Re: [Qemu-devel] [PATCH v2] qemu_mutex_iothread_locked not correctly synchronized

[David Engraf]

Am 26.11.2015 um 12:25 schrieb Stefan Weil:
> Am 26.11.2015 um 10:12 schrieb David Engraf:
> > Am 25.11.2015 um 17:16 schrieb Paolo Bonzini:
> > > On 25/11/2015 16:48, David Engraf wrote:
> > > > Indeed, TLS handling is broken. The address of iothread_locked is
> > > > always
> > > > the same between threads and I can see that a different thread sets
> > > > iothread_locked to false, thus my current thread uses an invalid state.
> > > > I will have to check why my compiler produces invalid TLS code.
> > >
> > > That rings a bell, I think there are different CRT libraries or
> > > something like that.  Stefan, what would break TLS under Windows?
> >
> > "--extra-cflags=-mthreads" is the solution. iothread_locked is unique
> > for each thread now. I saw that this is already mentioned in the
> > Documentation [1], but why isn't that enabled by default if QEMU
> > requires this option on Windows? Without this option, even the latest
> > version of gcc doesn't produce working TLS code.
> >
> > Many thanks for your support!
> >
> > David
> >
> > [1] http://wiki.qemu.org/Hosts/W32
>
> Hi David,
>
> I just prepared a patch which will enable that option by default
> for all compilations targeting Windows.
>
> Thanks for your report!

Thank you.

David