Any volunteers to review? =)
On 15/10/2018 18:11, Sergey Bylokhov wrote:
Hello.
Please review the fix for jdk 12.
Bug: https://bugs.openjdk.java.net/browse/JDK-8211992
Webrev: http://cr.openjdk.java.net/~serb/8211992/webrev.00
Short description:
The root cause is how we use CoreGraphics display ID. This identifier can
become non-valid at any time therefore methods, which is using this id should
be ready to it. And this bug found a few places which does not take care about
the rule above.
Long description:
In the CGraphicsDevice class we maintain the ID for the native screen. This
ID usually changed when the user adds/removes monitors to the system. Since
using invalid id can cause NULL result in the native code we tries to
workaround it by two steps:
Step (1) If the monitor is removed from the system, then we reassign its
displayid to the primary screen. So if the user will holds the reference to
this GDevice, it will use the MainDisplay. But note that if the user will
remove the main screen again then the old screen, which were removed
previously, will not be updated(but will use an invalid displayid).
Step (2) Some of the native methods in CGraphicsDevice class are ready to
NULL and provide some meaningful defaults, like 72 dpi. But some others methods
are not ready for that, like nativeGetDisplayMode/etc.
Fix description:
- I have minimized/dropped the usage of displayid outside of CGraphicsDevice
class, in CRobot it was unused, and the code from CGraphicsConfig.m was moved
to CGraphicsDevice.m.
- In CGraphicsEnvironment class we now maintain the list of old devices,
which is updated for all _displayReconfiguration events. This is the same
implementation as on windows in Win32GraphicsEnvironment.java
- I have added some default values to all native methods also. Just to cover
the rare case when we call the method and displayid became invalid at the same
moment.
--
Best regards, Sergey.
