MINOR: mux-h2: add a per-connection list of blocked streams

Currently the H2 mux doesn't have a list of all the streams blocking on
the H2 side. It only knows about those trying to send or waiting for a
connection window update. It is problematic to enforce timeouts because
we never know if a stream has to live as long as the data layer wants or
has to be timed out becase it's waiting for a stream window update. This
patch adds a new list, "blocked_list", to store streams blocking on
stream flow control, or later, dependencies. Streams blocked on sfctl
are now added there. It doesn't modify the rest of the logic.

(cherry picked from commit 9edf6dbecc9d50d3ab3764b307010a627e39117c)
[wt: dependency for next patch; removed traces]
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed