Issue #11657: Fix sending file descriptors over 255 over a multiprocessing Pipe.
Also added some tests.
diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py
index 6da4b17..935e224 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -15,6 +15,7 @@
import socket
import random
import logging
+import errno
from test import test_support
from StringIO import StringIO
_multiprocessing = test_support.import_module('_multiprocessing')
@@ -32,7 +33,7 @@
import multiprocessing.heap
import multiprocessing.pool
-from multiprocessing import util
+from multiprocessing import util, reduction
try:
from multiprocessing.sharedctypes import Value, copy
@@ -40,6 +41,11 @@
except ImportError:
HAS_SHAREDCTYPES = False
+try:
+ import msvcrt
+except ImportError:
+ msvcrt = None
+
#
#
#
@@ -68,6 +74,11 @@
WIN32 = (sys.platform == "win32")
+try:
+ MAXFD = os.sysconf("SC_OPEN_MAX")
+except:
+ MAXFD = 256
+
#
# Some tests require ctypes
#
@@ -1481,6 +1492,76 @@
self.assertRaises(ValueError, a.send_bytes, msg, 4, -1)
+ @classmethod
+ def _is_fd_assigned(cls, fd):
+ try:
+ os.fstat(fd)
+ except OSError as e:
+ if e.errno == errno.EBADF:
+ return False
+ raise
+ else:
+ return True
+
+ @classmethod
+ def _writefd(cls, conn, data, create_dummy_fds=False):
+ if create_dummy_fds:
+ for i in range(0, 256):
+ if not cls._is_fd_assigned(i):
+ os.dup2(conn.fileno(), i)
+ fd = reduction.recv_handle(conn)
+ if msvcrt:
+ fd = msvcrt.open_osfhandle(fd, os.O_WRONLY)
+ os.write(fd, data)
+ os.close(fd)
+
+ def test_fd_transfer(self):
+ if self.TYPE != 'processes':
+ self.skipTest("only makes sense with processes")
+ conn, child_conn = self.Pipe(duplex=True)
+
+ p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
+ p.start()
+ with open(test_support.TESTFN, "wb") as f:
+ fd = f.fileno()
+ if msvcrt:
+ fd = msvcrt.get_osfhandle(fd)
+ reduction.send_handle(conn, fd, p.pid)
+ p.join()
+ with open(test_support.TESTFN, "rb") as f:
+ self.assertEqual(f.read(), b"foo")
+
+ @unittest.skipIf(sys.platform == "win32",
+ "test semantics don't make sense on Windows")
+ @unittest.skipIf(MAXFD <= 256,
+ "largest assignable fd number is too small")
+ @unittest.skipUnless(hasattr(os, "dup2"),
+ "test needs os.dup2()")
+ def test_large_fd_transfer(self):
+ # With fd > 256 (issue #11657)
+ if self.TYPE != 'processes':
+ self.skipTest("only makes sense with processes")
+ conn, child_conn = self.Pipe(duplex=True)
+
+ p = self.Process(target=self._writefd, args=(child_conn, b"bar", True))
+ p.start()
+ with open(test_support.TESTFN, "wb") as f:
+ fd = f.fileno()
+ for newfd in range(256, MAXFD):
+ if not self._is_fd_assigned(newfd):
+ break
+ else:
+ self.fail("could not find an unassigned large file descriptor")
+ os.dup2(fd, newfd)
+ try:
+ reduction.send_handle(conn, newfd, p.pid)
+ finally:
+ os.close(newfd)
+ p.join()
+ with open(test_support.TESTFN, "rb") as f:
+ self.assertEqual(f.read(), b"bar")
+
+
class _TestListenerClient(BaseTestCase):
ALLOWED_TYPES = ('processes', 'threads')