collector is described. One aspect of such a technique includes maintaining a remembered set for a class set. The remembered set indicates whether instances of the class set are contained in one or more regions in memory, and in which regions the instances are contained. Upon performing an incremental garbage collection process for a subset of the regions in memory, the technique examines the remembered set to determine whether the class set includes instances in regions outside of the subset. If the remembered set indicates that the class set includes instances outside of the subset of regions, the technique identifies the class set as “live.” This will preclude unloading the class set from the subset of regions.

Abstract: An illustrative embodiment of a computer-implemented process for single pass marking of finalizable objects marks strong roots, marks finalizable roots and determines whether a strong work stack is empty. Responsive to a determination the strong work stack is empty the computer-implemented process determines whether a finalizable work stack is empty. Responsive to a determination the finalizable work stack is empty, synchronize threads, the computer-implemented process finalizes finalizable roots and merges mark maps to finish parallel marking.

Abstract: A method for efficiently implementing a remembered set for a region-based garbage collector includes maintaining, for each region in an object heap, a remembered set card list (RSCL). Each card in the RSCL identifies an area in the object heap that includes at least one object that references an object in the region associated with the RSCL. The method further establishes a collection set identifying a subset of regions in the object heap on which to perform partial garbage collection. Prior to performing the partial garbage collection, the method flushes cards from RSCLs associated with the collection set to the card table, globally discards cards that are about to be rebuilt from all RSCLs, and globally cleans the card table. The method then adds cards to the RSCLs for inter-region references discovered while traversing live objects in the collection set. A corresponding computer program product and apparatus are also disclosed.

Abstract: A method for performing garbage collection on an object heap is described. In one embodiment, such a method includes performing a copy phase on an object heap by copying live objects from a source space to a destination space. An abort condition is generated when copying an object from the source space to the destination space fails due to insufficient space. In response to the abort condition, tracing work and reference updating associated with the copy phase are terminated. A mark phase is then initiated that marks live objects in the source space. This mark phase resumes tracing work and reference updating terminated by the copy phase in order to avoid or minimize the repetition of work performed by the copy phase. A corresponding computer program product and system are also described.

Abstract: A method for performing garbage collection on an object heap is described. In one embodiment, such a method includes performing a copy phase on an object heap by copying live objects from a source space to a destination space. An abort condition is generated when copying an object from the source space to the destination space fails due to insufficient space. In response to the abort condition, tracing work and reference updating associated with the copy phase are terminated. A mark phase is then initiated that marks live objects in the source space. This mark phase resumes tracing work and reference updating terminated by the copy phase in order to avoid or minimize the repetition of work performed by the copy phase. A corresponding computer program product and system are also described.

Abstract: An operating system or virtual machine of an information handling system (IHS) initializes a garbage collector to provide object memory compaction during application execution. The operating system or virtual machine performs move and fixup management within heap or object memory stores. The garbage collector identifies holes or unused portions of heap memory and moves one or more objects during compaction operations. After the garbage collector moves the object, a fixup cache tool fixes up the object pointers within the object. The fixup cache tool maintains a fixup cache that includes pointer information corresponding to the objects that the garbage collector moves. The fixup cache tool employs the pointer information within the fixup cache to update or otherwise fixup the objects within the heap that the garbage collector moves during compaction operations. The fixup cache may provide predictive pointer update information during fixup operations for each object move within the heap.

Abstract: Illustrative embodiments provide a computer implemented method, an apparatus in the form of a data processing system and a computer program product for cache line reservations. In one embodiment, the computer implemented method comprises, dividing a memory into an unreserved section and a set of reserved sections. The method performs selected allocations of the memory only from the set of reserved sections, and performing un-selected allocations of the memory from the unreserved section. The method further mapping a specified selected allocation of the memory to a same corresponding line of cache memory each time the mapping for the specified selected allocation of the memory occurs, thereby maintaining locality.

Abstract: Automatic memory management with a generational copy collector garbage collection algorithm running on parallel threads to perform simultaneous and independent copying and scanning. An object is scanned. It is determined whether an object referenced within the slot of the object being scanned may be copied to the same generation as the scanned object. A mark may be made to indicate that the referenced object may be copied to a different generation than the scanned object. The mark defers the copying of the referenced object.

