Michael Alan Levin

US Patent:

8549486, Oct 1, 2013

Filed:

Apr 21, 2008

Appl. No.:

12/106811

Inventors:

Patrice Godefroid - Mercer Island WA, US
Michael Y. Levin - Sammamish WA, US
David Molnar - Berkeley CA, US

Assignee:

Microsoft Corporation - Redmond WA

International Classification:

G06F 9/44

US Classification:

717128

Abstract:

An exemplary method includes providing software for testing; during execution of the software, performing a symbolic execution of the software to produce path constraints; injecting issue constraints into the software where each issue constraint comprises a coded formula; solving the constraints using a constraint solver; based at least in part on the solving, generating input for testing the software; and testing the software using the generated input to check for violations of the injected issue constraints. Such a method can actively check properties of the software. Checking can be performed on a path for a given input using a constraint solver where, if the check fails for the given input, the constraint solver can also generate an alternative input for further testing of the software. Various exemplary methods, devices, systems, etc. , are disclosed.

US Patent:

20090228871, Sep 10, 2009

Filed:

Mar 10, 2008

Appl. No.:

12/045298

Inventors:

ANDREW EDWARDS - REDMOND WA, US
MICHAEL Y. LEVIN - SAMMAMISH WA, US
JORDAN TIGANI - SEATTLE WA, US
ZHENGHAO WANG - REDMOND WA, US
DENNIS JEFFREY - TUCSON AZ, US

Assignee:

MICROSOFT CORPORATION - Redmond WA

International Classification:

G06F 9/44

US Classification:

717128

Abstract:

Methods, systems, and computer-readable media having computer-executable instructions embodied thereon that, when executed, perform methods in accordance with embodiments hereof, for emulating behavior of a target program to identify defects therein. Emulation includes recording a trace file upon running machine-level instructions of the target program, collecting relevant events encountered upon replaying the trace file, expressing the relevant events as symbolic constraints, and solving the symbolic constraints for variant input parameters. Injecting the variant input parameters into the trace file causes the target program to follow various control paths, allowing for systematically searching the target program for defects. The procedure for security testing above can be repeated by employing a search-strategy algorithm that selects optimal control paths of the target program to evaluate. Accordingly, the search-strategy algorithm induces the target program to follow the optimal control paths such that an optimal portion of the target program is explored for defects.

US Patent:

20130159281, Jun 20, 2013

Filed:

Dec 15, 2011

Appl. No.:

13/327691

Inventors:

Jinlin Yang - Redmond WA, US
Michael Y. Levin - Sammamish WA, US

Assignee:

MICROSOFT CORPORATION - Redmond WA

International Classification:

G06F 17/30

US Classification:

707715, 707E17002

Abstract:

Embodiments are directed to replicating database tables for efficient data querying and to using a background task to update a database index table on a periodic basis. In one scenario, a computer system accesses an existing, original time-based database table that includes various entities and properties for each entity. Each entity also includes a time stamp value. The computer system receives an indication that the new index table is to be indexed according to a user-specified property and sorts the new index table based on both the value of the user-specified property and the time stamp value of the entity to which the user-specified property belongs. The computer system then periodically copies the entities and associated properties of the original time-based database table into a new database index table.