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From: Stefan Eissing <stefan.eissing@greenbytes.de>
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Subject: mpm_winnt lingering close
Message-Id: <C2C10FA7-70F7-4007-959E-E7DC1B16E093@greenbytes.de>
Date: Mon, 3 Apr 2017 15:07:22 +0200
To: dev@httpd.apache.org
archived-at: Mon, 03 Apr 2017 13:07:30 -0000

Steffen started testing and immediately found sth. Yeah! He sees many

[Mon Apr 03 14:20:28.390474 2017] [http2:warn] [pid 3180:tid 2880] =
[client 5.80.147.209:61342] AH10020: h2_session(106,DONE,0): session =
cleanup triggered by pool cleanup. this should have happened earlier =
already.

in his logs. The problem here is that mod_http2 would like to shutdown =
in ap_prep_lingering_close()
which is invoked by ap_lingering_close(). This is always done by =
mpm_event, worker and prefork AFAIK.

mpm_winnt has an optimization in line 814:
        ap_process_connection(c, context->sock);

        apr_socket_opt_get(context->sock, APR_SO_DISCONNECTED, =
&disconnected);

        if (!disconnected) {
            context->accept_socket =3D INVALID_SOCKET;
            if (!c->aborted) {=20
                ap_lingering_close(c);
            }
        }

So, if the connection is already gone or was aborted, it will not call
this and the "safe" shutdown is not triggered. "safe" insofar as
mod_http2 needs to shutdown the connection *before* mod_ssl does.

Question is: do we "fix" mpm_winnt or is there a better way for =
mod_http2 to shutdown the connection before mod_ssl does. This would =
need to work in async mpms for any connection state.

-Stefan=