python-testtools/testtools/tests/twistedsupport/test_spinner.py

328 lines
13 KiB
Python

# Copyright (c) testtools developers. See LICENSE for details.
"""Tests for the evil Twisted reactor-spinning we do."""
import os
import signal
from testtools.helpers import try_import
from testtools import skipIf
from testtools.matchers import (
Equals,
Is,
MatchesException,
Raises,
)
from ._helpers import NeedsTwistedTestCase
_spinner = try_import('testtools.twistedsupport._spinner')
defer = try_import('twisted.internet.defer')
Failure = try_import('twisted.python.failure.Failure')
class TestNotReentrant(NeedsTwistedTestCase):
def test_not_reentrant(self):
# A function decorated as not being re-entrant will raise a
# _spinner.ReentryError if it is called while it is running.
calls = []
@_spinner.not_reentrant
def log_something():
calls.append(None)
if len(calls) < 5:
log_something()
self.assertThat(
log_something, Raises(MatchesException(_spinner.ReentryError)))
self.assertEqual(1, len(calls))
def test_deeper_stack(self):
calls = []
@_spinner.not_reentrant
def g():
calls.append(None)
if len(calls) < 5:
f()
@_spinner.not_reentrant
def f():
calls.append(None)
if len(calls) < 5:
g()
self.assertThat(f, Raises(MatchesException(_spinner.ReentryError)))
self.assertEqual(2, len(calls))
class TestTrapUnhandledErrors(NeedsTwistedTestCase):
def test_no_deferreds(self):
marker = object()
result, errors = _spinner.trap_unhandled_errors(lambda: marker)
self.assertEqual([], errors)
self.assertIs(marker, result)
def test_unhandled_error(self):
failures = []
def make_deferred_but_dont_handle():
try:
1/0
except ZeroDivisionError:
f = Failure()
failures.append(f)
defer.fail(f)
result, errors = _spinner.trap_unhandled_errors(
make_deferred_but_dont_handle)
self.assertIs(None, result)
self.assertEqual(failures, [error.failResult for error in errors])
class TestRunInReactor(NeedsTwistedTestCase):
def make_reactor(self):
from twisted.internet import reactor
return reactor
def make_spinner(self, reactor=None):
if reactor is None:
reactor = self.make_reactor()
return _spinner.Spinner(reactor)
def make_timeout(self):
return 0.01
def test_function_called(self):
# run_in_reactor actually calls the function given to it.
calls = []
marker = object()
self.make_spinner().run(self.make_timeout(), calls.append, marker)
self.assertThat(calls, Equals([marker]))
def test_return_value_returned(self):
# run_in_reactor returns the value returned by the function given to
# it.
marker = object()
result = self.make_spinner().run(self.make_timeout(), lambda: marker)
self.assertThat(result, Is(marker))
def test_exception_reraised(self):
# If the given function raises an error, run_in_reactor re-raises that
# error.
self.assertThat(
lambda: self.make_spinner().run(self.make_timeout(), lambda: 1/0),
Raises(MatchesException(ZeroDivisionError)))
def test_keyword_arguments(self):
# run_in_reactor passes keyword arguments on.
calls = []
def function(*a, **kw):
return calls.extend([a, kw])
self.make_spinner().run(self.make_timeout(), function, foo=42)
self.assertThat(calls, Equals([(), {'foo': 42}]))
def test_not_reentrant(self):
# run_in_reactor raises an error if it is called inside another call
# to run_in_reactor.
spinner = self.make_spinner()
self.assertThat(lambda: spinner.run(
self.make_timeout(), spinner.run, self.make_timeout(),
lambda: None), Raises(MatchesException(_spinner.ReentryError)))
def test_deferred_value_returned(self):
# If the given function returns a Deferred, run_in_reactor returns the
# value in the Deferred at the end of the callback chain.
marker = object()
result = self.make_spinner().run(
self.make_timeout(), lambda: defer.succeed(marker))
self.assertThat(result, Is(marker))
def test_preserve_signal_handler(self):
signals = ['SIGINT', 'SIGTERM', 'SIGCHLD']
signals = list(filter(
None, (getattr(signal, name, None) for name in signals)))
for sig in signals:
self.addCleanup(signal.signal, sig, signal.getsignal(sig))
new_hdlrs = list(lambda *a: None for _ in signals)
for sig, hdlr in zip(signals, new_hdlrs):
signal.signal(sig, hdlr)
spinner = self.make_spinner()
spinner.run(self.make_timeout(), lambda: None)
self.assertItemsEqual(new_hdlrs, list(map(signal.getsignal, signals)))
def test_timeout(self):
# If the function takes too long to run, we raise a
# _spinner.TimeoutError.
timeout = self.make_timeout()
self.assertThat(
lambda: self.make_spinner().run(timeout, lambda: defer.Deferred()),
Raises(MatchesException(_spinner.TimeoutError)))
def test_no_junk_by_default(self):
# If the reactor hasn't spun yet, then there cannot be any junk.
spinner = self.make_spinner()
self.assertThat(spinner.get_junk(), Equals([]))
def test_clean_do_nothing(self):
# If there's nothing going on in the reactor, then clean does nothing
# and returns an empty list.
spinner = self.make_spinner()
result = spinner._clean()
self.assertThat(result, Equals([]))
def test_clean_delayed_call(self):
# If there's a delayed call in the reactor, then clean cancels it and
# returns an empty list.
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
call = reactor.callLater(10, lambda: None)
results = spinner._clean()
self.assertThat(results, Equals([call]))
self.assertThat(call.active(), Equals(False))
def test_clean_delayed_call_cancelled(self):
