Max Schaefer

Max Schaefer, Oxfordshire GB

Patent application number	Description	Published
20090234801	APPROXIMATING QUERY RESULTS BY RELATIONS OVER TYPES FOR ERROR DETECTION AND OPTIMIZATION - A method and system is provided for computing an approximation of the results of a query. The approximation represents a superset of all possible results, by computing a set of records of types (as opposed to a set of records of values, which is the normal result of a query). This is different from conventional systems, which typically infer types for each field individually. For each record of types, one may also keep track of equalities of fields to improve the precision of the approximation. The approximation can be used to detect erroneous parts of queries that always return an empty result, regardless of the contents of the data source. Furthermore, the same approximation is also useful in performing optimizations: first, by eliminating parts of procedure calls that are guaranteed to be irrelevant to the calling context, and second, by eliminating unnecessary type tests in the query.	09-17-2009

Max Schaefer, St. Clement'S GB

Patent application number	Description	Published
20110219361	CORRECT REFACTORING OF CONCURRENT SOFTWARE - Automated refactorings as implemented in modern IDEs for Java usually make no special provisions for concurrent code. Thus, refactored programs may exhibit unexpected new concurrent behaviors. We analyze the types of such behavioral changes caused by current refactoring engines and develop techniques to make them behavior-preserving, ranging from simple techniques to deal with concurrency-related language constructs to a framework that computes and tracks synchronization dependencies. By basing our development directly on the Java Memory Model we can state and prove precise correctness results about refactoring concurrent programs. We show that a broad range of refactorings are not influenced by concurrency at all, whereas other important refactorings can be made behavior-preserving for correctly synchronized programs by using our framework. Experience with a prototype implementation shows that our techniques are easy to implement and require only minimal changes to existing refactoring engines.	09-08-2011
20120174082	REFACTORING PROGRAMS FOR FLEXIBLE LOCKING - Disclosed is a novel computer implemented system, on demand service, computer program product and a method that provides a set of lock usages that improves concurrency resulting in execution performance of the software application by reducing lock contention through refactoring. More specifically, disclosed is a method to refactor a software application. The method starts with accessing at least a portion of a software application that can execute in an operating environment where there are more two or more threads of execution. Next, a determination is made if there is at least one lock used in the software application to enforce limits on accessing a resource. In response to determining that there is a lock with a first type of construct with a given set of features, the software application is refactored with the lock to preserve behavior of the software application.	07-05-2012

Max Schaefer, Oxford GB

Patent application number	Description	Published
20120016912	TYPE INFERENCE FOR DATALOG WITH COMPLEX TYPE HIERARCHIES - What is disclosed are a novel system and method for inferring types of database queries. In one embodiment a program and associated database schema that includes a type hierarchy is accessed. The program includes query operations to a database that contains relations described by a database schema. Types are inferred from definitions in the program by replacing each database relationship in the program by the types in the database schema. A new program is generated with the types that have been inferred with the new program only accessing unary relations in the database. In another embodiment, testing of each of the types that have been inferred is performed for type emptiness. In response to type emptiness being found for a type that have been inferred, a variety of different operations are performing including removing the type, providing a notification regarding the emptiness found for the type, and more.	01-19-2012
20150309790	SOURCE CODE VIOLATION MATCHING AND ATTRIBUTION - Methods, systems, and apparatus, including computer programs encoded on computer storage media, for matching and attributing code violations. One of the methods includes receiving a snapshot S of a code base of source code and a different snapshot T of the code base. Data representing first violations in the snapshot S and second violations in the snapshot T is received. Pairs of matching violations are determined using performing two or more matching processes, including performing a first matching process, the first matching process determining first pairs of matching violations according to a first matching algorithm and performing a second matching process, the second matching process determining second pairs of matching violations according to a second matching algorithm from violations not matched by the first matching process. The first pairs of matching violations and the second pairs of matching violations are included in the determined pairs of matching violations.	10-29-2015
20150324195	SOURCE CODE VIOLATION MATCHING AND ATTRIBUTION - Methods, systems, and apparatus, including computer programs encoded on computer storage media, for matching and attributing code violations. One of the methods includes receiving a snapshot S of a code base of source code and a different snapshot T of the code base. Data representing first violations in the snapshot S and second violations in the snapshot T is received. Pairs of matching violations are determined using performing two or more matching processes, including performing a first matching process, the first matching process determining first pairs of matching violations according to a first matching algorithm and performing a second matching process, the second matching process determining second pairs of matching violations according to a second matching algorithm from violations not matched by the first matching process. The first pairs of matching violations and the second pairs of matching violations are included in the determined pairs of matching violations.	11-12-2015
20160098271	SOURCE CODE VIOLATION MATCHING AND ATTRIBUTION - Methods, systems, and apparatus, including computer programs encoded on computer storage media, for matching and attributing code violations. One of the methods includes receiving a snapshot S of a code base of source code and a different snapshot T of the code base. Data representing first violations in the snapshot S and second violations in the snapshot T is received. Pairs of matching violations are determined using performing two or more matching processes, including performing a first matching process, the first matching process determining first pairs of matching violations according to a first matching algorithm and performing a second matching process, the second matching process determining second pairs of matching violations according to a second matching algorithm from violations not matched by the first matching process. The first pairs of matching violations and the second pairs of matching violations are included in the determined pairs of matching violations.	04-07-2016
20160132326	SOURCE CODE VIOLATION MATCHING AND ATTRIBUTION - Methods, systems, and apparatus, including computer programs encoded on computer storage media, for matching and attributing code violations. One of the methods includes receiving a snapshot S of a code base of source code and a different snapshot T of the code base. Data representing first violations in the snapshot S and second violations in the snapshot Tis received. Pairs of matching violations are determined using performing two or more matching processes, including performing a first matching process, the first matching process determining first pairs of matching violations according to a first matching algorithm and performing a second matching process, the second matching process determining second pairs of matching violations according to a second matching algorithm from violations not matched by the first matching process. The first pairs of matching violations and the second pairs of matching violations are included in the determined pairs of matching violations.	05-12-2016
20160140015	DISTRIBUTED ANALYSIS AND ATTRIBUTION OF SOURCE CODE - Methods, systems, and apparatus, including computer programs encoded on computer storage media, for distributing analysis tasks and attribution tasks. One of the methods includes receiving data representing a plurality of snapshots of a code base, wherein each snapshot comprises source code files, wherein one or more snapshots have a parent snapshot in the code base according to a revision graph of snapshots in the code base. An attribution set is generated from the plurality of snapshots, the attribution set having a target set of attributable snapshots to be attributed and a support set of all parent snapshots of all snapshots in the target set. An attribution task is distributed for the attribution set to a particular worker node of a plurality of worker nodes.	05-19-2016