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Issue #11743: Rewrite multiprocessing connection classes in pure Python.

This commit is contained in:
Antoine Pitrou 2011-05-09 17:04:27 +02:00
parent df77e3d4a0
commit 87cf220972
15 changed files with 490 additions and 983 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

315
Lib/multiprocessing/connection.py
View File

@ -34,19 +34,27 @@
__all__ = [ 'Client', 'Listener', 'Pipe' ]
import io
import os
import sys
import pickle
import select
import socket
import struct
import errno
import time
import tempfile
import itertools
import _multiprocessing
from multiprocessing import current_process, AuthenticationError
from multiprocessing import current_process, AuthenticationError, BufferTooShort
from multiprocessing.util import get_temp_dir, Finalize, sub_debug, debug
from multiprocessing.forking import duplicate, close
try:
from _multiprocessing import win32
except ImportError:
if sys.platform == 'win32':
raise
win32 = None
#
#
@ -110,6 +118,281 @@ def address_type(address):
else:
raise ValueError('address type of %r unrecognized' % address)
#
# Connection classes
#
class _ConnectionBase:
_handle = None
def __init__(self, handle, readable=True, writable=True):
handle = handle.__index__()
if handle < 0:
raise ValueError("invalid handle")
if not readable and not writable:
raise ValueError(
"at least one of `readable` and `writable` must be True")
self._handle = handle
self._readable = readable
self._writable = writable
def __del__(self):
if self._handle is not None:
self._close()
def _check_closed(self):
if self._handle is None:
raise IOError("handle is closed")
def _check_readable(self):
if not self._readable:
raise IOError("connection is write-only")
def _check_writable(self):
if not self._writable:
raise IOError("connection is read-only")
def _bad_message_length(self):
if self._writable:
self._readable = False
else:
self.close()
raise IOError("bad message length")
@property
def closed(self):
"""True if the connection is closed"""
return self._handle is None
@property
def readable(self):
"""True if the connection is readable"""
return self._readable
@property
def writable(self):
"""True if the connection is writable"""
return self._writable
def fileno(self):
"""File descriptor or handle of the connection"""
self._check_closed()
return self._handle
def close(self):
"""Close the connection"""
if self._handle is not None:
try:
self._close()
finally:
self._handle = None
def send_bytes(self, buf, offset=0, size=None):
"""Send the bytes data from a bytes-like object"""
self._check_closed()
self._check_writable()
m = memoryview(buf)
# HACK for byte-indexing of non-bytewise buffers (e.g. array.array)
if m.itemsize > 1:
m = memoryview(bytes(m))
n = len(m)
if offset < 0:
raise ValueError("offset is negative")
if n < offset:
raise ValueError("buffer length < offset")
if size is None:
size = n - offset
elif size < 0:
raise ValueError("size is negative")
elif offset + size > n:
raise ValueError("buffer length < offset + size")
self._send_bytes(m[offset:offset + size])
def send(self, obj):
"""Send a (picklable) object"""
self._check_closed()
self._check_writable()
buf = pickle.dumps(obj, protocol=pickle.HIGHEST_PROTOCOL)
self._send_bytes(memoryview(buf))
def recv_bytes(self, maxlength=None):
"""
Receive bytes data as a bytes object.
"""
self._check_closed()
self._check_readable()
if maxlength is not None and maxlength < 0:
raise ValueError("negative maxlength")
buf = self._recv_bytes(maxlength)
if buf is None:
self._bad_message_length()
return buf.getvalue()
def recv_bytes_into(self, buf, offset=0):
"""
Receive bytes data into a writeable buffer-like object.
Return the number of bytes read.
"""
self._check_closed()
self._check_readable()
with memoryview(buf) as m:
# Get bytesize of arbitrary buffer
itemsize = m.itemsize
bytesize = itemsize * len(m)
if offset < 0:
raise ValueError("negative offset")
elif offset > bytesize:
raise ValueError("offset too large")
result = self._recv_bytes()
size = result.tell()
if bytesize < offset + size:
raise BufferTooShort(result.getvalue())
# Message can fit in dest
result.seek(0)
result.readinto(m[offset // itemsize :
(offset + size) // itemsize])
return size
def recv(self):
"""Receive a (picklable) object"""
self._check_closed()
self._check_readable()
buf = self._recv_bytes()
return pickle.loads(buf.getbuffer())
def poll(self, timeout=0.0):
"""Whether there is any input available to be read"""
self._check_closed()
self._check_readable()
if timeout < 0.0:
timeout = None
return self._poll(timeout)
if win32:
class PipeConnection(_ConnectionBase):
"""
Connection class based on a Windows named pipe.
"""
def _close(self):
win32.CloseHandle(self._handle)
def _send_bytes(self, buf):
nwritten = win32.WriteFile(self._handle, buf)
assert nwritten == len(buf)
def _recv_bytes(self, maxsize=None):
buf = io.BytesIO()
bufsize = 512
if maxsize is not None:
bufsize = min(bufsize, maxsize)
try:
firstchunk, complete = win32.ReadFile(self._handle, bufsize)
except IOError as e:
if e.errno == win32.ERROR_BROKEN_PIPE:
raise EOFError
raise
lenfirstchunk = len(firstchunk)
buf.write(firstchunk)
if complete:
return buf
navail, nleft = win32.PeekNamedPipe(self._handle)
if maxsize is not None and lenfirstchunk + nleft > maxsize:
return None
lastchunk, complete = win32.ReadFile(self._handle, nleft)
assert complete
buf.write(lastchunk)
return buf
def _poll(self, timeout):
navail, nleft = win32.PeekNamedPipe(self._handle)
if navail > 0:
return True
elif timeout == 0.0:
return False
# Setup a polling loop (translated straight from old
# pipe_connection.c)
if timeout < 0.0:
deadline = None
else:
deadline = time.time() + timeout
delay = 0.001
max_delay = 0.02
while True:
time.sleep(delay)
navail, nleft = win32.PeekNamedPipe(self._handle)
if navail > 0:
return True
if deadline and time.time() > deadline:
return False
if delay < max_delay:
delay += 0.001
class Connection(_ConnectionBase):
"""
Connection class based on an arbitrary file descriptor (Unix only), or
a socket handle (Windows).
"""
if win32:
def _close(self):
win32.closesocket(self._handle)
_write = win32.send
_read = win32.recv
else:
def _close(self):
os.close(self._handle)
_write = os.write
_read = os.read
def _send(self, buf, write=_write):
remaining = len(buf)
while True:
n = write(self._handle, buf)
remaining -= n
if remaining == 0:
break
buf = buf[n:]
def _recv(self, size, read=_read):
buf = io.BytesIO()
remaining = size
while remaining > 0:
chunk = read(self._handle, remaining)
n = len(chunk)
if n == 0:
if remaining == size:
raise EOFError
else:
raise IOError("got end of file during message")
buf.write(chunk)
remaining -= n
return buf
def _send_bytes(self, buf):
# For wire compatibility with 3.2 and lower
n = len(buf)
self._send(struct.pack("=i", len(buf)))
# The condition is necessary to avoid "broken pipe" errors
# when sending a 0-length buffer if the other end closed the pipe.
if n > 0:
self._send(buf)
def _recv_bytes(self, maxsize=None):
buf = self._recv(4)
size, = struct.unpack("=i", buf.getvalue())
if maxsize is not None and size > maxsize:
return None
return self._recv(size)
def _poll(self, timeout):
r = select.select([self._handle], [], [], timeout)[0]
return bool(r)
#
# Public functions
#
@ -186,21 +469,19 @@ if sys.platform != 'win32':
'''
if duplex:
s1, s2 = socket.socketpair()
c1 = _multiprocessing.Connection(os.dup(s1.fileno()))
c2 = _multiprocessing.Connection(os.dup(s2.fileno()))
c1 = Connection(os.dup(s1.fileno()))
c2 = Connection(os.dup(s2.fileno()))
s1.close()
s2.close()
else:
fd1, fd2 = os.pipe()
c1 = _multiprocessing.Connection(fd1, writable=False)
c2 = _multiprocessing.Connection(fd2, readable=False)
c1 = Connection(fd1, writable=False)
c2 = Connection(fd2, readable=False)
return c1, c2
else:
from _multiprocessing import win32
def Pipe(duplex=True):
'''
Returns pair of connection objects at either end of a pipe
@ -234,8 +515,8 @@ else:
if e.args[0] != win32.ERROR_PIPE_CONNECTED:
raise
c1 = _multiprocessing.PipeConnection(h1, writable=duplex)
c2 = _multiprocessing.PipeConnection(h2, readable=duplex)
c1 = PipeConnection(h1, writable=duplex)
c2 = PipeConnection(h2, readable=duplex)
return c1, c2
@ -266,7 +547,7 @@ class SocketListener(object):
def accept(self):
s, self._last_accepted = self._socket.accept()
fd = duplicate(s.fileno())
conn = _multiprocessing.Connection(fd)
conn = Connection(fd)
s.close()
return conn
@ -298,7 +579,7 @@ def SocketClient(address):
raise
fd = duplicate(s.fileno())
conn = _multiprocessing.Connection(fd)
conn = Connection(fd)
return conn
#
@ -345,7 +626,7 @@ if sys.platform == 'win32':
except WindowsError as e:
if e.args[0] != win32.ERROR_PIPE_CONNECTED:
raise
return _multiprocessing.PipeConnection(handle)
return PipeConnection(handle)
@staticmethod
def _finalize_pipe_listener(queue, address):
@ -377,7 +658,7 @@ if sys.platform == 'win32':
win32.SetNamedPipeHandleState(
h, win32.PIPE_READMODE_MESSAGE, None, None
)
return _multiprocessing.PipeConnection(h)
return PipeConnection(h)
#
# Authentication stuff
@ -451,3 +732,7 @@ def XmlClient(*args, **kwds):
global xmlrpclib
import xmlrpc.client as xmlrpclib
return ConnectionWrapper(Client(*args, **kwds), _xml_dumps, _xml_loads)
# Late import because of circular import
from multiprocessing.forking import duplicate, close

