[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC v2 2/8] monitor: allow monitor to create thread to
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [RFC v2 2/8] monitor: allow monitor to create thread to poll |
Date: |
Fri, 8 Sep 2017 18:29:13 +0100 |
User-agent: |
Mutt/1.8.3 (2017-05-23) |
* Peter Xu (address@hidden) wrote:
> On Fri, Aug 25, 2017 at 10:30:42AM +0100, Dr. David Alan Gilbert wrote:
>
> [...]
>
> > > > c) As mentioned on irc there's fun to be had with cur_mon and error
> > > > handling - in my local world I have cur_mon declared as __thread
> > > > but never got around to thinking aobut what should set it up.
> > > > There's also 'wavcapture: Convert to error_report' that I posted
> > > > in March that got rid of some uses of cur_mon in wavcapture.c
> > > > for error_report.
> > >
> > > Yeh. I at least also see a positive ACK from Markus in the other
> > > thread for per-thread cur_mon, sounds like this is the right way to
> > > go.
> > >
> > > To setup cur_mon, what I can think of is create wrapper for
> > > pthread_create() in qemu_thread_create(). I see that we have done
> > > similar thing in util/qemu-thread-win32.c for Windows. With that we
> > > can setup the cur_mon before going into real thread function but in
> > > the right context, though we may need one more parameter for current
> > > qemu_thread_create():
> > >
> > > void qemu_thread_create(QemuThread *thread, const char *name,
> > > void *(*start_routine)(void*),
> > > void *arg, int mode, Monitor *mon);
> > >
> > > Then we can specify monitor for any new thread (default to cur_mon).
> > > For per-monitor threads, I think we need to pass in that specific mon.
> > >
> > > Is this doable?
> >
> > That would mean changing all the qemu_thread_create calls, but yes
> > I guess is doable. I'd thought the other way, perhaps you inherit
> > Monitor except in the case of when the monitor creates threads.
>
> Do you mean setup cur_mon in monitor threads?
>
> I'm afraid that may not be enough, since after we mark cur_mon as
> __thread variable, it should be NULL for each newly created threads,
> then we need to init them for every thread. Or anything I missed?
Right, I thought you'd modify qemu_thread_create to setup cur_mon in
new threads to the same as the parent.
Dave
> [...]
>
> > > >
> > > > d) I wonder if it's better to have thread as a flag, so that you have
> > > > to explicitly ask for a monitor to have it's own thread.
> > >
> > > This should be doable. Would a new parameter for "-qmp" and "-hmp"
> > > suffice?
> >
> > Yes.
>
> (I meant "-monitor" when saying "-hmp")
>
> Hmm, it seems not easy to simply add a new parameter for it, since we
> used "," already to parse the chardev params in monitor codes, like
> the usage of:
>
> -qmp telnet::8888,server,nowait
>
> So I cannot simply do:
>
> -qmp telnet::8888,server,nowait,threaded=on
>
> Or it will be treated for a parameter for chardev type "telnet".
>
> I can at least add something similar to QEMU_OPTION_qmp_pretty, like:
> QEMU_OPTION_qmp_threaded, and maybe I also need
> QEMU_OPTION_monitor_pretty. But I am thinking whether there can be
> anything better. Any suggestion from anyone?
>
> --
> Peter Xu
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK