Re: [Qemu-devel] [RFC] aio: add aio_context_acquire() and aio_context_release()

[Alex Bligh]

--On 27 August 2013 16:39:45 +0200 Stefan Hajnoczi <address@hidden> 
wrote:

> This patch implements aio_context_acquire() and aio_context_release().
> Note that existing aio_poll() callers do not need to worry about
> acquiring and releasing - it is only needed when multiple threads will
> call aio_poll() on the same AioContext.

I think this patch has another use.

For reasons I forget (init of the QemuTimerListGroup being one of them)
creation and deletion of AioContexts has to do be done with the BQL
held.

If a second thread is the ONLY user of the AioContext, this would allow
some synchronisation with the eventual deletion under the BQL on the
main thread.

--
Alex Bligh