ovsdb: Implement a "lock" feature in the database protocol.

This provides clients a way to coordinate their access to the database.
This is a voluntary, not mandatory, locking protocols, that is, clients
are not prevented from modifying the database unless they cooperate with
the locking protocol.  It is also not related to any of the ACID properties
of database transactions.  It is strictly a way for clients to coordinate
among themselves.

The following commit will introduce one user.

1 files changed, 3 insertions, 1 deletions

diff --git a/ovsdb/ovsdb.h b/ovsdb/ovsdb.h
index 834ff1a99..0d15ef2db 100644
--- a/ovsdb/ovsdb.h
+++ b/ovsdb/ovsdb.h
@@ -23,6 +23,7 @@
 
 struct json;
 struct ovsdb_log;
+struct ovsdb_session;
 struct ovsdb_txn;
 struct uuid;
 
@@ -71,7 +72,8 @@ struct json *ovsdb_to_json(const struct ovsdb *);
 
 struct ovsdb_table *ovsdb_get_table(const struct ovsdb *, const char *);
 
-struct json *ovsdb_execute(struct ovsdb *, const struct json *params,
+struct json *ovsdb_execute(struct ovsdb *, const struct ovsdb_session *,
+                           const struct json *params,
                            long long int elapsed_msec,
                            long long int *timeout_msec);