From 4ed5eb477a27e18a4d904c6675caf6aa0446b30b Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Wed, 9 Nov 2011 23:53:09 +1100
Subject: [PATCH] autotest: use a lock file

this ensures we don't run two copies of the tests at once
---
 Tools/autotest/autotest.py |  6 ++++++
 Tools/autotest/util.py     | 10 ++++++++++
 2 files changed, 16 insertions(+)

diff --git a/Tools/autotest/autotest.py b/Tools/autotest/autotest.py
index bad56d73b2..de2870ff41 100755
--- a/Tools/autotest/autotest.py
+++ b/Tools/autotest/autotest.py
@@ -243,6 +243,12 @@ def run_tests(steps):
 
     return passed
 
+
+lck = util.lock_file(util.reltopdir('../buildlogs/autotest.lck'))
+if lck is None:
+    print("autotest is locked - exiting")
+    sys.exit(0)
+
 try:
     if not run_tests(steps):
         sys.exit(1)
diff --git a/Tools/autotest/util.py b/Tools/autotest/util.py
index d27943fe22..df721ae68e 100644
--- a/Tools/autotest/util.py
+++ b/Tools/autotest/util.py
@@ -160,3 +160,13 @@ def loadfile(fname):
     r = f.read()
     f.close()
     return r
+
+def lock_file(fname):
+    '''lock a file'''
+    import fcntl
+    f = open(fname, mode='w')
+    try:
+        fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
+    except Exception:
+        return None
+    return f