[Spice-devel] [PATCH spice-gtk 2/2] clipboard: do not release between remote grabs
Marc-André Lureau
marcandre.lureau at gmail.com
Sun Mar 24 18:45:05 UTC 2019
Hi
On Sun, Mar 24, 2019 at 6:49 PM Jakub Janku <jjanku at redhat.com> wrote:
>
> Hi,
>
> On Thu, Mar 21, 2019 at 1:21 PM <marcandre.lureau at redhat.com> wrote:
> >
> > From: Marc-André Lureau <marcandre.lureau at redhat.com>
> >
> > Delay the release events for 0.5 sec. If no further grab comes in,
> > then release the grab. Otherwise, let's skip the release. This avoids
> > some races with clipboard managers.
> >
> > Related to:
> > https://gitlab.freedesktop.org/spice/spice-gtk/issues/82
> >
> > Signed-off-by: Marc-André Lureau <marcandre.lureau at redhat.com>
>
> In the 0.5 second period, any requests from apps in the client for
> clipboard data should be ignored since the vdagent can't provide the
> data any more, so we shouldn't request it.
> So I would add a condition to clipboard_get():
> if (s->clipboard_release_delay[selection]) {
> SPICE_DEBUG("...");
> return;
> }
yes, thanks
> > ---
> > src/spice-gtk-session.c | 80 ++++++++++++++++++++++++++++++++++++-----
> > 1 file changed, 72 insertions(+), 8 deletions(-)
> >
> > diff --git a/src/spice-gtk-session.c b/src/spice-gtk-session.c
> > index 0e748b6..d73a44b 100644
> > --- a/src/spice-gtk-session.c
> > +++ b/src/spice-gtk-session.c
> > @@ -59,6 +59,7 @@ struct _SpiceGtkSessionPrivate {
> > gboolean clip_hasdata[CLIPBOARD_LAST];
> > gboolean clip_grabbed[CLIPBOARD_LAST];
> > gboolean clipboard_by_guest[CLIPBOARD_LAST];
> > + guint clipboard_release_delay[CLIPBOARD_LAST];
> > /* auto-usbredir related */
> > gboolean auto_usbredir_enable;
> > int auto_usbredir_reqs;
> > @@ -95,6 +96,7 @@ struct _SpiceGtkSessionPrivate {
> >
> > /* ------------------------------------------------------------------ */
> > /* Prototypes for private functions */
> > +static void clipboard_release(SpiceGtkSession *self, guint selection);
> > static void clipboard_owner_change(GtkClipboard *clipboard,
> > GdkEventOwnerChange *event,
> > gpointer user_data);
> > @@ -247,6 +249,23 @@ static void spice_gtk_session_dispose(GObject *gobject)
> > G_OBJECT_CLASS(spice_gtk_session_parent_class)->dispose(gobject);
> > }
> >
> > +static void clipboard_release_delay_remove(SpiceGtkSession *self, guint selection,
> > + gboolean release_if_delayed)
> > +{
> > + SpiceGtkSessionPrivate *s = self->priv;
> > +
> > + if (!s->clipboard_release_delay[selection])
> > + return;
> > +
> > + if (release_if_delayed) {
> > + SPICE_DEBUG("delayed clipboard release, sel:%u", selection);
> > + clipboard_release(self, selection);
> > + }
> > +
> > + g_source_remove(s->clipboard_release_delay[selection]);
> > + s->clipboard_release_delay[selection] = 0;
> > +}
> > +
> > static void spice_gtk_session_finalize(GObject *gobject)
> > {
> > SpiceGtkSession *self = SPICE_GTK_SESSION(gobject);
> > @@ -256,6 +275,7 @@ static void spice_gtk_session_finalize(GObject *gobject)
> > /* release stuff */
> > for (i = 0; i < CLIPBOARD_LAST; ++i) {
> > g_clear_pointer(&s->clip_targets[i], g_free);
> > + clipboard_release_delay_remove(self, i, true);
> > }
> >
> > /* Chain up to the parent class */
> > @@ -815,6 +835,8 @@ static gboolean clipboard_grab(SpiceMainChannel *main, guint selection,
> > int m, n;
> > int num_targets = 0;
> >
> > + clipboard_release_delay_remove(self, selection, false);
> > +
> > cb = get_clipboard_from_selection(s, selection);
> > g_return_val_if_fail(cb != NULL, FALSE);
> >
> > @@ -1044,17 +1066,12 @@ static gboolean clipboard_request(SpiceMainChannel *main, guint selection,
> > return TRUE;
> > }
> >
