dbwrap: add comment describing behaviour of dbwrap_change_int32_atomic().

Michael
(This used to be commit f8f21c8e3922806230e240cb54205fc2db7a3619)

diff --git a/source3/lib/dbwrap_util.c b/source3/lib/dbwrap_util.c
index 7789f6922303734daf3c0d8622175b76c28397fe..09e9071d8c9a69c30b78c3d8a935e506fde792c3 100644 (file)
--- a/source3/lib/dbwrap_util.c
+++ b/source3/lib/dbwrap_util.c
@@ -138,6 +138,13 @@ uint32_t dbwrap_change_uint32_atomic(struct db_context *db, const char *keystr,
        return 0;
 }
 
+/**
+ * Atomic integer change (addition):
+ *
+ * if value does not exist yet in the db, use *oldval as initial old value.
+ * return old value in *oldval.
+ * store *oldval + change_val to db.
+ */
 int32 dbwrap_change_int32_atomic(struct db_context *db, const char *keystr,
                                 int32 *oldval, int32 change_val)
 {