mailing list of musl libc
 help / color / mirror / code / Atom feed
From: u-uy74@aetey.se
To: musl@lists.openwall.com
Subject: Re: setcontext/getcontext/makecontext missing?
Date: Sun, 7 Feb 2016 11:05:53 +0100	[thread overview]
Message-ID: <20160207100553.GJ25193@example.net> (raw)
In-Reply-To: <CAK4o1Wxe3JVvjcM=pJm+jMCsMwfk_-LfNpnjdL2YHxhVc+Mn+w@mail.gmail.com>

On Sat, Feb 06, 2016 at 09:20:49PM -0800, Justin Cormack wrote:
> > Thanks for pointing this out, if rt_sigprocmask can not be skipped
> > then indeed a switch becomes much more expensive.
> 
> Many users of this interface do not actually require this. Actually NetBSD
> makes the context functions syscalls themselves. And OpenBSD does not
> provide them at all.
> 
> I have taken to just including implementations (without the signal calls)
> in code that needs to use them

That's what Coda does.
This creates the burden to add the assembler code for new architectures
when necessary - or an option to resort to one of the heavier alternatives.

> with modifications to fix the prototype
> issues as most code only needs to pass a single argument. At one point I
> was going to do implementations for Musl but I think it is a bad idea.

I have to agree. Providing a non-compliant implementation in musl
would undermine its spirit (of standard-compliance).

OTOH a tiny standalone library with the adjusted API and without the
signal stuff *might* be actually a good fit for some applications,
especially for the old ones written to ucontext.

Rune



      reply	other threads:[~2016-02-07 10:05 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-04 14:09 Short, Todd
2016-02-04 14:54 ` Szabolcs Nagy
2016-02-04 15:41   ` Rich Felker
2016-02-04 16:22     ` u-uy74
2016-02-04 17:01       ` Szabolcs Nagy
2016-02-05  9:21         ` u-uy74
2016-02-04 19:24       ` Rich Felker
2016-02-05  9:58         ` u-uy74
2016-02-07  5:20           ` Justin Cormack
2016-02-07 10:05             ` u-uy74 [this message]

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=20160207100553.GJ25193@example.net \
    --to=u-uy74@aetey.se \
    --cc=musl@lists.openwall.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.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/musl/

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 NNTP newsgroup(s).