Hmm… it appears that in removing JavaNativeFoundation from the JDK the name of the run loop was changed from AWTRunLoopMode to javaRunLoopMode.
If that is correct, it is an incompatible change that breaks third party use of JavaNativeFoundation for running code on the main thread. It also sounds like a gratuitous change. > On Jun 27, 2021, at 10:24 AM, Alan Snyder <javali...@cbfiddle.com> wrote: > > I have a program that reliably deadlocks when run on JDK 17, but not on JDK > 16 (although that may be due to timing differences, so it may not imply a new > bug). > > It’s a fairly complicated situation. > > On the AWT thread, my program calls native code that displays a native file > dialog. My Java code sets up a secondary run loop. The native code blocks on > JNFRunLoop performOnMainThread to create the native file dialog. > > The AppKit implementation of the file dialog calls Java to get accessibility > information. This sets up a run loop on the main thread and upcalls to Java. > I presume this posts an AWT event. > > Before the AWT secondary run loop can process the request for accessibility > information, it runs an invocation event (previously posted by a timer) that > calls native code. This native code blocks attempting to perform code on the > main thread using JNFRunLoop. Apparently, this request is never processed and > the AWT thread remains blocked forever. > > If I change this latter native code to perform the main thread operation > without blocking, there is no deadlock and all is fine. > > But I have encountered other deadlocks (not reliably repeatable) where this > option is not available. Therefore, I would like to understand why this > deadlock is happening. > > With run loops on both threads, what would cause the deadlock? > > [Question: does JDK 17 and JNFRunLoop use the same NSString to identify the > java run loop mode? If not, might that matter?] > > I would appreciate any suggestions of what might be going wrong or how to > track it down. > > Alan >