5
Lib/multiprocessing/forking.py
View File

@ -183,7 +183,7 @@ else:
import time
from pickle import dump, load, HIGHEST_PROTOCOL
from _multiprocessing import win32, Connection, PipeConnection
from _multiprocessing import win32
from .util import Finalize
def dump(obj, file, protocol=None):
@ -411,6 +411,9 @@ else:
# Make (Pipe)Connection picklable
#
# Late import because of circular import
from .connection import Connection, PipeConnection
def reduce_connection(conn):
if not Popen.thread_is_spawning():
raise RuntimeError(

13
Lib/multiprocessing/reduction.py
View File

@ -44,7 +44,7 @@ import _multiprocessing
from multiprocessing import current_process
from multiprocessing.forking import Popen, duplicate, close, ForkingPickler
from multiprocessing.util import register_after_fork, debug, sub_debug
from multiprocessing.connection import Client, Listener
from multiprocessing.connection import Client, Listener, Connection
#
@ -159,7 +159,7 @@ def rebuild_handle(pickled_data):
return new_handle
#
# Register `_multiprocessing.Connection` with `ForkingPickler`
# Register `Connection` with `ForkingPickler`
#
def reduce_connection(conn):
@ -168,11 +168,11 @@ def reduce_connection(conn):
def rebuild_connection(reduced_handle, readable, writable):
handle = rebuild_handle(reduced_handle)
return _multiprocessing.Connection(
return Connection(
handle, readable=readable, writable=writable
)
ForkingPickler.register(_multiprocessing.Connection, reduce_connection)
ForkingPickler.register(Connection, reduce_connection)
#
# Register `socket.socket` with `ForkingPickler`
@ -201,6 +201,7 @@ ForkingPickler.register(socket.socket, reduce_socket)
#
if sys.platform == 'win32':
from multiprocessing.connection import PipeConnection
def reduce_pipe_connection(conn):
rh = reduce_handle(conn.fileno())
@ -208,8 +209,8 @@ if sys.platform == 'win32':
def rebuild_pipe_connection(reduced_handle, readable, writable):
handle = rebuild_handle(reduced_handle)
return _multiprocessing.PipeConnection(
return PipeConnection(
handle, readable=readable, writable=writable
)
ForkingPickler.register(_multiprocessing.PipeConnection, reduce_pipe_connection)
ForkingPickler.register(PipeConnection, reduce_pipe_connection)

