This appears to demonstrate the same bug found in #156. It looks like
cancelling a subactor with a child, while that child is running sync code,
can result in the child never getting cancelled due to some strange
condition where the internal nurseries aren't being torn down as
expected when a `trio.Cancelled` is raised.
The real issue is if the root nursery gets cancelled prior to
de-registration with the arbiter. This doesn't seem easy to
reproduce by side effect of a KBI however that is how it was
discovered in practise.
There was code from the last de-registration fix PR that I had commented
(to do with shielding arbiter dereg steps in `Actor._async_main()`) because
the block didn't seem to make a difference under infinite streaming
tests. Turns out it **for sure** is needed under certain conditions (likely
if the actor's root nursery is cancelled prior to actor nursery exit).
This was an attempt to simulate the failure mode if you manually close the
stream **before** cancelling the containing **actor**.
More tests to come I guess.
This truly reproduces #141. It turns out the problem only occurs when
we're cancelled in the middle of consuming "infinite streams".
Good news is this tests a lot of edge cases :)
- ease up on first stream test run deadline
- skip streaming tests in CI for mp backend, period
- give up on > 1 depth nested spawning with mp
- completely give up on slow spawning on windows
Verify ctrl-c, as a user would trigger it, properly cancels the actor
tree. This was an issue with `trio-run-in-process` that clearly wasn't
being handled correctly but for sure is now with the plain old
`trio` process spawner.
Resolves#115
Parametrize our docs example test to include all (now fixed) examples
from the `READ.rst`. The examples themselves have been fixed/corrected
to run but they haven't yet been updated in the actual docs. Once #99
lands these example scripts will be directly included in our
documentation so there will be no possibility of presenting incorrect
examples to our users! This technically fixes#108 even though the new
example aren't going to be included directly in our docs until #99
lands.
Apply the fix from @chrizzFTD where we invoke the entry point using
module exec mode on a ``__main__.py`` and import the
``test_example::`main()` from within that entry point script.
A per #98 we need tests for examples from the docs as they would be run
by a user copy and pasting the code. This adds a small system for loading
examples from an "examples/" directory and executing them in
a subprocess while checking the output. We can use this to also verify
end-to-end expected logging output on std streams (ex. logging on
stderr).
To expand this further we can parameterize the test list using the
contents of the examples directory instead of hardcoding the script
names as I've done here initially.
Also, fix up the current readme examples to have the required/proper `if
__name__ == '__main__'` script guard.
Tyler Goodlet
Guillermo Rodriguez