Tests that appropriate `Context` exit state, the relay of
a `ContextCancelled` error and its `.canceller: tuple[str, str]` value
are set when an inter-peer cancellation happens via an "out of band"
request method (in this case using `Portal.cancel_actor()` and that
cancellation is propagated "horizontally" to other peers. Verify that
any such cancellation scenario which also experiences an "error during
`ContextCancelled` handling" DOES NOT result in that further error being
suppressed and that the user's exception bubbles out of the
`Context.open_context()` block(s) appropriately!
Likely more tests to come as well as some factoring of the teardown
state checks where possible.
Pertains to serious testing the major work landing in #357
Move over relevant test from the "context semantics" test module which
was already verifying peer-caused-`ContextCancelled.canceller: tuple`
error info and propagation during an inter-peer cancellation scenario.
Also begin a more general set of inter-peer cancellation tests starting
with the simplest case where when a peer is cancelled the parent should
NOT get an "muted" `trio.Cancelled` and instead
a `tractor.ContextCancelled` with a `.canceller: tuple` which points to
the sibling actor which requested the peer cancel.
Demonstrates fixed size frame-oriented reads by the child where the
parent only transmits a "read" stream msg on "frame fill events" such
that the child incrementally reads the shm list data (much like in
a real-time-buffered streaming system).
This actually caught further runtime bugs so it's gud i tried..
Add overrun-ignore enabled / disabled cases and error catching for all
of them. More or less this should cover every possible outcome when
it comes to setting `allow_overruns: bool` i hope XD
Turns out stuff was totally broken in these cases because we're either
closing the underlying mem chan too early or not handling the
"allow_overruns" mode's cancellation correctly..
These will verify new changes to the runtime/messaging core which allows
us to adopt an "ignore cancel if requested by us" style handling of
`ContextCancelled` more like how `trio` does with
`trio.Nursery.cancel_scope.cancel()`. We now expect
a `ContextCancelled.canceller: tuple` which is set to the actor uid of
the actor which requested the cancellation which eventually resulted in
the remote error-msg.
Also adds some experimental tweaks to the "backpressure" test which it
turns out is very problematic in coordination with context cancellation
since blocking on the feed mem chan to some task will block the ipc msg
loop and thus handling of cancellation.. More to come to both the test
and core to address this hopefully since right now this test is failing.
With the new fancy `_pytest.pathlib.import_path()` we can do real
parametrization of the example-script-module code and thus configure
whether the child, parent, or both silently break the IPC connection.
Parametrize the test for all the above mentioned cases as well as the
case where the IPC never breaks but we still simulate the user hammering
ctl-c / SIGINT to terminate the actor tree. Adjust expected errors based
on each case and heavily document each of these.
Turns out this test was being silently ignored due to incorrect usage of
sync opening of our `.open_nursery()` block (with a `with` not `async
with`) and thus was an noop XD
Instead this fixes the test to call a `tractor` discovery built-in
without starting the runtime (which is now done implicitly when a user
opens a nursery) which should result in the prior expected outcome,
a `RuntimeError`.
Tyler Goodlet