Viewing file:  _unix.py (1.05 KB) -rw-r--r--
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import os
from ._api import BaseFileLock
try:
import fcntl
except ImportError:
fcntl = None
#: a flag to indicate if the fcntl API is available
has_fcntl = fcntl is not None
class UnixFileLock(BaseFileLock):
"""Uses the :func:`fcntl.flock` to hard lock the lock file on unix systems."""
def _acquire(self):
open_mode = os.O_RDWR | os.O_CREAT | os.O_TRUNC
fd = os.open(self._lock_file, open_mode)
try:
fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
except (OSError, IOError): # noqa: B014 # IOError is not OSError on python 2
os.close(fd)
else:
self._lock_file_fd = fd
def _release(self):
# Do not remove the lockfile:
# https://github.com/tox-dev/py-filelock/issues/31
# https://stackoverflow.com/questions/17708885/flock-removing-locked-file-without-race-condition
fd = self._lock_file_fd
self._lock_file_fd = None
fcntl.flock(fd, fcntl.LOCK_UN)
os.close(fd)
__all__ = [
"has_fcntl",
"UnixFileLock",
]
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