Re: [Qemu-devel] [PATCH 11/20] qemu-char: use a glib timeout instead of qemu-timer

[Laurent Desnogues]

On Fri, Mar 15, 2013 at 4:44 PM, Anthony Liguori <address@hidden> wrote:
> Laurent Desnogues <address@hidden> writes:
>
>> Hello,
>>
>> On Tue, Mar 5, 2013 at 6:51 PM, Amit Shah <address@hidden> wrote:
>>> From: Anthony Liguori <address@hidden>
>>>
>>> Signed-off-by: Anthony Liguori <address@hidden>
>>> Signed-off-by: Amit Shah <address@hidden>
>>> ---
>>>  qemu-char.c | 68 
>>> ++++++++++++++++++++++++++++++++++++++++---------------------
>>>  1 file changed, 45 insertions(+), 23 deletions(-)
>>>
>>> diff --git a/qemu-char.c b/qemu-char.c
>>> index eb0ac81..6dba943 100644
>>> --- a/qemu-char.c
>>> +++ b/qemu-char.c
>>> @@ -990,12 +990,50 @@ typedef struct {
>>>      int connected;
>>>      int polling;
>>>      int read_bytes;
>>> -    QEMUTimer *timer;
>>> +    guint timer_tag;
>>>  } PtyCharDriver;
>>>
>>>  static void pty_chr_update_read_handler(CharDriverState *chr);
>>>  static void pty_chr_state(CharDriverState *chr, int connected);
>>>
>>> +static gboolean pty_chr_timer(gpointer opaque)
>>> +{
>>> +    struct CharDriverState *chr = opaque;
>>> +    PtyCharDriver *s = chr->opaque;
>>> +
>>> +    if (s->connected) {
>>> +        goto out;
>>> +    }
>>> +    if (s->polling) {
>>> +        /* If we arrive here without polling being cleared due
>>> +         * read returning -EIO, then we are (re-)connected */
>>> +        pty_chr_state(chr, 1);
>>> +        goto out;
>>> +    }
>>> +
>>> +    /* Next poll ... */
>>> +    pty_chr_update_read_handler(chr);
>>> +
>>> +out:
>>> +    return FALSE;
>>> +}
>>> +
>>> +static void pty_chr_rearm_timer(CharDriverState *chr, int ms)
>>> +{
>>> +    PtyCharDriver *s = chr->opaque;
>>> +
>>> +    if (s->timer_tag) {
>>> +        g_source_remove(s->timer_tag);
>>> +        s->timer_tag = 0;
>>> +    }
>>> +
>>> +    if (ms == 1000) {
>>> +        s->timer_tag = g_timeout_add_seconds(1, pty_chr_timer, chr);
>>
>> It looks like g_timeout_add_seconds isn't available for
>> poor people using some old distros (glib 2.12.3 here).
>
> Can you test adding:
>
> #if !GLIB_CHECK_VERSION(2, 14, 0)
> static guint g_timeout_add_seconds(guint interval, GSourceFunc function,
>                                    gpointer data)
> {
>     return g_timeout_add(interval * 1000, function, data);
> }
> #endif

That works fine, thanks for looking!

> We probably should introduce a glib-compat to centralize work arounds
> for older versions of glib...

Agreed.

Thanks again,

Laurent

> Regards,
>
> Anthony Liguori
>
>>
>> Thanks,
>>
>> Laurent
>>
>>> +    } else {
>>> +        s->timer_tag = g_timeout_add(ms, pty_chr_timer, chr);
>>> +    }
>>> +}
>>> +
>>>  static int pty_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
>>>  {
>>>      PtyCharDriver *s = chr->opaque;
>>> @@ -1065,7 +1103,7 @@ static void 
>>> pty_chr_update_read_handler(CharDriverState *chr)
>>>       * timeout to the normal (much longer) poll interval before the
>>>       * timer triggers.
>>>       */
>>> -    qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 10);
>>> +    pty_chr_rearm_timer(chr, 10);
>>>  }
>>>
>>>  static void pty_chr_state(CharDriverState *chr, int connected)
>>> @@ -1080,7 +1118,7 @@ static void pty_chr_state(CharDriverState *chr, int 
>>> connected)
>>>          /* (re-)connect poll interval for idle guests: once per second.
>>>           * We check more frequently in case the guests sends data to
>>>           * the virtual device linked to our pty. */
>>> -        qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 1000);
>>> +        pty_chr_rearm_timer(chr, 1000);
>>>      } else {
>>>          if (!s->connected)
>>>              qemu_chr_generic_open(chr);
>>> @@ -1088,23 +1126,6 @@ static void pty_chr_state(CharDriverState *chr, int 
>>> connected)
>>>      }
>>>  }
>>>
>>> -static void pty_chr_timer(void *opaque)
>>> -{
>>> -    struct CharDriverState *chr = opaque;
>>> -    PtyCharDriver *s = chr->opaque;
>>> -
>>> -    if (s->connected)
>>> -        return;
>>> -    if (s->polling) {
>>> -        /* If we arrive here without polling being cleared due
>>> -         * read returning -EIO, then we are (re-)connected */
>>> -        pty_chr_state(chr, 1);
>>> -        return;
>>> -    }
>>> -
>>> -    /* Next poll ... */
>>> -    pty_chr_update_read_handler(chr);
>>> -}
>>>
>>>  static void pty_chr_close(struct CharDriverState *chr)
>>>  {
>>> @@ -1117,8 +1138,9 @@ static void pty_chr_close(struct CharDriverState *chr)
>>>      fd = g_io_channel_unix_get_fd(s->fd);
>>>      g_io_channel_unref(s->fd);
>>>      close(fd);
>>> -    qemu_del_timer(s->timer);
>>> -    qemu_free_timer(s->timer);
>>> +    if (s->timer_tag) {
>>> +        g_source_remove(s->timer_tag);
>>> +    }
>>>      g_free(s);
>>>      qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
>>>  }
>>> @@ -1170,7 +1192,7 @@ static CharDriverState *qemu_chr_open_pty(QemuOpts 
>>> *opts)
>>>      chr->chr_add_watch = pty_chr_add_watch;
>>>
>>>      s->fd = io_channel_from_fd(master_fd);
>>> -    s->timer = qemu_new_timer_ms(rt_clock, pty_chr_timer, chr);
>>> +    s->timer_tag = 0;
>>>
>>>      return chr;
>>>  }
>>> --
>>> 1.8.1.2
>>>
>>>
>