From: Petr Ovtchenkov <ptr@void-ptr.info>
To: Paolo Carlini <paolo.carlini@oracle.com>
Cc: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH 3/4] libstdc++: avoid character accumulation in istreambuf_iterator
Date: Thu, 16 Nov 2017 11:44:00 -0000 [thread overview]
Message-ID: <20171116144153.24d397b0@void-ptr.info> (raw)
In-Reply-To: <429dd8c9-a781-3e57-3242-92bd614adc26@oracle.com>
On Thu, 16 Nov 2017 12:29:37 +0100
Paolo Carlini <paolo.carlini@oracle.com> wrote:
> Hi,
>
> On 16/11/2017 12:03, Petr Ovtchenkov wrote:
> > On Thu, 16 Nov 2017 10:39:02 +0100
> > Paolo Carlini <paolo.carlini@oracle.com> wrote:
> >
> >> Hi,
> >>
> >> On 16/11/2017 06:31, Petr Ovtchenkov wrote:
> >>> Is we really worry about frozen sizeof of instantiated template?
> >> Yes we do. See https://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html
> >> under "Prohibited Changes", point 8.
> >>
> >> Of course removing the buffering has performance implications too -
> >> that's why it's there in the first place!
> > "buffering" here is a secondary buffering (after streambuf).
> > No relation to performance, but place for incoherence with
> > state of attached streambuf.
> It depends, we may be dealing with an unbuffered stream. For sure at the
> time we measured a performance impact in some cases, likewise whoever
> implemented it in the first place (not me) otherwise, again, why bothering?
This part of code is from SGI, so I suspect that nobody here really
measure performance difference between "bufferred" and "non-buffered"
implementations. Just because we have only implementation
with _M_c in isreambuf_iterator.
>
> Paolo.
>
--
- ptr
next prev parent reply other threads:[~2017-11-16 11:41 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-27 20:16 Make tests less istreambuf_iterator implementation dependent François Dumont
2017-09-28 12:12 ` Jonathan Wakely
2017-09-28 19:59 ` François Dumont
2017-09-28 21:56 ` Jonathan Wakely
2017-10-02 5:43 ` François Dumont
2017-10-03 14:20 ` Jonathan Wakely
2017-10-04 16:21 ` François Dumont
2017-10-04 23:23 ` Jonathan Wakely
2017-11-15 20:54 ` [PATCH 1/4] Revert "2017-10-04 Petr Ovtchenkov <ptr@void-ptr.info>" Petr Ovtchenkov
2017-11-15 20:58 ` [PATCH 2/4] libstdc++: istreambuf_iterator keep attached streambuf Petr Ovtchenkov
2017-11-15 20:52 ` [PATCH 3/4] libstdc++: avoid character accumulation in istreambuf_iterator Petr Ovtchenkov
2017-11-15 20:52 ` [PATCH 4/4] libstdc++: immutable _M_sbuf " Petr Ovtchenkov
2017-11-15 22:30 ` [PATCH 3/4] libstdc++: avoid character accumulation " Paolo Carlini
2017-11-16 6:00 ` Petr Ovtchenkov
2017-11-16 9:51 ` Paolo Carlini
2017-11-16 11:34 ` Petr Ovtchenkov
2017-11-16 11:35 ` Paolo Carlini
2017-11-16 11:44 ` Petr Ovtchenkov [this message]
2017-11-16 11:57 ` Paolo Carlini
2017-11-16 11:03 ` [PATCH 1/4] Revert "2017-10-04 Petr Ovtchenkov <ptr@void-ptr.info>" Jonathan Wakely
2017-11-16 11:39 ` Petr Ovtchenkov
2017-11-16 11:41 ` Jonathan Wakely
2017-11-16 11:42 ` Jonathan Wakely
2017-11-16 12:03 ` Petr Ovtchenkov
-- strict thread matches above, loose matches on Subject: below --
2017-10-13 17:22 Make istreambuf_iterator::_M_sbuf immutable and add debug checks François Dumont
2017-10-23 19:24 ` François Dumont
2017-11-06 21:20 ` François Dumont
2017-11-16 6:07 ` Petr Ovtchenkov
2017-11-16 11:29 ` Jonathan Wakely
2017-11-16 11:57 ` Jonathan Wakely
2017-11-16 12:25 ` Petr Ovtchenkov
2017-11-16 17:48 ` François Dumont
2017-11-16 18:24 ` Petr Ovtchenkov
2017-11-16 23:00 ` François Dumont
2017-09-23 7:10 [PATCH] libstdc++: istreambuf_iterator keep attached streambuf Petr Ovtchenkov
2017-09-25 13:46 ` Jonathan Wakely
2017-09-28 10:34 ` Jonathan Wakely
2017-09-28 12:06 ` Petr Ovtchenkov
2017-09-28 12:38 ` Jonathan Wakely
2017-10-03 20:39 ` Petr Ovtchenkov
2017-10-04 5:04 ` [PATCH v2] " Petr Ovtchenkov
2017-10-06 16:01 ` [PATCH] libstdc++: istreambuf_iterator proxy (was: keep attached streambuf) François Dumont
2017-10-06 18:03 ` Petr Ovtchenkov
2017-10-08 15:45 ` [PATCH] libstdc++: istreambuf_iterator proxy François Dumont
2017-10-09 19:35 ` Petr Ovtchenkov
2017-10-10 5:52 ` Petr Ovtchenkov
2017-10-10 14:22 ` [PATCH] libstdc++: istreambuf_iterator proxy (was: keep attached streambuf) Jonathan Wakely
2017-08-24 11:58 [PATCH] streambuf_iterator: avoid debug-dependent behaviour Petr Ovtchenkov
2017-09-01 9:10 ` Jonathan Wakely
2017-09-07 21:02 ` François Dumont
2017-09-08 5:47 ` Petr Ovtchenkov
2017-09-09 20:17 ` François Dumont
2017-09-21 5:46 ` François Dumont
2017-09-28 10:50 ` Jonathan Wakely
2017-09-28 10:58 ` Jonathan Wakely
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171116144153.24d397b0@void-ptr.info \
--to=ptr@void-ptr.info \
--cc=gcc-patches@gcc.gnu.org \
--cc=libstdc++@gcc.gnu.org \
--cc=paolo.carlini@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).