Re: [Qemu-devel] [PATCH v2 3/3] serial: poll the serial console with G_IO_HUP

[Paolo Bonzini <pbonzini@redhat.com>]

Il 30/06/2014 13:00, Roger Pau Monné ha scritto:
> Do I need to resend this? it's been more than a month without review.

I'll send a pull request for it.

Sorry for the delay.

Paolo

> On 13/06/14 17:35, Roger Pau Monné wrote:
>> Ping?
>>
>> On 23/05/14 17:57, Roger Pau Monne wrote:
>>> On FreeBSD polling a master pty while the other end is not connected
>>> with G_IO_OUT only results in an endless wait. This is different from
>>> the Linux behaviour, that returns immediately. In order to demonstrate
>>> this, I have the following example code:
>>>
>>> http://xenbits.xen.org/people/royger/test_poll.c
>>>
>>> When executed on Linux:
>>>
>>> $ ./test_poll
>>> In callback
>>>
>>> On FreeBSD instead, the callback never gets called:
>>>
>>> $ ./test_poll
>>>
>>> So, in order to workaround this, poll the source with G_IO_HUP (which
>>> makes the code behave the same way on both Linux and FreeBSD).
>>>
>>> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
>>> Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>>> Cc: Michael Tokarev <mjt@tls.msk.ru>
>>> Cc: "Andreas Färber" <afaerber@suse.de>
>>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>>> Cc: xen-devel@lists.xenproject.org
>>> ---
>>> Changes since v1:
>>>  - Fix other users of qemu_chr_fe_add_watch to use G_IO_HUP.
>>> ---
>>>  hw/char/serial.c         |    2 +-
>>>  hw/char/virtio-console.c |    3 ++-
>>>  hw/usb/redirect.c        |    2 +-
>>>  monitor.c                |    2 +-
>>>  4 files changed, 5 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/hw/char/serial.c b/hw/char/serial.c
>>> index f4d167f..2a2c9e5 100644
>>> --- a/hw/char/serial.c
>>> +++ b/hw/char/serial.c
>>> @@ -246,7 +246,7 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque)
>>>          serial_receive1(s, &s->tsr, 1);
>>>      } else if (qemu_chr_fe_write(s->chr, &s->tsr, 1) != 1) {
>>>          if (s->tsr_retry >= 0 && s->tsr_retry < MAX_XMIT_RETRY &&
>>> -            qemu_chr_fe_add_watch(s->chr, G_IO_OUT, serial_xmit, s) > 0) {
>>> +            qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, serial_xmit, s) > 0) {
>>>              s->tsr_retry++;
>>>              return FALSE;
>>>          }
>>> diff --git a/hw/char/virtio-console.c b/hw/char/virtio-console.c
>>> index 6c8be0f..38e290a 100644
>>> --- a/hw/char/virtio-console.c
>>> +++ b/hw/char/virtio-console.c
>>> @@ -69,7 +69,8 @@ static ssize_t flush_buf(VirtIOSerialPort *port,
>>>          if (!k->is_console) {
>>>              virtio_serial_throttle_port(port, true);
>>>              if (!vcon->watch) {
>>> -                vcon->watch = qemu_chr_fe_add_watch(vcon->chr, G_IO_OUT,
>>> +                vcon->watch = qemu_chr_fe_add_watch(vcon->chr,
>>> +                                                    G_IO_OUT|G_IO_HUP,
>>>                                                      chr_write_unblocked, vcon);
>>>              }
>>>          }
>>> diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
>>> index 287a505..06e757d 100644
>>> --- a/hw/usb/redirect.c
>>> +++ b/hw/usb/redirect.c
>>> @@ -284,7 +284,7 @@ static int usbredir_write(void *priv, uint8_t *data, int count)
>>>      r = qemu_chr_fe_write(dev->cs, data, count);
>>>      if (r < count) {
>>>          if (!dev->watch) {
>>> -            dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT,
>>> +            dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT|G_IO_HUP,
>>>                                                 usbredir_write_unblocked, dev);
>>>          }
>>>          if (r < 0) {
>>> diff --git a/monitor.c b/monitor.c
>>> index 593679a..ae1c539 100644
>>> --- a/monitor.c
>>> +++ b/monitor.c
>>> @@ -304,7 +304,7 @@ void monitor_flush(Monitor *mon)
>>>              mon->outbuf = tmp;
>>>          }
>>>          if (mon->watch == 0) {
>>> -            mon->watch = qemu_chr_fe_add_watch(mon->chr, G_IO_OUT,
>>> +            mon->watch = qemu_chr_fe_add_watch(mon->chr, G_IO_OUT|G_IO_HUP,
>>>                                                 monitor_unblocked, mon);
>>>          }
>>>      }
>>>
>>
>>
>