The Memory Level Paralysm in a Camel Garbage Collector

Stephen Dolan works on Jane Street’s Tools and Compilers team where he focuses on the OCaml compiler. In this episode, Stephen and Ron take a trip down memory lane, discussing how to manage computer memory efficiently and safely. They consider trade-offs between reference counting and garbage collection, the surprising gains achieved by prefetching, and how new language features like local allocation and unboxed types could give OCaml users more control over their memory.

You can find the transcript for this episode  on our website.

Some links to topics that came up in the discussion:

• Stephen’s command-line JSON processor, jq
• Stephen’s Cambridge dissertation, “Algebraic Subtyping”, and a protoype implementation of mlsub, a language based on those ideas.
• A post from Stephen on how to benchmark different memory allocators.
• A Jane Street tech talk on “Unboxed Types for OCaml”, and an RFC in the OCaml RFC repo.
• A paper from Stephen and KC Sivaramakrishnan called “Bounding Data Races in Space and Time”, which is all about a new and better memory model for Multicore OCaml.
• Another paper describing the design of OCaml’s multicore GC.
• The Rust RFC for Higher-ranked trait bounds.