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Re: [SG14] SG14 June 12 Zoom call

From: Patrice Roy <patricer_at_[hidden]>
Date: Wed, 12 Jun 2019 16:06:29 -0400
Thanks Staffan and everyone attending. I could not make it today (had to go
to the bird doctor with two of our parrots) so these meeting notes are
quite appreciated!

Le mer. 12 juin 2019 à 16:02, Tjernstrom, Staffan via SG14 <
sg14_at_[hidden]> a écrit :

>
>
>
>
> *From:* SG14 [mailto:sg14-bounces_at_[hidden]] *On Behalf Of *Michael
> Wong via SG14
> *Sent:* Wednesday, June 12, 2019 9:50 AM
> *To:* Low Latency:Game Dev/Financial/Trading/Simulation/Embedded Devices <
> sg14_at_[hidden]>
> *Cc:* Michael Wong <fraggamuffin_at_[hidden]>
> *Subject:* [SG14] SG14 June 12 Zoom call
>
>
>
> Michael Wong is inviting you to a scheduled Zoom meeting.
>
> Topic: SG14 Low Latency Monthly
> Join URL: https://iso.zoom.us/j/406503386
> Time: Apr 17, 2019 2:00 PM Eastern Time (US and Canada)
> Apr 17, 2019 2:00 PM
> May 8, 2019 2:00 PM
> Jun 12, 2019 2:00 PM
> Jul 10, 2019 2:00 PM
> Aug 14, 2019 2:00 PM
> Sep 11, 2019 2:00 PM
> Oct 9, 2019 2:00 PM
> Please download and import the following iCalendar (.ics) files to
> your
> calendar system.
> Monthly:
>
> https://iso.zoom.us/meeting/406503386/ics?icsToken=8d46c9bf03730dd553cc4f9306ceedfc45867014725c0aca989cb39d9602ae7c
>
> Join from PC, Mac, Linux, iOS or Android: https://iso.zoom.us/j/406503386
>
> Or iPhone one-tap :
> US: +16468769923,,406503386# or +16699006833,,406503386#
> Or Telephone:
> Dial(for higher quality, dial a number based on your current
> location):
> US: +1 646 876 9923 or +1 669 900 6833 or +1 408 638 0968 or 877
> 369 0926 (Toll Free) or 877 853 5247 (Toll Free)
> Meeting ID: 406 503 386
> International numbers available: https://zoom.us/u/abhaIjFKLZ
>
> Or Skype for Business (Lync):
> https://iso.zoom.us/skype/406503386
>
> Agenda:
>
> 1. Opening and introductions
>
> 1.1 Roll call of participants
>
> Staffan Tjernstrom, Michael Wong, Ben Craig, Billy Baker,Brett, Charles
> Bay, David Stone, Jan Wilmans, John McFarlane, Matthew Butler, Rene
> Rivera(Partial), Ronen Friedman, Guy Davidson (Partial)
>
> 1.2 Adopt agenda
>
> Adopted
>
> 1.3 Approve minutes from previous meeting, and approve publishing
> previously approved minutes to ISOCPP.org
>
> Approved
>
> 1.4 Action items from previous meetings
>
> 2. Main issues (125 min)
>
> 2.1 General logistics
>
> Review last call discussions.
>
> 2.2 Paper reviews
> 2.2.1 Embedded/freestanding vs hosted
>
> Ben Craig:
>
> The drafts of D1641R0.0 "Freestanding Library: Rewording the Status Quo"
> and D1642R0.0 "Freestanding Library: Easy [utilities]". These papers can
> also be reached at the following URLs:
>
>
> https://raw.githack.com/ben-craig/freestanding_proposal/master/library/status_quo.html
>
>
> https://raw.githack.com/ben-craig/freestanding_proposal/master/library/easy_utilities.html
>
> These are follow-on papers from P0829 "Freestanding Proposal". I'm still
> going in that direction, just with lots of little papers now, instead of
> one big paper.
>
> Summary of freestanding Kona evening session discussions
> http://wiki.edg.com/bin/view/Wg21kona2019/SG14FreestandingImplementations
>
> Outcome from Dec call:
> In the SG14 session, he mentioned 2 that he prefers
> * Freestanding is signal / interrupt safe
> * Freestanding requires no special dispensation from the operating
> environment above what freestanding C99 requires
>
> But there are other possible directions
> * Freestanding should be as small as possible
> * Freestanding has all the same core language features as hosted
>
> Nov Evening Session:
> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1376r0.html
>
> Papers now have P Numbers
>
> Trying to keep a small number of papers in flight at any point in time
> just in time LWG changes their editorial policy.
>
> Discussion/Clarification that we’re removing the requirement for
> freestanding not to provide feature test macros for non-freestanding
> features.
>
> Discussion of what to do in those cases where we want to not include the
> whole overload set. Std::abs() with the floating point overloads is a case
