""" Cancellation and error propagation """ from functools import partial import os import signal import platform import time from itertools import repeat from typing import Type import pytest import trio import tractor from tractor._testing import ( tractor_test, ) from tractor._testing.trace import FailAfterWTraceFactory from tractor.trionics import ( collapse_eg, gather_contexts, ) from .conftest import no_windows _non_linux: bool = platform.system() != 'Linux' _friggin_windows: bool = platform.system() == 'Windows' pytestmark = [ # Multi-actor cancel cascades under # `--spawn-backend=subint` trip the abandoned-subint # GIL-hostage class — a stuck subint can starve the # parent's trio loop and block cancel-delivery. # Apply the skip module-wide rather than per-test # since every test here exercises the same cascade. pytest.mark.skipon_spawn_backend( 'subint', reason=( 'XXX SUBINT GIL-CONTENTION HANGING TEST XXX\n' 'Cancel cascades under ' '`--spawn-backend=subint` trip the abandoned-subint ' 'GIL-hostage class — see\n' ' - `ai/conc-anal/subint_sigint_starvation_issue.md` ' '(GIL-hostage, SIGINT-unresponsive)\n' ' - `ai/conc-anal/subint_cancel_delivery_hang_issue.md` ' '(sibling: parent parks on dead chan)\n' ' - https://github.com/goodboy/tractor/issues/379 ' '(subint umbrella)\n' ) ), pytest.mark.usefixtures( 'reap_subactors_per_test', # NOTE, cancellation tests stress the SIGKILL # `hard_kill` path which leaks UDS sock-files when # the subactor's IPC server `finally:` cleanup # doesn't run. Track per-test for blame attribution. 'track_orphaned_uds_per_test', # NOTE, cancel-cascade timing races (see # `test_nested_multierrors`) can also leave a # subactor spinning at 100% CPU when its cancel # signal got swallowed mid-handshake. Catches the # runaway-loop class that doesn't leak UDS socks # but burns the box. 'detect_runaway_subactors_per_test', ), ] async def assert_err(delay=0): await trio.sleep(delay) assert 0 @tractor.context async def assert_err_ctx( ctx: tractor.Context, delay: float = 0, ) -> None: ''' `@context` shim around `assert_err()` so the multi-actor error tests can fan-out one-shot erroring subactors via `Portal.open_context()` + `gather_contexts()` instead of the removed `ActorNursery.run_in_actor()` (#477). ''' await ctx.started() await trio.sleep(delay) assert 0 async def sleep_forever(): await trio.sleep_forever() async def do_nuthin(): # just nick the scheduler await trio.sleep(0) @pytest.mark.parametrize( 'args_err', [ # expected to be thrown in assert_err ({}, AssertionError), # argument mismatch raised in _invoke() ({'unexpected': 10}, TypeError) ], ids=['no_args', 'unexpected_args'], ) def test_remote_error( reg_addr: tuple, args_err: tuple[dict, Type[Exception]], set_fork_aware_capture, ): ''' Verify an error raised in a subactor that is propagated to the parent nursery, contains the underlying boxed builtin error type info and causes cancellation and reraising all the way up the stack. ''' args, errtype = args_err async def main(): async with tractor.open_nursery( registry_addrs=[reg_addr], ) as nursery: # `to_actor.run()` blocks on the one-shot's result and # raises the remote error directly here in the caller's # task (a bad-arg `TypeError` likewise relays as a # `RemoteActorError`). try: await tractor.to_actor.run( assert_err, an=nursery, name='errorer', **args ) except tractor.RemoteActorError as err: assert err.boxed_type == errtype print("Look Maa that actor failed hard, hehh") raise # ensure boxed errors if args: with pytest.raises(tractor.RemoteActorError) as excinfo: trio.run(main) assert excinfo.value.boxed_type == errtype else: # the root task will also error on the `Portal.result()` # call so we expect an error from there AND the child. # |_ tho seems like on new `trio` this doesn't always # happen? with pytest.raises(( BaseExceptionGroup, tractor.RemoteActorError, )) as