Abstract: In a UPnP network, a system and method have been provided for multicasting a byebye message by proxy. The method comprises: maintaining a list of available networked devices; maintaining a record of advertised UPnP elements; comparing the list of available networked devices to the record of advertised UPnP elements; and, multicasting a byebye message by proxy, for advertised UPnP elements associated with networked devices that are no longer available. The comparison of the list of available networked devices to the record of UPnP elements includes determining advertised UPnP elements in the record that cannot be cross-referenced to available networked devices. The method further comprises removing UPnP elements from the record in response to the comparison.

Abstract: A computer-implementable method, system and apparatus. The frequency of reference to an object, also known as “hotness,” can be collected as a part of a profiling phase during a runtime operation of data-processing system by permitting each reference to the object during the runtime operation to randomly guess a predetermined value associated with the object, such that a correct guess thereof implies that the object is referenced frequently. Thereafter, the frequency of reference to the object can be validated by identifying a particular value in a header associated with the object, in response to collecting the frequency of reference to the object during the profiling phase, thereby increasing the scalability and efficiency of the runtime operation while permitting data associated with the frequency of reference to the object to other applications for immediate use.

Abstract: Illustrative embodiments provide a computer implemented method, an apparatus in the form of a data processing system and a computer program product for cache line reservations. In one embodiment, the computer implemented method comprises, dividing a memory into an unreserved section and a set of reserved sections. The method performs selected allocations of the memory only from the set of reserved sections, and performing un-selected allocations of the memory from the unreserved section. The method further mapping a specified selected allocation of the memory to a same corresponding line of cache memory each time the mapping for the specified selected allocation of the memory occurs, thereby maintaining locality.

Abstract: A method and system for processing information is provided. A negotiable instrument may be scanned to determine a first amount and a second amount. A comparing module compares the first amount to the second amount, and a value for the negotiable instrument is determined based on the amounts. The value can be compared to the amounts to determine if a predetermined error has been committed in entering the value. If so, the value may be corrected.

Abstract: A traditional passive thermal management system can only be used effectively in a single orientation because it relies on the buoyancy of the heated air to create natural convection. A passive thermal management system is provided which includes means for transferring heat away from a heat source (10) in any orientation. The system comprises a heat pipe (14) which is thermally coupled to the heat source (10). The heat pipe (14) is capable of transferring heat away from the heat source (10), wherein this heat is transferred along the length of the heat pipe (14). Thermally coupled to the heat pipe (14) is a fin system (12), which provides a means for extraction of the heat from the heat pipe (14) and transfer of this heat to the environment thereby dissipating the heat generated at the heat source (10). The fin system (12) is configured to provide a desired level of heat transfer to the environment independent of the orientation of the thermal management system.

Abstract: A system and method are provided for reestablishing communication periods in a rendezvous scheduled communication system. The method comprises: establishing a plurality of time points (TPs); initiating a new communication period at a TP; terminating the new communication period and, then, resuming a previously established communication period. The new communication period may be terminated because a link cannot be established or alternately, the new communication period ends before the occurrence of the next TP because there is no further information to exchange. The system and method effectively extends the duration of communication periods for communication links where information exchange is required. It does this by allowing unused portions of communication periods for other communication links to be used on links where information exchanged is desired.

Abstract: An optical system design for measuring the velocity of fluids flowing through pipes or other conduits is disclosed. The optical system is comprised of a means for delivering two beams through a window in the wall of the pipe, focused to two points aligned along an axis of the pipe and separated by a known distance, and means for detecting light that is scattered by particles carried in the fluid stream through a second window, that is disposed on the opposite side of the pipe. By measuring the time delay between detected signals, the velocity of the fluid can be determined. The delivered light beams are focused in a shallow cone of light and are blocked by an obstruction disposed behind the second window. The scattered light passes through an aperture behind the second window that surrounds the obscuration, and is focused on to a detector surface.