cpython/Lib/test/test_selectors.py

618 lines
20 KiB
Python

import errno
import os
import random
import selectors
import signal
import socket
import sys
from test import support
from test.support import is_apple, os_helper, socket_helper
from time import sleep
import unittest
import unittest.mock
import tempfile
from time import monotonic as time
try:
import resource
except ImportError:
resource = None
if support.is_emscripten or support.is_wasi:
raise unittest.SkipTest("Cannot create socketpair on Emscripten/WASI.")
if hasattr(socket, 'socketpair'):
socketpair = socket.socketpair
else:
def socketpair(family=socket.AF_INET, type=socket.SOCK_STREAM, proto=0):
with socket.socket(family, type, proto) as l:
l.bind((socket_helper.HOST, 0))
l.listen()
c = socket.socket(family, type, proto)
try:
c.connect(l.getsockname())
caddr = c.getsockname()
while True:
a, addr = l.accept()
# check that we've got the correct client
if addr == caddr:
return c, a
a.close()
except OSError:
c.close()
raise
def find_ready_matching(ready, flag):
match = []
for key, events in ready:
if events & flag:
match.append(key.fileobj)
return match
class BaseSelectorTestCase:
def make_socketpair(self):
rd, wr = socketpair()
self.addCleanup(rd.close)
self.addCleanup(wr.close)
return rd, wr
def test_register(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
key = s.register(rd, selectors.EVENT_READ, "data")
self.assertIsInstance(key, selectors.SelectorKey)
self.assertEqual(key.fileobj, rd)
self.assertEqual(key.fd, rd.fileno())
self.assertEqual(key.events, selectors.EVENT_READ)
self.assertEqual(key.data, "data")
# register an unknown event
self.assertRaises(ValueError, s.register, 0, 999999)
# register an invalid FD
self.assertRaises(ValueError, s.register, -10, selectors.EVENT_READ)
# register twice
self.assertRaises(KeyError, s.register, rd, selectors.EVENT_READ)
# register the same FD, but with a different object
self.assertRaises(KeyError, s.register, rd.fileno(),
selectors.EVENT_READ)
def test_unregister(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
s.register(rd, selectors.EVENT_READ)
s.unregister(rd)
# unregister an unknown file obj
self.assertRaises(KeyError, s.unregister, 999999)
# unregister twice
self.assertRaises(KeyError, s.unregister, rd)
def test_unregister_after_fd_close(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
r, w = rd.fileno(), wr.fileno()
s.register(r, selectors.EVENT_READ)
s.register(w, selectors.EVENT_WRITE)
rd.close()
wr.close()
s.unregister(r)
s.unregister(w)
@unittest.skipUnless(os.name == 'posix', "requires posix")
def test_unregister_after_fd_close_and_reuse(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
r, w = rd.fileno(), wr.fileno()
s.register(r, selectors.EVENT_READ)
s.register(w, selectors.EVENT_WRITE)
rd2, wr2 = self.make_socketpair()
rd.close()
wr.close()
os.dup2(rd2.fileno(), r)
os.dup2(wr2.fileno(), w)
self.addCleanup(os.close, r)
self.addCleanup(os.close, w)
s.unregister(r)
s.unregister(w)
def test_unregister_after_socket_close(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
s.register(rd, selectors.EVENT_READ)
s.register(wr, selectors.EVENT_WRITE)
rd.close()
wr.close()
s.unregister(rd)
s.unregister(wr)
def test_modify(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
key = s.register(rd, selectors.EVENT_READ)
# modify events
key2 = s.modify(rd, selectors.EVENT_WRITE)
self.assertNotEqual(key.events, key2.events)
self.assertEqual(key2, s.get_key(rd))
s.unregister(rd)
# modify data
d1 = object()
d2 = object()
key = s.register(rd, selectors.EVENT_READ, d1)
