static SUPERVISOR: Mutex<Option<Supervisor>>Expand description
A handle to the single, shared supervisor process across all MiriMachines.
Since it would be very difficult to trace multiple FFI calls in parallel, we
need to ensure that either (a) only one MiriMachine is performing an FFI call
at any given time, or (b) there are distinct supervisor and child processes for
each machine. The former was chosen here.
This should only contain a None if the supervisor has not (yet) been initialised;
otherwise, if init_sv was called and did not error, this will always be nonempty.