def lock_tables()

in core/lib/payload/copy.py [0:0]

• 29 lines of code
• 7 McCabe index (conditional complexity)

    def lock_tables(self, tables):
        for _ in range(self.lock_max_attempts):
            # We use a threading.Timer with a second connection in order to
            # kill any selects on top of the tables being altered if we could
            # not lock the tables in time
            another_conn = self.get_conn(self._current_db)
            kill_timer = Timer(
                self.lock_max_wait_before_kill_seconds,
                self.kill_selects,
                args=(tables, another_conn),
            )
            # keeping a reference to kill timer helps on tests
            self._last_kill_timer = kill_timer
            kill_timer.start()

            try:
                self.execute_sql(sql.lock_tables(tables))
                # It is best to cancel the timer as soon as possible
                kill_timer.cancel()
                log.info(
                    "Successfully lock table(s) for write: {}".format(", ".join(tables))
                )
                break
            except MySQLdb.MySQLError as e:
                errcode, errmsg = e.args
                # 1205 is timeout and 1213 is deadlock
                if errcode in (1205, 1213):
                    log.warning("Retry locking because of error: {}".format(e))
                else:
                    raise
            finally:
                # guarantee that we dont leave a stray kill timer running
                # or any open resources
                kill_timer.cancel()
                kill_timer.join()
                another_conn.close()

        else:
            # Cannot lock write after max lock attempts
            raise OSCError("FAILED_TO_LOCK_TABLE", {"tables": ", ".join(tables)})