Function accept_handler

scripts/tornado_source_code/tornado/netutil.py:243–273

(fd: socket.socket, events: int)

    removed = [False]

    def accept_handler(fd: socket.socket, events: int) -> None:
        # More connections may come in while we're handling callbacks;
        # to prevent starvation of other tasks we must limit the number
        # of connections we accept at a time.  Ideally we would accept
        # up to the number of connections that were waiting when we
        # entered this method, but this information is not available
        # (and rearranging this method to call accept() as many times
        # as possible before running any callbacks would have adverse
        # effects on load balancing in multiprocess configurations).
        # Instead, we use the (default) listen backlog as a rough
        # heuristic for the number of connections we can reasonably
        # accept at once.
        for i in range(_DEFAULT_BACKLOG):
            if removed[0]:
                # The socket was probably closed
                return
            try:
                connection, address = sock.accept()
            except socket.error as e:
                # _ERRNO_WOULDBLOCK indicate we have accepted every
                # connection that is available.
                if errno_from_exception(e) in _ERRNO_WOULDBLOCK:
                    return
                # ECONNABORTED indicates that there was a connection
                # but it was closed while still in the accept queue.
                # (observed on FreeBSD).
                if errno_from_exception(e) == errno.ECONNABORTED:
                    continue
                raise
            set_close_exec(connection.fileno())
            callback(connection, address)

    def remove_handler() -> None:
        io_loop.remove_handler(sock)