This took a ton of tinkering and a rework of the actor nursery tear down
logic. The main changes include:
- each subprocess is now spawned from inside a trio task
from one of two containing nurseries created in the body of
`tractor.open_nursery()`: one for `run_in_actor()` processes and one for
`start_actor()` "daemons". This is to address the need for
`trio-run-in_process.open_in_process()` opening a nursery which must
be closed from the same task that opened it. Using this same approach
for `multiprocessing` seems to work well. The nurseries are waited in
order (rip actors then daemon actors) during tear down which allows
for avoiding the recursive re-entry of `ActorNursery.wait()` handled
prior.
- pull out all the nested functions / closures that were in
`ActorNursery.wait()` and move into the `_spawn` module such that
that process shutdown logic takes place in each containing task's
code path. This allows for vastly simplifying `.wait()` to just contain an
event trigger which initiates process waiting / result collection.
Likely `.wait()` should just be removed since it can no longer be used
to synchronously wait on the actor nursery.
- drop `ActorNursery.__aenter__()` / `.__atexit__()` and move this
"supervisor" tear down logic into the closing block of `open_nursery()`.
This not only cleans makes the code more comprehensible it also
makes our nursery implementation look more like the one in `trio`.
Resolves#93
Get a few more things working:
- fail reliably when remote module loading goes awry
- do a real hacky job of module loading using `sys.path` stuffsies
- we're still totally borked when trying to spin up and quickly cancel
a bunch of subactors...
It's a small move forward I guess.
Add full support for using the "spawn" process starting method as per:
https://docs.python.org/3/library/multiprocessing.html#contexts-and-start-methods
Add a `spawn_method` argument to `tractor.run()` for specifying the
desired method explicitly. By default use the "fastest" method available.
On *nix systems this is the original "forkserver" method.
This should be the solution to getting windows support!
Resolves#60
Tyler Goodlet
Tyler Goodlet
Christian López Barrón