for handler in handlers:
            if handler == sentinel:
                 #Todo: enyone has an idea how to avoid
                 #going through handlers twice?
                 #a dirty hack might be to search it by hand starting
                 #from len(handlers) that should be faster for longer lists
                break
            guard, d = handler
            if not callable(guard):
                logger.info('bogus guard in handler for %s'%m)
                continue
            if guard(m):
                done = True
                if logger_messages.isEnabledFor(logging.DEBUG):
                    logger.debug(
                        "firing handler for %s: %s",
                        _MSG_TYPE_DSCS[hdlr_type], m.getName())
                try:
                    d.callback(m)
                    handlers.remove(handler)
                except defer.AlreadyCalledError, e:
                    logger.exception(
                        "Message handled twice resulted in AlreadyCalledError. Swallowing.")
                break
        handlers.remove(sentinel)