Ejemplo n.º 1
0
/* Callback to be used by connection I/O handlers upon completion. It propagates
 * connection flags to the stream interface, updates the stream (which may or
 * may not take this opportunity to try to forward data), then update the
 * connection's polling based on the channels and stream interface's final
 * states. The function always returns 0.
 */
static int si_conn_wake_cb(struct connection *conn)
{
	struct stream_interface *si = conn->owner;
	struct channel *ic = si_ic(si);
	struct channel *oc = si_oc(si);

	/* First step, report to the stream-int what was detected at the
	 * connection layer : errors and connection establishment.
	 */
	if (conn->flags & CO_FL_ERROR)
		si->flags |= SI_FL_ERR;

	if (unlikely(!(conn->flags & (CO_FL_WAIT_L4_CONN | CO_FL_WAIT_L6_CONN | CO_FL_CONNECTED)))) {
		si->exp = TICK_ETERNITY;
		oc->flags |= CF_WRITE_NULL;
	}

	/* Second step : update the stream-int and channels, try to forward any
	 * pending data, then possibly wake the stream up based on the new
	 * stream-int status.
	 */
	stream_int_notify(si);

	/* Third step : update the connection's polling status based on what
	 * was done above (eg: maybe some buffers got emptied).
	 */
	if (channel_is_empty(oc))
		__conn_data_stop_send(conn);


	if (si->flags & SI_FL_WAIT_ROOM) {
		__conn_data_stop_recv(conn);
	}
	else if ((ic->flags & (CF_SHUTR|CF_READ_PARTIAL|CF_DONT_READ)) == CF_READ_PARTIAL &&
		 channel_may_recv(ic)) {
		__conn_data_want_recv(conn);
	}
	return 0;
}
Ejemplo n.º 2
0
/* Updates the polling status of a connection outside of the connection handler
 * based on the channel's flags and the stream interface's flags. It needs to be
 * called once after the channels' flags have settled down and the stream has
 * been updated. It is not designed to be called from within the connection
 * handler itself.
 */
void stream_int_update_conn(struct stream_interface *si)
{
	struct channel *ic = si_ic(si);
	struct channel *oc = si_oc(si);
	struct connection *conn = __objt_conn(si->end);

	if (!(ic->flags & CF_SHUTR)) {
		/* Read not closed */
		if ((ic->flags & CF_DONT_READ) || !channel_may_recv(ic))
			__conn_data_stop_recv(conn);
		else
			__conn_data_want_recv(conn);
	}

	if (!(oc->flags & CF_SHUTW)) {
		/* Write not closed */
		if (channel_is_empty(oc))
			__conn_data_stop_send(conn);
		else
			__conn_data_want_send(conn);
	}

	conn_cond_update_data_polling(conn);
}
Ejemplo n.º 3
0
/* This function is used for inter-stream-interface calls. It is called by the
 * producer to inform the consumer side that it may be interested in checking
 * for data in the buffer. Note that it intentionally does not update timeouts,
 * so that we can still check them later at wake-up.
 */
static void stream_int_chk_snd_conn(struct stream_interface *si)
{
	struct channel *ob = si->ob;
	struct connection *conn = __objt_conn(si->end);

	if (unlikely(si->state > SI_ST_EST || (ob->flags & CF_SHUTW)))
		return;

	if (unlikely(channel_is_empty(ob)))  /* called with nothing to send ! */
		return;

	if (!ob->pipe &&                          /* spliced data wants to be forwarded ASAP */
	    !(si->flags & SI_FL_WAIT_DATA))       /* not waiting for data */
		return;

	if (conn->flags & (CO_FL_DATA_WR_ENA|CO_FL_CURR_WR_ENA)) {
		/* already subscribed to write notifications, will be called
		 * anyway, so let's avoid calling it especially if the reader
		 * is not ready.
		 */
		return;
	}

