RFR 8247966: runtime/logging/loadLibraryTest/LoadLibraryTest.java failed "RuntimeException: 'Unloaded library with handle' missing from stdout/stderr"
harold.seigel at oracle.com
Wed Jun 24 12:08:32 UTC 2020
On 6/24/2020 12:17 AM, David Holmes wrote:
> 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! :)
> On 24/06/2020 3:45 am, Harold Seigel wrote:
>> 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:
>> 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
More information about the hotspot-runtime-dev