Bug: 5156144
Input channels could leak or simply live longer than they should
in some cases.
1. Monitor channels (used by the pointer location overlay) are never
unregistered, so they would leak.
Added code to handle failures in the receive callback by closing
the input channel.
2. The DragState held onto its input window and application handles
even after the input channel was disposed.
Added code to null these handles out when they are no longer needed.
3. Input channels previously used as input event targets would stick
around until the targets were cleared (usually on the next
event).
Added code to detect when the input dispatcher is in
an idle state and to proactively clear the targets then
to ensure that resources are released promptly.
4. Native input window handles held onto the input channel even
after the input window was removed from the input dispatcher.
Consequently, the input channel would not be disposed until
the input window handle itself was freed. Since the input
window handle is held from managed code, this meant that the
window's input channel could stick around until the next GC.
Refactored the input window handle to separate the properties
(info) and identify (handle) state into different objects.
Then modified the dispatcher to release the properties (info)
when no longer needed, including the input channel.
7. The pointer location overlay does not actually use its
standard input channel, only the monitor input channel.
Added INPUT_FEATURE_NO_INPUT_CHANNEL to allow windows to
request that they not be provided with an input channel
at all.
Improved some of the error handling logic to emit the status
code as part of the exception message.
Change-Id: I01988d4391a70c6678c8b0e936ca051af680b1a5
This change moves the cached window and application input state
into the handle objects themselves. It simplifies the dispatcher
somewhat because it no longer needs to fix up references to
transient InputWindow objects each time the window list is updated.
This change will also make it easier to optimize setInputWindows
to avoid doing a lot of redundant data copying. In principle, only
the modified fields need to be updated. However, for now we
continue to update all fields in unison as before.
It turns out that the input dispatcher was inappropriately retaining
pointers to InputWindow objects within the mWindows InputWindow
vector. This vector is copy-on-write so it is possible and the
item pointers to change if an editing operation is performed on
the vector when it does not exclusively own the underlying
SharedBuffer. This bug was uncovered by a previous change that
replaced calls to clear() and appendVector() with a simple use
of operator= which caused the buffer to be shared. Consequently
after editItemAt was called (which it shouldn't have, actually)
the buffer was copied and the cached InputWindow pointers became
invalid. Oops. This change fixes the problem.
Change-Id: I0a259339a6015fcf9113dc4081a6875e047fd425
This change implements two heuristics.
1. When events are older than 10 seconds, they are dropped.
2. If the application is currently busy processing an event and
the user touches a window belonging to a different application
then we drop the currently queued events so the other application
can start processing the gesture immediately.
Note that the system takes care of synthesizing cancelation events
automatically for any events that it drops.
Added some new handle types to allow the native dispatcher to
indirectly refer to the WindowManager's window state and app window
token. This was done to enable the dispatcher to identify the
application to which each window belongs but it also eliminates
some lookup tables and linear searches through the window list
on each key press.
Bug: 3224911
Change-Id: I9dae8dfe23d195d76865f97011fe2f1d351e2940
