Hi
On Tue, Aug 28, 2018 at 5:52 AM Peter Xu <pet...@redhat.com> wrote:
>
> On Tue, Aug 28, 2018 at 12:23:19AM +0200, Marc-André Lureau wrote:
> > terminal3270 is uses the front-end side of the chardev. It shouldn't
> > create sources from backend side context. Fwiw, send_timing_mark_cb
> > calls qemu_chr_fe_write_all() which should be thread safe.
> >
> > This partially reverts changes from commit
> > 2c716ba1506769c9be2caa02f0f6d6e7c00f4304.
>
> I don't fully understand too on why "It shouldn't create sources from
> backend side context". Could you explain a bit?
A frontend shouldn't use a backend function, and doesn't have to use
the backend gmaincontext.
>
> If you don't want the backend gcontext to be exposed to the frontend,
> IMHO the simplest thing is just to use the NULL gcontext in
> qemu_chr_timeout_add_ms() which is a one-liner change. I don't see
> much point on re-using the GSource tags since IMHO GSource pointer is
> always superior to the old tag system.
Using the tag or the GSource * doesn't change much afaik. Not only
this is not a hot path, but glib gmain code does create the tag on
attach anyway. You may be marginally faster on remove/detach by
avoiding one lookup.
(btw, I think both tag and GSource* are as old)
>
> >
> > CC: Peter Xu <pet...@redhat.com>
> > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> > ---
> > hw/char/terminal3270.c | 15 ++++++---------
> > 1 file changed, 6 insertions(+), 9 deletions(-)
> >
> > diff --git a/hw/char/terminal3270.c b/hw/char/terminal3270.c
> > index e9c45e55b1..35b079d5c4 100644
> > --- a/hw/char/terminal3270.c
> > +++ b/hw/char/terminal3270.c
> > @@ -31,7 +31,7 @@ typedef struct Terminal3270 {
> > uint8_t outv[OUTPUT_BUFFER_SIZE];
> > int in_len;
> > bool handshake_done;
> > - GSource *timer_src;
> > + guint timer_tag;
> > } Terminal3270;
> >
> > #define TYPE_TERMINAL_3270 "x-terminal3270"
> > @@ -47,10 +47,9 @@ static int terminal_can_read(void *opaque)
> >
> > static void terminal_timer_cancel(Terminal3270 *t)
> > {
> > - if (t->timer_src) {
> > - g_source_destroy(t->timer_src);
> > - g_source_unref(t->timer_src);
> > - t->timer_src = NULL;
> > + if (t->timer_tag) {
> > + g_source_remove(t->timer_tag);
> > + t->timer_tag = 0;
> > }
> > }
> >
> > @@ -100,8 +99,7 @@ static void terminal_read(void *opaque, const uint8_t
> > *buf, int size)
> > assert(size <= (INPUT_BUFFER_SIZE - t->in_len));
> >
> > terminal_timer_cancel(t);
> > - t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
> > - send_timing_mark_cb, t);
> > + t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
> > memcpy(&t->inv[t->in_len], buf, size);
> > t->in_len += size;
> > if (t->in_len < 2) {
> > @@ -160,8 +158,7 @@ static void chr_event(void *opaque, int event)
> > * char-socket.c. Once qemu receives the terminal-type of the
> > * client, mark handshake done and trigger everything rolling
> > again.
> > */
> > - t->timer_src = qemu_chr_timeout_add_ms(t->chr.chr, 600 * 1000,
> > - send_timing_mark_cb, t);
> > + t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t);
> > break;
> > case CHR_EVENT_CLOSED:
> > sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END;
> > --
> > 2.18.0.547.g1d89318c48
> >
>
> Regards,
>
> --
> Peter Xu
>
--
Marc-André Lureau
