273 lines
8.3 KiB
Python

import time
from typing import Awaitable, Callable, Protocol, TypeVar
import outcome
import pytest
import trio
from .. import _core
from .._core._tests.tutil import slow
from .._timeouts import (
TooSlowError,
fail_after,
fail_at,
move_on_after,
move_on_at,
sleep,
sleep_forever,
sleep_until,
)
from ..testing import assert_checkpoints
T = TypeVar("T")
async def check_takes_about(f: Callable[[], Awaitable[T]], expected_dur: float) -> T:
start = time.perf_counter()
result = await outcome.acapture(f)
dur = time.perf_counter() - start
print(dur / expected_dur)
# 1.5 is an arbitrary fudge factor because there's always some delay
# between when we become eligible to wake up and when we actually do. We
# used to sleep for 0.05, and regularly observed overruns of 1.6x on
# Appveyor, and then started seeing overruns of 2.3x on Travis's macOS, so
# now we bumped up the sleep to 1 second, marked the tests as slow, and
# hopefully now the proportional error will be less huge.
#
# We also also for durations that are a hair shorter than expected. For
# example, here's a run on Windows where a 1.0 second sleep was measured
# to take 0.9999999999999858 seconds:
# https://ci.appveyor.com/project/njsmith/trio/build/1.0.768/job/3lbdyxl63q3h9s21
# I believe that what happened here is that Windows's low clock resolution
# meant that our calls to time.monotonic() returned exactly the same
# values as the calls inside the actual run loop, but the two subtractions
# returned slightly different values because the run loop's clock adds a
# random floating point offset to both times, which should cancel out, but
# lol floating point we got slightly different rounding errors. (That
# value above is exactly 128 ULPs below 1.0, which would make sense if it
# started as a 1 ULP error at a different dynamic range.)
assert (1 - 1e-8) <= (dur / expected_dur) < 1.5
return result.unwrap()
# How long to (attempt to) sleep for when testing. Smaller numbers make the
# test suite go faster.
TARGET = 1.0
@slow
async def test_sleep() -> None:
async def sleep_1() -> None:
await sleep_until(_core.current_time() + TARGET)
await check_takes_about(sleep_1, TARGET)
async def sleep_2() -> None:
await sleep(TARGET)
await check_takes_about(sleep_2, TARGET)
with assert_checkpoints():
await sleep(0)
# This also serves as a test of the trivial move_on_at
with move_on_at(_core.current_time()):
with pytest.raises(_core.Cancelled):
await sleep(0)
@slow
async def test_move_on_after() -> None:
async def sleep_3() -> None:
with move_on_after(TARGET):
await sleep(100)
await check_takes_about(sleep_3, TARGET)
async def test_cannot_wake_sleep_forever() -> None:
# Test an error occurs if you manually wake sleep_forever().
task = trio.lowlevel.current_task()
async def wake_task() -> None:
await trio.lowlevel.checkpoint()
trio.lowlevel.reschedule(task, outcome.Value(None))
async with trio.open_nursery() as nursery:
nursery.start_soon(wake_task)
with pytest.raises(RuntimeError):
await trio.sleep_forever()
class TimeoutScope(Protocol):
def __call__(self, seconds: float, *, shield: bool) -> trio.CancelScope: ...