excinfo: trio.run(main) # ensure boxed errors are `errtype` err: BaseException = excinfo.value if isinstance(err, BaseExceptionGroup): suberrs: list[BaseException] = err.exceptions else: suberrs: list[BaseException] = [err] for exc in suberrs: assert exc.boxed_type == errtype def test_multierror( reg_addr: tuple[str, int], start_method: str, # parametrized set_fork_aware_capture, #: Callable, ): ''' Verify concurrent one-shot subactors erroring propagate a remote error out of the `gather_contexts()` fan-out — grouped as a `BaseExceptionGroup`, or (under cancel-on-first, where the 2nd errorer is cancelled before relaying its own exc) collapsed to a single `RemoteActorError`. NB the legacy `run_in_actor()` reaped *all* children at nursery teardown so this always yielded a BEG-of-N; the `to_actor` fan-out is cancel-on-first, so accept either shape. ''' async def main(): async with tractor.open_nursery( registry_addrs=[reg_addr], ) as an: portals = [ await an.start_actor( f'errorer{i}', enable_modules=[__name__], ) for i in range(2) ] # both one-shot subactors error concurrently, so the # `gather_contexts()` task-nursery collects them into a # `BaseExceptionGroup` (was two non-blocking # `run_in_actor()`s reaped at nursery teardown). async with gather_contexts( mngrs=[ p.open_context(assert_err_ctx) for p in portals ], ): pass with pytest.raises(( BaseExceptionGroup, tractor.RemoteActorError, )): trio.run(main) async def do_nothing(): pass @pytest.mark.parametrize( 'mechanism', [ 'nursery_cancel', KeyboardInterrupt, ]) def test_cancel_single_subactor( reg_addr: tuple, mechanism: str|KeyboardInterrupt, ): ''' Ensure a ``ActorNursery.start_actor()`` spawned subactor cancels when the nursery is cancelled. ''' async def spawn_actor(): ''' Spawn an actor that blocks indefinitely then cancel via either `ActorNursery.cancel()` or an exception raise. ''' async with tractor.open_nursery( registry_addrs=[reg_addr], ) as nursery: portal = await nursery.start_actor( 'nothin', enable_modules=[__name__], ) assert (await portal.run(do_nothing)) is None if mechanism == 'nursery_cancel': # would hang otherwise await nursery.cancel() else: raise mechanism if mechanism == 'nursery_cancel': trio.run(spawn_actor) else: with pytest.raises(mechanism): trio.run(spawn_actor) async def stream_forever(): for i in repeat("I can see these little future bubble things"): # each yielded value is sent over the ``Channel`` to the # parent actor yield i await trio.sleep(0.01) @tractor_test( timeout=6, ) async def test_cancel_infinite_streamer( reg_addr: tuple, start_method: str, set_fork_aware_capture, ): # stream for at most 1 seconds with ( trio.fail_after(4), trio.move_on_after(1) as cancel_scope ): async with tractor.open_nursery() as n: portal = await n.start_actor( 'donny', enable_modules=[__name__], ) # this async for loop streams values from the above # async generator running in a separate process async with portal.open_stream_from(stream_forever) as stream: async for letter in stream: print(letter) # we support trio's cancellation system assert cancel_scope.cancelled_caught assert n.cancel_called @pytest.mark.parametrize( 'num_actors_and_errs', [ # daemon actors sit idle while one-shot task actors error out (1, tractor.RemoteActorError, AssertionError, (assert_err, {}), None), (2, BaseExceptionGroup, AssertionError, (assert_err, {}), None), (3, BaseExceptionGroup, AssertionError, (assert_err, {}), None), # 1 daemon actor errors out while one-shot task actors sleep forever (3, tractor.RemoteActorError, AssertionError, (sleep_forever, {}), (assert_err, {}, True)), # daemon actors error out after brief delay while one-shot task # actors complete quickly (3, tractor.RemoteActorError, AssertionError, (do_nuthin, {}), (assert_err, {'delay': 1}, True)), # daemon complete quickly delay