key2 = s.modify(rd, selectors.EVENT_READ, d2)
self.assertEqual(key.events, key2.events)
self.assertNotEqual(key.data, key2.data)
self.assertEqual(key2, s.get_key(rd))
self.assertEqual(key2.data, d2)
# modify unknown file obj
self.assertRaises(KeyError, s.modify, 999999, selectors.EVENT_READ)
# modify use a shortcut
d3 = object()
s.register = unittest.mock.Mock()
s.unregister = unittest.mock.Mock()
s.modify(rd, selectors.EVENT_READ, d3)
self.assertFalse(s.register.called)
self.assertFalse(s.unregister.called)
def test_modify_unregister(self):
# Make sure the fd is unregister()ed in case of error on
# modify(): http://bugs.python.org/issue30014
if self.SELECTOR.__name__ == 'EpollSelector':
patch = unittest.mock.patch(
'selectors.EpollSelector._selector_cls')
elif self.SELECTOR.__name__ == 'PollSelector':
patch = unittest.mock.patch(
'selectors.PollSelector._selector_cls')
elif self.SELECTOR.__name__ == 'DevpollSelector':
patch = unittest.mock.patch(
'selectors.DevpollSelector._selector_cls')
else:
raise self.skipTest("")
with patch as m:
m.return_value.modify = unittest.mock.Mock(
side_effect=ZeroDivisionError)
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
s.register(rd, selectors.EVENT_READ)
self.assertEqual(len(s._map), 1)
with self.assertRaises(ZeroDivisionError):
s.modify(rd, selectors.EVENT_WRITE)
self.assertEqual(len(s._map), 0)
def test_close(self):
s = self.SELECTOR()
self.addCleanup(s.close)
mapping = s.get_map()
rd, wr = self.make_socketpair()
s.register(rd, selectors.EVENT_READ)
s.register(wr, selectors.EVENT_WRITE)
s.close()
self.assertRaises(RuntimeError, s.get_key, rd)
self.assertRaises(RuntimeError, s.get_key, wr)
self.assertRaises(KeyError, mapping.__getitem__, rd)
self.assertRaises(KeyError, mapping.__getitem__, wr)
self.assertEqual(mapping.get(rd), None)
self.assertEqual(mapping.get(wr), None)
def test_get_key(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
key = s.register(rd, selectors.EVENT_READ, "data")
self.assertEqual(key, s.get_key(rd))
# unknown file obj
self.assertRaises(KeyError, s.get_key, 999999)
def test_get_map(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
sentinel = object()
keys = s.get_map()
self.assertFalse(keys)
self.assertEqual(len(keys), 0)
self.assertEqual(list(keys), [])
self.assertEqual(keys.get(rd), None)
self.assertEqual(keys.get(rd, sentinel), sentinel)
key = s.register(rd, selectors.EVENT_READ, "data")
self.assertIn(rd, keys)
self.assertEqual(key, keys.get(rd))
self.assertEqual(key, keys[rd])
self.assertEqual(len(keys), 1)
self.assertEqual(list(keys), [rd.fileno()])
self.assertEqual(list(keys.values()), [key])
# unknown file obj
with self.assertRaises(KeyError):
keys[999999]
# Read-only mapping
with self.assertRaises(TypeError):
del keys[rd]
def test_select(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
s.register(rd, selectors.EVENT_READ)
wr_key = s.register(wr, selectors.EVENT_WRITE)
result = s.select()
for key, events in result:
self.assertTrue(isinstance(key, selectors.SelectorKey))
self.assertTrue(events)
self.assertFalse(events & ~(selectors.EVENT_READ |
selectors.EVENT_WRITE))
self.assertEqual([(wr_key, selectors.EVENT_WRITE)], result)
def test_select_read_write(self):
# gh-110038: when a file descriptor is registered for both read and
# write, the two events must be seen on a single call to select().
s = self.SELECTOR()
self.addCleanup(s.close)
sock1, sock2 = self.make_socketpair()
sock2.send(b"foo")
my_key = s.register(sock1, selectors.EVENT_READ | selectors.EVENT_WRITE)
seen_read, seen_write = False, False
result = s.select()
