David C Nesbitt

US Patent:

6546412, Apr 8, 2003

Filed:

Nov 7, 1997

Appl. No.:

08/966381

Inventors:

Sang W. Kim - Lawndale CA
David P. Nesbitt - Redondo Beach CA
Steve A. Okamoto - Torrance CA
Jennifer D. Thomas - Hermosa Beach CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06F 900

US Classification:

709104, 709107

Abstract:

Temporary states are used transitionally in run-time situations and are unknown to the object database. A temporary state is created if, when an object is performing a requested event, interim work needs to be performed before the object reaches a permanent destination state. Use of a temporary state is transparent to the caller of the requested event. Within a single flow of control, an unlimited number of nested locks may be acquired. A request to unlock an object will only truly unlock the object if the unlock requester is at the highest level of locking. For recursive or embedded functions, no knowledge of the previous locking condition is necessary. Attribute-based locking provides a mechanism for allowing only certain members of the system to lock an object for writing while the object is in a predetermined state. However, any thread may obtain a read lock on an object in order to examine its attributes. This may be expanded to state that the system may restrict locking of an object or entity based upon any attribute in the database or upon any combination or logical expression of these attributes.

US Patent:

6631009, Oct 7, 2003

Filed:

Sep 24, 1999

Appl. No.:

09/404171

Inventors:

Jennifer D. Thomas - Hermosa Beach CA
David P. Nesbitt - Redondo Beach CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06F 1500

US Classification:

358 115, 358 112, 358 113, 709102, 709103

Abstract:

A document printing system involves multi-threaded processing of a document object. A deadlock situation between a preprocessing thread and a cancellation thread can be averted with a time-out locking mechanism. After the cancellation thread has locked the document object, its sets a cancel flag, then waits for preprocessing to complete. Meanwhile, the preprocessing thread may request a lock of the document object. If so, it will specify a maximum time-out period. After expiration of the time-out period, a timed-out status response will be sent from the document object to the preprocessing thread. The preprocessing thread will then poll the document object for a cancel flag. A cancel flag will be set on the document object only if the cancellation thread has requested the document object perform a cancellation operation. If there is no cancel flag, the preprocessing thread will again request a lock of the document object with a maximum time-out period. If there is a cancel flag, the preprocessing thread will send a cancellation complete signal to the document object.

US Patent:

6971100, Nov 29, 2005

Filed:

Apr 5, 2002

Appl. No.:

10/115914

Inventors:

Sang W. Kim - Lawndale CA, US
David P. Nesbitt - Redondo Beach CA, US
Steve A. Okamoto - Torrance CA, US
Jennifer D. Thomas - Hermosa Beach CA, US

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06F009/46

US Classification:

718102

Abstract:

Temporary states are used transitionally in run-time situations and are unknown to the object database. A temporary state is created if, when an object is performing a requested event, interim work needs to be performed before the object reaches a permanent destination state. Use of a temporary state is transparent to the caller of the requested event.

US Patent:

59785608, Nov 2, 1999

Filed:

Nov 7, 1997

Appl. No.:

8/966409

Inventors:

Joseph Z. Fung - Artesia CA
Shengkuo Fan - Los Angeles CA
David Paul Nesbitt - Redondo Beach CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06K 100
H04N 121
H04N 100

US Classification:

395114

Abstract:

A distributed printing system that more optimally distributes job requests within a distributed printing system based on more detailed information about the particular attributes of each output device. In particular, additional printer attributes are used that allow greater utilization of a plurality of attached printers having differing capabilities. These attributes include "max-concurrent-jobs-processing" (MCJP), "number-of-jobs-on-device" (NJOD) and "number-of-cascaded-jobs" (NCJ), and a attribute value "saturated" for the attribute "printer-state". The attribute MCJP is an integer value that is based on the capabilities of the printer. NJOB and NCJ attributes allow monitoring of jobs sent to each printer for supported and unsupported printers. If NJOB or NCJ are greater than MCJP, then the attribute "printer-state" is set to "saturated", prohibiting further spooling of print jobs to that particular printer.