while one-shot task # actors error after brief delay (3, BaseExceptionGroup, AssertionError, (assert_err, {'delay': 1}), (do_nuthin, {}, False)), ], ids=[ '1_one_shot_fails', '2_one_shots_fail', '3_one_shots_fail', '1_daemon_actors_fail', '1_daemon_actors_fail_all_one_shots_dun_quick', 'no_daemon_actors_fail_all_one_shots_sleep_then_fail', ], ) @tractor_test( timeout=10, ) async def test_some_cancels_all( num_actors_and_errs: tuple, reg_addr: tuple, start_method: str, loglevel: str, set_fork_aware_capture, #: Callable, ): ''' Verify a subset of failed subactors causes all others in the nursery to be cancelled just like the strategy in trio. This is the first and only supervisory strategy at the moment. One-shot subactors run as concurrent `to_actor.run()` tasks in a local task-nursery so their errors raise WHILE the actor-nursery block is still open (vs the legacy `run_in_actor()` teardown-reap); the first error cancels the sibling one-shots (whose `trio.Cancelled`s the task-nursery absorbs) so the group shape is 1..num_actors `RemoteActorError`s depending on relay-vs-cancel timing — with `collapse_eg()` unwrapping the deterministic single-error cases to a bare `RemoteActorError`. ''' ( num_actors, first_err, err_type, one_shot_func, da_func, ) = num_actors_and_errs try: async with tractor.open_nursery() as an: # spawn the same number of deamon actors which should be cancelled dactor_portals = [] for i in range(num_actors): dactor_portals.append(await an.start_actor( f'deamon_{i}', enable_modules=[__name__], )) func, kwargs = one_shot_func async with ( collapse_eg(), trio.open_nursery() as tn, ): for i in range(num_actors): # schedule one-shot task actor(s); errors # raise into this task-nursery scope. tn.start_soon( partial( tractor.to_actor.run, func, an=an, name=f'actor_{i}', **kwargs, ) ) if da_func: func, kwargs, expect_error = da_func for portal in dactor_portals: # if this function fails then we should error # here and the nursery should teardown all # other actors try: await portal.run(func, **kwargs) except tractor.RemoteActorError as err: assert err.boxed_type == err_type # we only expect this first error to propogate # (all other daemons are cancelled before they # can be scheduled) num_actors = 1 # reraise so nursery teardown is triggered raise else: if expect_error: pytest.fail( "Deamon call should fail at checkpoint?") # should error here with a `RemoteActorError` or a beg of them except ( BaseExceptionGroup, tractor.RemoteActorError, ) as _err: err = _err if isinstance(err, BaseExceptionGroup): # only the concurrent multi-error cases can group; the # relay-vs-cancel race means anywhere from 1 (all # siblings cancelled before relaying) up to all # `num_actors` errors may populate the group. assert first_err is BaseExceptionGroup assert 1 <= len(err.exceptions) <= num_actors for exc in err.exceptions: assert isinstance(exc, tractor.RemoteActorError) assert exc.boxed_type == err_type else: assert err.boxed_type == err_type assert an.cancel_called is True assert not an._children else: pytest.fail("Should have gotten a remote assertion error?") async def spawn_and_error( breadth: int, depth: int, ) -> None: name = tractor.current_actor().name async with tractor.open_nursery() as nursery: for i in range(breadth): if depth > 0: args = ( spawn_and_error, ) kwargs = { 'name': f'spawner_{i}_depth_{depth}', 'breadth': breadth, 'depth': depth - 1, } else: args = ( assert_err, ) kwargs = { 'name': f'{name}_errorer_{i}', } await nursery.run_in_actor(*args, **kwargs) # NOTE: `main_thread_forkserver` capture-fd hang class is no # longer skipped here — `--capture=sys` (the new `pyproject.toml` # default) sidesteps the pipe-buffer-fill deadlock for # `test_nested_multierrors`. See # `ai/conc-anal/subint_forkserver_test_cancellation_leak_issue.md` # / #449 for the post-mortem. # @pytest.mark.timeout( # 