Re: [Qemu-devel] Guest application reading from pl011 without device driver

[Jiahuan Zhang]

On 22 March 2017 at 12:27, Paolo Bonzini <address@hidden> wrote:

>
>
> On 22/03/2017 11:28, Jiahuan Zhang wrote:
> >
> >     A function that lets a process sleep until data is available on the
> >     socket.  The solution is to rewrite Windows chardev handling in QEMU
> to
> >     use threads or overlapped I/O.
> >
> > Yes, socket is working well. Will you add the "select" to pipe
> > implementation?
>
> It's Windows that doesn't support it (the Windows function name is
> WaitForSingleObject).


Hi, I have checked the Windows chardev implimentation in QEMU.
I learned from char-win-stdio.c to using thread and WaitForSingleObject for
interlocking.
char-win-stdio.c uses qemu_add_wait_object().
Char-pipe.c uses qemu_add_polling_cb().
I found all over qemu, only char-pipe uses qemu_add_polling_cb().
Does this mean that somebody has already looked into this issue,
and failed in using qemu_add_wait_object(),
and then he/she created qemu_add_polling_cb()?

If so, what I am going to do is just something has been proved to be
useless.
Please tell me if my guess is true.

Best,
Huan

>
> Paolo
>
> > Or shall I look into it and fix? Since in my case, I prefer windows pipe
> > to socket.
> > But if I do, definitly, I will spend much more effort than you, the
> experts.
>