Tue Mar 2, 2010, 11:00-12:00, 4549 BH

Concurrent Collections: A New Approach to Parallel Programming

Kathleen Knobe
Intel

A common approach in designing parallel languages is to provide some high level 
handles to manipulate the use of the parallel platform.  This exposes some aspects 
of the target platform, for example, shared vs. distributed memory.  It may expose 
some but not all types of parallelism, for example, data parallelism but not 
task parallelism.  This approach must find a balance between the desire to provide 
a simple view for the domain expert and provide sufficient power for tuning.  
This is hard for any given architecture and harder if the language is to apply to 
a range of architectures.  Either simplicity or power is lost.

Instead of viewing the language design problem as one of providing the programmer 
with high level handles, we view the problem as one of designing an interface. 
On one side of this interface is the programmer (domain expert) who knows the 
application but needs no knowledge of any aspects of the platform.  On the other 
side of the interface is the performance expert (programmer or program) who 
demands maximal flexibility for optimizing the mapping to a wide range of target 
platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, 
etc.) but needs no knowledge of the domain.  

Concurrent Collections (CnC) is based on this separation of concerns. 
The talk will present CnC and its benefits.

About the speaker:  Kathleen Knobe worked at Compass (aka Massachusetts Computer 
Associates) from 1980 to 1991 designing compilers for a wide range of parallel 
platforms for Thinking Machines, MasPar, Alliant, Numerix, and several 
government projects.  In 1991 she decided to finish her education. 
After graduating from MIT in 1997, she joined Digital Equipment’s Cambridge 
Research Lab (CRL).  She stayed through the DEC/Compaq/HP mergers and when CRL 
was acquired and absorbed by Intel.  She currently works in the Software 
Solutions Group / Software Pathfinding and Innovation / Scalable Tools (SSG/SPI/ST).

Her professional interests focused on parallelism through compiler technology 
runtime system design and language design.  Her major projects include the 
Subspace Model of computation (a compiler internal form for parallelism), 
Data Optimization (compiler transformations for locality), Array Static 
Single Assignment form (a method of achieving for array elements the advantages 
that SSA has for scalars), Weak Dynamic Single Assignment form (a global method 
for eliminating overwriting of data to maximize scheduling flexibility), 
Stampede (a programming model for streaming media applications), and 
Concurrent Collections.

Host: Jens Palsberg