Clement R Attanasio

6470361, Oct 22, 2002

Jan 10, 2000

09/480186

Bowen Alpern - Peekskill NY
Clement Richard Attanasio - Cortlandt Manor NY
Stephen Edwin Smith - Mahopac NY

International Business Machines Corporation - Armonk NY

G06F 1200

707206, 707 1

A method and apparatus are provided for the efficient management of remembered sets in a generational garbage collection scheme. The present invention detects when an old object has a pointer to a young object, and needs to be added to the remembered set. A write buffer and a temporary buffer are used to create and maintain the remembered set. Entries in the write and temporary buffers are used as part of the root set for creating the remembered set for the next garbage collection. A barrier bit associated with each object differentiates generations in the generational garbage collection scheme and is used to determine whether to make an entry into a write buffer when a reference to another object is stored into an object. Objects that have survived one or more collections, but not the minimum number, N, of collections to be considered an old object are referred to as âmiddle-agedâ objects. During a minor garbage collection, the write buffer is scanned.

6496866, Dec 17, 2002

Apr 9, 1999

09/289225

Clement Richard Attanasio - Peekskill NY
German Sergio Goldszmidt - Dobbs Ferry NY
Stephen Edwin Smith - Mahopac NY

International Business Machines Corporation - Armonk NY

G06F 15173

709239, 714 2, 714 15, 714 20, 714100

A TCP-connection-router performs encapsulated clustering by dividing each encapsulated cluster into several Virtual EC (VECs), dynamically distributing incoming connections within a VEC based on current server load metrics according to a configurable policy. In one embodiment, the connection router supports dynamic configuration of the cluster, and enables transparent recovery which provides uninterrupted service to the VEC clients.

6510440, Jan 21, 2003

Jan 10, 2000

09/480189

Bowen Alpern - Peekskill NY
Clement Richard Attanasio - Cortlandt Manor NY
Stephen Edwin Smith - Mahopac NY

International Business Machines Corporation - Armonk NY

G06F 1200

707206, 707200

A method and apparatus are disclosed for efficiently creating and maintaining a remembered set in a generational garbage collection scheme using a write buffer and a barrier bit associated with each object. A barrier bit associated with each object differentiates generations in a generational garbage collection scheme. When an object is first created, the barrier bit of the object is set to zero. The barrier bit is set when the object becomes old, for example, after surviving a first garbage collection. The barrier bit is used to determine whether to make an entry into a write buffer when a reference to another object is stored into an object. An entry is made in the write buffer only if the barrier bit of the object that is written into is set. At the end of each garbage collection, entries in the write buffer are added to the remembered set for the next garbage collection if the objects satisfy the criterion for membership, i. e. , they are live and may contain pointers to objects in a younger generation.

53718526, Dec 6, 1994

Oct 14, 1992

7/960742

Clement R. Attanasio - Peekskill NY
Stephen E. Smith - Mahopac NY

International Business Machines Corporation - Armonk NY

G06F 1300

395200

The present invention provides a method and apparatus for enabling a cluster of computers to appear as a single computer to host computers outside the cluster. A host computer communicates only with a gateway to access destination nodes and processes within the cluster. The gateway has at least one message switch which processes incoming and outgoing port type messages crossing the cluster boundary. This processing comprises examining certain information on the message headers and then changing some of this header information either to route an incoming message to the proper computer node, port and process or to make an outgoing message appear as if originated at the gateway node. The message switch uses a table to match incoming messages to a particular routing function which can be run to perform the changes necessary to correctly route different kinds of messages.

59180170, Jun 29, 1999

Aug 23, 1996

8/701939

Clement Richard Attanasio - Peekskill NY
German Sergio Goldszmidt - Dobbs Ferry NY
Guerney Douglas Holloway Hunt - Wappingers Falls NY
Stephen Edwin Smith - Mahopac NY

Internatioinal Business Machines Corp. - Armonk NY

G06F 300

39520054

A TCP-connection-router performs encapsulated clustering by dividing each encapsulated cluster into several Virtual EC (VECs), dynamically distributing incoming connections within a VEC based on current server load metrics according to a configurable policy. In one embodiment, the connection router supports dynamic configuration of the cluster, and enables transparent recovery which provides uninterrupted service to the VEC clients.

40878562, May 2, 1978

Jun 30, 1976

5/701058

Clement Richard Attanasio - Peekskill NY

International Business Machines Corporation - Armonk NY

G06F 1300

364200

A computer operating system security mechanism employing a non-penetrable hardware means for storing privileged instruction identification data for preventing direct unauthorized access to certain privileged instructions forming a part of the computer operating system; and further including memory address data boundary storage means for each said privileged instruction for preventing indirect access to such privileged instructions in memory by unauthorized branch instructions. The mechanism includes means associated with the computing system instruction register for recognizing privileged instruction and branch instructions. Storage means are included for each privileged instruction it is desired to protect for storing the address of the privileged instruction itself in memory, and both the upper and lower boundary address in memory relating to each such privileged instruction. Whenever a privileged instruction is recognized its address as specified in the running program is compared with the present security mechanism address for said privileged instruction and if there is "no match" a security violation signal and interrupt will be produced. Similarly when any branch instruction is recognized, its address is checked with all privileged instruction boundaries and if found to lie within any stored boundary a security violation and interrupt will similarly be signaled.

56689438, Sep 16, 1997

May 24, 1996

8/653098

Clement Richard Attanasio - Peekskill NY
Maria Angela Butrico - Blauvelt NY
James Lyle Peterson - Austin TX
Christos Alkiviadis Polyzois - White Plains NY
Stephen Edwin Smith - Mahopac NY

International Business Machines Corporation - Armonk NY

G06F 1100

39518205

A system and method for recovering from failures in the disk access path of a clustered computing system. Each node of the clustered computing system is provided with proxy software for handling physical disk access requests from applications executing on the node and for directing the disk access requests to an appropriate server to which the disk is physically attached. The proxy software on each node maintains state information for all pending requests originating from that node. In response to detection of a failure along the disk access path, the proxy software on all of the nodes directs all further requests for disk access to a secondary node physically attached to the same disk.

39964493, Dec 7, 1976

Aug 25, 1975

5/607410

Clement Richard Attanasio - Peekskill NY
Laszlo Antal Belady - Yorktown Heights NY

International Business Machines Corporation - Armonk NY

G06K 500
H04Q 502

235 617R

An operating system authenticator for determining if an operating system being loaded in a computer is valid. A user's identification code or secret key which is unique to the operating system, and a verifier value which is a predetermined function of a valid operating system and the identification code are respectively stored. A hash function, which is a function of the operating system being loaded and the identification code, is generated by the authenticator. After the operating system is loaded, the hash function is used as an authenticating value and compared with the verifier value for determining the authenticity of the loaded operating system.