US Patent:

60550635, Apr 25, 2000

Filed:

Nov 7, 1997

Appl. No.:

8/966406

Inventors:

Jennifer Y. Yang - Manhattan Beach CA
David P. Nesbitt - Redondo Beach CA
Ton H. Truong - Westminster CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06F 1500

US Classification:

358 115

Abstract:

A utility that defines additional attributes that would cater to a user's needs provides dynamically extended printing capabilities. The system architecture allows the information to be pushed down transparently to the receiving end, which understands the semantics of the given information. One possible function of the system administrators can be to define information to monitor for accounting purposes. The utility allows additional printer features to be incorporated without disrupting the existing system.

US Patent:

59319194, Aug 3, 1999

Filed:

Nov 7, 1997

Appl. No.:

8/966405

Inventors:

Jennifer D. Thomas - Hermosa Beach CA
Sang W. Kim - Lawndale CA
David P. Nesbitt - Redondo Beach CA
Steve A. Okamoto - Torrance CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06F 15163
G06F 1730

US Classification:

709303

Abstract:

Temporary states are used transitionally in run-time situations and are unknown to the object database. A temporary state is created if, when an object is performing a requested event, interim work needs to be performed before the object reaches a permanent destination state. Use of a temporary state is transparent to the caller of the requested event. Within a single flow of control, an unlimited number of nested locks may be acquired. A request to unlock an object will only truly unlock the object if the unlock requester is at the highest level of locking. For recursive or embedded functions, no knowledge of the previous locking condition is necessary. Attribute-based locking provides a mechanism for allowing only certain members of the system to lock an object for writing while the object is in a predetermined state. However, any thread may obtain a read lock on an object in order to examine its attributes. This may be expanded to state that the system may restrict locking of an object or entity based upon any attribute in the database or upon any combination or logical expression of these attributes.

US Patent:

63212498, Nov 20, 2001

Filed:

Apr 28, 1998

Appl. No.:

9/066767

Inventors:

David P. Nesbitt - Redondo Beach CA

Assignee:

Xerox Corporation - Stamford CT

International Classification:

G06F 1516

US Classification:

709202

Abstract:

A method and apparatus are provided to enable other system elements to obtain configuration attribute modifications from a print management system. An attribute broker provides two methods, register and advertise, to facilitate necessary configuration changes. The register method is called by other system elements to indicate an interest in a particular attribute. In registering interest in an attribute, the system element provides a callback function. The attribute broker maintains a list of all attributes that have been registered and keeps the set of callback functions for each registered attribute. Whenever a server configuration attribute is modified, the server object uses the advertise method to provide the attribute information to any system element that has registered interest in that attribute. Upon receiving the advertisement of an attribute, the attribute broker checks to see if any callback functions have been registered for that attribute. If so, the attribute broker calls each callback function.

US Patent:

60819065, Jun 27, 2000

Filed:

Nov 21, 1997

Appl. No.:

8/975860

Inventors:

Takeshi Nishizawa - Torrance CA
David P. Nesbitt - Redondo Beach CA
Ton H. Truong - Westminster CA

Assignee:

Fuji Xerox Co., Ltd. - Tokyo
Xerox Corporation - Stamford CT

International Classification:

G06F 1100

US Classification:

714 2

Abstract:

A method and apparatus for parallel processing of remote procedure call (RPC) requests from clients includes placing the remote procedure call requests in a queue and storing them in a memory. A response is immediately returned to the client indicating receipt of the processing request. The RPC requests are retrieved from the queue and processed in parallel. Notification of the completed processing is provided to a notification client. In the event of a server fault or system failure, the processing requests are retrieved from the memory upon system restoration, and replaced into the queue in the order they were received by the server.