int mariadb_cancel(MYSQL * mysql);
Immediately aborts a connection by making all subsequent read/write operations fail. mariadb_cancel() does not invalidate memory used for mysql structure, nor close any communication channels. To free the memory, mysql_close() must be called. mariadb_cancel() is useful to break long queries in situations where sending KILL is not possible.
mariadb_cancel() was added in Connector/C 3.0