10, # method='thread', # ) @pytest.mark.parametrize( 'depth', [1, 3], ids='depth={}'.format, ) @tractor_test( # XXX this OUTER `trio.fail_after` wall MUST exceed the # largest INNER `fail_after_w_trace()` budget set in the body # below (max = the MTF depth=3 == 30s case, further scaled by # `cpu_scaling_factor()` on CI/throttle). Otherwise it fires # FIRST and pre-empts the inner snapshot-capturing deadline, # turning a graceful `TooSlowError`+ptree-dump into an opaque # outer timeout-kill (the prior `timeout=10` did exactly this # — it was *smaller* than the 12s trio depth=3 budget, so the # depth-3 case `FAILED` on slow CI instead of dumping). # Trio backend is fast and won't notice the extra budget. # See `ai/conc-anal/cancel_cascade_too_slow_under_main_thread_forkserver_issue.md`. timeout=40, ) async def test_nested_multierrors( reg_addr: tuple, loglevel: str, start_method: str, set_fork_aware_capture, fail_after_w_trace: FailAfterWTraceFactory, request: pytest.FixtureRequest, depth: int, ): ''' Test that failed actor sets are wrapped in `BaseExceptionGroup`s. Parametrized over recursion `depth ∈ {1, 3}`: - `depth=1`: shallow tree (2 spawners × 2 errorers, 2 levels). Cascade completes well within budget on ALL backends including MTF — regression-safety green case. - `depth=3`: deep tree (2 spawners × recursive depth-3 spawn-and-error). On `main_thread_forkserver` this trips the cancel-cascade shape-mismatch bug class (see `ai/conc-anal/cancel_cascade_too_slow_under_main_thread_forkserver_issue.md`) — xfailed below. ''' # XXX: `multiprocessing.forkserver` can't handle nested # spawning at any depth — hangs / broken-pipes. Pre-existing # backend limitation, NOT depth-specific. if start_method == 'forkserver': pytest.skip("Forksever sux hard at nested spawning...") subactor_breadth = 2 # MTF backend trips a probabilistic timing race in the # cancel-cascade — NOT depth-gated; depth amplifies the # variance so depth=3 misses nearly every run while # depth=1 misses occasionally. Both get the xfail mark # (with `strict=False`) since the bug class can fire at # either depth. # # The scenario in detail: # # T=0 spawn spawner_0 + spawner_1 in parallel # T=t1 spawner_0's child errors → # RemoteActorError reaches root nursery # T=t1+ε root nursery starts cancelling # spawner_1's portal-wait # T=t2 spawner_1's child errors → tries to send # RemoteActorError back # # if t2 < t1+ε: BEG = [RAE, RAE] ← clean (xpass) # if t2 > t1+ε: BEG = [RAE, Cancelled] ← race tripped (xfail) # # i.e. the assertion below (`isinstance(_, RemoteActorError)`) # fails iff cancel-delivery beats the other tree's natural # error-propagation. Depth amplifies `t2-t1` variance # (longer per-tree paths = more skew); under MTF the # fork-spawn jitter + UDS-contention widens both `t1` and # `t2` further. # # With `strict=False` the clean-cascade cases (most # depth=1 runs, rare depth=3 runs) report as `xpassed` # while the race-tripped cases report as `xfailed` — # neither flakes `--lf`. When MTF cancel-cascade # eventually speeds up enough to close the race even at # depth=3, BOTH variants will reliably `xpass` and # pytest will yell — our signal to drop the marker. See # `ai/conc-anal/cancel_cascade_too_slow_under_main_thread_forkserver_issue.md`. # # Probe CPU throttle ONCE up-front (folds in the sustained-load # power-cap that static freq reads miss): used BOTH to inflate # the deadline budget below AND to xfail depth=3, whose failure # mode under throttle is a runtime-internal reap deadline — not # a test-budget miss. See `scripts/cpu-perf-check`. from .conftest import cpu_perf_headroom headroom: float = cpu_perf_headroom() if start_method == 'main_thread_forkserver': request.node.add_marker( pytest.mark.xfail( strict=False, reason=( f'MTF cancel-cascade shape-mismatch at ' f'depth={depth} (Cancelled