Debugging concurrent systems is pretty hard, and we worked already for a while to make things a bit better. However, a big remaining problem is that bugs are not easily reproduced.
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.
Note: This post is meant for people familiar with Truffle. For introductory material, please see for instance this list.
This post, the fourth in the series, is about my current work on concurrency and tooling. As mentioned before, I believe that there is not a single concurrency model that is suitable for all problems we might want to solve. Actually, I think, this can be stated even stronger: Not a single concurrency model is appropriate for a majority of the problems we want to solve.