Microsoft Technology Licensing, LLC

Weirong Zhu

Yosseff Levanoni

Lingli Zhang

David L Detlefs

Paul F Ringseth

Amit Kumar Agarwal

Sukhdeep S Sodhi

Michael M Magruder

Charles David Callahan, Ii

Timothy Lawrence Harris

Andrew L Bliss

John Lee Rapp

Dana D Groff

John Joseph Duffy

Vinod Grover

Stephen Harris Toub

Martin Abadi

Donald James McCrady

Alexander Dadiomov

Rick Molloy

Matthew B Tolton

Christopher William Dern

Yongkang Zhu

A high level programming language provides a read-only communication operator that prevents a computational space from being written. An indexable type with a rank and element type defines the computational space. For an input indexable type, the read-only communication operator produces an output indexable type with the same rank and element type as the input indexable type but ensures that the output indexable type may not be written. The read-only communication operator ensures that any attempt to write to the output indexable type will be detected as an error at compile time.

Read-only communication operator

Embodiments are directed to optimizing data transfers between heterogeneous memory arenas. In one scenario, a computer system receives an indication that a data chunk is to be transferred from a first memory arena to a third memory arena, and then determines that for the data chunk to be transferred from the first memory arena to the third arena, the data chunk is to be transferred from the first memory arena to a second memory arena, and from the second memory arena to the third memory arena. The computer system divides the data chunk into smaller data portions and copies a first data portion from the first memory arena to the second memory arena. The computer system then copies the first data portion from the second memory arena to the third memory arena and copies a second data portion from the first memory arena to the second memory arena in parallel.

Optimizing data transfers between heterogeneous memory arenas

A software transactional memory system implements a lightweight key-based action framework. The framework includes a set of unified application programming interfaces (APIs) exposed by an STM library that allow clients to implement actions that can be registered, queried, and updated using specific keys by transactions or transaction nests in STM code. Each action includes a key, state information, and a set of one or more callbacks that can be hooked to the validation, commit, abort, and/or re-execution phases of transaction execution. The actions extend the built-in concurrency controls of the STM system with customized control logics, support transaction nesting semantics, and enable integration with garbage collection systems.

Action framework in software transactional memory

A software transactional memory system is provided that creates an array of transactional locks for each array object that is accessed by transactions. The system divides the array object into non-overlapping portions and associates each portion with a different transactional lock. The system acquires transactional locks for transactions that access corresponding portions of the array object. By doing so, different portions of the array object can be accessed by different transactions concurrently. The system may use a shared shadow or undo copy for accesses to the array object.

Array object concurrency in STM

The present invention extends to methods, systems, and computer program products for emulating pointers. Pointers can be emulated by replacing the pointers with a &#x3c;variable#, offset&#x3e; pair and replacing each dereference site with a switch on the tag and a switch body that executes the emulated pointer access on the corresponding variable the pointer points to. Data flow optimizations can be used to reduce the number of switches and/or reduce the number of cases which need be considered at each emulated pointer access sites.

Emulating pointers

The present invention extends to methods, systems, and computer program products for aliasing buffers. Embodiment of the inventions supporting buffer aliasing through introduction of a level of indirection between a source program's buffer accesses and the target executable physical buffers, and binding the logical buffer accesses to actual physical buffer accesses at runtime. A variety of techniques for can be used supporting runtime aliasing of buffers, in a system which otherwise disallows such runtime aliasing between separately defined buffers in the target executable code. Binding of logical buffer accesses in the source program to the actual physical buffers defined in the target executable code is delayed until runtime.

Aliasing buffers

A high level programming language provides an extensible set of transformations for use on indexable types in a data parallel processing environment. A compiler for the language implements each transformation as a map from indexable types to allow each transformation to be applied to other transformations. At compile time, the compiler identifies sequences of the transformations on each indexable type in data parallel source code and generates data parallel executable code to implement the sequences as a combined operation at runtime using the transformation maps. The compiler also incorporates optimizations that are based on the sequences of transformations into the data parallel executable code.

Indexable type transformations

A compile environment is provided in a computer system that allows programmers to program both CPUs and data parallel devices (e.g., GPUs) using a high level general purpose programming language that has data parallel (DP) extensions. A compilation process translates modular DP code written in the general purpose language into DP device source code in a high level DP device programming language using a set of binding descriptors for the DP device source code. A binder generates a single, self-contained DP device source code unit from the set of binding descriptors. A DP device compiler generates a DP device executable for execution on one or more data parallel devices from the DP device source code unit.

Binding data parallel device source code

A software transactional memory (STM) system allows the composition of traditional lock based synchronization with transactions in STM code. The STM system acquires each traditional lock the first time that a corresponding traditional lock acquire is encountered inside a transaction and defers all traditional lock releases until a top level transaction in a transaction nest commits or aborts. The STM system maintains state information associated with traditional lock operations in transactions and uses the state information to eliminate deferred traditional lock operations that are redundant. The STM system integrates with systems that implement garbage collection.

Composition of locks in software transactional memory

A high level programming language provides a co-map communication operator that maps an input indexable type to an output indexable type according to a function. The function maps an index space corresponding to the output indexable type to an index space corresponding to the input indexable type. By doing so, the co-map communication operator lifts a function on an index space to a function on an indexable type to allow composability with other communication operators.

Co-map communication operator

The present invention extends to methods, systems, and computer program products for debugging in a multiple address space environment. Embodiments of the invention include techniques for recording debug information used for translating between an abstract unified address space and multiple address spaces at a target system (e.g., a co-processor, such as, a GPU or other accelerator). A table is stored in the recorded debug information. The table includes one or more entries mapping compiler assigned IDs to address spaces. During debugging within a symbolic debugger, the recorded debug information can be used for viewing program data across multiple address spaces in a live debugging session.

Debugging in a multiple address space environment

A software transactional memory system is provided with overflow handling. The system includes a global version counter with an epoch number and a version number. The system accesses the global version counter prior to and subsequent to memory accesses of transactions to validate read accesses of the transaction. The system includes mechanisms to detect global version number overflow and may allow some or all transactions to execute to completion subsequent to the global version number overflowing. The system also provides publication, privatization, and granular safety properties.

Growing community of inventors

Kirkland, WA, United States of America

Weirong Zhu