On Thu, 7 Dec 2023 03:03:59 GMT, Sergey Bylokhov <s...@openjdk.org> wrote:
> The fix for a regression caused by the > https://bugs.openjdk.org/browse/JDK-6508941. it does not take into account > RPC_E_CHANGED_MODE when COM was already initialized using > COINIT_MULTITHREADED mode. > > @aivanov-jdk please take a look. src/java.desktop/windows/native/libawt/windows/awt_Desktop.cpp line 99: > 97: ::CoUninitialize(); > 98: } > 99: } I'm unsure this is the right thing to do. The documentation for [`ShellExecute`](https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutew) mentions, <q cite="https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutew";>Some Shell extensions require the COM single-threaded apartment (STA) type.</q> I believe this is true for most shell extensions because they deal with UI. At the same time, <q cite="https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutew";>There are certainly instances where `ShellExecute` does not use one of these types of Shell extension and those instances would not require COM to be initialized at all.</q> So, if the current thread initialised COM as MTA, the call to `ShellExecute` would likely fail if it needs COM to perform the requested action as it requires STA in majority of cases. A workaround would be to hand off the task to a special thread, or just fail straight away as the code does right now. Otherwise, the errors could be sporadic and unpredictable: some calls complete successfully whereas others fail. Could this code use [`ComInvoker`](https://github.com/openjdk/jdk/blob/58530f4098538f490cfea58f2382d0997841c171/src/java.desktop/windows/classes/sun/awt/shell/Win32ShellFolderManager2.java#L572) from `Win32ShellFolderManager2`? ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/17010#discussion_r1419118913
