[bitbake-devel] [PATCH 3/3] persist_data.py: Immediately get exclusive lock in __setitem__

[Chris Laplante]

To avoid races, SQLTable::__setitem__ needs an exclusive lock for the
entire transaction, not just the INSERT/UPDATE part.

Signed-off-by: Chris Laplante <chris.laplante at agilent.com>
---
 lib/bb/persist_data.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/bb/persist_data.py b/lib/bb/persist_data.py
index de8f87a..7357ab2 100644
--- a/lib/bb/persist_data.py
+++ b/lib/bb/persist_data.py
@@ -179,6 +179,9 @@ class SQLTable(collections.MutableMapping):
         elif not isinstance(value, str):
             raise TypeError('Only string values are supported')
 
+        # Ensure the entire transaction (including SELECT) executes under write lock
+        cursor.execute("BEGIN EXCLUSIVE")
+
         cursor.execute("SELECT * from %s where key=?;" % self.table, [key])
         row = cursor.fetchone()
         if row is not None:
-- 
2.7.4