> > -static void clipboard_release(SpiceMainChannel *main, guint selection,
> > - gpointer user_data)
> > +static void clipboard_release(SpiceGtkSession *self, guint selection)
> > {
> > - g_return_if_fail(SPICE_IS_GTK_SESSION(user_data));
> > -
> > - SpiceGtkSession *self = user_data;
> > SpiceGtkSessionPrivate *s = self->priv;
> > GtkClipboard* clipboard = get_clipboard_from_selection(s, selection);
> >
> > - if (!clipboard)
> > - return;
> > + g_return_if_fail(clipboard != NULL);
> >
> > s->nclip_targets[selection] = 0;
> >
> > @@ -1064,6 +1081,53 @@ static void clipboard_release(SpiceMainChannel *main, guint selection,
> > s->clipboard_by_guest[selection] = FALSE;
> > }
> >
> > +typedef struct SpiceGtkClipboardRelease {
> > + SpiceGtkSession *self;
> > + guint selection;
> > +} SpiceGtkClipboardRelease;
> > +
> > +static gboolean clipboard_release_timeout(gpointer user_data)
> > +{
> > + SpiceGtkClipboardRelease *rel = user_data;
> > +
> > + clipboard_release_delay_remove(rel->self, rel->selection, true);
> > +
> > + return G_SOURCE_REMOVE;
> > +}
> > +
> > +/*
> > + * The agents send release between two grabs. This may trigger
> > + * clipboard managers trying to grab the clipboard. We end up with two
> > + * sides, client and remote, racing for the clipboard grab, and
> > + * believing each other is the owner.
> > + *
> > + * Workaround this problem by delaying the release event by 0.5 sec.
> > + * FIXME: protocol change to solve the conflict and set client priority.
> > + */
> > +#define CLIPBOARD_RELEASE_DELAY 500 /* ms */
> > +
> > +static void clipboard_release_delay(SpiceMainChannel *main, guint selection,
> > + gpointer user_data)
> > +{
> > + SpiceGtkSession *self = SPICE_GTK_SESSION(user_data);
> > + SpiceGtkSessionPrivate *s = self->priv;
> > + GtkClipboard* clipboard = get_clipboard_from_selection(s, selection);
> > + SpiceGtkClipboardRelease *rel;
> > +
> > + if (!clipboard)
> > + return;
> > +
> > + clipboard_release_delay_remove(self, selection, true);
> > +
> > + rel = g_new0(SpiceGtkClipboardRelease, 1);
> > + rel->self = self;
> > + rel->selection = selection;
> > + s->clipboard_release_delay[selection] =
> > + g_timeout_add_full(G_PRIORITY_DEFAULT, CLIPBOARD_RELEASE_DELAY,
> > + clipboard_release_timeout, rel, g_free);
> > +
> > +}
> > +
> > static void channel_new(SpiceSession *session, SpiceChannel *channel,
> > gpointer user_data)
> > {
> > @@ -1080,7 +1144,7 @@ static void channel_new(SpiceSession *session, SpiceChannel *channel,
> > g_signal_connect(channel, "main-clipboard-selection-request",
> > G_CALLBACK(clipboard_request), self);
> > g_signal_connect(channel, "main-clipboard-selection-release",
> > - G_CALLBACK(clipboard_release), self);
> > + G_CALLBACK(clipboard_release_delay), self);
>
> I find the naming you're introducing here rather confusing.
> I wouldn't change the signal handler name to "clipboard_release_delay".
yes, let's not rename it. With
VD_AGENT_CAP_CLIPBOARD_NO_RELEASE_ON_REGRAB implementation, it won't
be delayed either.
> What about using the word "pending" instead of "delay"?
> So:
> clipboard_release_delay --> clipboard_release_pending
Delay or pending doesn't make much difference to me.
> clipboard_release_delay_remove --> clipboard_release_pending_clear
Again I don't care much. I prefer "remove", since that's the term used
for GSources. But if you feel strongly about "clear", that works for
me too.
>
> > }
> > if (SPICE_IS_INPUTS_CHANNEL(channel)) {
> > spice_g_signal_connect_object(channel, "inputs-modifiers",
> > --
> > 2.21.0.4.g36eb1cb9cf
> >
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--
Marc-André Lureau
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