Ejemplo n.º 1
0
/* default update function for embedded tasks, to be used at the end of the i/o handler */
static void stream_int_update_embedded(struct stream_interface *si)
{
	int old_flags = si->flags;

	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 (si->state != SI_ST_EST)
		return;

	if ((si->ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == CF_SHUTW_NOW &&
	    channel_is_empty(si->ob))
		si_shutw(si);

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

	/* we're almost sure that we need some space if the buffer is not
	 * empty, even if it's not full, because the applets can't fill it.
	 */
	if ((si->ib->flags & (CF_SHUTR|CF_DONT_READ)) == 0 && !channel_is_empty(si->ib))
		si->flags |= SI_FL_WAIT_ROOM;

	if (si->ob->flags & CF_WRITE_ACTIVITY) {
		if (tick_isset(si->ob->wex))
			si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
	}

	if (si->ib->flags & CF_READ_ACTIVITY ||
	    (si->ob->flags & CF_WRITE_ACTIVITY && !(si->flags & SI_FL_INDEP_STR))) {
		if (tick_isset(si->ib->rex))
			si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
	}

	/* save flags to detect changes */
	old_flags = si->flags;
	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);

	if (((si->ib->flags & CF_READ_PARTIAL) && !channel_is_empty(si->ib)) &&
	    (si->ib->cons->flags & SI_FL_WAIT_DATA)) {
		si_chk_snd(si->ib->cons);
		/* check if the consumer has freed some space */
		if (!channel_full(si->ib))
			si->flags &= ~SI_FL_WAIT_ROOM;
	}

	/* Note that we're trying to wake up in two conditions here :
	 *  - special event, which needs the holder task attention
	 *  - status indicating that the applet can go on working. This
	 *    is rather hard because we might be blocking on output and
	 *    don't want to wake up on input and vice-versa. The idea is
	 *    to only rely on the changes the chk_* might have performed.
	 */
	if (/* check stream interface changes */
	    ((old_flags & ~si->flags) & (SI_FL_WAIT_ROOM|SI_FL_WAIT_DATA)) ||

	    /* 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)))))) {
		if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
			task_wakeup(si->owner, TASK_WOKEN_IO);
	}
	if (si->ib->flags & CF_READ_ACTIVITY)
		si->ib->flags &= ~CF_READ_DONTWAIT;
}
Ejemplo n.º 2
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;
}
Ejemplo n.º 3
0
/* This function is the equivalent to stream_int_update() except that it's
 * designed to be called from outside the stream handlers, typically the lower
 * layers (applets, connections) after I/O completion. After updating the stream
 * interface and timeouts, it will try to forward what can be forwarded, then to
 * wake the associated task up if an important event requires special handling.
 * It should not be called from within the stream itself, stream_int_update()
 * is designed for this.
 */
void stream_int_notify(struct stream_interface *si)
{
	struct channel *ic = si_ic(si);
	struct channel *oc = si_oc(si);

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

	/* indicate that we may be waiting for data from the output channel */
	if ((oc->flags & (CF_SHUTW|CF_SHUTW_NOW)) == 0 && channel_may_recv(oc))
		si->flags |= SI_FL_WAIT_DATA;

	/* update OC timeouts and wake the other side up if it's waiting for room */
	if (oc->flags & CF_WRITE_ACTIVITY) {
		if ((oc->flags & (CF_SHUTW|CF_WRITE_PARTIAL)) == CF_WRITE_PARTIAL &&
		    !channel_is_empty(oc))
			if (tick_isset(oc->wex))
				oc->wex = tick_add_ifset(now_ms, oc->wto);

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

		if (likely((oc->flags & (CF_SHUTW|CF_WRITE_PARTIAL|CF_DONT_READ)) == CF_WRITE_PARTIAL &&
			   channel_may_recv(oc) &&
			   (si_opposite(si)->flags & SI_FL_WAIT_ROOM)))
			si_chk_rcv(si_opposite(si));
	}

	/* Notify the other side when we've injected data into the IC that
	 * needs to be forwarded. We can do fast-forwarding as soon as there
	 * are output data, but we avoid doing this if some of the data are
	 * not yet scheduled for being forwarded, because it is very likely
	 * that it will be done again immediately afterwards once the following
	 * data are parsed (eg: HTTP chunking). We only SI_FL_WAIT_ROOM once
	 * we've emptied *some* of the output buffer, and not just when there
	 * is available room, because applets are often forced to stop before
	 * the buffer is full. We must not stop based on input data alone because
	 * an HTTP parser might need more data to complete the parsing.
	 */
	if (!channel_is_empty(ic) &&
	    (si_opposite(si)->flags & SI_FL_WAIT_DATA) &&
	    (ic->buf->i == 0 || ic->pipe)) {
		int new_len, last_len;

		last_len = ic->buf->o;
		if (ic->pipe)
			last_len += ic->pipe->data;

		si_chk_snd(si_opposite(si));

		new_len = ic->buf->o;
		if (ic->pipe)
			new_len += ic->pipe->data;

		/* check if the consumer has freed some space either in the
		 * buffer or in the pipe.
		 */
		if (channel_may_recv(ic) && new_len < last_len)
			si->flags &= ~SI_FL_WAIT_ROOM;
	}

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

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

	    /* changes on the consumption side */
	    (oc->flags & (CF_WRITE_NULL|CF_WRITE_ERROR)) ||
	    ((oc->flags & CF_WRITE_ACTIVITY) &&
	     ((oc->flags & CF_SHUTW) ||
	      ((oc->flags & CF_WAKE_WRITE) &&
	       (si_opposite(si)->state != SI_ST_EST ||
	        (channel_is_empty(oc) && !oc->to_forward)))))) {
		task_wakeup(si_task(si), TASK_WOKEN_IO);
	}
	if (ic->flags & CF_READ_ACTIVITY)
		ic->flags &= ~CF_READ_DONTWAIT;

	stream_release_buffers(si_strm(si));
}