Re: [quicwg/base-drafts] Execute the PTO alarm immediately if in the past (#4831)

[Martin Thomson <[e-mail]>]

@martinthomson commented on this pull request.



> @@ -664,8 +664,11 @@ data it can send is limited to three times the amount of data received,
 as specified in {{Section 8.1 of QUIC-TRANSPORT}}. If no additional data can be
 sent, the server's PTO timer MUST NOT be armed until datagrams have been
 received from the client, because packets sent on PTO count against the
-anti-amplification limit. Note that the server could fail to validate the
-client's address even if 0-RTT is accepted.
+anti-amplification limit.  The server's PTO timer could be re-armed to a time
+in the past after being amplification limited, in which case it is executed
+immediately. Doing so avoids sending new 1-RTT packets prior to packets
+critical to the completion of the handshake.  Note that the server could fail
+to validate the client's address even if 0-RTT is accepted.

This last sentence is now poorly connected to ... well ... anything.  I know that you are looking to avoid too many changes, but the instant you changed the pseudocode, any hope of that went out the window.  I think that we can cut this last sentence.

> +      // PTO would have already expired, execute it
+      // immediately.

```suggestion
      // Execute any PTO that might have expired
      // while the amplification limit applied.
```

> +anti-amplification limit.  The server's PTO timer could be re-armed to a time
+in the past after being amplification limited, in which case it is executed
+immediately. Doing so avoids sending new 1-RTT packets prior to packets
+critical to the completion of the handshake.  Note that the server could fail

What about a new paragraph instead:

> When the server receives a datagram from the client, the amplification limit is increased.  After an increase to the amplification limit, the server restarts any PTO timer that might have been suppressed.  If the timer would have expired during the time that the server was unable to send, the server immediately processes that event.  It is important that the server send any probes for Initial and Handshake packet number spaces before sending 1-RTT packets as the handshake might not complete otherwise.

Much more text, but clearer.

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