Oracle International Corporation

Sun Microsystems, Inc.

Guy L Steele

Brian Goetz

Victor M Luchangco

David R Chase

Mark S Moir

Nir N Shavit

John Robert Rose

Daniel Nussbaum

Jean-Baptiste Tristan

Justin R Hilburn

Karl B Naden

Marc R Tremblay

Ole Agesen

Christine H Flood

Michael Louis Wick

Paul A Martin

Gavin Mark Bierman

Jan-Willem Maessen

Adam Pocock

Joshua J Bloch

Michael Denis O'Connor

Eric E Allen

Steve Heller

Eric Allen

Systems and methods are disclosed to build and execute a decision system based on multiple machine learned decision models. In embodiments, the decision system performs a hashing technique to reduce relevant features of the input data into a feature vector for each decision model. The feature vector reduces the dimensionality of the feature universe of the input data, and its use allows the decision models to be trained and executed using less computing resources. In embodiments, the decision system implements an ensembled decision model that makes decisions based on a combination function that combines the decision results of the individual models in the ensemble. The decision models employ different hashing techniques to hash the input features differently, so that errors caused by the feature hashing of individual models are reduced in the aggregate.

Ensembled decision systems using feature hashing models

In one approach, a method comprises receiving one or more higher-level instructions specifying to assign a value of a particular value type to a particular container of a plurality of containers, wherein the plurality of containers represent a data structure for maintaining one or more variables during execution of a block of code, wherein at least two containers of the plurality of containers are different sizes; generating one or more lower-level instructions that assign the value to the particular container based on applying one or more assignment rules to the one or more higher-level instructions based on the particular value type and executing the one or more lower-level instructions.

Handling value types

A novel data-parallel algorithm is presented for topic modeling on a highly-parallel hardware architectures. The algorithm is a Markov-Chain Monte Carlo algorithm used to estimate the parameters of the LDA topic model. This algorithm is based on a highly parallel partially-collapsed Gibbs sampler, but replaces a stochastic step that draws from a distribution with an optimization step that computes the mean of the distribution directly and deterministically. This algorithm is correct, it is statistically performant, and it is faster than state-of-the art algorithms because it can exploit the massive amounts of parallelism by processing the algorithm on a highly-parallel architecture, such as a GPU. Furthermore, the partially-collapsed Gibbs sampler converges about as fast as the collapsed Gibbs sampler and identifies solutions that are as good, or even better, as the collapsed Gibbs sampler.

Data-parallel parameter estimation of the Latent Dirichlet allocation model by greedy Gibbs sampling

Techniques for flow-based scoping are disclosed. A first code segment in a sequence of same-level code segments encapsulates a first lower-level lexical scope. The first lower-level scope is inclusive of scoping provided for the sequence of same-level code segments. The first code segment comprises a condition and an uninitialized variable. If executed, the first code segment causes the condition to be evaluated. If the condition is satisfied, the uninitialized variable is initialized and made available only within the first lower-level lexical scope. If a second code segment (a) references the uninitialized variable and (b) is in the sequence of same-level code segments or in a second lower-level lexical scope outside of the first lower-level lexical scope, an error message is presented indicating that the uninitialized variable is out of scope for the second code segment.

Flow-based scoping

The disclosed embodiments provide a system that facilitates the development and execution of a software program. During runtime of the software program, the system obtains a function call associated with an overloaded function and a generic type hierarchy. Next, the system determines an applicability of an implementation of the overloaded function to the function call. Finally, the system selects the implementation for invocation by the function call based on the determined applicability and a partial order of implementations for the overloaded function.

Dispatch predicate for overloaded functions using type intervals

The disclosed embodiments provide a system that facilitates the development and execution of a software program. During runtime of the software program, the system obtains a function call associated with an overloaded function and a generic type hierarchy that lacks contravariance. Next, the system determines an applicability of an implementation of the overloaded function to the function call. Finally, the system selects the implementation for invocation by the function call based on the determined applicability and a partial order of implementations for the overloaded function.

Fast dispatch predicate for overloaded functions with generic type hierarchies that lack contravariance

One embodiment of the present invention provides a system that facilitates performing operations on a lock-free double-ended queue (deque). This deque is implemented as a doubly-linked list of nodes formed into a ring, so that node pointers in one direction form an inner ring, and node pointers in the other direction form an outer ring. The deque has an inner hat, which points to a node next to the last occupied node along the inner ring, and an outer hat, which points to a node next to the last occupied node along the outer ring. The system uses a double compare-and-swap (DCAS) operation while performing pop and push operations onto either end of the deque, as well as growing and shrinking operations to change the number of nodes that are in the ring used by the deque.

Lock-free double-ended queue based on a dynamic ring

In general, in one aspect, the invention relates to a method for integrating dimensional analysis in a program comprising defining a specific dimension class within the program, wherein the specific dimension class is an instance of the dimension meta-class, defining an instantiation of a unit class within the program, wherein the instantiation of the unit class comprises the specific dimension class as a type parameter associated with the instantiation of the unit class, defining a method within the program using the instantiation of the unit class and the specific dimension class, and compiling the program to generate an executable code corresponding to the program, wherein the program is written in an object-oriented language.

Method and apparatus for dimensional analysis encoded in metatypes and generics

A computer system implementing transient blocking synchronization allows a memory location leased by a first process to be read-accessible to another process. In other words, more than one thread may have read-only type leases on a given memory location at a given time. Such 'shared' leases expire when respective lease periods of the shared leases elapse.

Shared lease instruction support for transient blocking synchronization

A computer system uses transient blocking synchronization for performing operations on shared memory. When performing operations on more than one memory location, the computer system obtains transient exclusive access to a first memory location. The computer system then obtains transient exclusive access to a second memory location, where the transient exclusive access to the second memory location does not expire prior to an expiration of the transient exclusive access to the first memory location or until explicitly unleased.

Exclusive lease instruction support for transient blocking synchronization

One embodiment of the present invention provides a system that facilitates importing static members of a class. During operation, the system examines code associated with a compilation unit to locate a static import declaration that identifies one or more static members of the class to import. Upon finding such a static import declaration, the system records the static import declaration in a symbol table used to compile the compilation unit. This allows the names for the one or more static members of the class to appear within the compilation unit without being prefixed with a name for the class.

Method and apparatus for importing static members of a class

In computer systems which do not inherently distinguish between references and primitive values within a program stack a method and apparatus to assist exact garbage collection techniques utilizes a stack tag cache which operates in conjunction with a program stack and supplies a tag item for every entry in the process stack. The value of a tag item indicates whether the stack entry is either a reference to another memory location or a primitive value, i.e. integer or floating point number. The arrangements and values of the tag items are correlated with changes to the program stack. The stack tag cache includes facilities for swapping the contents of the cache in the event of a trap or context switch, as well as means for redundantly verifying the tag value with intended instruction operand types.

Growing community of inventors

Lexington, MA, United States of America

Guy L Steele