# If there's a delayed call that's just been cancelled, then it's no
# longer there.
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
call = reactor.callLater(10, lambda: None)
call.cancel()
results = spinner._clean()
self.assertThat(results, Equals([]))
def test_clean_selectables(self):
# If there's still a selectable (e.g. a listening socket), then
# clean() removes it from the reactor's registry.
#
# Note that the socket is left open. This emulates a bug in trial.
from twisted.internet.protocol import ServerFactory
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
port = reactor.listenTCP(0, ServerFactory(), interface='127.0.0.1')
spinner.run(self.make_timeout(), lambda: None)
results = spinner.get_junk()
self.assertThat(results, Equals([port]))
def test_clean_running_threads(self):
import threading
import time
current_threads = list(threading.enumerate())
reactor = self.make_reactor()
timeout = self.make_timeout()
spinner = self.make_spinner(reactor)
spinner.run(timeout, reactor.callInThread, time.sleep, timeout / 2.0)
self.assertThat(list(threading.enumerate()), Equals(current_threads))
def test_leftover_junk_available(self):
# If 'run' is given a function that leaves the reactor dirty in some
# way, 'run' will clean up the reactor and then store information
# about the junk. This information can be got using get_junk.
from twisted.internet.protocol import ServerFactory
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
port = spinner.run(
self.make_timeout(), reactor.listenTCP, 0, ServerFactory(),
interface='127.0.0.1')
self.assertThat(spinner.get_junk(), Equals([port]))
def test_will_not_run_with_previous_junk(self):
# If 'run' is called and there's still junk in the spinner's junk
# list, then the spinner will refuse to run.
from twisted.internet.protocol import ServerFactory
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
timeout = self.make_timeout()
spinner.run(timeout, reactor.listenTCP, 0, ServerFactory(), interface='127.0.0.1')
self.assertThat(lambda: spinner.run(timeout, lambda: None),
Raises(MatchesException(_spinner.StaleJunkError)))
def test_clear_junk_clears_previous_junk(self):
# If 'run' is called and there's still junk in the spinner's junk
# list, then the spinner will refuse to run.
from twisted.internet.protocol import ServerFactory
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
timeout = self.make_timeout()
port = spinner.run(timeout, reactor.listenTCP, 0, ServerFactory(),
interface='127.0.0.1')
junk = spinner.clear_junk()
self.assertThat(junk, Equals([port]))
self.assertThat(spinner.get_junk(), Equals([]))
@skipIf(os.name != "posix", "Sending SIGINT with os.kill is posix only")
def test_sigint_raises_no_result_error(self):
# If we get a SIGINT during a run, we raise _spinner.NoResultError.
SIGINT = getattr(signal, 'SIGINT', None)
if not SIGINT:
self.skipTest("SIGINT not available")
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
timeout = self.make_timeout()
reactor.callLater(timeout, os.kill, os.getpid(), SIGINT)
self.assertThat(
lambda: spinner.run(timeout * 5, defer.Deferred),
Raises(MatchesException(_spinner.NoResultError)))
self.assertEqual([], spinner._clean())
@skipIf(os.name != "posix", "Sending SIGINT with os.kill is posix only")
def test_sigint_raises_no_result_error_second_time(self):
# If we get a SIGINT during a run, we raise _spinner.NoResultError.
# This test is exactly the same as test_sigint_raises_no_result_error,
# and exists to make sure we haven't futzed with state.
self.test_sigint_raises_no_result_error()
@skipIf(os.name != "posix", "Sending SIGINT with os.kill is posix only")
def test_fast_sigint_raises_no_result_error(self):
# If we get a SIGINT during a run, we raise _spinner.NoResultError.
SIGINT = getattr(signal, 'SIGINT', None)
if not SIGINT:
self.skipTest("SIGINT not available")
reactor = self.make_reactor()
spinner = self.make_spinner(reactor)
timeout = self.make_timeout()
reactor.callWhenRunning(os.kill, os.getpid(), SIGINT)
self.assertThat(
lambda: spinner.run(timeout * 5, defer.Deferred),
Raises(MatchesException(_spinner.NoResultError)))
self.assertEqual([], spinner._clean())
@skipIf(os.name != "posix", "Sending SIGINT with os.kill is posix only")
def test_fast_sigint_raises_no_result_error_second_time(self):
self.test_fast_sigint_raises_no_result_error()
def test_fires_after_timeout(self):
# If we timeout, but the Deferred actually ends up firing after the
# time out (perhaps because Spinner's clean-up code is buggy, or
# perhaps because the code responsible for the callback is in a
# thread), then the next run of a spinner works as intended,
# completely isolated from the previous run.
# Ensure we've timed out, and that we have a handle on the Deferred
# that didn't fire.
reactor = self.make_reactor()
spinner1 = self.make_spinner(reactor)
timeout = self.make_timeout()
deferred1 = defer.Deferred()
self.expectThat(
lambda: spinner1.run(timeout, lambda: deferred1),
Raises(MatchesException(_spinner.TimeoutError)))
# Make a Deferred that will fire *after* deferred1 as long as the
# reactor keeps spinning. We don't care that it's a callback of
# deferred1 per se, only that it strictly fires afterwards.
marker = object()
deferred2 = defer.Deferred()
deferred1.addCallback(
lambda ignored: reactor.callLater(0, deferred2.callback, marker))
def fire_other():
"""Fire Deferred from the last spin while waiting for this one."""
deferred1.callback(object())
return deferred2
spinner2 = self.make_spinner(reactor)
self.assertThat(spinner2.run(timeout, fire_other), Is(marker))
def test_suite():
from unittest import TestLoader
return TestLoader().loadTestsFromName(__name__)