def db_query_execute(cls, cur, query, values, verbose=True):
        """
        Execute a query.
        Handle db timeouts.
        Abort on failure.
        """
        timeout = 1.0

        if verbose:
            log.debug(cls.db_format_query(query, values))

        while True:
            try:
                ret = cur.execute(query, values)
                return ret
            except sqlite3.OperationalError as oe:
                if oe.message == "database is locked":
                    timeout = timeout * 2 + timeout * random.random()
                    log.error("Query timed out due to lock; retrying in %s: %s" % (timeout, cls.db_format_query( query, values )))
                    time.sleep(timeout)
                
                else:
                    log.exception(oe)
                    log.error("FATAL: failed to execute query (%s, %s)" % (query, values))
                    log.error("\n".join(traceback.format_stack()))
                    os.abort()

            except Exception, e:
                log.exception(e)
                log.error("FATAL: failed to execute query (%s, %s)" % (query, values))
                log.error("\n".join(traceback.format_stack()))
                os.abort()
Execute a query.
        Handle db timeouts.
        Abort on failure.