Re: [Qemu-devel] [RFC v6 22/27] qmp: isolate responses into io thread

[Fam Zheng <famz@redhat.com>]

On Tue, 12/19 16:45, Peter Xu wrote:
> For those monitors who has enabled IO thread, we'll offload the

s/has/have/

> responding procedure into IO thread.  The main reason is that chardev is
> not thread safe, and we need to do all the read/write IOs in the same
> thread.  For use_io_thr=true monitors, that thread is the IO thread.
> 
> We do this isolation in similar pattern as what we have done to the
> request queue: we first create one response queue for each monitor, then
> instead of reply directly in main thread, we queue the responses and

s/reply/replying/

s/main thread/the main thread/

> kick the IO thread to do the rest of the job for us.
> 
> A funny thing after doing this is that, when the QMP clients send "quit"
> to QEMU, it's possible that we close the IOThread even earlier than
> replying to that "quit".  So another thing we need to do before cleaning
> up the monitors is that we need to flush the response queue (we don't
> need to do that for command queue; after all we are quitting) to make
> sure replies for handled commands are always flushed back to clients.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Fam Zheng <famz@redhat.com>