12
Lib/test/test_multiprocessing.py
View File

@ -1915,9 +1915,15 @@ class TestInvalidHandle(unittest.TestCase):
@unittest.skipIf(WIN32, "skipped on Windows")
def test_invalid_handles(self):
conn = _multiprocessing.Connection(44977608)
self.assertRaises(IOError, conn.poll)
self.assertRaises(IOError, _multiprocessing.Connection, -1)
conn = multiprocessing.connection.Connection(44977608)
try:
self.assertRaises((ValueError, IOError), conn.poll)
finally:
# Hack private attribute _handle to avoid printing an error
# in conn.__del__
conn._handle = None
self.assertRaises((ValueError, IOError),
multiprocessing.connection.Connection, -1)
#
# Functions used to create test cases from the base ones in this module

2
Misc/NEWS
View File

@ -140,6 +140,8 @@ Core and Builtins
Library
-------
- Issue #11743: Rewrite multiprocessing connection classes in pure Python.
- Issue #11164: Stop trying to use _xmlplus in the xml module.
- Issue #11888: Add log2 function to math module. Patch written by Mark

527
Modules/_multiprocessing/connection.h
View File

@ -1,527 +0,0 @@
/*
* Definition of a `Connection` type.
* Used by `socket_connection.c` and `pipe_connection.c`.
*
* connection.h
*
* Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt
*/
#ifndef CONNECTION_H
#define CONNECTION_H
/*
* Read/write flags
*/
#define READABLE 1
#define WRITABLE 2
#define CHECK_READABLE(self) \
if (!(self->flags & READABLE)) { \
PyErr_SetString(PyExc_IOError, "connection is write-only"); \
return NULL; \
}
#define CHECK_WRITABLE(self) \
if (!(self->flags & WRITABLE)) { \
PyErr_SetString(PyExc_IOError, "connection is read-only"); \
return NULL; \
}
/*
* Allocation and deallocation
*/
static PyObject *
connection_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
ConnectionObject *self;
HANDLE handle;
BOOL readable = TRUE, writable = TRUE;
static char *kwlist[] = {"handle", "readable", "writable", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kwds, F_HANDLE "|ii", kwlist,
&handle, &readable, &writable))
return NULL;
if (handle == INVALID_HANDLE_VALUE || (Py_ssize_t)handle < 0) {
PyErr_Format(PyExc_IOError, "invalid handle %zd",
(Py_ssize_t)handle);
return NULL;
}
if (!readable && !writable) {
PyErr_SetString(PyExc_ValueError,
"either readable or writable must be true");
return NULL;
}
self = PyObject_New(ConnectionObject, type);
if (self == NULL)
return NULL;
self->weakreflist = NULL;
self->handle = handle;
self->flags = 0;
if (readable)
self->flags |= READABLE;
if (writable)
self->flags |= WRITABLE;
assert(self->flags >= 1 && self->flags <= 3);
return (PyObject*)self;
}
static void
connection_dealloc(ConnectionObject* self)
{
if (self->weakreflist != NULL)
PyObject_ClearWeakRefs((PyObject*)self);
if (self->handle != INVALID_HANDLE_VALUE) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
}
PyObject_Del(self);
}
/*
* Functions for transferring buffers
*/
static PyObject *
connection_sendbytes(ConnectionObject *self, PyObject *args)
{
Py_buffer pbuffer;
char *buffer;
Py_ssize_t length, offset=0, size=PY_SSIZE_T_MIN;
int res;
if (!PyArg_ParseTuple(args, F_RBUFFER "*|" F_PY_SSIZE_T F_PY_SSIZE_T,
&pbuffer, &offset, &size))
return NULL;
buffer = pbuffer.buf;
length = pbuffer.len;
CHECK_WRITABLE(self); /* XXX release buffer in case of failure */
if (offset < 0) {
PyBuffer_Release(&pbuffer);
PyErr_SetString(PyExc_ValueError, "offset is negative");
return NULL;
}
if (length < offset) {
PyBuffer_Release(&pbuffer);
PyErr_SetString(PyExc_ValueError, "buffer length < offset");
return NULL;
}
if (size == PY_SSIZE_T_MIN) {
size = length - offset;
} else {
if (size < 0) {
PyBuffer_Release(&pbuffer);
PyErr_SetString(PyExc_ValueError, "size is negative");
return NULL;
}
if (offset + size > length) {
PyBuffer_Release(&pbuffer);
PyErr_SetString(PyExc_ValueError,
"buffer length < offset + size");
return NULL;
}
}
res = conn_send_string(self, buffer + offset, size);
PyBuffer_Release(&pbuffer);
if (res < 0) {
if (PyErr_Occurred())
return NULL;
else
return mp_SetError(PyExc_IOError, res);
}
Py_RETURN_NONE;
}
static PyObject *
connection_recvbytes(ConnectionObject *self, PyObject *args)
{
char *freeme = NULL;
Py_ssize_t res, maxlength = PY_SSIZE_T_MAX;
PyObject *result = NULL;
if (!PyArg_ParseTuple(args, "|" F_PY_SSIZE_T, &maxlength))
return NULL;
CHECK_READABLE(self);
if (maxlength < 0) {
PyErr_SetString(PyExc_ValueError, "maxlength < 0");
return NULL;
}
res = conn_recv_string(self, self->buffer, CONNECTION_BUFFER_SIZE,
&freeme, maxlength);
if (res < 0) {
if (res == MP_BAD_MESSAGE_LENGTH) {
if ((self->flags & WRITABLE) == 0) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
} else {
self->flags = WRITABLE;
}
}
mp_SetError(PyExc_IOError, res);
} else {
if (freeme == NULL) {
result = PyBytes_FromStringAndSize(self->buffer, res);
} else {
result = PyBytes_FromStringAndSize(freeme, res);
PyMem_Free(freeme);
}
}
return result;
}
static PyObject *
connection_recvbytes_into(ConnectionObject *self, PyObject *args)
{
char *freeme = NULL, *buffer = NULL;
Py_ssize_t res, length, offset = 0;
PyObject *result = NULL;
Py_buffer pbuf;
CHECK_READABLE(self);
if (!PyArg_ParseTuple(args, "w*|" F_PY_SSIZE_T,
&pbuf, &offset))
return NULL;
buffer = pbuf.buf;
length = pbuf.len;
if (offset < 0) {
PyErr_SetString(PyExc_ValueError, "negative offset");
goto _error;
}
if (offset > length) {
PyErr_SetString(PyExc_ValueError, "offset too large");
goto _error;
}
res = conn_recv_string(self, buffer+offset, length-offset,
&freeme, PY_SSIZE_T_MAX);
if (res < 0) {
if (res == MP_BAD_MESSAGE_LENGTH) {
if ((self->flags & WRITABLE) == 0) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
} else {
self->flags = WRITABLE;
}
}
mp_SetError(PyExc_IOError, res);
} else {
if (freeme == NULL) {
result = PyInt_FromSsize_t(res);
} else {
result = PyObject_CallFunction(BufferTooShort,
F_RBUFFER "#",
freeme, res);
PyMem_Free(freeme);
if (result) {
PyErr_SetObject(BufferTooShort, result);