	/* Before calling the data-level operations, we have to prepare
	 * the polling flags to ensure we properly detect changes.
	 */
	conn_refresh_polling_flags(conn);
	__conn_data_want_send(conn);

	if (!(conn->flags & (CO_FL_HANDSHAKE|CO_FL_WAIT_L4_CONN|CO_FL_WAIT_L6_CONN))) {
		si_conn_send(conn);
		if (conn->flags & CO_FL_ERROR) {
			/* Write error on the file descriptor */
			__conn_data_stop_both(conn);
			si->flags |= SI_FL_ERR;
			goto out_wakeup;
		}
	}

	/* OK, so now we know that some data might have been sent, and that we may
	 * have to poll first. We have to do that too if the buffer is not empty.
	 */
	if (channel_is_empty(ob)) {
		/* the connection is established but we can't write. Either the
		 * buffer is empty, or we just refrain from sending because the
		 * ->o limit was reached. Maybe we just wrote the last
		 * chunk and need to close.
		 */
		__conn_data_stop_send(conn);
		if (((ob->flags & (CF_SHUTW|CF_AUTO_CLOSE|CF_SHUTW_NOW)) ==
		     (CF_AUTO_CLOSE|CF_SHUTW_NOW)) &&
		    (si->state == SI_ST_EST)) {
			si_shutw(si);
			goto out_wakeup;
		}

		if ((ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == 0)
			si->flags |= SI_FL_WAIT_DATA;
		ob->wex = TICK_ETERNITY;
	}
	else {
		/* Otherwise there are remaining data to be sent in the buffer,
		 * which means we have to poll before doing so.
		 */
		__conn_data_want_send(conn);
		si->flags &= ~SI_FL_WAIT_DATA;
		if (!tick_isset(ob->wex))
			ob->wex = tick_add_ifset(now_ms, ob->wto);
	}

	if (likely(ob->flags & CF_WRITE_ACTIVITY)) {
		/* update timeout if we have written something */
		if ((ob->flags & (CF_SHUTW|CF_WRITE_PARTIAL)) == CF_WRITE_PARTIAL &&
		    !channel_is_empty(ob))
			ob->wex = tick_add_ifset(now_ms, ob->wto);

		if (tick_isset(si->ib->rex) && !(si->flags & SI_FL_INDEP_STR)) {
			/* Note: to prevent the client from expiring read timeouts
			 * during writes, we refresh it. We only do this if the
			 * interface is not configured for "independent streams",
			 * because for some applications it's better not to do this,
			 * for instance when continuously exchanging small amounts
			 * of data which can full the socket buffers long before a
			 * write timeout is detected.
			 */
			si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
		}
	}

	/* in case of special condition (error, shutdown, end of write...), we
	 * have to notify the task.
	 */
	if (likely((ob->flags & (CF_WRITE_NULL|CF_WRITE_ERROR|CF_SHUTW)) ||
	          ((ob->flags & CF_WAKE_WRITE) &&
	           ((channel_is_empty(si->ob) && !ob->to_forward) ||
	            si->state != SI_ST_EST)))) {
	out_wakeup:
		if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
			task_wakeup(si->owner, TASK_WOKEN_IO);
	}

	/* commit possible polling changes */
	conn_cond_update_polling(conn);
}
Ejemplo n.º 4
0
/* Callback to be used by connection I/O handlers upon completion. It differs from
 * the update function in that it is designed to be called by lower layers after I/O
 * events have been completed. It will also try to wake the associated task up if
 * an important event requires special handling. It relies on the connection handler
 * to commit any polling updates. The function always returns 0.
 */
static int si_conn_wake_cb(struct connection *conn)
{
	struct stream_interface *si = conn->owner;

	DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
		__FUNCTION__,
		si, si->state, si->ib->flags, si->ob->flags);

	if (conn->flags & CO_FL_ERROR)
		si->flags |= SI_FL_ERR;

	/* check for recent connection establishment */
	if (unlikely(!(conn->flags & (CO_FL_WAIT_L4_CONN | CO_FL_WAIT_L6_CONN | CO_FL_CONNECTED)))) {
		si->exp = TICK_ETERNITY;
		si->ob->flags |= CF_WRITE_NULL;
	}

