From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin-patches@cygwin.com
Subject: Re: [PATCH 0/2] Provide virtual /dev/fd and /dev/{stdin, stdout, stderr} symlinks
Date: Mon, 28 Feb 2022 10:24:18 +0100 [thread overview]
Message-ID: <YhyUwucjllyFpkRy@calimero.vinschen.de> (raw)
In-Reply-To: <nycvar.QRO.7.76.6.2202251645090.11118@tvgsbejvaqbjf.bet>
On Feb 25 16:46, Johannes Schindelin wrote:
> Hi Corinna,
>
> On Tue, 22 Feb 2022, Corinna Vinschen wrote:
>
> > On Feb 21 14:36, Johannes Schindelin wrote:
> > > These symbolic links are crucial e.g. to support process substitution (Bash's
> > > very nice `<(SOME-COMMAND)` feature).
> > >
> > > For various reasons, it is a bit cumbersome (or impossible) to generate these
> > > symbolic links in all circumstances where Git for Windows wants to use its
> > > close fork of the Cygwin runtime.
> > >
> > > Therefore, let's just handle these symbolic links as implicit, virtual ones.
> > >
> > > If there is appetite for it, I wonder whether we should do something similar
> > > for `/dev/shm` and `/dev/mqueue`? Are these even still used in Cygwin?
> >
> > "still used"? These are the dirs to store POSIX semaphors, message
> > queues and shared mem objects.
>
> Okay. I guess we do not really use them in Git for Windows ;-)
Probably not. I'm not aware that git uses POSIX IPC objects.
> > These have to be real on-disk dirs.
>
> Could I ask you to help me understand why? Do they have to be writable? Or
> do the things that are written into them have to be persisted between
> Cygwin sessions?
Cygwin uses ordinary on-disk files to emulate the objects, and
they have to persist over process exits. Unfortunately I don't
see any other way to create persistent objects from user space.
Corinna
next prev parent reply other threads:[~2022-02-28 9:24 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-21 13:36 [PATCH 0/2] Provide virtual /dev/fd and /dev/{stdin,stdout,stderr} symlinks Johannes Schindelin
2022-02-21 13:36 ` [PATCH 1/2] Implicitly support the /dev/fd symlink and friends Johannes Schindelin
2022-02-21 13:36 ` [PATCH 2/2] Regenerate devices.cc Johannes Schindelin
2022-02-22 12:34 ` [PATCH 0/2] Provide virtual /dev/fd and /dev/{stdin,stdout,stderr} symlinks Corinna Vinschen
2022-02-25 15:46 ` [PATCH 0/2] Provide virtual /dev/fd and /dev/{stdin, stdout, stderr} symlinks Johannes Schindelin
2022-02-28 9:24 ` Corinna Vinschen [this message]
2022-02-28 9:57 ` Corinna Vinschen
2023-03-28 8:34 ` Johannes Schindelin
2022-02-25 18:35 ` [PATCH 0/2] Provide virtual /dev/fd and /dev/{stdin,stdout,stderr} symlinks Brian Inglis
2023-03-28 8:36 ` Johannes Schindelin
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