bitbake: persist_data.py: Immediately get exclusive lock in __setitem__

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

(Bitbake rev: 2ba2f224b50956313f5c2ba01942143b4d6098f2)

Signed-off-by: Chris Laplante <chris.laplante@agilent.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit feb43e7c30f5bfab75d718896c45df621810d06f)
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/bitbake/lib/bb/persist_data.py b/bitbake/lib/bb/persist_data.py
index de8f87a8bf..7357ab2d44 100644
--- a/bitbake/lib/bb/persist_data.py
+++ b/bitbake/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: