add flocker

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/flocker.py b/src/flocker.py
new file mode 100644
index 0000000..8965ee2
--- /dev/null
+++ b/src/flocker.py
@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+'''
+featherweight – A lightweight terminal news feed reader
+
+Copyright © 2013  Mattias Andrée (maandree@member.fsf.org)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+'''
+import fcntl
+
+
+def flock(file, exclusive, nonblocking = False):
+    locktype = (fcntl.LOCK_EX if exclusive else fcntl.LOCK_SH) | (fcntl.LOCK_NB if nonblocking else 0)
+    fcntl(file.fileno(), locktype)
+
+
+def unflock(file):
+    fcntl(file.fileno(), LOCK_UN)
+