races ' f'RemoteActorError in BEG); see conc-anal/' 'cancel_cascade_too_slow_under_main_thread_forkserver_issue.md' ), ) ) # Under CPU throttle (incl. the sustained-load power-cap that # static freq reads miss) the DEEP depth=3 tree trips tractor's # INTERNAL reap deadlines (`soft_kill`/`hard_kill` # `move_on_after`/`terminate_after=1.6`) before slow subprocs # exit, injecting a `Cancelled(source='deadline')` into the BEG # — the SAME shape-mismatch class as the MTF xfail above, and # NOT fixable by inflating the test-level budget (the Cancelled # is minted inside the runtime, not by our `fail_after`). # xfail(strict=False) so it auto-clears the moment the box is # un-throttled (`headroom == 1.`); depth=1's shallow tree stays # under those internal deadlines so it just rides the budget # inflation below. See `scripts/cpu-perf-check`. elif ( depth == 3 and headroom != 1. ): request.node.add_marker( pytest.mark.xfail( strict=False, reason=( 'CPU throttled — tractor reap deadline injects ' 'Cancelled into BEG; see conc-anal/' 'trio_033_cancel_cascade_slowdown_depth3_issue.md' ), ) ) # Per-backend/-depth budgets: in the non-hang case the # whole spawn + cancel-cascade should complete in well # under these. On the borderline hang case the # `fail_after_w_trace` fires `TooSlowError` AND captures a # ptree/wchan/py-spy snapshot to # `$XDG_CACHE_HOME/tractor/hung-dumps/` for offline # inspection. See # `ai/conc-anal/cancel_cascade_too_slow_under_main_thread_forkserver_issue.md`. # # NOTE: the `trio` depth=3 budget was bumped 6 -> 12s after # the `trio` 0.29 -> 0.33 lock bump (commit c7741bba) slowed # the depth-3 cancel-cascade from <6s to ~7-8s; the 6s # deadline was firing and its `Cancelled(source='deadline')` # (trio 0.33 cancel-reason metadata) collapsed a BEG branch, # breaking the `RemoteActorError` assertion below. depth=1 # still finishes in ~3s so keeps the 6s budget. See # `ai/conc-anal/trio_033_cancel_cascade_slowdown_depth3_issue.md`. match (start_method, depth): case ('trio', 1): timeout = 6 case ('trio', 3): timeout = 12 case ('main_thread_forkserver', 1): timeout = 16 case ('main_thread_forkserver', 3): timeout = 30 # any other fork-based backend (`mp_spawn` et al) pays # the same per-spawn round-trip costs as MTF so rides # its budgets; without a default arm `timeout` is left # unbound -> `UnboundLocalError` at the scaling below. case (_, 1): timeout = 16 case (_, 3): timeout = 30 # inflate the budget by the throttle headroom probed above so # a slow box doesn't masquerade as a deadline regression. # NOTE, `headroom = cpu_perf_headroom()` (set above) is the # SUPERSET of `cpu_scaling_factor()` — it folds in the static # cpu-freq scaling + slow-CI bump AND the sustained-load # throttle probe this depth-3 cascade was the poster child for. if headroom != 1.: timeout *= headroom async with fail_after_w_trace(timeout): try: async with tractor.open_nursery() as nursery: for i in range(subactor_breadth): await nursery.run_in_actor( spawn_and_error, name=f'spawner_{i}', breadth=subactor_breadth, depth=depth, ) except BaseExceptionGroup as err: assert len(err.exceptions) == subactor_breadth for subexc in err.exceptions: # verify first level actor errors are wrapped as remote if _friggin_windows: # windows is often too slow and cancellation seems # to happen before an actor is spawned if isinstance(subexc, trio.Cancelled): continue elif isinstance(subexc, tractor.RemoteActorError): # on windows it seems we can't exactly be sure wtf # will happen.. assert subexc.boxed_type in ( tractor.RemoteActorError, trio.Cancelled, BaseExceptionGroup, ) elif isinstance(subexc, BaseExceptionGroup): for subsub in subexc.exceptions: if subsub in (tractor.RemoteActorError,): subsub = subsub.boxed_type assert type(subsub) in ( trio.Cancelled, BaseExceptionGroup, ) else: assert isinstance(subexc, tractor.RemoteActorError) if