	/* process consumer side */
	if (channel_is_empty(si->ob)) {
		if (((si->ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == CF_SHUTW_NOW) &&
		    (si->state == SI_ST_EST))
			stream_int_shutw_conn(si);
		__conn_data_stop_send(conn);
		si->ob->wex = TICK_ETERNITY;
	}

	if ((si->ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == 0 && !channel_full(si->ob))
		si->flags |= SI_FL_WAIT_DATA;

	if (si->ob->flags & CF_WRITE_ACTIVITY) {
		/* update timeouts if we have written something */
		if ((si->ob->flags & (CF_SHUTW|CF_WRITE_PARTIAL)) == CF_WRITE_PARTIAL &&
		    !channel_is_empty(si->ob))
			if (tick_isset(si->ob->wex))
				si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);

		if (!(si->flags & SI_FL_INDEP_STR))
			if (tick_isset(si->ib->rex))
				si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);

		if (likely((si->ob->flags & (CF_SHUTW|CF_WRITE_PARTIAL|CF_DONT_READ)) == CF_WRITE_PARTIAL &&
			   !channel_full(si->ob) &&
			   (si->ob->prod->flags & SI_FL_WAIT_ROOM)))
			si_chk_rcv(si->ob->prod);
	}

	/* process producer side.
	 * We might have some data the consumer is waiting for.
	 * We can do fast-forwarding, but we avoid doing this for partial
	 * buffers, because it is very likely that it will be done again
	 * immediately afterwards once the following data is parsed (eg:
	 * HTTP chunking).
	 */
	if (((si->ib->flags & CF_READ_PARTIAL) && !channel_is_empty(si->ib)) &&
	    (si->ib->pipe /* always try to send spliced data */ ||
	     (si->ib->buf->i == 0 && (si->ib->cons->flags & SI_FL_WAIT_DATA)))) {
		int last_len = si->ib->pipe ? si->ib->pipe->data : 0;

		si_chk_snd(si->ib->cons);

		/* check if the consumer has freed some space either in the
		 * buffer or in the pipe.
		 */
		if (!channel_full(si->ib) &&
		    (!last_len || !si->ib->pipe || si->ib->pipe->data < last_len))
			si->flags &= ~SI_FL_WAIT_ROOM;
	}

	if (si->flags & SI_FL_WAIT_ROOM) {
		__conn_data_stop_recv(conn);
		si->ib->rex = TICK_ETERNITY;
	}
	else if ((si->ib->flags & (CF_SHUTR|CF_READ_PARTIAL|CF_DONT_READ)) == CF_READ_PARTIAL &&
		 !channel_full(si->ib)) {
		/* we must re-enable reading if si_chk_snd() has freed some space */
		__conn_data_want_recv(conn);
		if (!(si->ib->flags & CF_READ_NOEXP) && tick_isset(si->ib->rex))
			si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
	}

	/* wake the task up only when needed */
	if (/* changes on the production side */
	    (si->ib->flags & (CF_READ_NULL|CF_READ_ERROR)) ||
	    si->state != SI_ST_EST ||
	    (si->flags & SI_FL_ERR) ||
	    ((si->ib->flags & CF_READ_PARTIAL) &&
	     (!si->ib->to_forward || si->ib->cons->state != SI_ST_EST)) ||

	    /* changes on the consumption side */
	    (si->ob->flags & (CF_WRITE_NULL|CF_WRITE_ERROR)) ||
	    ((si->ob->flags & CF_WRITE_ACTIVITY) &&
	     ((si->ob->flags & CF_SHUTW) ||
	      ((si->ob->flags & CF_WAKE_WRITE) &&
	       (si->ob->prod->state != SI_ST_EST ||
	        (channel_is_empty(si->ob) && !si->ob->to_forward)))))) {
		task_wakeup(si->owner, TASK_WOKEN_IO);
	}
	if (si->ib->flags & CF_READ_ACTIVITY)
		si->ib->flags &= ~CF_READ_DONTWAIT;
	return 0;
}