RFR(S): 8191229: serviceability/jvmti/GetOwnedMonitorInfo/GetOwnedMonitorInfoTest.java fails with NoClassDefFoundError

[David Holmes]

Hi Chris,

On 7/12/2017 8:38 AM, Chris Plummer wrote:
> Hello,
> 
> Please review the following:
> 
> https://bugs.openjdk.java.net/browse/JDK-8191229
> http://cr.openjdk.java.net/~cjplummer/8191229/webrev.00/

I expected to see the initialization done in JNI_OnLoad, not in a new 
init() method.

David
-----

> The test is testing contended monitor support. After registering the 
> callback, it gets an unexpected notification of a contended monitor, 
> which is happening while the finalizer thread is running. In the 
> callback the test does a FindClass to find a test class, but the 
> classloader context is not correct when the finalizer thread is current, 
> so FindClass fails and leaves an exception pending (probably blowing 
> away the finalzer thread) and also (separately) causes the test to fail. 
> It's unknown why this callback is suddenly being triggered, but the 
> callback itself is not a bug, and the test needs to defend against it.
> 
> The fix is to lookup the test class during test initialization and keep 
> it cached, rather than look it up every time there is a contended 
> monitor callback.
> 
> thanks,
> 
> Chris