@pytest.mark.parametrize("scope", [move_on_after, fail_after])
async def test_context_shields_from_outer(scope: TimeoutScope) -> None:
with _core.CancelScope() as outer, scope(TARGET, shield=True) as inner:
outer.cancel()
try:
await trio.lowlevel.checkpoint()
except trio.Cancelled:
pytest.fail("shield didn't work")
inner.shield = False
with pytest.raises(trio.Cancelled):
await trio.lowlevel.checkpoint()
@slow
async def test_move_on_after_moves_on_even_if_shielded() -> None:
async def task() -> None:
with _core.CancelScope() as outer, move_on_after(TARGET, shield=True):
outer.cancel()
# The outer scope is cancelled, but this task is protected by the
# shield, so it manages to get to sleep until deadline is met
await sleep_forever()
await check_takes_about(task, TARGET)
@slow
async def test_fail_after_fails_even_if_shielded() -> None:
async def task() -> None:
with pytest.raises(TooSlowError), _core.CancelScope() as outer, fail_after(
TARGET,
shield=True,
):
outer.cancel()
# The outer scope is cancelled, but this task is protected by the
# shield, so it manages to get to sleep until deadline is met
await sleep_forever()
await check_takes_about(task, TARGET)
@slow
async def test_fail() -> None:
async def sleep_4() -> None:
with fail_at(_core.current_time() + TARGET):
await sleep(100)
with pytest.raises(TooSlowError):
await check_takes_about(sleep_4, TARGET)
with fail_at(_core.current_time() + 100):
await sleep(0)
async def sleep_5() -> None:
with fail_after(TARGET):
await sleep(100)
with pytest.raises(TooSlowError):
await check_takes_about(sleep_5, TARGET)
with fail_after(100):
await sleep(0)
async def test_timeouts_raise_value_error() -> None:
# deadlines are allowed to be negative, but not delays.
# neither delays nor deadlines are allowed to be NaN
nan = float("nan")
for fun, val in (
(sleep, -1),
(sleep, nan),
(sleep_until, nan),
):
with pytest.raises(
ValueError,
match="^(deadline|`seconds`) must (not )*be (non-negative|NaN)$",
):
await fun(val)
for cm, val in (
(fail_after, -1),
(fail_after, nan),
(fail_at, nan),
(move_on_after, -1),
(move_on_after, nan),
(move_on_at, nan),
):
with pytest.raises(
ValueError,
match="^(deadline|`seconds`) must (not )*be (non-negative|NaN)$",
):
with cm(val):
pass # pragma: no cover
async def test_timeout_deadline_on_entry(mock_clock: _core.MockClock) -> None:
rcs = move_on_after(5)
assert rcs.relative_deadline == 5
mock_clock.jump(3)
start = _core.current_time()
with rcs as cs:
assert cs.is_relative is None
# This would previously be start+2
assert cs.deadline == start + 5
assert cs.relative_deadline == 5
cs.deadline = start + 3
assert cs.deadline == start + 3
assert cs.relative_deadline == 3
cs.relative_deadline = 4
assert cs.deadline == start + 4
assert cs.relative_deadline == 4
rcs = move_on_after(5)
assert rcs.shield is False
rcs.shield = True
assert rcs.shield is True
mock_clock.jump(3)
start = _core.current_time()
with rcs as cs:
assert cs.deadline == start + 5
assert rcs is cs
async def test_invalid_access_unentered(mock_clock: _core.MockClock) -> None:
cs = move_on_after(5)
mock_clock.jump(3)
start = _core.current_time()
match_str = "^unentered relative cancel scope does not have an absolute deadline"
with pytest.warns(DeprecationWarning, match=match_str):
assert cs.deadline == start + 5
mock_clock.jump(1)
# this is hella sketchy, but they *have* been warned
with pytest.warns(DeprecationWarning, match=match_str):
assert cs.deadline == start + 6
with pytest.warns(DeprecationWarning, match=match_str):
cs.deadline = 7
# now transformed into absolute
assert cs.deadline == 7
assert not cs.is_relative
cs = move_on_at(5)
match_str = (
"^unentered non-relative cancel scope does not have a relative deadline$"
)
with pytest.raises(RuntimeError, match=match_str):
assert cs.relative_deadline
with pytest.raises(RuntimeError, match=match_str):
cs.relative_deadline = 7
@pytest.mark.xfail(reason="not implemented")
async def test_fail_access_before_entering() -> None: # pragma: no cover
my_fail_at = fail_at(5)
assert my_fail_at.deadline # type: ignore[attr-defined]
my_fail_after = fail_after(5)
assert my_fail_after.relative_deadline # type: ignore[attr-defined]