Py_DECREF(result);
}
goto _error;
}
}
_cleanup:
PyBuffer_Release(&pbuf);
return result;
_error:
result = NULL;
goto _cleanup;
}
/*
* Functions for transferring objects
*/
static PyObject *
connection_send_obj(ConnectionObject *self, PyObject *obj)
{
char *buffer;
int res;
Py_ssize_t length;
PyObject *pickled_string = NULL;
CHECK_WRITABLE(self);
pickled_string = PyObject_CallFunctionObjArgs(pickle_dumps, obj,
pickle_protocol, NULL);
if (!pickled_string)
goto failure;
if (PyBytes_AsStringAndSize(pickled_string, &buffer, &length) < 0)
goto failure;
res = conn_send_string(self, buffer, (int)length);
if (res < 0) {
mp_SetError(PyExc_IOError, res);
goto failure;
}
Py_XDECREF(pickled_string);
Py_RETURN_NONE;
failure:
Py_XDECREF(pickled_string);
return NULL;
}
static PyObject *
connection_recv_obj(ConnectionObject *self)
{
char *freeme = NULL;
Py_ssize_t res;
PyObject *temp = NULL, *result = NULL;
CHECK_READABLE(self);
res = conn_recv_string(self, self->buffer, CONNECTION_BUFFER_SIZE,
&freeme, PY_SSIZE_T_MAX);
if (res < 0) {
if (res == MP_BAD_MESSAGE_LENGTH) {
if ((self->flags & WRITABLE) == 0) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
} else {
self->flags = WRITABLE;
}
}
mp_SetError(PyExc_IOError, res);
} else {
if (freeme == NULL) {
temp = PyBytes_FromStringAndSize(self->buffer, res);
} else {
temp = PyBytes_FromStringAndSize(freeme, res);
PyMem_Free(freeme);
}
}
if (temp)
result = PyObject_CallFunctionObjArgs(pickle_loads,
temp, NULL);
Py_XDECREF(temp);
return result;
}
/*
* Other functions
*/
static PyObject *
connection_poll(ConnectionObject *self, PyObject *args)
{
PyObject *timeout_obj = NULL;
double timeout = 0.0;
int res;
CHECK_READABLE(self);
if (!PyArg_ParseTuple(args, "|O", &timeout_obj))
return NULL;
if (timeout_obj == NULL) {
timeout = 0.0;
} else if (timeout_obj == Py_None) {
timeout = -1.0; /* block forever */
} else {
timeout = PyFloat_AsDouble(timeout_obj);
if (PyErr_Occurred())
return NULL;
if (timeout < 0.0)
timeout = 0.0;
}
Py_BEGIN_ALLOW_THREADS
res = conn_poll(self, timeout, _save);
Py_END_ALLOW_THREADS
switch (res) {
case TRUE:
Py_RETURN_TRUE;
case FALSE:
Py_RETURN_FALSE;
default:
return mp_SetError(PyExc_IOError, res);
}
}
static PyObject *
connection_fileno(ConnectionObject* self)
{
if (self->handle == INVALID_HANDLE_VALUE) {
PyErr_SetString(PyExc_IOError, "handle is invalid");
return NULL;
}
return PyInt_FromLong((long)self->handle);
}
static PyObject *
connection_close(ConnectionObject *self)
{
if (self->handle != INVALID_HANDLE_VALUE) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
}
Py_RETURN_NONE;
}
static PyObject *
connection_repr(ConnectionObject *self)
{
static char *conn_type[] = {"read-only", "write-only", "read-write"};
assert(self->flags >= 1 && self->flags <= 3);
return FROM_FORMAT("<%s %s, handle %zd>",
conn_type[self->flags - 1],
CONNECTION_NAME, (Py_ssize_t)self->handle);
}
/*
* Getters and setters
*/
static PyObject *
connection_closed(ConnectionObject *self, void *closure)
{
return PyBool_FromLong((long)(self->handle == INVALID_HANDLE_VALUE));
}
static PyObject *
connection_readable(ConnectionObject *self, void *closure)
{
return PyBool_FromLong((long)(self->flags & READABLE));
}
static PyObject *
connection_writable(ConnectionObject *self, void *closure)
{
return PyBool_FromLong((long)(self->flags & WRITABLE));
}
/*
* Tables
*/
static PyMethodDef connection_methods[] = {
{"send_bytes", (PyCFunction)connection_sendbytes, METH_VARARGS,
"send the byte data from a readable buffer-like object"},
{"recv_bytes", (PyCFunction)connection_recvbytes, METH_VARARGS,
"receive byte data as a string"},
{"recv_bytes_into",(PyCFunction)connection_recvbytes_into,METH_VARARGS,
"receive byte data into a writeable buffer-like object\n"
"returns the number of bytes read"},
{"send", (PyCFunction)connection_send_obj, METH_O,
"send a (picklable) object"},
{"recv", (PyCFunction)connection_recv_obj, METH_NOARGS,
"receive a (picklable) object"},
{"poll", (PyCFunction)connection_poll, METH_VARARGS,
"whether there is any input available to be read"},
{"fileno", (PyCFunction)connection_fileno, METH_NOARGS,
"file descriptor or handle of the connection"},
{"close", (PyCFunction)connection_close, METH_NOARGS,
"close the connection"},
{NULL} /* Sentinel */
};
static PyGetSetDef connection_getset[] = {
{"closed", (getter)connection_closed, NULL,
"True if the connection is closed", NULL},
{"readable", (getter)connection_readable, NULL,
"True if the connection is readable", NULL},
{"writable", (getter)connection_writable, NULL,
"True if the connection is writable", NULL},
{NULL}
};
/*
* Connection type
*/
PyDoc_STRVAR(connection_doc,
"Connection type whose constructor signature is\n\n"
" Connection(handle, readable=True, writable=True).\n\n"
"The constructor does *not* duplicate the handle.");
PyTypeObject CONNECTION_TYPE = {
PyVarObject_HEAD_INIT(NULL, 0)
/* tp_name */ "_multiprocessing." CONNECTION_NAME,
/* tp_basicsize */ sizeof(ConnectionObject),
/* tp_itemsize */ 0,
/* tp_dealloc */ (destructor)connection_dealloc,
/* tp_print */ 0,
/* tp_getattr */ 0,
/* tp_setattr */ 0,
/* tp_reserved */ 0,
/* tp_repr */ (reprfunc)connection_repr,
/* tp_as_number */ 0,
/* tp_as_sequence */ 0,
/* tp_as_mapping */ 0,
/* tp_hash */ 0,
/* tp_call */ 0,
/* tp_str */ 0,
/* tp_getattro */ 0,
/* tp_setattro */ 0,
/* tp_as_buffer */ 0,
/* tp_flags */ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
Py_TPFLAGS_HAVE_WEAKREFS,
/* tp_doc */ connection_doc,
/* tp_traverse */ 0,
/* tp_clear */ 0,
/* tp_richcompare */ 0,
/* tp_weaklistoffset */ offsetof(ConnectionObject, weakreflist),
/* tp_iter */ 0,
/* tp_iternext */ 0,
/* tp_methods */ connection_methods,
/* tp_members */ 0,
/* tp_getset */ connection_getset,
/* tp_base */ 0,
/* tp_dict */ 0,
/* tp_descr_get */ 0,
/* tp_descr_set */ 0,
/* tp_dictoffset */ 0,
/* tp_init */ 0,
/* tp_alloc */ 0,
/* tp_new */ connection_new,
};
#endif /* CONNECTION_H */

