David P Grove

US Patent:

6857120, Feb 15, 2005

Filed:

Nov 1, 2000

Appl. No.:

09/703530

Inventors:

Matthew R. Arnold - Ridgefield Park NJ, US
Stephen J. Fink - Yorktown Heights NY, US
David P. Grove - Ridgefield CT, US
Michael J. Hind - Cortlandt Manor NY, US
Peter F. Sweeney - Spring Valley NY, US
John Whaley - Stanford CA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F009/45

US Classification:

717157, 717127, 717131, 717133, 717153

Abstract:

A method for characterizing runtime behavior of a computer program executing in an execution environment comprising: generating a call stack runtime data structure for tracking methods currently active in an executing program thread, an active method on the call stack is represented by a frame; determining condition for sampling an executing program to determine current program behavior; and, upon determination of a sampling condition, the sampling including examining at least one frame in the call stack in response to evaluate context of one or more methods represented in the call stack, the at least one frame in the call stack providing context relating to an executing program's calling structure.

US Patent:

6971091, Nov 29, 2005

Filed:

Nov 1, 2000

Appl. No.:

09/703316

Inventors:

Matthew R. Arnold - Ridgefield Park NJ, US
Stephen J. Fink - Yorktown Heights NY, US
David P. Grove - Ridgefield CT, US
Michael J. Hind - Cortlandt Manor NY, US
Peter F. Sweeney - Spring Valley NY, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F009/45

US Classification:

717145, 717130, 717140, 717153, 718 1

Abstract:

A sampling-based system and method for adaptively optimizing a computer program executing in an execution environment that comprises one or more compiler devices for providing various levels of program optimization. The system comprises a runtime measurements sub-system for monitoring execution of the computer program to be optimized, the monitoring including obtaining raw profile data samples and characterizing the raw profile data; a controller device for receiving the characterized raw profile data from the runtime measurements sub-system and analyzing the data for determining whether a level of program optimization for the executing program is to be performed by a compiler device, the controller generating a compilation plan in accordance with a determined level of optimization; and, a recompilation sub-system for receiving a compilation plan from the controller and invoking a compiler device for performing the level of program optimization of the executing program in accordance with the compilation plan.

US Patent:

7103877, Sep 5, 2006

Filed:

Nov 1, 2000

Appl. No.:

09/703527

Inventors:

Matthew R. Arnold - Ridgefield Park NJ, US
Stephen J. Fink - Yorktown Heights NY, US
David P. Grove - Ridgefield CT, US
Michael J. Hind - Cortlandt Manor NY, US
Peter F. Sweeney - Spring Valley NY, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 9/45

US Classification:

717130, 714 35

Abstract:

A system and method for characterizing runtime behavior of a computer program executing in an execution environment, the method comprising: identifying one or more instances of yield points in a program to be executed, each yield point indicating a potential sampling operation during program execution; during program execution, in response to an identified yield point instance, ascertaining a state of the execution environment for indicating whether a sampling operation is to be performed; and, when the state of the execution environment indicates a sampling operation, recording relevant information for characterizing behavior of the execution environment. Relevant information for characterizing program behavior includes frequencies of methods executed in the program, and calling context associated with methods called by the program. Different mechanisms are provided for determining the sampling condition including the setting of a trigger bit by a runtime system, or, determining a sampling operations based on a fixed percentage of all executed yield points taken.

US Patent:

7150009, Dec 12, 2006

Filed:

Dec 10, 2002

Appl. No.:

10/315270

Inventors:

David F. Bacon - Sleepy Hollow NY, US
Stephen J. Fink - Yorktown Heights NY, US
David P. Grove - Ridgefield CT, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 9/44
G11C 29/00

US Classification:

717127, 714 38, 717131

Abstract:

A method for implementing an object model for an object-oriented programming language. Also contemplated is a method whereby some object state is materialized directly in those objects deemed likely to use such a state, but is externalized for those objects deemed unlikely to use the state.

US Patent:

7457940, Nov 25, 2008

Filed:

Nov 16, 2004

Appl. No.:

10/989088

Inventors:

David Francis Bacon - Sleepy Hollow NY, US
Perry Cheng - New City NY, US
David Paul Grove - Ridgefield CT, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 5/00

US Classification:

712221

Abstract:

A system and method for managing data includes executing a set of instructions which are used for operating on compressed data and another set of instructions (e. g. , different instructions) which are used for operating on uncompressed data.

US Patent:

7548940, Jun 16, 2009

Filed:

Jun 10, 2005

Appl. No.:

11/149686

Inventors:

David F. Bacon - Sleepy Hollow NY, US
Perry Chang - New City NY, US
David Grove - Ridgefield CT, US
Martin T. Vechev - Port Moody, CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 17/00
G06F 13/00

US Classification:

707206, 707202, 707205, 711154

Abstract:

Disclosed are a partial heap garbage collector, and a partial heap garbage collection method, that during collection checks the time remaining (or equivalently the time taken so far, or the work done so far) to complete the partial heap collection. In a preferred embodiment, the partial heap collection is guaranteed to complete within a fixed time interval. For example, this guarantee may be obtained by applying a worst-case execution time (WCET) and sizing a nursery so that complete evacuation of the nursery can always be achieved on time. As an alternative, a technique, referred to as syncopation, may be used to allow generational collection to be used despite variance in program behavior over the short time scales in which a nursery can be collected. Syncopation may be accomplished via allocation control or via collection control.

US Patent:

7596569, Sep 29, 2009

Filed:

Sep 24, 2004

Appl. No.:

10/948786

Inventors:

David Francis Bacon - Sleepy Hollow NY, US
Perry Sze-Din Cheng - New City NY, US
David Paul Grove - Ridgefield CT, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 7/00

US Classification:

707100, 707205, 707206, 711170, 711173, 711219

Abstract:

A system includes a processor for executing a collector program to perform a method (e. g. , a method of collection). The method includes using an object model during a collection phase that is different than an object model used during program execution. The processor may also perform a method including assigning a hash code to at least some objects, and consulting a structure that maintains a mapping of objects to hashcode values to determine said hashcode for one of said objects. The processor may also perform a method including storing a class pointer and garbage collector state information in a single word, and accessing said class pointer by masking out non-class bits.

US Patent:

7756911, Jul 13, 2010

Filed:

Jun 9, 2006

Appl. No.:

11/449774

Inventors:

David Francis Bacon - Sleepy Hollow NY, US
Perry Sze-Din Cheng - New York City NY, US
David Paul Grove - Ridgefield CT, US
Daniel J. Spoonhower - Pittsburgh PA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 12/00
G06F 17/30

US Classification:

707813, 707999206

Abstract:

A method (and system) for executing a task includes executing a first task in which garbage is collected using a garbage collector, and executing a second task, the garbage collector being preemptable (e. g. , preempted) by the second task.