+ if (lock_name && !idl->lock_name) {
+ /* Acquire new lock. */
+ idl->lock_name = xstrdup(lock_name);
+ ovsdb_idl_send_lock_request(idl);
+ }
+}
+
+/* Returns true if 'idl' is configured to obtain a lock and owns that lock.
+ *
+ * Locking and unlocking happens asynchronously from the database client's
+ * point of view, so the information is only useful for optimization (e.g. if
+ * the client doesn't have the lock then there's no point in trying to write to
+ * the database). */
+bool
+ovsdb_idl_has_lock(const struct ovsdb_idl *idl)
+{
+ return idl->has_lock;
+}
+
+/* Returns true if 'idl' is configured to obtain a lock but the database server
+ * has indicated that some other client already owns the requested lock. */
+bool
+ovsdb_idl_is_lock_contended(const struct ovsdb_idl *idl)
+{
+ return idl->is_lock_contended;
+}
+
+static void
+ovsdb_idl_update_has_lock(struct ovsdb_idl *idl, bool new_has_lock)
+{
+ if (new_has_lock && !idl->has_lock) {
+ if (!idl->monitor_request_id) {
+ idl->change_seqno++;
+ } else {
+ /* We're waiting for a monitor reply, so don't signal that the
+ * database changed. The monitor reply will increment change_seqno
+ * anyhow. */
+ }
+ idl->is_lock_contended = false;
+ }
+ idl->has_lock = new_has_lock;
+}
+
+static void
+ovsdb_idl_send_lock_request__(struct ovsdb_idl *idl, const char *method,
+ struct json **idp)
+{
+ ovsdb_idl_update_has_lock(idl, false);
+
+ json_destroy(idl->lock_request_id);
+ idl->lock_request_id = NULL;
+
+ if (jsonrpc_session_is_connected(idl->session)) {
+ struct json *params;
+
+ params = json_array_create_1(json_string_create(idl->lock_name));
+ jsonrpc_session_send(idl->session,
+ jsonrpc_create_request(method, params, idp));
+ }
+}
+
+static void
+ovsdb_idl_send_lock_request(struct ovsdb_idl *idl)
+{
+ ovsdb_idl_send_lock_request__(idl, "lock", &idl->lock_request_id);
+}
+
+static void
+ovsdb_idl_send_unlock_request(struct ovsdb_idl *idl)
+{
+ ovsdb_idl_send_lock_request__(idl, "unlock", NULL);
+}
+
+static void
+ovsdb_idl_parse_lock_reply(struct ovsdb_idl *idl, const struct json *result)
+{
+ bool got_lock;
+
+ json_destroy(idl->lock_request_id);
+ idl->lock_request_id = NULL;
+
+ if (result->type == JSON_OBJECT) {
+ const struct json *locked;
+
+ locked = shash_find_data(json_object(result), "locked");
+ got_lock = locked && locked->type == JSON_TRUE;
+ } else {
+ got_lock = false;
+ }
+
+ ovsdb_idl_update_has_lock(idl, got_lock);
+ if (!got_lock) {
+ idl->is_lock_contended = true;
+ }
+}
+
+static void
+ovsdb_idl_parse_lock_notify(struct ovsdb_idl *idl,
+ const struct json *params,
+ bool new_has_lock)
+{
+ if (idl->lock_name
+ && params->type == JSON_ARRAY
+ && json_array(params)->n > 0
+ && json_array(params)->elems[0]->type == JSON_STRING) {
+ const char *lock_name = json_string(json_array(params)->elems[0]);
+
+ if (!strcmp(idl->lock_name, lock_name)) {
+ ovsdb_idl_update_has_lock(idl, new_has_lock);
+ if (!new_has_lock) {
+ idl->is_lock_contended = true;
+ }
+ }
+ }
+}