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

[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