depth > 0 and subactor_breadth > 1: # XXX not sure what's up with this.. # on windows sometimes spawning is just too slow and # we get back the (sent) cancel signal instead if _friggin_windows: if isinstance(subexc, tractor.RemoteActorError): assert subexc.boxed_type in ( BaseExceptionGroup, tractor.RemoteActorError ) else: assert isinstance(subexc, BaseExceptionGroup) else: assert subexc.boxed_type is ExceptionGroup else: assert subexc.boxed_type in ( tractor.RemoteActorError, trio.Cancelled ) @no_windows def test_cancel_via_SIGINT( reg_addr: tuple, loglevel: str, start_method: str, ): ''' Ensure that a control-C (SIGINT) signal cancels both the parent and child processes in trionic fashion ''' pid: int = os.getpid() async def main(): with trio.fail_after(2): async with tractor.open_nursery( registry_addrs=[reg_addr], ) as tn: await tn.start_actor('sucka') if 'mp' in start_method: time.sleep(0.1) os.kill(pid, signal.SIGINT) await trio.sleep_forever() with pytest.raises(KeyboardInterrupt): trio.run(main) @no_windows def test_cancel_via_SIGINT_other_task( reg_addr: tuple, loglevel: str, start_method: str, spawn_backend: str, ): ''' Ensure that a control-C (SIGINT) signal cancels both the parent and child processes in trionic fashion even a subprocess is started from a seperate ``trio`` child task. ''' from .conftest import cpu_perf_headroom pid: int = os.getpid() timeout: float = ( 4 if _non_linux else 2 ) if _friggin_windows: # smh timeout += 1 # latency headroom for static cpu-freq scaling + sustained-load # throttle + CI (auto-cpufreq et al.); see `cpu_perf_headroom()`. headroom: float = cpu_perf_headroom() if headroom != 1.: timeout *= headroom async def spawn_and_sleep_forever( task_status=trio.TASK_STATUS_IGNORED ): async with tractor.open_nursery( registry_addrs=[reg_addr], ) as tn: for i in range(3): await tn.run_in_actor( sleep_forever, name='namesucka', ) task_status.started() await trio.sleep_forever() async def main(): # should never timeout since SIGINT should cancel the current program with trio.fail_after(timeout): async with trio.open_nursery() as tn: await tn.start(spawn_and_sleep_forever) if 'mp' in spawn_backend: time.sleep(0.1) os.kill(pid, signal.SIGINT) # SIGINT -> `KeyboardInterrupt`; under `trio>=0.25`'s strict # exception-groups the KI surfaces wrapped in a (cancel-padded) # `BaseExceptionGroup` rather than bare — so accept either form # (replaces the now-deprecated `strict_exception_groups=False`, # and `collapse_eg()` can't help since the group is multi-exc: # the KI rides alongside the child-task `Cancelled`s). with pytest.raises(BaseException) as excinfo: trio.run(main) exc = excinfo.value assert ( isinstance(exc, KeyboardInterrupt) or ( isinstance(exc, BaseExceptionGroup) and exc.subgroup(KeyboardInterrupt) is not None ) ) async def spin_for(period=3): "Sync sleep." print(f'sync sleeping in sub-sub for {period}\n') time.sleep(period) async def spawn_sub_with_sync_blocking_task(): async with tractor.open_nursery() as an: print('starting sync blocking subactor..\n') await an.run_in_actor( spin_for, name='sleeper', ) print('exiting first subactor layer..\n') @pytest.mark.parametrize( 'man_cancel_outer', [ False, # passes if delay != 2 # always causes an unexpected eg-w-embedded-assert-err? pytest.param(True, marks=pytest.mark.xfail( reason=( 'always causes an unexpected eg-w-embedded-assert-err?' ) ), ), ], ) @no_windows def test_cancel_while_childs_child_in_sync_sleep( loglevel: str, start_method: str, is_forking_spawner: bool, debug_mode: bool, reg_addr: tuple, man_cancel_outer: bool, ): ''' Verify that a child cancelled while executing sync code is torn down even when that cancellation is triggered by the parent 2 nurseries "up". Though the grandchild should stay blocking its actor runtime, its parent should issue a "zombie reaper" to