save results in sorted order to avoid deadlock

1 files changed, 8 insertions, 2 deletions

diff --git a/rtss14/database.py b/rtss14/database.py
index d3d10fe..2357b02 100755
--- a/rtss14/database.py
+++ b/rtss14/database.py
@@ -384,8 +384,10 @@ def store_sched_results(db_name, data, ndp = 0):
         # must be merged with prior results in the 'scaled_sched_results' table
         c = conn.cursor(db.cursors.DictCursor)
         try:
-            # get IDs for all design points
-            dp_ids = [lookup_dp_id(c, d.dp) for d in data]
+            # get IDs for all design points.
+            # sort to ensure that we update scaled design points
+            # in a consistent order (no deadlocks!).
+            dp_ids = sorted([lookup_dp_id(c, d.dp) for d in data])
 
             # insert the normal sched data in one go
             begin_sync(conn, c)
@@ -406,6 +408,10 @@ def store_sched_results(db_name, data, ndp = 0):
             # TODO: mark unsaved design points as not taken in dp_pending
             # rethrow
             raise e
+        except BaseException, e:
+            print 'Caught unknown exception. Rolling back transaction before exiting.'
+            rollback(conn)
+            raise e
         c.close()
         if ndp > 0:
             fetched = __get_design_points(conn, ndp)