My primary research area is programming languages, in which I study concurrency, polymorphism, monitoring/visualization/debugging, and persistence.

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Concurrency

Virtually all computers support multiple simultaneous threads of execution in the form of multi-threading, multi-core, and multi-processors; programming multiple threads is more complex than a single thread, and is called concurrent programming. My initial work in concurrency began by providing concurrency for the C language, called the μSystem. While much was learned about designing and constructing thread libraries during this project, the work was abandoned because it is impossible to construct statically type-safe direct communication among threads in C.

Subsequently, the work shifted to C++ because of its object-oriented features allowing concurrent communication to be statically type-safe. However, it is still impossible to add concurrency without extending C++; as a result, a new concurrent dialect of C++ was created, called μC++.

Polymorphism

The ability to write generic reusable programs, called polymorphism, is fundamental to advanced software engineering. I am interested in static type-systems providing polymorphism without the use of nominal inheritance (object-oriented programming). The problem with nominal inheritance is the restrictions it imposes on reuse because of the rigid use of a hierarchy to express relationships among types. Instead I adopt a more flexible approach using duck typing implemented by parametric polymorphism and extensive overloading to provide a more general type-system. This work has resulted in a new dialect of C language, called C∀ (C-for-all).

Monitoring, Visualization and Debugging

Getting a concurrent program to work correctly, efficiently and with maximal parallelism can be very difficult. I develop techniques and tools to help understand the dynamic behaviour of a concurrent program with the goal of increasing program performance. This work has produced a toolkit for monitoring, visualizing, and debugging μC++ programs, called MVD.

Persistence

Data structures containing pointers (versus values) cannot be stored directly to/from disk, because pointers represent absolute locations in memory. I am also interested in memory-mapped single-level stores, which allow data, including pointers, to be transparently transferred to and retrieved from disk storage implicitly via virtual memory. To handle the address consistency problem, i.e., pointers to addresses that have changed location, exact positioning of data is used so no relocation or adjusting of pointers is necessary. This work has produced a toolkit, called μDatabase, for building persistent data structures using the exact-positioning approach to memory-mapped single-level stores.

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Papers, Supervision

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Technical Writing

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