V8 is asynchronous but single threaded, elixir gets m:n threaded. Job cancellation is trivial, safe, and automatically recovers the resource in elixir (the gpu devs have hooked cleanup in to the BEAM GC, because that is a thing). Moreover, if the caller of the agent asynchronously controlling the gpu is cancelled, it will also release the gpu automatically (in most cases, if you use the stdlib otp features instead of trying to build with primitives)
AFAIK V8 does make use of threads internally via libuv in order to make truly concurrent system calls. GPU device comms should fit perfectly in that design.
