sapling/eden/fs/integration/oexcl_test.py
Wez Furlong bccda176d4 eden: implement O_EXCL open flags
Summary:
This enables O_EXCL to function by allowing the create routine to
move its folly::File instance down in to the underlying FileData instance.

Previously we would close and then re-open the file; this would discard
any of the natural gating for the open call that is performed by the kernel
for the underlying filesystem in the overlay.

Reviewed By: bolinfest

Differential Revision: D3513758

fbshipit-source-id: 85967a3b7affa1b1df46842be8ba21c8fbb843a6
2016-07-05 19:54:21 -07:00

41 lines
1.3 KiB
Python

#!/usr/bin/env python3
#
# Copyright (c) 2016, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree. An additional grant
# of patent rights can be found in the PATENTS file in the same directory.
from .lib import testcase
import errno
import os
class OpenExclusiveTest(testcase.EdenTestCase):
def test_oexcl(self):
eden = self.init_git_eden()
filename = os.path.join(eden.mount_path, 'makeme')
fd = os.open(filename, os.O_EXCL | os.O_CREAT | os.O_RDWR)
self.assertGreater(fd, -1, msg='Opened file exclusively')
try:
os.write(fd, b'foo\n')
finally:
os.close(fd)
with self.assertRaises(OSError) as context:
fd = os.open(filename, os.O_EXCL | os.O_CREAT | os.O_RDWR)
if fd != -1:
os.close(fd)
self.assertEqual(errno.EEXIST, context.exception.errno,
msg='O_EXCL for an existing file raises EEXIST')
os.unlink(filename)
fd = os.open(filename, os.O_EXCL | os.O_CREAT | os.O_RDWR)
self.assertGreater(fd, -1,
msg='Subsequent O_EXCL is not blocked after ' +
'removing the file')
os.close(fd)