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

["Roger Pau Monné" <roger.pau@citrix.com>]

Do I need to resend this? it's been more than a month without review.

Roger.

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);
>>          }
>>      }
>>
> 
>