Server grabs are not as evil as you might expect, but there is agreement
in that their usage should be limited.
Server grabs can cause things to go rather wrong when mutter emits
a signal while it has grabbed the server. If the receiver of that signal
waits for a synchronous action performed by another client, then you
have a deadlock. This happens with Mali binary GLESv2 drivers :(
https://bugzilla.gnome.org/show_bug.cgi?id=721345
The compositor code used to handle X windows that didn't have a
corresponding MetaWindow (see commit d538690b), which is why the
attribute query is separated.
As that doesn't happen any more, we can clean up. No functional changes.
Suggested by Owen Taylor.
https://bugzilla.gnome.org/show_bug.cgi?id=721345
Remove some obvious server grabs from the window creation codepath,
also ones that are taken at startup.
During startup, there is no need to grab: we install the event handlers
before querying for the already-existing windows, so there is no danger
that we will 'lose' some window. We might try to create a window twice
(if it comes back in the original query and then we get an event for it)
but the code is already protected against such conditions.
When windows are created later, we also do not need grabs, we just need
appropriate error checking as the window may be destroyed at any time
(or it may have already been destroyed).
The stack tracker is unaffected here - as it listens to CreateNotify and
DestroyNotify events and responds directly, the internal stack
representation will always be consistent even if the window goes away while
we are processing MapRequest or similar.
https://bugzilla.gnome.org/show_bug.cgi?id=721345
The return code of XGetWindowAttributes() indicates whether an error
was encountered or not. There is no need to specifically check the error
trap.
The trap around XAddToSaveSet() was superfluous. We have a global error
trap to ignore any errors here, and there is no need to XSync() as GDK
will later ignore the error asynchronously if one is raised.
Also move common error exit path to an error label.
https://bugzilla.gnome.org/show_bug.cgi?id=721345
In meta_screen_manage_all_windows() we can use our own stack
tracker to get the list of windows - no need to query X again.
A copy is needed because the stack gets modified as part of the loop.
Specifically, meta_stack_tracker_get_stack() at this time returns the
predicted stack, and meta_window_new() performs a few operations
(e.g. framing) which cause immediate changes to the predicted stack.
https://bugzilla.gnome.org/show_bug.cgi?id=721345
meta_window_ensure_frame() creates its own grab and has a comment
claiming that it must be called under a grab too.
But the reasoning given in the comment does not seem relevant here.
We only frame non-override-redirect windows, so we are creating
the frame in response to MapRequest. There is no way that the child
could receive a MapNotify at this point, since that only happens
much later, once we go through the CALC_SHOWING queue and call
XMapWindow() from meta_window_show().
Remove the unnecessary grab.
https://bugzilla.gnome.org/show_bug.cgi?id=721345
Server grabs are not as evil as you might expect, but there is agreement
in that their usage should be limited.
Server grabs can cause things to go rather wrong when mutter emits
a signal while it has grabbed the server. If the receiver of that signal
waits for a synchronous action performed by another client, then you
have a deadlock. This happens with Mali binary GLESv2 drivers :(
https://bugzilla.gnome.org/show_bug.cgi?id=721345
The compositor code used to handle X windows that didn't have a
corresponding MetaWindow (see commit d538690b), which is why the
attribute query is separated.
As that doesn't happen any more, we can clean up. No functional changes.
Suggested by Owen Taylor.
https://bugzilla.gnome.org/show_bug.cgi?id=721345
As logind can give us a new FD at any time when it resumes. Theoretically,
this is still technically wrong, as the MetaCursorTracker holds onto it.
We'll fix this after we port to logind.
When we move focus elsewhere when unmanaging a window, we *need* to move
the focus, so if the target is globally active, move the focus to the
no-focus-window in anticipation that the focus will normally get moved
to the right window when the target window responds to WM_TAKE_FOCUS.
If the window doesn't respond to WM_TAKE_FOCUS, then focus will be left
on the no-focus-window, but there's no way to distinguish whether the
app will respond or not.
https://bugzilla.gnome.org/show_bug.cgi?id=711618
When we move focus elsewhere when unmanaging a window, we *need* to move
the focus, so if the target is globally active, move the focus to the
no-focus-window in anticipation that the focus will normally get moved
to the right window when the target window responds to WM_TAKE_FOCUS.
If the window doesn't respond to WM_TAKE_FOCUS, then focus will be left
on the no-focus-window, but there's no way to distinguish whether the
app will respond or not.
https://bugzilla.gnome.org/show_bug.cgi?id=711618
When a client spontaneously focuses their window, perhaps in response
to WM_TAKE_FOCUS we'll get a FocusOut/FocusIn pair with same serial.
Updating display->focus_serial in response to FocusOut then was causing
us to ignore FocusIn and think that the focus was not on any window.
We need to distinguish this spontaneous case from the case where we
set the focus ourselves - when we set the focus ourselves, we're careful
to combine the SetFocus with a property change so that we know definitively
what focus events we have already accounted for.
https://bugzilla.gnome.org/show_bug.cgi?id=720558
When a client spontaneously focuses their window, perhaps in response
to WM_TAKE_FOCUS we'll get a FocusOut/FocusIn pair with same serial.
Updating display->focus_serial in response to FocusOut then was causing
us to ignore FocusIn and think that the focus was not on any window.
We need to distinguish this spontaneous case from the case where we
set the focus ourselves - when we set the focus ourselves, we're careful
to combine the SetFocus with a property change so that we know definitively
what focus events we have already accounted for.
https://bugzilla.gnome.org/show_bug.cgi?id=720558
Initial placement during meta_window_constrain() can result in changes
to the borders, so we need to recompute our border sizes after
constraining. This fixes incorrect window borders on
initially maximized windows.
https://bugzilla.gnome.org/show_bug.cgi?id=720417
Initial placement during meta_window_constrain() can result in changes
to the borders, so we need to recompute our border sizes after
constraining. This fixes incorrect window borders on
initially maximized windows.
https://bugzilla.gnome.org/show_bug.cgi?id=720417
Currently the only way to move a window to another monitor via
keyboard is to start a move operation and move it manually using
arrow keys. We do have all the bits of a dedicated keybinding in
place already, so offer it as a more comfortable alternative.
https://bugzilla.gnome.org/show_bug.cgi?id=671054
Currently the only way to move a window to another monitor via
keyboard is to start a move operation and move it manually using
arrow keys. We do have all the bits of a dedicated keybinding in
place already, so offer it as a more comfortable alternative.
https://bugzilla.gnome.org/show_bug.cgi?id=671054
The shadow is added in the paint step, not as a separate actor,
so the raise is a no-op. It also gets rid of an annoying misspelling
that's driving me crazy.
The shadow is added in the paint step, not as a separate actor,
so the raise is a no-op. It also gets rid of an annoying misspelling
that's driving me crazy.
