When an actor has already been registered with the arbiter it should
exist in the registry and thus the wait event should have been removed.
Check that the registry indeed holds an event before clearing it.
This is purely for documentation purposes for now as it should be
obvious a bunch of the signatures aren't using the correct "generics"
syntax (i.e. the use of `(str, int)` instead of `typing.Tuple[str, int])`)
in a bunch of places. We're also not using a type checker yet and besides,
`trio` doesn't really expose a lot of its internal types very well.
2SQASH
Something changed in 3.7 (likely to do with changes to the core
import system) that requires explicitly importing our version
of `forkserver.main()` in order to guarantee the server runs our
module code. Override `forkserver.ensure_running()`; specifically,
modify the python launch command.
This ensures that internal errors received from a remote actor are
indeed raised even in the `MainProcess` **before** comms tasks are
cancelled. Internal error in this case means any error packet received
on a channel that doesn't have a `cid` header. RPC errors (which **do**
have a `cid` header) are still forwarded to the consuming caller as usual.
If an internal error is bubbled up from some sub-actor throw that error
into the `MainProcess` "main" async function / coro in order to trigger
nursery teardowns (i.e. cancellations) that need to be done.
I'll likely change this shortly back to where we run a "main task"
inside `actor._async_main()`...
Allows for waiting on another actor (by name) to register with the
arbiter. This makes synchronized actor spawning and consecutive task
coordination easier to accomplish from within sub-actors.
Resolves#31