Re: [RFC PATCH 2/2] migration/multifd: Move semaphore release into main thread

[Juan Quintela]

Fabiano Rosas <farosas@suse.de> wrote:
> Fabiano Rosas <farosas@suse.de> writes:
>
>> Peter Xu <peterx@redhat.com> writes:
>>
>>> On Thu, Nov 09, 2023 at 01:58:56PM -0300, Fabiano Rosas wrote:

>> I think we historically stumbled upon the fact that qemu_thread_join()
>> is not the same as pthread_join(). The former takes a pointer and is not
>> safe to call with a NULL QemuThread. That seems to be the reason for the
>> p->running check before it.
>
> Scratch this part, the QemuThread is not a pointer.
>
> ...should it be? Because then we can test p->thread instead of
> p->running, which would be more precise and would dispense the
> thread_created flag.

You still need to make sure that you don't join the thread twice.
And we do the qemu_pthread_join() without any lock.

Later, Juan.