[Bug libstdc++/62313] Data race in debug iterators

["redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62313

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to François Dumont from comment #4)
> For me there is no bug. Standard containers are known to not be thread safe.

No, containers are known to be thread-safe, when used correctly.

> I don't know what  Standard points are talking about it but what I consider
> as valid was iterating through the container from different threads. However
> in your case you are doing some iterator operations, no matter how simple
> they are,  in one thread while modifying the container from another and this
> require you to put some mutex in place to do so.

No it doesn't.

Only the main thread accesses the container. The other thread simply reads and
writes global iterator objects, which are distinct memory locations from the
container and so can be accessed concurrently. See 17.6.5.9
[res.on.data.races]: "-7- Implementations may share their own internal objects
between threads if the objects are not visible to users and are protected
against data races."

> I think you will experiment the same issue with all versions of the Standard
> lib, even the oldest ones. Synchronization of the list of iterators has
> never been plan to cover this kind of usage which is considered as invalid.

No, this is a bug.
>From gcc-bugs-return-460283-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Mon Sep 01 09:57:56 2014
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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug fortran/62174] Component declarations overwrite types of Cray Pointee variables
Date: Mon, 01 Sep 2014 09:57:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idb174

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Patches should go to the gcc-patches at gcc.gnu.org mailing list (and in case
of Fortran FE patches also CC fortran at gcc.gnu.org ml).  That is where patch
review happens.  For a one-liner change like this, I think you don't need
Copyright assignment, but if you plan to submit further patches, please
consider following https://gcc.gnu.org/contribute.html