Merge lp:~allenap/maas/database-locks-revisited-at-start-up--1.5 into lp:maas/1.5

[Gavin Panella]

Backport of trunk r2400: Lock for start-up in a transaction.

MAAS's database locking code has become more strict and fixing this was missed out.

[Gavin Panella (allenap)]

review: Approve

=== modified file 'src/maasserver/start_up.py'
--- src/maasserver/start_up.py	2014-04-15 07:42:50 +0000
+++ src/maasserver/start_up.py	2014-06-03 15:54:57 +0000
@@ -18,7 +18,10 @@
 
 from textwrap import dedent
 
-from django.db import connection
+from django.db import (
+    connection,
+    transaction,
+    )
 from maasserver import (
     eventloop,
     locks,
@@ -51,8 +54,9 @@
     but this method uses file-based locking to ensure that the methods it calls
     internally are not ran concurrently.
     """
-    with locks.startup:
-        inner_start_up()
+    with transaction.atomic():
+        with locks.startup:
+            inner_start_up()
 
     eventloop.start().wait(10)