<AWT Dev> [11] Review Request: 8189604 possible hang in sun.awt.shell.Win32ShellFolder2$KnownFolderDefinition::<clinit>

[Sergey Bylokhov]

Hello.
Please review the fix for jdk11.

Bug: https://bugs.openjdk.java.net/browse/JDK-8189604
Webrev: http://cr.openjdk.java.net/~serb/8189604/webrev.00

We have a cyclic dependency in Win32ShellFolder2$KnownFolderDefinition, 
which can cause a deadlock if this class is initialized on "non-COM" thread.

1. - Static initialization of Win32ShellFolder2$KnownFolderDefinition
2. -- Win32ShellFolder2.getLibraries();
3. --- invoke Win32ShellFolder2.loadKnownFolders() on "COM-thread" and wait
4. ---- in the native call 
env->FindClass("sun/awt/shell/Win32ShellFolder2$KnownFolderDefinition");
5. ---- deadlock. because initialization of KnownFolderDefinition was 
blocked at step 3.

In the fix this dependency is broken, so the new class KnownLibraries is 
not depends from its own initialization.


-- 
Best regards, Sergey.