RFR 8153629: Need to cover JVMTI's GetOwnedMonitorStackDepthInfo function

[serguei.spitsyn at oracle.com]

Hi Daniil,

It is pretty good in general.
Thank you for taking care about it!

Some comments though.

The test case is too trivial.
I'd suggest to extend it to have at least a couple of locks in the 
returned array.
One way to do it would be to add a instance synchronized method and
invoke it from the synchronized statement of the tested Thread.
Then the verifyOwnedMonitors() can be invoked from this method.

A couple of comments on the native agent.

72         // JNI_OnLoad has not been called yet, so can't possibly be an instance of TEST_CLASS.

Could you, please, rewrite this comment?
Maybe just tell that there probably was an error in loading the TEST_CLASS.
What about moving the FindClass(env, TEST_CLASS) to the 
verifyOwnedMonitors() function?
It will make the testClass variable local.

  200                 fprintf(stderr, "VerifyOwnedMonitors: FAIL: stackDepthInfo[0].stack_depth should be 1.\n");

  207         fprintf(stderr, "VerifyOwnedMonitors: FAIL: monitorCount should be 1.\n");


It'd better to rephrase the messages above to tell about actual values 
vs expected.
It normally simplifies the analysis of failures as there is no need to find
what values were printed before and that they are exactly what needed 
for comparison.

Thanks,
Serguei



On 1/11/18 17:45, Daniil Titov wrote:
> Hello,
>
> Please review the following fix that adds a jtreg test for GetOwnedMonitorStackDepthInfo JVMTI function.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8153629
> Webrev: http://cr.openjdk.java.net/~dtitov/8153629/webrev.00
>
>
> The tests ran successfully with Mach5.
>
> Best regards,
> Daniil
>
>