compositor: add weston_client_start()

weston_client_start() is a new wrapper around weston_client_launch(),
that does the process tracking on its own, and logs the process exit
status.

When users of weston_client_start() want to know when the process exits,
they should hook into the wl_client destroy signal. This works for cases
where the client is not expected to disconnect without exiting.

As wl_client destructor and the sigchld handler run in arbitary order,
it is usually difficult for users to maintain both struct weston_process
and a struct wl_client pointer. You would need to wait for both
destructor and handler to have run, before attempting to respawn the
client.

This new function relieves the caller from the burden of maintaining the
struct weston_process, assuming the caller is only interested in client
disconnects.

Cc: Boyan Ding <stu_dby@126.com>
Cc: Derek Foreman <derekf@osg.samsung.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Derek Foreman <derekf@osg.samsung.com>
shell: fix race on desktop-shell exit

The desktop shell plugin registers both a wl_client destroy signal
listener, and a sigchld handler, when launching weston-desktop-shell.
However, nothing guarantees in which order do the wl_client destructor
and the sigchld handler run.

Luckily, the sigchld handler cannot interrupt any code, because we
handle the signal via signalfd, which means it is handled like any event
in the compositor's main event loop.

Still, shell.c has a race, that when lost, can cause a crash, as
described in bug #82957.

If the sigchld handler happens to run first, it will try to launch a new
weston-desktop-shell without removing the destroy listener from the old
wl_client first. This leads to list corruption, that may cause a crash
when the old wl_client gets destroyed.

Simply removing the destroy listener in the sigchld handler is not
enough, because respawning sets shell->child.client pointer, and if
the wl_client destructor runs after, it will reset it to NULL.

OTOH, the wl_client destroy handler cannot reset shell->child.process,
because that would cause the sigchld handler in weston core to not find
the process tracker anymore, and report that an unknown process exited.

Turns out, that to make everything work, we would need to wait for both
the wl_client destructor and the sigchld handler to have run, before
respawn. This gets tricky.

Instead, solve the problem by removing shell->child.process. Use the new
weston_client_start() which automatically creates and manages the struct
weston_process. The shell does not need to know about the process exit,
it only needs to know about the client disconnect. Weston-desktop-shell
will never attempt to reconnect, and it would not work even if it did,
so disconnect is equivalent to weston-desktop-shell exiting.

This should permanently solve the race for weston-desktop-shell.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=82957
Cc: Boyan Ding <stu_dby@126.com>
Cc: Derek Foreman <derekf@osg.samsung.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Derek Foreman <derekf@osg.samsung.com>
compositor: leave no zombie behind

When SIGCHLD fires, we may have more than one zombie to be collected.
Run waitpid() in a loop until no more zombies are found, and clean them
all up.

It looks like the SIGCHLD signalfd does not trigger again for remaining
zombies, so we need the loop.

This works around a crash in text_backend_notified_destroy, which ends
up using stale input_method.client if the sigchld handler is not called.
The crash could be triggered by removing both weston-desktop-shell and
weston-keyboard, so that both would try to respawn and give up, and then
quitting Weston.

Cc: rawoul@gmail.com
Cc: Boyan Ding <stu_dby@126.com>
Cc: Derek Foreman <derekf@osg.samsung.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Derek Foreman <derekf@osg.samsung.com>
simple-shm: remove an unnecessary call of wl_display_get_fd()

Reviewed-by: Nils Chr. Brause <nilschrbrause@gmail.com>
multi-resource: remove an unnecessary call of wl_display_get_fd()

Signed-off-by: Ryo Munakata <ryomnktml@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
simple-egl: fix opaque and 16 bits mode options

In those cases we were writing to the wrong EGL config attribute.

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
desktop-shell: properly set background widget as opaque

Toytoolkit resets the opaque region which was set manually using the
wayland protocol directly, so use the widget API instead.

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
pixman-renderer: free shadow buffer on renderer destruction

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
shell: quit weston, if weston-desktop-shell dies early

If weston-desktop-shell dies soon after launch, or maybe cannot be
executed at all, let weston exit rather than letting the user stare at a
black screen.

But, do not exit weston, if weston-desktop-shell dies later, as the user
may already have apps open, and those apps would likely still function
correctly. This gives the user the opportunity to save his work and
close the apps properly.

This should make one class of "I see only black screen" failures obvious.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
compositor: add a way to change the keyboard locks

This adds a function weston_keyboard_set_locks() which can be used to
change the state of the num lock and the caps locks, changing the leds too.
Only the evdev and libinput backends supports this, since it doesn't make
sense for embedded sessions.

Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
compositor: add an option to set the default numlock value

Add a new "numlock-on" option in the [keyboard] section of weston.ini
which, if set to true, is used to enable the numlock of the keyboards
attached at startup.

Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
xwm: Check whether the seat is NULL when needed in weston_wm_handle_button

XCB and wayland input event handling exists together in xwm, which can
cause problems. weston_wm_handle_button is called via XCB events, while
it calls weston_wm_pick_seat_for_window, which uses info from compositor
(pure wayland). It is also true in setting and removing flags of frames.
Races can happen in between, when resize of moving flag of the frame is
still set while the button has been released, the picked seat will be
NULL in weston_wm_handle_button, causing crash. We can safely ignore
moving or resizing if this happens. The same applies to c06a180d.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=82827
Signed-off-by: Boyan Ding <stu_dby@126.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
pixman-renderer: fail to zoom more gracefully

When zoom is activated in the pixman rendered the log is filled with warnings
and all rendering stops.  With this patch the warning is generated once and
rendering continues without zooming.

Closes bug 80258

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=80258
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
pixman-renderer: copy_to_hw_buffer: don't leak output_region

This was reported by Valgrind.

Signed-off-by: Ryo Munakata <ryomnktml@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
desktop-shell: implement touch popup grabs

Acked-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
xwm: Do not activate override redirect windows

We shouldn't do WM-y things on an O-R window, including setting input
focus to it.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=81273
Signed-off-by: Boyan Ding <stu_dby@126.com>
Tested-by: Ryo Munakata <ryomnktml@gmail.com>
Acked-by: Christopher Michael <cp.michael@samsung.com>
clients: Maximize window when double click on title bar

Signed-off-by: Xiong Zhang <panda0626@gmail.com>
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>