> in point. Certain of the swap() cases may also be troublesome. For these
> papers we think we’re ok, but the issue will very likely crop up in the
> later papers that start dealing with more string like things.
>
> Calling the type operator new/delete is ok, but calling the global
> operator new/delete is not. Hence unique_ptr<> makes it in.
>
> Both papers need champions for Cologne.
>
> 2.2.2 Concurrent Queue from David Stone
>
> In response to P0260r3, an overview of the current art. Separate out
> concurrent vs non-concurrent is a viable strategy. Also papers by Guy
> Davidson (D????), P1470r0, and others.
>
> Additional queues from Tony Van Eerd, and the Folly Team.
>
> 2.2.3 Error Size Benchmarking by Ben Craig
>
> P1640R0: Error size benchmarking
>
>
> https://raw.githack.com/ben-craig/error_bench/master/error_size_benchmarking.html
> <https://urldefense.proofpoint.com/v2/url?u=https-3A__raw.githack.com_ben-2Dcraig_error-5Fbench_master_error-5Fsize-5Fbenchmarking.html&d=DwMGaQ&c=r2dcLCtU9q6n0vrtnDw9vg&r=bHyceIQQHQvbfTSwvF3b5ym3XCQIh0_iFRNJbNk-FCc&m=_OFSroXnnYHKfBQqw8TVSac0et4fEQ80IMeaj-lWcD4&s=LGjT-TVB94ptHzUmdPNh4LJr1eMpKuAcmL7pQSWzxxA&e=>
>
> Initial error neutral size cost is relative to the stripped_abort case.
>
> Question about whether unreachable would be an even lower bound. No
> measurements as of yet.
>
> Visual Studio has different implementation strategies between 32-bit and
> 64-bit compilations.
>
> The light bars show the need imposed by the platform ABI to store unwind
> information on 64-bit. That restriction is not necessarily there on WinX32,
> or indeed on some embedded platforms.
>
> The first time that you call a function (say a C function) that is not
> marked noexcept, with exceptions turned on, you pay the exception size
> penalty. This happens for Visual Studio in /EHc mode when calling abort().
>
> As ever with microbenchmarks there was some necessary fighting the
> optimizer.
>
> DG will be very interesting in these results.
>
> 2.2.4 Linear Algebra update from April 3rd
> http://lists.isocpp.org/sg14/2019/04/0076.php
>
> Michael gave a quick update on the current status. The idea of row and
> column vector is still a topic of discussion. There is a contrasting paper
> preferring a more eager evaluation technique from National Labs, avoiding
> expression templates.
>
> Next call: July 10 2 PM EDT – will very likely be cancelled due to Cologne.
>
> Backup date is August 14 2 PM EDT.
>
> 2.2.5: Any serious study on cost of Exception vs cost of Error Codes
>
> 2.2.6 any other proposal for reviews?
>
> 2.3 Domain-specific discussions
>
> 2.3.1 Embedded domain discussions: Ben Craig, Wooter and Odin Holmes
> 2.3.3 Games Domain: John McFarlane, Guy Davidson and Paul Hampson
> 2.3.4 Finance Domain: Carl Cooke, Neal Horlock, Mateusz Pusz and Clay
> Trychta
>
> 2.4 Other Papers and proposals
>
> 2.5 Future F2F meetings:
>
> 2.6 future C++ Standard meetings:
> https://isocpp.org/std/meetings-and-participation/upcoming-meetings
>
> - *2019-07-15 to 20: Cologne, Germany; *Nicolai Josuttis
> - *2019-11-04 to 09: Belfast, Northern Ireland;* Archer Yates
> -
> - 2020-02-10 to 15: Prague, Czech Republic
>
> - 2020-06-01 to 06: Bulgaria
> - 2020-11: (New York, tentative)
> - 2021-02-22 to 27: Kona, HI, USA
>
> 3. Any other business
> Reflector
> https://groups.google.com/a/isocpp.org/forum/?fromgroups=#!forum/sg14
> As well as look through papers marked "SG14" in recent standards committee
> paper mailings:
> http://open-std.org/jtc1/sc22/wg21/docs/papers/2015/
> http://open-std.org/jtc1/sc22/wg21/docs/papers/2016/
>
> Code and proposal Staging area
> https://github.com/WG21-SG14/SG14
> 4. Review
>
> 4.1 Review and approve resolutions and issues [e.g., changes to SG's
> working draft]
>
> 4.2 Review action items (5 min)
>
> 5. Closing process
>
> 5.1 Establish next agenda
>
> TBD
>
> 5.2 Future meeting
> Apr 17: todays call
> May 8
> June 12: June 17 mailing deadline
> July 10: likely cancelled due to Cologne Meeting July 15
>
> ------------------------------
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Received on 2019-06-12 15:09:21