Fwd: Re: RFR: 8079408: Reimplement TraceClassLoading, TraceClassUnloading, and TraceClassLoaderData with Unified Logging.

[Coleen Phillimore]

Yes, this test looks really good.  Thanks Ioi for figuring out the 
vagaries of jtreg.

Coleen

On 1/28/16 2:29 PM, Max Ockner wrote:
> Forwarded private discussion with Ioi about changing the test to use 
> ClassUnloadCommon.
>
> Hopefully nearing the end:
>
> Webrev: http://cr.openjdk.java.net/~mockner/classload.08/
>
> -------- Original Message --------
> Subject:     Re: RFR: 8079408: Reimplement TraceClassLoading, 
> TraceClassUnloading, and TraceClassLoaderData with Unified Logging.
> Date:     Thu, 28 Jan 2016 10:57:15 -0800
> From:     Ioi Lam <ioi.lam at oracle.com>
> To:     Max Ockner <max.ockner at oracle.com>
>
>
>
> Hi Max,
>
> Thanks for doing this. Also, I sent the e-mail to you personally, so 
> you may want to post the new version in the open list for record purpose.
>
> Thanks
> - Ioi
>
> On 1/28/16 8:11 AM, Max Ockner wrote:
>> Ioi,
>> I have replaced my test with this test that you have given me (thank 
>> you!)
>> I also have removed the commented out section which used to test for 
>> "making nmethod ...", and I have added the comment that you suggested 
>> at the top of ClassUnloadCommon.java
>> Thanks,
>> Max
>> On 1/27/2016 7:13 PM, Ioi Lam wrote:
>>>
>>>
>>> On 1/27/16 12:51 PM, Max Ockner wrote:
>>>> Though Ioi suggested I change my new test, I have not done that. I 
>>>> was recommended to copy from runtime/ClassUnload/UnloadTest.java 
>>>> instead of rolling my own test for class unloading. I mentioned 
>>>> that it was tricky to make the new test work, but it was tricky 
>>>> because I was trying to copy from UnloadTest.java. This test refers 
>>>> to a class "test.Empty" from a "classes" library, but the new test 
>>>> has a processBuilder which I think does not play nicely with the 
>>>> class path for  "test.Empty". In the end it was much easier to 
>>>> hardcode the entire test into one place than to follow 
>>>> UnloadTest.java and refer to extra libraries.
>>>>
>>>
>>> Hi Max,
>>>
>>> I've written a version of ClassLoadUnloadTest.java using 
>>> ClassUnloadCommon. The main trick is here:
>>>
>>>         Collections.addAll(argsList, "-Dtest.classes=" + 
>>> System.getProperty("test.classes","."));
>>>
>>> That's because of this line in ClassUnloadCommon:
>>>
>>>             return new URLClassLoader(new URL[] {
>>> Paths.get(System.getProperty("test.classes",".") + 
>>> File.separatorChar + "classes").toUri().toURL(),
>>>             }, null);
>>>
>>> When Jtreg launches a sub-process, it strips off all the Java system 
>>> properties, so you need to add the "-D" in the command-line.
>>>
>>> I also disabled the test related to "making nmethod ... unloadable". 
>>> As Rachel found out in JDK-8146137, the compiler is unpredictable. 
>>> Even if you invoke a method 10001 times, there's no guaranteed that 
>>> it will always be compiled. Since this is not an 'easy-to-test' 
>>> feature, we should just skip it.
>>>
>>> I would also suggest adding this to the header of 
>>> ClassUnloadCommon.java
>>>
>>> /*
>>>  * To use ClassUnloadCommon from a sub-process, see 
>>> hotspot/test/runtime/logging/ClassLoadUnloadTest.java
>>>  * for an example.
>>>  */
>>>
>>> What do you think?
>>> - Ioi
>>
>
>
>