From: Iain Sandoe <iain@sandoe.co.uk>
To: "Nicolas König" <koenigni@student.ethz.ch>,
"Fortran List" <fortran@gcc.gnu.org>
Cc: Thomas Koenig <tkoenig@netcologne.de>, dhumieres.dominique@free.fr
Subject: Re: Update on shared memory coarrays
Date: Sun, 3 Jan 2021 15:42:52 +0000 [thread overview]
Message-ID: <FEE3EEB3-0A22-4728-B62A-59665760AC69@sandoe.co.uk> (raw)
In-Reply-To: <2007278F-63EE-427A-BFB6-A504E96D3572@sandoe.co.uk>
(continuing the monologue)
Iain Sandoe <iain@sandoe.co.uk> wrote:
> Iain Sandoe <iain@sandoe.co.uk> wrote:
>
>> Iain Sandoe <iain@sandoe.co.uk> wrote:
>>
>>> Iain Sandoe <iain@sandoe.co.uk> wrote:
>
> However shm_open interface *does* appear to allow arbitrary sized
> segments [at least not reporting an error to the first call to
> ftruncate()] - but to deny a resize once created.
>
> seems more background reading will be needed …
So… Posix 1003 says...
[SHM] If fildes refers to a shared memory object, ftruncate() shall set
the size of the shared memory object to length.
… which means it "should work as observed on Linux "…
… BUT…. Posix 1003 also says
[SHM] Shared Memory Objects
The functionality described is optional. The functionality described is
also an extension to the ISO C standard.
… so support is optional and a failure in partial support is not an actual
bug in compliance …
(we can file a radar, and maybe it gets fixed at some point - but that’s no
help to all the existing system versions)
=====
whether there’s some way to coerce the alternate interfaces into working,
remains to be seen
Iain
next prev parent reply other threads:[~2021-01-03 15:43 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-29 19:09 dhumieres.dominique
2020-11-30 6:21 ` Thomas Koenig
2020-11-30 15:41 ` dhumieres.dominique
2020-11-30 22:13 ` Thomas Koenig
2020-12-02 17:41 ` dhumieres.dominique
2020-12-03 7:27 ` Thomas Koenig
2020-12-21 12:24 ` dhumieres.dominique
2020-12-21 13:04 ` Thomas Koenig
2020-12-22 12:28 ` dhumieres.dominique
2020-12-22 15:10 ` Thomas Koenig
2020-12-22 16:12 ` Paul Richard Thomas
2020-12-23 9:09 ` Thomas Koenig
2020-12-23 9:38 ` Paul Richard Thomas
2020-12-23 10:47 ` Thomas Koenig
2020-12-26 12:10 ` Paul Richard Thomas
2020-12-26 13:01 ` Thomas Koenig
2020-12-27 15:38 ` Thomas Koenig
2020-12-23 16:42 ` Nicolas König
2020-12-23 17:25 ` dhumieres.dominique
2020-12-27 17:10 ` Nicolas König
2021-01-01 13:51 ` dhumieres.dominique
2021-01-01 16:16 ` Thomas Koenig
2021-01-01 16:41 ` dhumieres.dominique
2021-01-02 20:45 ` Thomas Koenig
2021-01-02 20:55 ` Iain Sandoe
2021-01-02 21:43 ` Thomas Koenig
2021-01-02 22:37 ` Nicolas König
2021-01-02 21:44 ` Iain Sandoe
2021-01-02 22:09 ` Iain Sandoe
2021-01-03 10:46 ` Iain Sandoe
2021-01-03 14:54 ` Iain Sandoe
2021-01-03 15:42 ` Iain Sandoe [this message]
2021-01-03 21:53 ` Thomas Koenig
2021-01-04 2:34 ` Iain Sandoe
2021-01-04 18:54 ` Nicolas König
2021-01-05 13:11 ` Iain Sandoe
2021-01-05 13:23 ` Iain Sandoe
2021-01-05 13:27 ` Thomas Koenig
2021-01-05 13:34 ` Iain Sandoe
2021-01-05 14:54 ` Nicolas König
2021-01-05 14:28 ` Iain Sandoe
2021-01-05 15:45 ` Nicolas König
[not found] ` <BAD6EA1D-BB9F-4905-ADD1-76FA1D6B9591@sandoe.co.uk>
2021-01-05 17:11 ` Nicolas König
2021-01-06 16:56 ` Iain Sandoe
-- strict thread matches above, loose matches on Subject: below --
2020-11-29 13:10 Nicolas König
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