23
Modules/_multiprocessing/multiprocessing.c
View File

@ -49,16 +49,6 @@ mp_SetError(PyObject *Type, int num)
case MP_MEMORY_ERROR:
PyErr_NoMemory();
break;
case MP_END_OF_FILE:
PyErr_SetNone(PyExc_EOFError);
break;
case MP_EARLY_END_OF_FILE:
PyErr_SetString(PyExc_IOError,
"got end of file during message");
break;
case MP_BAD_MESSAGE_LENGTH:
PyErr_SetString(PyExc_IOError, "bad message length");
break;
case MP_EXCEPTION_HAS_BEEN_SET:
break;
default:
@ -257,12 +247,6 @@ PyInit__multiprocessing(void)
BufferTooShort = PyObject_GetAttrString(temp, "BufferTooShort");
Py_XDECREF(temp);
/* Add connection type to module */
if (PyType_Ready(&ConnectionType) < 0)
return NULL;
Py_INCREF(&ConnectionType);
PyModule_AddObject(module, "Connection", (PyObject*)&ConnectionType);
#if defined(MS_WINDOWS) || \
(defined(HAVE_SEM_OPEN) && !defined(POSIX_SEMAPHORES_NOT_ENABLED))
/* Add SemLock type to module */
@ -286,13 +270,6 @@ PyInit__multiprocessing(void)
#endif
#ifdef MS_WINDOWS
/* Add PipeConnection to module */
if (PyType_Ready(&PipeConnectionType) < 0)
return NULL;
Py_INCREF(&PipeConnectionType);
PyModule_AddObject(module, "PipeConnection",
(PyObject*)&PipeConnectionType);
/* Initialize win32 class and add to multiprocessing */
temp = create_win32_namespace();
if (!temp)

24
Modules/_multiprocessing/multiprocessing.h
View File

@ -118,11 +118,8 @@
#define MP_SUCCESS (0)
#define MP_STANDARD_ERROR (-1)
#define MP_MEMORY_ERROR (-1001)
#define MP_END_OF_FILE (-1002)
#define MP_EARLY_END_OF_FILE (-1003)
#define MP_BAD_MESSAGE_LENGTH (-1004)
#define MP_SOCKET_ERROR (-1005)
#define MP_EXCEPTION_HAS_BEEN_SET (-1006)
#define MP_SOCKET_ERROR (-1002)
#define MP_EXCEPTION_HAS_BEEN_SET (-1003)
PyObject *mp_SetError(PyObject *Type, int num);
@ -135,7 +132,6 @@ extern PyObject *pickle_loads;
extern PyObject *pickle_protocol;
extern PyObject *BufferTooShort;
extern PyTypeObject SemLockType;
extern PyTypeObject ConnectionType;
extern PyTypeObject PipeConnectionType;
extern HANDLE sigint_event;
@ -161,26 +157,10 @@ extern HANDLE sigint_event;
# define Py_TPFLAGS_HAVE_WEAKREFS 0
#endif
/*
* Connection definition
*/
#define CONNECTION_BUFFER_SIZE 1024
typedef struct {
PyObject_HEAD
HANDLE handle;
int flags;
PyObject *weakreflist;
char buffer[CONNECTION_BUFFER_SIZE];
} ConnectionObject;
/*
* Miscellaneous
*/
#define MAX_MESSAGE_LENGTH 0x7fffffff
#ifndef MIN
# define MIN(x, y) ((x) < (y) ? x : y)
# define MAX(x, y) ((x) > (y) ? x : y)

