python tests: Added fcntl module for Windows

This is needed for lockf function used to lock the PID file on Windows.
ioctl and fcntl functions are not implemented at this time because they are
not used by any script.

Signed-off-by: Paul-Daniel Boca <pboca@cloudbasesolutions.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Signed-off-by: Gurucharan Shetty <guru@ovn.org>

python/automake.mk

@@ -11,6 +11,7 @@ ovstest_pyfiles = \
 ovs_pyfiles = \
 	python/ovs/__init__.py \
 	python/ovs/daemon.py \
+	python/ovs/fcntl_win.py \
 	python/ovs/db/__init__.py \
 	python/ovs/db/data.py \
 	python/ovs/db/error.py \

python/ovs/fcntl_win.py

@@ -0,0 +1,42 @@
+# Copyright (c) 2016 Cloudbase Solutions Srl
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import errno
+import win32con
+import win32file
+import pywintypes
+import msvcrt
+
+LOCK_EX = win32con.LOCKFILE_EXCLUSIVE_LOCK
+LOCK_SH = 0  # the default
+LOCK_NB = win32con.LOCKFILE_FAIL_IMMEDIATELY
+LOCK_UN = 0x80000000  # unlock - non-standard
+
+
+def lockf(fd, flags, length=0xFFFF0000, start=0, whence=0):
+    overlapped = pywintypes.OVERLAPPED()
+    hfile = msvcrt.get_osfhandle(fd.fileno())
+    if LOCK_UN & flags:
+        ret = win32file.UnlockFileEx(hfile, 0, start, length, overlapped)
+    else:
+        try:
+            ret = win32file.LockFileEx(hfile, flags, start, length, overlapped)
+        except:
+            raise IOError(errno.EAGAIN, "", "")
+
+    return ret
+
+
+def flock(fd, flags):
+    lockf(fd, flags, 0xFFFF0000, 0, 0)