# We get the read and write either in the same result entry or in two
# distinct entries with the same key.
self.assertLessEqual(len(result), 2)
for key, events in result:
self.assertTrue(isinstance(key, selectors.SelectorKey))
self.assertEqual(key, my_key)
self.assertFalse(events & ~(selectors.EVENT_READ |
selectors.EVENT_WRITE))
if events & selectors.EVENT_READ:
self.assertFalse(seen_read)
seen_read = True
if events & selectors.EVENT_WRITE:
self.assertFalse(seen_write)
seen_write = True
self.assertTrue(seen_read)
self.assertTrue(seen_write)
def test_context_manager(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
with s as sel:
sel.register(rd, selectors.EVENT_READ)
sel.register(wr, selectors.EVENT_WRITE)
self.assertRaises(RuntimeError, s.get_key, rd)
self.assertRaises(RuntimeError, s.get_key, wr)
def test_fileno(self):
s = self.SELECTOR()
self.addCleanup(s.close)
if hasattr(s, 'fileno'):
fd = s.fileno()
self.assertTrue(isinstance(fd, int))
self.assertGreaterEqual(fd, 0)
def test_selector(self):
s = self.SELECTOR()
self.addCleanup(s.close)
NUM_SOCKETS = 12
MSG = b" This is a test."
MSG_LEN = len(MSG)
readers = []
writers = []
r2w = {}
w2r = {}
for i in range(NUM_SOCKETS):
rd, wr = self.make_socketpair()
s.register(rd, selectors.EVENT_READ)
s.register(wr, selectors.EVENT_WRITE)
readers.append(rd)
writers.append(wr)
r2w[rd] = wr
w2r[wr] = rd
bufs = []
while writers:
ready = s.select()
ready_writers = find_ready_matching(ready, selectors.EVENT_WRITE)
if not ready_writers:
self.fail("no sockets ready for writing")
wr = random.choice(ready_writers)
wr.send(MSG)
for i in range(10):
ready = s.select()
ready_readers = find_ready_matching(ready,
selectors.EVENT_READ)
if ready_readers:
break
# there might be a delay between the write to the write end and
# the read end is reported ready
sleep(0.1)
else:
self.fail("no sockets ready for reading")
self.assertEqual([w2r[wr]], ready_readers)
rd = ready_readers[0]
buf = rd.recv(MSG_LEN)
self.assertEqual(len(buf), MSG_LEN)
bufs.append(buf)
s.unregister(r2w[rd])
s.unregister(rd)
writers.remove(r2w[rd])
self.assertEqual(bufs, [MSG] * NUM_SOCKETS)
@unittest.skipIf(sys.platform == 'win32',
'select.select() cannot be used with empty fd sets')
def test_empty_select(self):
# Issue #23009: Make sure EpollSelector.select() works when no FD is
# registered.
s = self.SELECTOR()
self.addCleanup(s.close)
self.assertEqual(s.select(timeout=0), [])
def test_timeout(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
s.register(wr, selectors.EVENT_WRITE)
t = time()
self.assertEqual(1, len(s.select(0)))
self.assertEqual(1, len(s.select(-1)))
self.assertLess(time() - t, 0.5)
s.unregister(wr)
s.register(rd, selectors.EVENT_READ)
t = time()
self.assertFalse(s.select(0))
self.assertFalse(s.select(-1))
self.assertLess(time() - t, 0.5)
t0 = time()
self.assertFalse(s.select(1))
t1 = time()
dt = t1 - t0
# Tolerate 2.0 seconds for very slow buildbots
self.assertTrue(0.8 <= dt <= 2.0, dt)
@unittest.skipUnless(hasattr(signal, "alarm"),
"signal.alarm() required for this test")
def test_select_interrupt_exc(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
class InterruptSelect(Exception):
pass
def handler(*args):
raise InterruptSelect
orig_alrm_handler = signal.signal(signal.SIGALRM, handler)
self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
try:
signal.alarm(1)
s.register(rd, selectors.EVENT_READ)
t = time()
# select() is interrupted by a signal which raises an exception
with self.assertRaises(InterruptSelect):
s.select(30)
# select() was interrupted before the timeout of 30 seconds
self.assertLess(time() - t, 5.0)
finally:
signal.alarm(0)
@unittest.skipUnless(hasattr(signal, "alarm"),
"signal.alarm() required for this test")
def test_select_interrupt_noraise(self):
s = self.SELECTOR()
self.addCleanup(s.close)
rd, wr = self.make_socketpair()
orig_alrm_handler = signal.signal(signal.SIGALRM, lambda *args: None)
self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
try:
signal.alarm(1)
s.register(rd, selectors.EVENT_READ)
t = time()
# select() is interrupted by a signal, but the signal handler doesn't
# raise an exception, so select() should by retries with a recomputed
# timeout
self.assertFalse(s.select(1.5))
self.assertGreaterEqual(time() - t, 1.0)
finally:
signal.alarm(0)
class ScalableSelectorMixIn:
# see issue #18963 for why it's skipped on older OS X versions
@support.requires_mac_ver(10, 5)
@unittest.skipUnless(resource, "Test needs resource module")
@support.requires_resource('cpu')
def test_above_fd_setsize(self):