149
Modules/_multiprocessing/pipe_connection.c
View File

@ -1,149 +0,0 @@
/*
* A type which wraps a pipe handle in message oriented mode
*
* pipe_connection.c
*
* Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt
*/
#include "multiprocessing.h"
#define CLOSE(h) CloseHandle(h)
/*
* Send string to the pipe; assumes in message oriented mode
*/
static Py_ssize_t
conn_send_string(ConnectionObject *conn, char *string, size_t length)
{
DWORD amount_written;
BOOL ret;
Py_BEGIN_ALLOW_THREADS
ret = WriteFile(conn->handle, string, length, &amount_written, NULL);
Py_END_ALLOW_THREADS
if (ret == 0 && GetLastError() == ERROR_NO_SYSTEM_RESOURCES) {
PyErr_Format(PyExc_ValueError, "Cannnot send %" PY_FORMAT_SIZE_T "d bytes over connection", length);
return MP_STANDARD_ERROR;
}
return ret ? MP_SUCCESS : MP_STANDARD_ERROR;
}
/*
* Attempts to read into buffer, or if buffer too small into *newbuffer.
*
* Returns number of bytes read. Assumes in message oriented mode.
*/
static Py_ssize_t
conn_recv_string(ConnectionObject *conn, char *buffer,
size_t buflength, char **newbuffer, size_t maxlength)
{
DWORD left, length, full_length, err;
BOOL ret;
*newbuffer = NULL;
Py_BEGIN_ALLOW_THREADS
ret = ReadFile(conn->handle, buffer, MIN(buflength, maxlength),
&length, NULL);
Py_END_ALLOW_THREADS
if (ret)
return length;
err = GetLastError();
if (err != ERROR_MORE_DATA) {
if (err == ERROR_BROKEN_PIPE)
return MP_END_OF_FILE;
return MP_STANDARD_ERROR;
}
if (!PeekNamedPipe(conn->handle, NULL, 0, NULL, NULL, &left))
return MP_STANDARD_ERROR;
full_length = length + left;
if (full_length > maxlength)
return MP_BAD_MESSAGE_LENGTH;
*newbuffer = PyMem_Malloc(full_length);
if (*newbuffer == NULL)
return MP_MEMORY_ERROR;
memcpy(*newbuffer, buffer, length);
Py_BEGIN_ALLOW_THREADS
ret = ReadFile(conn->handle, *newbuffer+length, left, &length, NULL);
Py_END_ALLOW_THREADS
if (ret) {
assert(length == left);
return full_length;
} else {
PyMem_Free(*newbuffer);
return MP_STANDARD_ERROR;
}
}
/*
* Check whether any data is available for reading
*/
static int
conn_poll(ConnectionObject *conn, double timeout, PyThreadState *_save)
{
DWORD bytes, deadline, delay;
int difference, res;
BOOL block = FALSE;
if (!PeekNamedPipe(conn->handle, NULL, 0, NULL, &bytes, NULL))
return MP_STANDARD_ERROR;
if (timeout == 0.0)
return bytes > 0;
if (timeout < 0.0)
block = TRUE;
else
/* XXX does not check for overflow */
deadline = GetTickCount() + (DWORD)(1000 * timeout + 0.5);
Sleep(0);
for (delay = 1 ; ; delay += 1) {
if (!PeekNamedPipe(conn->handle, NULL, 0, NULL, &bytes, NULL))
return MP_STANDARD_ERROR;
else if (bytes > 0)
return TRUE;
if (!block) {
difference = deadline - GetTickCount();
if (difference < 0)
return FALSE;
if ((int)delay > difference)
delay = difference;
}
if (delay > 20)
delay = 20;
Sleep(delay);
/* check for signals */
Py_BLOCK_THREADS
res = PyErr_CheckSignals();
Py_UNBLOCK_THREADS
if (res)
return MP_EXCEPTION_HAS_BEEN_SET;
}
}
/*
* "connection.h" defines the PipeConnection type using the definitions above
*/
#define CONNECTION_NAME "PipeConnection"
#define CONNECTION_TYPE PipeConnectionType
#include "connection.h"

