diff options
| -rw-r--r-- | Lib/multiprocessing/connection.py | 10 | ||||
| -rw-r--r-- | Lib/multiprocessing/forkserver.py | 6 | ||||
| -rw-r--r-- | Lib/multiprocessing/managers.py | 6 | ||||
| -rw-r--r-- | Lib/multiprocessing/util.py | 23 | ||||
| -rw-r--r-- | Lib/test/_test_multiprocessing.py | 13 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2020-03-09-01-45-06.bpo-39850.eaJNIE.rst | 5 |
6 files changed, 58 insertions, 5 deletions
diff --git a/Lib/multiprocessing/connection.py b/Lib/multiprocessing/connection.py index c9f995e..510e4b5 100644 --- a/Lib/multiprocessing/connection.py +++ b/Lib/multiprocessing/connection.py @@ -73,6 +73,11 @@ def arbitrary_address(family): if family == 'AF_INET': return ('localhost', 0) elif family == 'AF_UNIX': + # Prefer abstract sockets if possible to avoid problems with the address + # size. When coding portable applications, some implementations have + # sun_path as short as 92 bytes in the sockaddr_un struct. + if util.abstract_sockets_supported: + return f"\0listener-{os.getpid()}-{next(_mmap_counter)}" return tempfile.mktemp(prefix='listener-', dir=util.get_temp_dir()) elif family == 'AF_PIPE': return tempfile.mktemp(prefix=r'\\.\pipe\pyc-%d-%d-' % @@ -102,7 +107,7 @@ def address_type(address): return 'AF_INET' elif type(address) is str and address.startswith('\\\\'): return 'AF_PIPE' - elif type(address) is str: + elif type(address) is str or util.is_abstract_socket_namespace(address): return 'AF_UNIX' else: raise ValueError('address type of %r unrecognized' % address) @@ -597,7 +602,8 @@ class SocketListener(object): self._family = family self._last_accepted = None - if family == 'AF_UNIX': + if family == 'AF_UNIX' and not util.is_abstract_socket_namespace(address): + # Linux abstract socket namespaces do not need to be explicitly unlinked self._unlink = util.Finalize( self, os.unlink, args=(address,), exitpriority=0 ) diff --git a/Lib/multiprocessing/forkserver.py b/Lib/multiprocessing/forkserver.py index 87ebef6..215ac39 100644 --- a/Lib/multiprocessing/forkserver.py +++ b/Lib/multiprocessing/forkserver.py @@ -55,7 +55,8 @@ class ForkServer(object): os.waitpid(self._forkserver_pid, 0) self._forkserver_pid = None - os.unlink(self._forkserver_address) + if not util.is_abstract_socket_namespace(self._forkserver_address): + os.unlink(self._forkserver_address) self._forkserver_address = None def set_forkserver_preload(self, modules_names): @@ -135,7 +136,8 @@ class ForkServer(object): with socket.socket(socket.AF_UNIX) as listener: address = connection.arbitrary_address('AF_UNIX') listener.bind(address) - os.chmod(address, 0o600) + if not util.is_abstract_socket_namespace(address): + os.chmod(address, 0o600) listener.listen() # all client processes own the write end of the "alive" pipe; diff --git a/Lib/multiprocessing/managers.py b/Lib/multiprocessing/managers.py index 1f9c2da..1668220 100644 --- a/Lib/multiprocessing/managers.py +++ b/Lib/multiprocessing/managers.py @@ -1262,8 +1262,12 @@ if HAS_SHMEM: def __init__(self, *args, **kwargs): Server.__init__(self, *args, **kwargs) + address = self.address + # The address of Linux abstract namespaces can be bytes + if isinstance(address, bytes): + address = os.fsdecode(address) self.shared_memory_context = \ - _SharedMemoryTracker(f"shmm_{self.address}_{getpid()}") + _SharedMemoryTracker(f"shm_{address}_{getpid()}") util.debug(f"SharedMemoryServer started by pid {getpid()}") def create(self, c, typeid, /, *args, **kwargs): diff --git a/Lib/multiprocessing/util.py b/Lib/multiprocessing/util.py index 4bc7782..32c7a96 100644 --- a/Lib/multiprocessing/util.py +++ b/Lib/multiprocessing/util.py @@ -102,6 +102,29 @@ def log_to_stderr(level=None): _log_to_stderr = True return _logger + +# Abstract socket support + +def _platform_supports_abstract_sockets(): + if sys.platform == "linux": + return True + if hasattr(sys, 'getandroidapilevel'): + return True + return False + + +def is_abstract_socket_namespace(address): + if not address: + return False + if isinstance(address, bytes): + return address[0] == 0 + elif isinstance(address, str): + return address[0] == "\0" + raise TypeError('address type of {address!r} unrecognized') + + +abstract_sockets_supported = _platform_supports_abstract_sockets() + # # Function returning a temp directory which will be removed on exit # diff --git a/Lib/test/_test_multiprocessing.py b/Lib/test/_test_multiprocessing.py index 73dc75d..b985d51 100644 --- a/Lib/test/_test_multiprocessing.py +++ b/Lib/test/_test_multiprocessing.py @@ -3274,6 +3274,19 @@ class _TestListener(BaseTestCase): if self.TYPE == 'processes': self.assertRaises(OSError, l.accept) + @unittest.skipUnless(util.abstract_sockets_supported, + "test needs abstract socket support") + def test_abstract_socket(self): + with self.connection.Listener("\0something") as listener: + with self.connection.Client(listener.address) as client: + with listener.accept() as d: + client.send(1729) + self.assertEqual(d.recv(), 1729) + + if self.TYPE == 'processes': + self.assertRaises(OSError, listener.accept) + + class _TestListenerClient(BaseTestCase): ALLOWED_TYPES = ('processes', 'threads') diff --git a/Misc/NEWS.d/next/Library/2020-03-09-01-45-06.bpo-39850.eaJNIE.rst b/Misc/NEWS.d/next/Library/2020-03-09-01-45-06.bpo-39850.eaJNIE.rst new file mode 100644 index 0000000..bb00dd8 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-03-09-01-45-06.bpo-39850.eaJNIE.rst @@ -0,0 +1,5 @@ +:mod:`multiprocessing` now supports abstract socket addresses (if abstract sockets +are supported in the running platform). When creating arbitrary addresses (like when +default-constructing :class:`multiprocessing.connection.Listener` objects) abstract +sockets are preferred to avoid the case when the temporary-file-generated address is +too large for an AF_UNIX socket address. Patch by Pablo Galindo. |