Hi, I'm a Servo developer who worked on some of the Rust code that's in Firefox. Calls between C++ and Rust code in Firefox all go through "extern C" functions

Hi, I'm a Servo developer who worked on some of the Rust code that's in Firefox. Calls between C++ and Rust code in Firefox all go through "extern C" functions. Some of the code involves reference-counted smart pointers. We use RAII wrapper types in both Rust and C++ to ensure that refcounts are incremented and decremented correctly on either side of the FFI boundary. P.S. This old blog post is not about Rust-in-Firefox, but it does cover a related topic: How the Servo browser engine (written in Rust) interacts with the Spidermonkey JavaScript engine (written in C++ and embedded in both Gecko and Servo), including garbage-collected JavaScript objects: https://research.mozilla.org/2014/08/26/javascript-servos-only-garbage-collector/ https://research.mozilla.org/2014/08/26/javascript-servos-on...