X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=tools.py;h=f4496e13a4eff31802957c4e0acb6c0533e41328;hb=04a528370f6e237c08e26de5272e3ac418bb8057;hp=f41f981ce971bfed797ac6649e824a951d745842;hpb=8043da14ad0a8f76c20c8ff4e5ce2d8e1c2131df;p=nodemanager.git

diff --git a/tools.py b/tools.py
index f41f981..f4496e1 100644
--- a/tools.py
+++ b/tools.py
@@ -6,6 +6,7 @@ import os
 import pwd
 import tempfile
 import threading
+import fcntl
 
 import logger
 
@@ -88,3 +89,17 @@ def write_temp_file(do_write, mode=None, uidgid=None):
     try: do_write(f)
     finally: f.close()
     return temporary_filename
+
+
+class NMLock:
+    def __init__(self, file):
+        self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
+        flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
+        flags |= fcntl.FD_CLOEXEC
+        fcntl.fcntl(self.fd, fcntl.F_SETFD, flags)
+    def __del__(self):
+        os.close(self.fd)
+    def acquire(self):
+        fcntl.lockf(self.fd, fcntl.LOCK_EX)
+    def release(self):
+        fcntl.lockf(self.fd, fcntl.LOCK_UN)