202
Modules/_multiprocessing/socket_connection.c
View File

@ -1,202 +0,0 @@
/*
* A type which wraps a socket
*
* socket_connection.c
*
* Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt
*/
#include "multiprocessing.h"
#ifdef MS_WINDOWS
# define WRITE(h, buffer, length) send((SOCKET)h, buffer, length, 0)
# define READ(h, buffer, length) recv((SOCKET)h, buffer, length, 0)
# define CLOSE(h) closesocket((SOCKET)h)
#else
# define WRITE(h, buffer, length) write(h, buffer, length)
# define READ(h, buffer, length) read(h, buffer, length)
# define CLOSE(h) close(h)
#endif
/*
* Send string to file descriptor
*/
static Py_ssize_t
_conn_sendall(HANDLE h, char *string, size_t length)
{
char *p = string;
Py_ssize_t res;
while (length > 0) {
res = WRITE(h, p, length);
if (res < 0)
return MP_SOCKET_ERROR;
length -= res;
p += res;
}
return MP_SUCCESS;
}
/*
* Receive string of exact length from file descriptor
*/
static Py_ssize_t
_conn_recvall(HANDLE h, char *buffer, size_t length)
{
size_t remaining = length;
Py_ssize_t temp;
char *p = buffer;
while (remaining > 0) {
temp = READ(h, p, remaining);
if (temp <= 0) {
if (temp == 0)
return remaining == length ?
MP_END_OF_FILE : MP_EARLY_END_OF_FILE;
else
return temp;
}
remaining -= temp;
p += temp;
}
return MP_SUCCESS;
}
/*
* Send a string prepended by the string length in network byte order
*/
static Py_ssize_t
conn_send_string(ConnectionObject *conn, char *string, size_t length)
{
Py_ssize_t res;
/* The "header" of the message is a 32 bit unsigned number (in
network order) which specifies the length of the "body". If
the message is shorter than about 16kb then it is quicker to
combine the "header" and the "body" of the message and send
them at once. */
if (length < (16*1024)) {
char *message;
message = PyMem_Malloc(length+4);
if (message == NULL)
return MP_MEMORY_ERROR;
*(UINT32*)message = htonl((UINT32)length);
memcpy(message+4, string, length);
Py_BEGIN_ALLOW_THREADS
res = _conn_sendall(conn->handle, message, length+4);
Py_END_ALLOW_THREADS
PyMem_Free(message);
} else {
UINT32 lenbuff;
if (length > MAX_MESSAGE_LENGTH)
return MP_BAD_MESSAGE_LENGTH;
lenbuff = htonl((UINT32)length);
Py_BEGIN_ALLOW_THREADS
res = _conn_sendall(conn->handle, (char*)&lenbuff, 4) ||
_conn_sendall(conn->handle, string, length);
Py_END_ALLOW_THREADS
}
return res;
}
/*
* Attempts to read into buffer, or failing that into *newbuffer
*
* Returns number of bytes read.
*/
static Py_ssize_t
conn_recv_string(ConnectionObject *conn, char *buffer,
size_t buflength, char **newbuffer, size_t maxlength)
{
int res;
UINT32 ulength;
*newbuffer = NULL;
Py_BEGIN_ALLOW_THREADS
res = _conn_recvall(conn->handle, (char*)&ulength, 4);
Py_END_ALLOW_THREADS
if (res < 0)
return res;
ulength = ntohl(ulength);
if (ulength > maxlength)
return MP_BAD_MESSAGE_LENGTH;
if (ulength <= buflength) {
Py_BEGIN_ALLOW_THREADS
res = _conn_recvall(conn->handle, buffer, (size_t)ulength);
Py_END_ALLOW_THREADS
return res < 0 ? res : ulength;
} else {
*newbuffer = PyMem_Malloc((size_t)ulength);
if (*newbuffer == NULL)
return MP_MEMORY_ERROR;
Py_BEGIN_ALLOW_THREADS
res = _conn_recvall(conn->handle, *newbuffer, (size_t)ulength);
Py_END_ALLOW_THREADS
return res < 0 ? (Py_ssize_t)res : (Py_ssize_t)ulength;
}
}
/*
* Check whether any data is available for reading -- neg timeout blocks
*/
static int
conn_poll(ConnectionObject *conn, double timeout, PyThreadState *_save)
{
int res;
fd_set rfds;
/*
* Verify the handle, issue 3321. Not required for windows.
*/
#ifndef MS_WINDOWS
if (((int)conn->handle) < 0 || ((int)conn->handle) >= FD_SETSIZE) {
Py_BLOCK_THREADS
PyErr_SetString(PyExc_IOError, "handle out of range in select()");
Py_UNBLOCK_THREADS
return MP_EXCEPTION_HAS_BEEN_SET;
}
#endif
FD_ZERO(&rfds);
FD_SET((SOCKET)conn->handle, &rfds);
if (timeout < 0.0) {
res = select((int)conn->handle+1, &rfds, NULL, NULL, NULL);
} else {
struct timeval tv;
tv.tv_sec = (long)timeout;
tv.tv_usec = (long)((timeout - tv.tv_sec) * 1e6 + 0.5);
res = select((int)conn->handle+1, &rfds, NULL, NULL, &tv);
}
if (res < 0) {
return MP_SOCKET_ERROR;
} else if (FD_ISSET(conn->handle, &rfds)) {
return TRUE;
} else {
assert(res == 0);
return FALSE;
}
}
/*
* "connection.h" defines the Connection type using defs above
*/
#define CONNECTION_NAME "Connection"
#define CONNECTION_TYPE ConnectionType
#include "connection.h"

166
Modules/_multiprocessing/win32_functions.c
View File

@ -215,6 +215,164 @@ win32_WaitNamedPipe(PyObject *self, PyObject *args)
Py_RETURN_NONE;
}
static PyObject *
win32_closesocket(PyObject *self, PyObject *args)
{
HANDLE handle;
int ret;
if (!PyArg_ParseTuple(args, F_HANDLE ":closesocket" , &handle))
return NULL;
Py_BEGIN_ALLOW_THREADS
ret = closesocket((SOCKET) handle);
Py_END_ALLOW_THREADS
if (ret)
return PyErr_SetExcFromWindowsErr(PyExc_IOError, WSAGetLastError());
Py_RETURN_NONE;
}
static PyObject *
win32_recv(PyObject *self, PyObject *args)
{
HANDLE handle;
int size, nread;
PyObject *buf;
if (!PyArg_ParseTuple(args, F_HANDLE "i:recv" , &handle, &size))
return NULL;
buf = PyBytes_FromStringAndSize(NULL, size);
if (!buf)
return NULL;
Py_BEGIN_ALLOW_THREADS
nread = recv((SOCKET) handle, PyBytes_AS_STRING(buf), size, 0);
Py_END_ALLOW_THREADS
if (nread < 0) {
Py_DECREF(buf);
return PyErr_SetExcFromWindowsErr(PyExc_IOError, WSAGetLastError());
}
_PyBytes_Resize(&buf, nread);
return buf;
}
static PyObject *
win32_send(PyObject *self, PyObject *args)
{
HANDLE handle;
Py_buffer buf;
int ret;
if (!PyArg_ParseTuple(args, F_HANDLE "y*:send" , &handle, &buf))
return NULL;
Py_BEGIN_ALLOW_THREADS
ret = send((SOCKET) handle, buf.buf, buf.len, 0);
Py_END_ALLOW_THREADS
PyBuffer_Release(&buf);
if (ret < 0)
return PyErr_SetExcFromWindowsErr(PyExc_IOError, WSAGetLastError());
return PyLong_FromLong(ret);
}
static PyObject *
win32_WriteFile(PyObject *self, PyObject *args)
{
HANDLE handle;
Py_buffer buf;
int written;
BOOL ret;
if (!PyArg_ParseTuple(args, F_HANDLE "y*:WriteFile" , &handle, &buf))
return NULL;
Py_BEGIN_ALLOW_THREADS
ret = WriteFile(handle, buf.buf, buf.len, &written, NULL);
Py_END_ALLOW_THREADS
PyBuffer_Release(&buf);
if (!ret)
return PyErr_SetExcFromWindowsErr(PyExc_IOError, 0);
return PyLong_FromLong(written);
}
static PyObject *
win32_ReadFile(PyObject *self, PyObject *args)
{
HANDLE handle;
int size;
DWORD nread;
PyObject *buf;
BOOL ret;
if (!PyArg_ParseTuple(args, F_HANDLE "i:ReadFile" , &handle, &size))
return NULL;
buf = PyBytes_FromStringAndSize(NULL, size);
if (!buf)
return NULL;
Py_BEGIN_ALLOW_THREADS
ret = ReadFile(handle, PyBytes_AS_STRING(buf), size, &nread, NULL);
Py_END_ALLOW_THREADS
if (!ret && GetLastError() != ERROR_MORE_DATA) {
Py_DECREF(buf);
return PyErr_SetExcFromWindowsErr(PyExc_IOError, 0);
}
if (_PyBytes_Resize(&buf, nread))
return NULL;
return Py_BuildValue("NN", buf, PyBool_FromLong(ret));
}
static PyObject *
win32_PeekNamedPipe(PyObject *self, PyObject *args)
{
HANDLE handle;
int size = 0;
PyObject *buf = NULL;
DWORD nread, navail, nleft;
BOOL ret;
if (!PyArg_ParseTuple(args, F_HANDLE "|i:PeekNamedPipe" , &handle, &size))
return NULL;
if (size < 0) {
PyErr_SetString(PyExc_ValueError, "negative size");
return NULL;
}
if (size) {
buf = PyBytes_FromStringAndSize(NULL, size);
if (!buf)
return NULL;
Py_BEGIN_ALLOW_THREADS
ret = PeekNamedPipe(handle, PyBytes_AS_STRING(buf), size, &nread,
&navail, &nleft);
Py_END_ALLOW_THREADS
if (!ret) {
Py_DECREF(buf);
return PyErr_SetExcFromWindowsErr(PyExc_IOError, 0);
}
if (_PyBytes_Resize(&buf, nread))
return NULL;
return Py_BuildValue("Nii", buf, navail, nleft);
}
else {
Py_BEGIN_ALLOW_THREADS
ret = PeekNamedPipe(handle, NULL, 0, NULL, &navail, &nleft);
Py_END_ALLOW_THREADS
if (!ret) {
return PyErr_SetExcFromWindowsErr(PyExc_IOError, 0);
}
return Py_BuildValue("ii", navail, nleft);
}
}
static PyMethodDef win32_methods[] = {
WIN32_FUNCTION(CloseHandle),
WIN32_FUNCTION(GetLastError),
@ -223,8 +381,14 @@ static PyMethodDef win32_methods[] = {
WIN32_FUNCTION(ConnectNamedPipe),
WIN32_FUNCTION(CreateFile),
WIN32_FUNCTION(CreateNamedPipe),
WIN32_FUNCTION(ReadFile),
WIN32_FUNCTION(PeekNamedPipe),
WIN32_FUNCTION(SetNamedPipeHandleState),
WIN32_FUNCTION(WaitNamedPipe),
WIN32_FUNCTION(WriteFile),
WIN32_FUNCTION(closesocket),
WIN32_FUNCTION(recv),
WIN32_FUNCTION(send),
{NULL}
};
@ -244,6 +408,8 @@ create_win32_namespace(void)
Py_INCREF(&Win32Type);
WIN32_CONSTANT(F_DWORD, ERROR_ALREADY_EXISTS);
WIN32_CONSTANT(F_DWORD, ERROR_BROKEN_PIPE);
WIN32_CONSTANT(F_DWORD, ERROR_NO_SYSTEM_RESOURCES);
WIN32_CONSTANT(F_DWORD, ERROR_PIPE_BUSY);
WIN32_CONSTANT(F_DWORD, ERROR_PIPE_CONNECTED);
WIN32_CONSTANT(F_DWORD, ERROR_SEM_TIMEOUT);

