On Fri, 16 Feb 2024 08:46:10 GMT, Christoph Langer <clan...@openjdk.org> wrote:
>> The assertions reported in the bug were observed spuriously and here and >> there broke tests in some Windows configurations. >> For instance [JDK-8266129](https://bugs.openjdk.org/browse/JDK-8266129), >> [JDK-8269529](https://bugs.openjdk.org/browse/JDK-8269529) or >> [JDK-8323664](https://bugs.openjdk.org/browse/JDK-8323664) came up due to >> this. >> >> The problem is that in Windows environments without a valid display, e.g. >> started by system services or via PowerShell Remoting, one sees a Monitor >> with name 'Windisc' in `EnumDisplayMonitors`. >> However, it seems to be some kind of a pseudo device where you can not get a >> DC via `CreateDC`. This behavior/monitor type doesn't seem to be well >> documented, though. >> >> I hereby modify the device initialization code to only count/detect monitors >> where CreateDC returns non-NULL in Devices.cpp. I also add some more >> checking/error handling to AwtWin32GraphicsDevice::Initialize() for >> correctness. >> >> Furthermore, I re-enable the test >> `javax/swing/reliability/HangDuringStaticInitialization.java` for Windows >> Debug VMs, which reverts the fix from JDK-8269529 that should not be >> necessary any more. > > Christoph Langer has updated the pull request incrementally with one > additional commit since the last revision: > > Little cleanup src/java.desktop/windows/native/libawt/windows/Devices.cpp line 93: > 91: int g_nMonitorCounter; > 92: int g_nMonitorLimit; > 93: HMONITOR* g_hmpMonitors; These global variables — `g_nMonitorCounter`, `g_nMonitorLimit`, `g_hmpMonitors` — could be `static` as well. In fact, they can be encapsulated in the relevant functions which need them by using the last parameter of [`EnumDisplayMonitors`](https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-enumdisplaymonitors). For `CountMonitors`, using `&nMonitorCounter` will be enough; for `CollectMonitors`, the three variables need to be encapsulated in a local structure the pointer to which is passed. However, it's likely not worth the effort… If it works, don't touch it. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/17614#discussion_r1492345167