# A scalable implementation should have no problem with more than
# FD_SETSIZE file descriptors. Since we don't know the value, we just
# try to set the soft RLIMIT_NOFILE to the hard RLIMIT_NOFILE ceiling.
soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
try:
resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))
self.addCleanup(resource.setrlimit, resource.RLIMIT_NOFILE,
(soft, hard))
NUM_FDS = min(hard, 2**16)
except (OSError, ValueError):
NUM_FDS = soft
# guard for already allocated FDs (stdin, stdout...)
NUM_FDS -= 32
s = self.SELECTOR()
self.addCleanup(s.close)
for i in range(NUM_FDS // 2):
try:
rd, wr = self.make_socketpair()
except OSError:
# too many FDs, skip - note that we should only catch EMFILE
# here, but apparently *BSD and Solaris can fail upon connect()
# or bind() with EADDRNOTAVAIL, so let's be safe
self.skipTest("FD limit reached")
try:
s.register(rd, selectors.EVENT_READ)
s.register(wr, selectors.EVENT_WRITE)
except OSError as e:
if e.errno == errno.ENOSPC:
# this can be raised by epoll if we go over
# fs.epoll.max_user_watches sysctl
self.skipTest("FD limit reached")
raise
try:
fds = s.select()
except OSError as e:
if e.errno == errno.EINVAL and is_apple:
# unexplainable errors on macOS don't need to fail the test
self.skipTest("Invalid argument error calling poll()")
raise
self.assertEqual(NUM_FDS // 2, len(fds))
class DefaultSelectorTestCase(BaseSelectorTestCase, unittest.TestCase):
SELECTOR = selectors.DefaultSelector
class SelectSelectorTestCase(BaseSelectorTestCase, unittest.TestCase):
SELECTOR = selectors.SelectSelector
@unittest.skipUnless(hasattr(selectors, 'PollSelector'),
"Test needs selectors.PollSelector")
class PollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
unittest.TestCase):
SELECTOR = getattr(selectors, 'PollSelector', None)
@unittest.skipUnless(hasattr(selectors, 'EpollSelector'),
"Test needs selectors.EpollSelector")
class EpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
unittest.TestCase):
SELECTOR = getattr(selectors, 'EpollSelector', None)
def test_register_file(self):
# epoll(7) returns EPERM when given a file to watch
s = self.SELECTOR()
with tempfile.NamedTemporaryFile() as f:
with self.assertRaises(IOError):
s.register(f, selectors.EVENT_READ)
# the SelectorKey has been removed
with self.assertRaises(KeyError):
s.get_key(f)
@unittest.skipUnless(hasattr(selectors, 'KqueueSelector'),
"Test needs selectors.KqueueSelector)")
class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
unittest.TestCase):
SELECTOR = getattr(selectors, 'KqueueSelector', None)
def test_register_bad_fd(self):
# a file descriptor that's been closed should raise an OSError
# with EBADF
s = self.SELECTOR()
bad_f = os_helper.make_bad_fd()
with self.assertRaises(OSError) as cm:
s.register(bad_f, selectors.EVENT_READ)
self.assertEqual(cm.exception.errno, errno.EBADF)
# the SelectorKey has been removed
with self.assertRaises(KeyError):
s.get_key(bad_f)
def test_empty_select_timeout(self):
# Issues #23009, #29255: Make sure timeout is applied when no fds
# are registered.
s = self.SELECTOR()
self.addCleanup(s.close)
t0 = time()
self.assertEqual(s.select(1), [])
t1 = time()
dt = t1 - t0
# Tolerate 2.0 seconds for very slow buildbots
self.assertTrue(0.8 <= dt <= 2.0, dt)
@unittest.skipUnless(hasattr(selectors, 'DevpollSelector'),
"Test needs selectors.DevpollSelector")
class DevpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn,
unittest.TestCase):
SELECTOR = getattr(selectors, 'DevpollSelector', None)
def tearDownModule():
support.reap_children()
if __name__ == "__main__":
unittest.main()