This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: thread-local storage: c front end and generic backend patch
- From: "Joseph S. Myers" <jsm28 at cam dot ac dot uk>
- To: Gabriel Dos Reis <gdr at codesourcery dot com>
- Cc: Richard Henderson <rth at redhat dot com>, Mark Mitchell <mark at codesourcery dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 22 May 2002 22:44:19 +0100 (BST)
- Subject: Re: thread-local storage: c front end and generic backend patch
On 22 May 2002, Gabriel Dos Reis wrote:
> | This is intentionally vague. Why would we mention pthread_create
> | here when the run-time might actually use some other thread library?
>
> Being more specifc about the semantics is really needed for proving
> and/or maintaining the invariant that a change to compiler (be it an
> advanced optimization or implementation of standard features) does not
> break the semantics of that extension. In shrot, we need to know what
> it is supposed to mean in order to prove that some change is correct.
>
> I think the issue is important so that we don't gloss over it.
There is the underlying problem here that POSIX needs to come with a set
of edits for the C standard to explain how it profiles that standard to
provide for threads (and for signal handling that isn't always undefined
behavior). However, it doesn't. In turn there are the problems of lack
of precise definition of object semantics in the C standard, which should
be addressed for it to serve properly as a base standard being profiled to
add threads, concurrency, etc..
--
Joseph S. Myers
jsm28@cam.ac.uk