hard kill it after sufficient timeout. ''' if start_method == 'forkserver': pytest.skip( "`multiprocessing`'s forkserver sux hard at " "resuming from sync sleep..." ) async def main(): # # XXX BIG TODO NOTE XXX # # it seems there's a strange race that can happen # where where the fail-after will trigger outer scope # .cancel() which then causes the inner scope to raise, # # BaseExceptionGroup('Exceptions from Trio nursery', [ # BaseExceptionGroup('Exceptions from Trio nursery', # [ # Cancelled(), # Cancelled(), # ] # ), # AssertionError('assert 0') # ]) # # WHY THIS DOESN'T MAKE SENSE: # --------------------------- # - it should raise too-slow-error when too slow.. # * verified that using simple-cs and manually cancelling # you get same outcome -> indicates that the fail-after # can have its TooSlowError overriden! # |_ to check this it's easy, simplly decrease the timeout # as per the var below. # # - when using the manual simple-cs the outcome is different # DESPITE the `assert 0` which means regardless of the # inner scope effectively failing in the same way, the # bubbling up **is NOT the same**. # # delays trigger diff outcomes.. # --------------------------- # as seen by uncommenting various lines below there is from # my POV an unexpected outcome due to the delay=2 case. # # delay = 1 # no AssertionError in eg, TooSlowError raised. # delay = 2 # is AssertionError in eg AND no TooSlowError !? # is AssertionError in eg AND no _cs cancellation. delay = ( 6 if ( _non_linux or is_forking_spawner ) else 4 ) with trio.fail_after(delay) as _cs: # with trio.CancelScope() as cs: # ^XXX^ can be used instead to see same outcome. async with ( # tractor.trionics.collapse_eg(), # doesn't help tractor.open_nursery( hide_tb=False, debug_mode=debug_mode, registry_addrs=[reg_addr], ) as an, ): await an.run_in_actor( spawn_sub_with_sync_blocking_task, name='sync_blocking_sub', ) await trio.sleep(1) if man_cancel_outer: print('Cancelling manually in root') _cs.cancel() # trigger exc-srced taskc down # the actor tree. print('RAISING IN ROOT') assert 0 with pytest.raises(AssertionError): trio.run(main) def test_fast_graceful_cancel_when_spawn_task_in_soft_proc_wait_for_daemon( start_method: str, ): ''' This is a very subtle test which demonstrates how cancellation during process collection can result in non-optimal teardown performance on daemon actors. The fix for this test was to handle ``trio.Cancelled`` specially in the spawn task waiting in `proc.wait()` such that ``Portal.cancel_actor()`` is called before executing the "hard reap" sequence (which has an up to 3 second delay currently). In other words, if we can cancel the actor using a graceful remote cancellation, and it's faster, we might as well do it. ''' kbi_delay = 0.5 timeout: float = 2.9 if _friggin_windows: # smh timeout += 1 # CPU-scaling / sustained-throttle / CI latency headroom — macOS # CI especially is slow for this graceful-vs-hard-reap timing # race; see `cpu_perf_headroom()`. from .conftest import cpu_perf_headroom timeout *= cpu_perf_headroom() async def main(): start = time.time() try: async with trio.open_nursery() as nurse: async with tractor.open_nursery() as tn: p = await tn.start_actor( 'fast_boi', enable_modules=[__name__], ) async def delayed_kbi(): await trio.sleep(kbi_delay) print(f'RAISING KBI after {kbi_delay} s') raise KeyboardInterrupt # start task which raises a kbi **after** # the actor nursery ``__aexit__()`` has # been run. nurse.start_soon(delayed_kbi) await p.run(do_nuthin) # need to explicitly re-raise the lone kbi..now except* KeyboardInterrupt as kbi_eg: assert (len(excs := kbi_eg.exceptions) == 1) raise excs[0] finally: duration = time.time() - start if duration > timeout: raise trio.TooSlowError( 'daemon cancel was slower then necessary..' ) with pytest.raises(KeyboardInterrupt): trio.run(main)