diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/selectors.py | 74 | ||||
| -rw-r--r-- | Lib/test/test_selectors.py | 96 |
2 files changed, 124 insertions, 46 deletions
diff --git a/Lib/selectors.py b/Lib/selectors.py index c533f13..a44d5e9 100644 --- a/Lib/selectors.py +++ b/Lib/selectors.py @@ -25,6 +25,9 @@ def _fileobj_to_fd(fileobj): Returns: corresponding file descriptor + + Raises: + ValueError if the object is invalid """ if isinstance(fileobj, int): fd = fileobj @@ -55,7 +58,8 @@ class _SelectorMapping(Mapping): def __getitem__(self, fileobj): try: - return self._selector._fd_to_key[_fileobj_to_fd(fileobj)] + fd = self._selector._fileobj_lookup(fileobj) + return self._selector._fd_to_key[fd] except KeyError: raise KeyError("{!r} is not registered".format(fileobj)) from None @@ -89,6 +93,15 @@ class BaseSelector(metaclass=ABCMeta): Returns: SelectorKey instance + + Raises: + ValueError if events is invalid + KeyError if fileobj is already registered + OSError if fileobj is closed or otherwise is unacceptable to + the underlying system call (if a system call is made) + + Note: + OSError may or may not be raised """ raise NotImplementedError @@ -101,6 +114,13 @@ class BaseSelector(metaclass=ABCMeta): Returns: SelectorKey instance + + Raises: + KeyError if fileobj is not registered + + Note: + If fileobj is registered but has since been closed this does + *not* raise OSError (even if the wrapped syscall does) """ raise NotImplementedError @@ -114,6 +134,9 @@ class BaseSelector(metaclass=ABCMeta): Returns: SelectorKey instance + + Raises: + Anything that unregister() or register() raises """ self.unregister(fileobj) return self.register(fileobj, events, data) @@ -177,22 +200,41 @@ class _BaseSelectorImpl(BaseSelector): # read-only mapping returned by get_map() self._map = _SelectorMapping(self) + def _fileobj_lookup(self, fileobj): + """Return a file descriptor from a file object. + + This wraps _fileobj_to_fd() to do an exhaustive search in case + the object is invalid but we still have it in our map. This + is used by unregister() so we can unregister an object that + was previously registered even if it is closed. It is also + used by _SelectorMapping. + """ + try: + return _fileobj_to_fd(fileobj) + except ValueError: + # Do an exhaustive search. + for key in self._fd_to_key.values(): + if key.fileobj is fileobj: + return key.fd + # Raise ValueError after all. + raise + def register(self, fileobj, events, data=None): if (not events) or (events & ~(EVENT_READ | EVENT_WRITE)): raise ValueError("Invalid events: {!r}".format(events)) - key = SelectorKey(fileobj, _fileobj_to_fd(fileobj), events, data) + key = SelectorKey(fileobj, self._fileobj_lookup(fileobj), events, data) if key.fd in self._fd_to_key: - raise KeyError("{!r} (FD {}) is already " - "registered".format(fileobj, key.fd)) + raise KeyError("{!r} (FD {}) is already registered" + .format(fileobj, key.fd)) self._fd_to_key[key.fd] = key return key def unregister(self, fileobj): try: - key = self._fd_to_key.pop(_fileobj_to_fd(fileobj)) + key = self._fd_to_key.pop(self._fileobj_lookup(fileobj)) except KeyError: raise KeyError("{!r} is not registered".format(fileobj)) from None return key @@ -200,7 +242,7 @@ class _BaseSelectorImpl(BaseSelector): def modify(self, fileobj, events, data=None): # TODO: Subclasses can probably optimize this even further. try: - key = self._fd_to_key[_fileobj_to_fd(fileobj)] + key = self._fd_to_key[self._fileobj_lookup(fileobj)] except KeyError: raise KeyError("{!r} is not registered".format(fileobj)) from None if events != key.events: @@ -352,7 +394,12 @@ if hasattr(select, 'epoll'): def unregister(self, fileobj): key = super().unregister(fileobj) - self._epoll.unregister(key.fd) + try: + self._epoll.unregister(key.fd) + except OSError: + # This can happen if the FD was closed since it + # was registered. + pass return key def select(self, timeout=None): @@ -409,11 +456,20 @@ if hasattr(select, 'kqueue'): if key.events & EVENT_READ: kev = select.kevent(key.fd, select.KQ_FILTER_READ, select.KQ_EV_DELETE) - self._kqueue.control([kev], 0, 0) + try: + self._kqueue.control([kev], 0, 0) + except OSError: + # This can happen if the FD was closed since it + # was registered. + pass if key.events & EVENT_WRITE: kev = select.kevent(key.fd, select.KQ_FILTER_WRITE, select.KQ_EV_DELETE) - self._kqueue.control([kev], 0, 0) + try: + self._kqueue.control([kev], 0, 0) + except OSError: + # See comment above. + pass return key def select(self, timeout=None): diff --git a/Lib/test/test_selectors.py b/Lib/test/test_selectors.py index f5e67b1..c8c16d5 100644 --- a/Lib/test/test_selectors.py +++ b/Lib/test/test_selectors.py @@ -1,4 +1,5 @@ import errno +import os import random import selectors import signal @@ -49,13 +50,17 @@ def find_ready_matching(ready, flag): class BaseSelectorTestCase(unittest.TestCase): + 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 = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() key = s.register(rd, selectors.EVENT_READ, "data") self.assertIsInstance(key, selectors.SelectorKey) @@ -81,9 +86,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() s.register(rd, selectors.EVENT_READ) s.unregister(rd) @@ -94,13 +97,51 @@ class BaseSelectorTestCase(unittest.TestCase): # 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) + + 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 = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() key = s.register(rd, selectors.EVENT_READ) @@ -138,9 +179,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() s.register(rd, selectors.EVENT_READ) s.register(wr, selectors.EVENT_WRITE) @@ -153,9 +192,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() key = s.register(rd, selectors.EVENT_READ, "data") self.assertEqual(key, s.get_key(rd)) @@ -167,9 +204,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() keys = s.get_map() self.assertFalse(keys) @@ -194,9 +229,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() s.register(rd, selectors.EVENT_READ) wr_key = s.register(wr, selectors.EVENT_WRITE) @@ -214,9 +247,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() with s as sel: sel.register(rd, selectors.EVENT_READ) @@ -247,9 +278,7 @@ class BaseSelectorTestCase(unittest.TestCase): w2r = {} for i in range(NUM_SOCKETS): - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() s.register(rd, selectors.EVENT_READ) s.register(wr, selectors.EVENT_WRITE) readers.append(rd) @@ -293,9 +322,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.close) + rd, wr = self.make_socketpair() s.register(wr, selectors.EVENT_WRITE) t = time() @@ -322,9 +349,7 @@ class BaseSelectorTestCase(unittest.TestCase): s = self.SELECTOR() self.addCleanup(s.close) - rd, wr = socketpair() - self.addCleanup(rd.close) - self.addCleanup(wr.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) @@ -364,16 +389,13 @@ class ScalableSelectorMixIn: for i in range(NUM_FDS // 2): try: - rd, wr = socketpair() + 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") - self.addCleanup(rd.close) - self.addCleanup(wr.close) - try: s.register(rd, selectors.EVENT_READ) s.register(wr, selectors.EVENT_WRITE) |