International Business Machines Corporation

Robert Carl Seemann

Elliot Karl Kolodner

John Clarence Endicott

Mark Douglas Schroeder

Mark Robert Funk

Timothy Joseph Torzewski

Daniel Rodman Hicks

John Gerard Nistler

Jon H Peterson

Donald Arthur Morrison

Arthur Douglas Smet

Robert Anthony Petrillo

Larry Keith McMains

An object oriented mechanism and method provide exact information about the current invocation stack even when methods are inlined. A virtual stack frame mechanism determines whether a called method has been inlined, and counts both virtual frames and real frames when determining information corresponding to a called method. The virtual stack frame mechanism is preferably implemented in an object oriented class that provides methods for determining information corresponding to a called method.

Object oriented apparatus and method for preserving stack frame identity during inlined method calls

A computer system, program product, and method of collecting interned data utilize an interned indicator for an internable data element that indicates whether such a data element is in fact interned within an intern data structure. By maintaining this information, iteration completely through the intern data structure during collection may be avoided, thereby reducing the overhead and improving the efficiency of the collection process. In addition, a computer system, program product, and method of collecting interned data may also determine during a second stage of a collection cycle whether an interned data element, which was determined to be unreachable during a first stage of the collection cycle, has subsequently been accessed through an intern data structure since the beginning of the first stage of the collection cycle. By making this determination, interned data that has been made reachable as a result of an access through the intern data structure that occurs after the beginning of the first stage of the current collection cycle is prevented from being collected.

Computer system, program product and method of collecting interned data

A computer system, program product, and method of managing weak references with a concurrent mark sweep collector inhibit access, while processing weak references, to only those weak references whose referenced objects have not yet been determined to be strongly-reachable (i.e., reachable other than through a weak reference) during a current collection cycle. As such, access to specific weak references during processing thereof by a concurrent mark sweep collector is selectively inhibited to ensure synchronization for all weak references without necessarily stopping the execution of all program threads that attempt to access such weak references while executing in a computer system, thereby minimizing the processing overhead of managing weak references and improving system performance.

Computer system, program product and method of managing weak references

According to the present invention, pool allocation and process assignment mechanisms create process nodal affinity in a NUMA multiprocessor system for enhanced performance. The multiprocessor system includes multiple interconnected multiprocessing nodes that each contain one or more processors and a local main memory, the system main storage being distributed among the local main memories of the multiprocessing nodes in a NUMA architecture. A pool reservation mechanism reserves pools of memory space within the logical main storage, and the pool allocation mechanism allocates those pools to real pages in the local main-memory of multiprocessing nodes. Processes to be created on the multiprocessor are given an attribute that indicates an associated pool. Upon creation, the process assignment mechanism will only assign a process to a multiprocessing node that has been allocated the pool indicated by the process' attribute. This process nodal affinity increases accesses by the assigned process to local main storage of that node, thereby enhancing system performance.

Process assignment by nodal affinity in a myultiprocessor system having

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Rochester, MN, United States of America

Robert Carl Seemann