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.
