Due to being a compositor, kwin has to conform to some certain
interfaces. It means a lot of virtual functions and function tables to
integrate with C APIs. Naturally, we not always want to use every
argument in such functions.
Since we get -Wunused-parameter from -Wall, we have to plumb those
unused arguments in order to suppress compiler warnings at the moment.
However, I don't think that extra work is worth it. We cannot change or
alter prototypes in any way to fix the warning the desired way. Q_UNUSED
and similar macros are not good indicators of whether an argument is
used too, we tend to overlook putting or removing those macros. I've
also noticed that Q_UNUSED are not used to guide us with the removal no
longer needed parameters.
Therefore, I think it's worth adding -Wno-unused-parameter compiler
option to stop the compiler producing warnings about unused parameters.
It changes nothing except that we don't need to put Q_UNUSED anymore,
which can be really cumbersome sometimes. Note that it doesn't affect
unused variables, you'll still get a -Wunused-variable compiler warning
if a variable is unused.
Unfortunately, we cannot just simply unset the wl_global's user data.
The compositor still needs to process client requests after the global
has been removed, for example bind requests or the requests that create
new resources.
CCBUG: 435258
Destroying a global leads to a race on the client. If a client binds
at just the wrong moment they will use an invalid ID and cause a
protocol error. The current best thing to do is to announce the removal
then remove the global (and thus the ID) only after a delay. Non-ideal,
but better than nothing.
Pragmatically this affects only:
Blur/Contrast/Slide/Output/OutputDevice
See https://gitlab.freedesktop.org/wayland/wayland/issues/10 for more.
Summary:
Destroying the SlideInterface on the server side before the client has a
chance to cleanup results in a protocol error:
wl_display@1: error 0: invalid object 7
Which would terminate the client. If we would not destroy the resource,
but only delete the SlideInterface it could result in heap-use-after-free.
So just don't do anything, the client needs to cleanup which will result
in the SlideInterface being deleted.
Reviewers: #plasma
Subscribers: plasma-devel
Tags: #plasma
Differential Revision: https://phabricator.kde.org/D1714
Summary:
The destructor was not properly implement. Let's use the generic one
from Resource.
Test case is adjusted to verify that the SlideInterface gets cleaned up.
Reviewers: #plasma
Subscribers: plasma-devel
Tags: #plasma
Differential Revision: https://phabricator.kde.org/D1713
Summary:
Not needed as the dtor of the Resource ensures that the wl_resource
gets destroyed.
Reviewers: #plasma
Subscribers: plasma-devel
Tags: #plasma
Differential Revision: https://phabricator.kde.org/D1680
