MINOR: quic: create a global list dedicated for closing QUIC conns

When a CONNECTION_CLOSE is emitted or received, a QUIC connection enters
respectively in draining or closing state. These states are a loose
equivalent of TCP TIME_WAIT. No data can be exchanged anymore but the
connection is maintained during a certain timer to handle packet
reordering or loss.

A new global list has been defined for QUIC connections in
closing/draining state inside thread_ctx structure. Each time a
connection enters in one of this state, it will be moved from the
default global list to the new closing list.

The objective of this patch is to quickly filter connections on
closing/draining. Most notably, this will be used to wake up these
connections and avoid that haproxy process stopping is delayed by them.

A dedicated function qc_detach_th_ctx_list() has been implemented to
transfer a quic-conn from one list instance to the other. This takes
care of back-references attach to a quic-conn instance in case of a
running "show quic".

This should be backported up to 2.7.
2 files changed