Solaar/lib/solaar/appinstance.py

48 lines
1.0 KiB
Python

#
#
#
from __future__ import absolute_import, division, print_function, unicode_literals
#
#
#
import fcntl as _fcntl
import os.path as _path
import os as _os
def check():
# ensure no more than a single instance runs at a time
lock_fd = None
for p in _os.environ.get('XDG_RUNTIME_DIR'), '/run/lock', '/var/lock', _os.environ.get('TMPDIR', '/tmp'):
if p and _path.isdir(p) and _os.access(p, _os.W_OK):
lock_path = _path.join(p, 'solaar.single-instance.%d' % _os.getuid())
try:
lock_fd = open(lock_path, 'wb')
# print ("Single instance lock file is %s" % lock_path)
break
except:
pass
if lock_fd:
try:
_fcntl.flock(lock_fd, _fcntl.LOCK_EX | _fcntl.LOCK_NB)
return lock_fd
except IOError as e:
if e.errno == 11:
import sys
sys.exit("solaar: error: Solaar is already running.")
else:
raise
else:
import sys
print ("solaar: warning: failed to create single instance lock file, ignoring.", file=sys.stderr)
def close(lock_fd):
if lock_fd:
_fcntl.flock(lock_fd, _fcntl.LOCK_UN)
lock_fd.close()