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.
CC: Peter Xu <peterx@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@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
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?
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.
>
> CC: Peter Xu <peterx@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@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
Hi
On Tue, Aug 28, 2018 at 5:52 AM Peter Xu <peterx@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 <peterx@redhat.com>
> > Signed-off-by: Marc-André Lureau <marcandre.lureau@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
On Tue, Aug 28, 2018 at 11:09:28AM +0200, Marc-André Lureau wrote: > Hi > > On Tue, Aug 28, 2018 at 5:52 AM Peter Xu <peterx@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. I did some convertions in the past year to convert tag -> GSource and that shows some differences when we want non-default gcontexts... Otherwise I won't bother. :) > 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) I am not strong on this, but my rule is that if I don't have explicit reason to change a code I keep it there. Here I don't see an obvious reason to switch back to the tag things (not to mention that I still think GSource is better, always). Thanks, -- Peter Xu
Hi On Tue, Aug 28, 2018 at 12:20 PM Peter Xu <peterx@redhat.com> wrote: > > On Tue, Aug 28, 2018 at 11:09:28AM +0200, Marc-André Lureau wrote: > > Hi > > > > On Tue, Aug 28, 2018 at 5:52 AM Peter Xu <peterx@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. > > I did some convertions in the past year to convert tag -> GSource and > that shows some differences when we want non-default gcontexts... > Otherwise I won't bother. :) It doesn't need a specific context here, does it? > > > 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) > > I am not strong on this, but my rule is that if I don't have explicit > reason to change a code I keep it there. Here I don't see an obvious > reason to switch back to the tag things (not to mention that I still > think GSource is better, always). As I explained, you shouldn't use backend fonctions in the frontend, and there is no reason to use the backend context. I try to keep all the sources created around chardev under control, and this one is incorrect imho. Using g_timeout_add() is convenient, since it does all the work you do manually by creating a source, setting callback, attaching, unref etc. And it uses the default context, which is in general the right thing. I can do all the manual work and keep the GSource* around, but I don't think that helps in any way here. > > Thanks, > > -- > Peter Xu -- Marc-André Lureau
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