[OpenJDK 2D-Dev] RFR: 8252133 The java/awt/GraphicsDevice/DisplayModes/CycleDMImage.java fails if metal pipeline is active

[Phil Race]

Sergey,

The priority now is to flush outstanding review requests ahead of the skara transition. I should have made that clearer in my email but I think new requests such as this will need to wait. Especially anything that requires some deep thought by a reviewer as we have just one working day left.

-Phil.

> On Aug 29, 2020, at 5:29 PM, Sergey Bylokhov <Sergey.Bylokhov at oracle.com> wrote:
> 
> Hello.
> Please review the fix for jdk/client.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8252133
> Fix: http://cr.openjdk.java.net/~serb/8252133/webrev.00
> 
> This bug easily reproduced by the test in question on the dual video card systems
> when the metal pipeline is active. But it is possible to reproduce it in the OGL
> pipeline as well, but it is required some additional steps.
> 
> 
> Problem description:
>  Our CGraphicsEnvironment maintains the list of active graphics devices. The one
> important feature of this CGraphicsEnvironment is to invalidate the old devices and
> map them to the new devices. For example, if the user got a reference to the device,
> and this device was removed then this reference will refer to the main screen.
> 
> The problem in the current implementation arise when the system has two video cards:
> 1 The user get some GraphicsDevice
> 2 The user sets the full-screen window for this device
> 3 The user change screen resolution for this device
> 4 The resolution of the screen is not changed ->> BUG.
> 
> The problem is that somewhere after step 1 or 2 and before step 3 the macOS decided
> to switch to the discrete video card, but it does not report the old device(integrated VC)
> as removed, because actually no screens were removed.
> 
> Since it was not reported as removed we did not invalidate it and did not map it to the
> new device ->> request to change the screen resolution at step 3 send to some non existed
> deviceID.
> 
> As a fix I suggest to change this logic:
> - Invalidate devices reported by macOS as removed
> - Initialize the main screen
> - Initialize all NEW screens
> 
> To this logic:
> - Ignore devices reported by the macOS as removed
> - Initialize the main screen
> - Initialize all NEW screens
> - Check that the main device is in the list of all NEW devices
> - Invalidate all OLD devices which are not in the list of NEW devices
> 
> 
> -- 
> Best regards, Sergey.