Re: Connection-level flow control and DATA frame against closed state streams

On Thu, Aug 8, 2013 at 12:45 AM, Martin Thomson <martin.thomson@gmail.com>wrote:

> This doesn't affect the sender, but the receiver does need to account
> for this.  The proposed statement loses that little gotcha.  Can you
> raise an issue for this?  I'll see if I can make it a little bit
> clearer.
>
>
Sure. https://github.com/http2/http2-spec/issues/225

Best regards,

Tatsuhiro Tsujikawa


>  On 7 August 2013 16:23, Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
> wrote:
> > Hi,
> >
> > Section 5.1. Stream States says that:
> >
> > """
> > closed:
> >       The "closed" state is the terminal state.
> >
> >       An endpoint MUST NOT send frames on a closed stream.  An endpoint
> >       that receives a frame after receiving a RST_STREAM or a frame
> >       containing a END_STREAM flag on that stream MUST treat that as a
> >       stream error (Section 5.4.2) of type STREAM_CLOSED.
> >
> >       If this state is reached as a result of sending a RST_STREAM
> >       frame, the peer that receives the RST_STREAM might have already
> >       sent - or enqueued for sending - frames on the stream that cannot
> >       be withdrawn.  An endpoint that sends a RST_STREAM frame MUST
> >       ignore frames that it receives on closed streams after it has sent
> >       a RST_STREAM frame.  An endpoint MAY choose to limit the period
> >       over which it ignores frames and treat frames that arrive after
> >       this time as being in error.
> > """
> >
> > My understanding is that DATA frames received in this closed state is
> still
> > under the connection-level flow control. This may be obvious because the
> > sender of DATA frame may send those frames before got RST_STREAM from the
> > remote and could not re-calculate connection-level window after
> RST_STREAM
> > was received.
> > But stating that explicitly in this section helps implementers and is a
> good
> > note for the test case.
> > Maybe just like this:
> >
> > """
> > A flow controlled frame received in this state is still subject to the
> > connection-level flow control.
> > """
> >
> > Best regards,
> >
> > Tatsuhiro Tsujikawa
> >
> >
>