Stefan Marr

Associate Professor (Senior Lecturer)
and Royal Society Industry Fellow

Stefan Marr I am working at the School of Computing at the University of Kent. My work focuses on programming language implementation techniques, complex concurrent systems, and tooling.

Much of work revolves around making interpreters faster, detecting and preventing concurrency bugs at run time, and use modern language runtime systems to provide programmers with better tooling.

For contact details see my page at the School of Computing.

Archive of posts with the tag Concurrency Models

Nov 17, 2023: The Changing “Guarantees” Given by Python's Global Interpreter Lock

In this blog post, I will look into the implementation details of CPython’s Global Interpreter Lock (GIL) and how they changed between Python 3.9 and the current development branch that will become Python 3.13.
Oct 15, 2017: Debugging Concurrency Is Hard, but We Can Do Something About It!

When we have to debug applications that use concurrency, perhaps written in Java, all we get from the debugger is a list of threads, perhaps some information about held locks, and the ability to step through each thread separately.
Jul 15, 2014: Why is Concurrent Programming hard?

In short, I think, it is hard because on the one hand there is not a single concurrency abstraction that fits all problems, and on the other hand the various different abstractions are rarely designed to be used in combination with each other.
Feb 17, 2014: Towards Composable Concurrency Abstractions

One of the big questions that came up during my PhD was: ok, now you got your fancy ownership-based metaobject protocol, and you can implement actors, agents, communicating sequential processes, software transactional memory, and many others, but now what? How are you going to use all of these in concert in one application? Finding a satisfying answer is unfortunately far from trivial.