350 if (!isAccelerationEnabled()) {
351 // Ideally there is no need to re-create a software
surface. But
352 // some OSs allow changes to display state at runtime.
Such a
353 // provision would cause mismatch in graphics
configuration of the
354 // display and the surface. Hence we re-create the
software surface
355 // as well.
356 sdBackup = null;
357 sdCurrent = getBackupSurface();
358 }
359 }
It seems that the surface is always recreated when the acceleration is
not enabled. May be it should be only done when the graphics
configuration transform scales are differ from the ones from vImg
graphics configuration?
Thanks,
Alexandr.
On 10/14/2016 1:38 PM, Prahalad Kumar Narayanan wrote:
Hello Everyone
Good day to you.
Request your time in reviewing the fix for-
Bug : JDK-8165212
Title : VolatileImage should not be compatible with
GraphicsConfiguration which transform is changed
Description on the bug-
. As per the bug, Volatile Image's graphics configuration is
not updated when the host machine display's DPI is changed at runtime
(while still running the java app). In addition, the method
contentsLost() does not return true when display’s DPI is modified.
. It is important to note that, the issue is not reproducible
with D3D/OpenGL backend. It is reproducible with non-accelerated
Volatile Image.
Root Cause
. A callback method- displayChanged() in
VolatileSurfaceManager.java is invoked when display's settings (DPI)
is modified.
. The callback method, currently, updates the graphics
configuration only for Accelerated volatile image. Graphics
configuration is not updated for non-accelerated system memory based
VolatileImage.
. Until recently, there wasn't any need for updating graphics
configuration for non-accelerated volatileImage. However, Win 8.1 and
above provide feature to dynamically update the DPI setting (without
requiring for log-off/ log-in), which causes the current bug.
Bug Fix
. First, the callback method is modified to update graphics
configuration for non-accelerated volatile image also.
. An update to graphics configuration might require re-creation
of the surface. Especially, when the scale factor is increased. Hence
the system memory based backupSurface is re-created here.
. The above change is followed by change to Validate() API, so
that the backup surface re-creation in displayChanged() method,
correctly returns IMAGE_RESTORED from validate() API. This way, the
code flow for non-accelerated Volatile Images behaves just the same
way as accelerated volatile images.
. Approximately 81 Jtreg test cases (that contained
VolatileImage) were run on win7, linux, and osx. No new regressions
have been found after the modification.
. In addition, a manual test case has been provided to ensure
the proper functioning of the fix
Kindly review the changes and provide your suggestions
Review link: http://cr.openjdk.java.net/~pnarayanan/8165212/webrev.00/
Thank you for your time in review
Have a good day
Prahalad N.
