* JShell shotdown's doc says this:

" This occurs either because the client process has ended (e.g. called System.exit(0)) or the connection has been shutdown, as by close(). Each call adds a new subscription."

So, a separate process for execution is hinted in this method -- but I don't remember reading a summary of execution model. i.e., javac for compilation but execution is out of process via JDI. Perhaps that may be documented in summary?