move the code for single-instance check into its own file

lib/solaar/appinstance.py

@@ -0,0 +1,47 @@
+#
+#
+#
+
+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()

lib/solaar/gtk.py

@@ -125,40 +125,13 @@ def main():
 	_require('gi.repository.Gtk', 'gir1.2-gtk-3.0')
 	args = _parse_arguments()
 
-	# ensure no more than a single instance runs at a time
+	from . import appinstance
-	import os.path as _path
+	appid = appinstance.check()
-	import os as _os
-	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:
-		import fcntl as _fcntl
-		try:
-			_fcntl.flock(lock_fd, _fcntl.LOCK_EX | _fcntl.LOCK_NB)
-		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)
-
 	try:
 		_run(args)
 	finally:
-		if lock_fd:
+		appinstance.close(appid)
-			_fcntl.flock(lock_fd, _fcntl.LOCK_UN)
+
-			lock_fd.close()
 
 if __name__ == '__main__':
 	main()