RFR 8247966: runtime/logging/loadLibraryTest/LoadLibraryTest.java failed "RuntimeException: 'Unloaded library with handle' missing from stdout/stderr"

[David Holmes]

Hi Harold,

This looks good. I had envisaged a simple sleep to keep the main thread 
around for a few seconds longer, but actually being able to detect the 
library must have been unloaded is much neater! :)

Thanks,
David

On 24/06/2020 3:45 am, Harold Seigel wrote:
> Hi,
> 
> Please review this small change to fix logging test 
> LoadLibraryTest.java.  The fix prevents the main thread from terminating 
> before the Cleaner thread has had a chance to unload native library 
> "LoadLibraryClass".  It does this in the following way.
> 
> Java has a restriction that a native library can only be loaded by one 
> class loader.  The JDK is able to implement this restriction by 
> synchronizing access to loading and unloading native libraries.  (See 
> synchronization on static object loadedLibraryNames in 
> jdk/internal/loader/NativeLibraries.java.) So, the code in the test that 
> checks if the class that loaded the native library was unloaded, was 
> changed to try to load the native library.  If it was able to load the 
> native library then it knows that the Cleaner thread has finished 
> unloading the library.  If not, it waits a little and checks again in a 
> polling loop.
> 
> Open Webrev: 
> http://cr.openjdk.java.net/~hseigel/bug_8247966/webrev/index.html
> 
> JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8247966
> 
> The modified test was tested on Linux-x64, Linux-aarch64, Windows, and 
> Mac OS X and run 500+ times using Window-x64 fastdebug builds.
> 
> Thanks, Harold
>