8
PC/VC6/_multiprocessing.dsp
View File

@ -97,18 +97,10 @@ SOURCE=..\..\Modules\_multiprocessing\multiprocessing.c
# End Source File
# Begin Source File
SOURCE=..\..\Modules\_multiprocessing\pipe_connection.c
# End Source File
# Begin Source File
SOURCE=..\..\Modules\_multiprocessing\semaphore.c
# End Source File
# Begin Source File
SOURCE=..\..\Modules\_multiprocessing\socket_connection.c
# End Source File
# Begin Source File
SOURCE=..\..\Modules\_multiprocessing\win32_functions.c
# End Source File
# End Target

12
PC/VS8.0/_multiprocessing.vcproj
View File

@ -522,10 +522,6 @@
RelativePath="..\..\Modules\_multiprocessing\multiprocessing.h"
>
</File>
<File
RelativePath="..\..\Modules\_multiprocessing\connection.h"
>
</File>
</Filter>
<Filter
Name="Source Files"
@ -534,18 +530,10 @@
RelativePath="..\..\Modules\_multiprocessing\multiprocessing.c"
>
</File>
<File
RelativePath="..\..\Modules\_multiprocessing\pipe_connection.c"
>
</File>
<File
RelativePath="..\..\Modules\_multiprocessing\semaphore.c"
>
</File>
<File
RelativePath="..\..\Modules\_multiprocessing\socket_connection.c"
>
</File>
<File
RelativePath="..\..\Modules\_multiprocessing\win32_functions.c"
>

12
PCbuild/_multiprocessing.vcproj
View File

@ -522,10 +522,6 @@
RelativePath="..\Modules\_multiprocessing\multiprocessing.h"
>
</File>
<File
RelativePath="..\Modules\_multiprocessing\connection.h"
>
</File>
</Filter>
<Filter
Name="Source Files"
@ -534,18 +530,10 @@
RelativePath="..\Modules\_multiprocessing\multiprocessing.c"
>
</File>
<File
RelativePath="..\Modules\_multiprocessing\pipe_connection.c"
>
</File>
<File
RelativePath="..\Modules\_multiprocessing\semaphore.c"
>
</File>
<File
RelativePath="..\Modules\_multiprocessing\socket_connection.c"
>
</File>
<File
RelativePath="..\Modules\_multiprocessing\win32_functions.c"
>

3
setup.py
View File

@ -1353,14 +1353,11 @@ class PyBuildExt(build_ext):
if platform == 'win32':
multiprocessing_srcs = [ '_multiprocessing/multiprocessing.c',
'_multiprocessing/semaphore.c',
'_multiprocessing/pipe_connection.c',
'_multiprocessing/socket_connection.c',
'_multiprocessing/win32_functions.c'
]
else:
multiprocessing_srcs = [ '_multiprocessing/multiprocessing.c',
'_multiprocessing/socket_connection.c'
]
if (sysconfig.get_config_var('HAVE_SEM_OPEN') and not
sysconfig.get_config_var('POSIX_SEMAPHORES_NOT_ENABLED')):