RFR 8214572: nsk/jvmti/unit/ForceEarlyReturn/earlyretbase should not suspend the thread when the top frame executes JVMCI code

Tue Dec 4 19:40:37 UTC 2018

Hi Daniil,

It looks good in general.
Thank you for the update!

I have some minor comment though.

http://cr.openjdk.java.net/%7Edtitov/8214572/webrev.02/test/hotspot/jtreg/vmTestbase/nsk/share/jvmti/jvmti_tools.h.udiff.html

+/**
+* This method suspends the thread while ensuring the top frame executes 
the test method
+* rather then JVMCI code triggered by invocation counter overflow.
+*/
+int suspendThreadAtMethod(jvmtiEnv *jvmti, jclass cls, jobject thread, 
jmethodID method);

The comment above is not precise as it tells nothing about top frame.

I like this one from implementation:

+ // We need to ensure that the thread is suspended at the right place
+ // when the top frame belongs to the test rather then to JVMCI code.

So, the can be rephrased to something like:

+ // This method makes the thread to be suspended at the right place
+ // when the top frame belongs to the test rather then to JVMCI code.

No need in another webrev if you fix the comment.

Thanks,
Serguei

On 12/4/18 10:24 AM, Daniil Titov wrote:
>
> Hi Serguei and JC,
>
> Thank you for reviewing this change. And many thanks to David and Dean 
> for answering JVMCI questions.
>
> Please review a new version of the fix that moves the most of the new 
> code in a helper method ( as JC suggested) and corrects error 
> messages. I also excluded the changes in 
> test/hotspot/jtreg/ProblemList-graal.txt from this webrev.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8214572
>
> Webrev:http://cr.openjdk.java.net/~dtitov/8214572/webrev.02/ 
> <http://cr.openjdk.java.net/%7Edtitov/8214572/webrev.02/>
>
> Thanks,
>
> --Daniil
>
> *From: *"serguei.spitsyn at oracle.com" <serguei.spitsyn at oracle.com>
> *Date: *Monday, December 3, 2018 at 4:14 PM
> *To: *Daniil Titov <daniil.x.titov at oracle.com>, serviceability-dev 
> <serviceability-dev at openjdk.java.net>
> *Subject: *Re: RFR 8214572: 
> nsk/jvmti/unit/ForceEarlyReturn/earlyretbase should not suspend the 
> thread when the top frame executes JVMCI code
>
> Hi Daniil,
>
> It looks good in general.
>
> I have two comments though.
>
> -vmTestbase/nsk/jvmti/unit/ForceEarlyReturn/earlyretbase/TestDescription.java       
> 8195635   generic-all
>
>   It is not a good idea to remove the test from the ProblemList before 
> the 8195635 is fixed.
>
> 148     if(method == midActiveMethod) {
>   149         printf("<<<<<<<< SuspendThread() is successfully done\n");
> 150     } else {
> 151         printf("Warning: method \"activeMethod\" was missed\n");
> 152         errCode = STATUS_FAILED;
> 153     }
>
>  I'd suggest to tweak the error message to something like:
>    "Failed in the suspThread: was not able to suspend thread with the 
> activeMethod() on top\n");
>
>
> Thanks,
> Serguei
>
> *From: *JC Beyler <jcbeyler at google.com>
> *Date: *Friday, November 30, 2018 at 7:47 PM
> *To: *<daniil.x.titov at oracle.com>
> *Cc: *<serviceability-dev at openjdk.java.net>
> *Subject: *Re: RFR 8214572: 
> nsk/jvmti/unit/ForceEarlyReturn/earlyretbase should not suspend the 
> thread when the top frame executes JVMCI code
>
> Hi Daniil,
>
> The webrev looks good but I have a few comments and questions (if you 
> don't mind :-)):
>
> Comments:
>
>   - You say that normally the test will be removed from the problem 
> list once the two fixes are done but in this webrev, you've already 
> removed it (I can't see the other case so I can't see if it is 
> resolved :-))
>
>   - now that we are in C++ for the tests, could we not declare the 
> variables at their first use instead of doing the pedantic top of the 
> block C style?
>
>   - I feel that this sort of "wait until we are not in JVMCI frames" 
> might happen a lot, maybe we could move that code into a helper method 
> (+ it cleans the method a bit to just concentrate on the rest) and 
> then if needed we can make it public to other tests?
>
> Questions because I'm not familiar with JVMCI consequences so not 
> really comments on the webrev but so that I know:
>
>   - Is it normaly that you can suspend when you are in a JVMCI frame? 
> will/is there not a better way that we could detect that we are in a 
> JVMCI frame? Is it always safe to suspend a JVMCI frame?
>
> Thanks!
>
> Jc
>
>
>
>
> On 11/30/18 19:08, Daniil Titov wrote:
>
>     Please review the change for nsk/jvmti/unit/ForceEarlyReturn/earlyretbase test. The problem here is that before doing an early force return the test doesn't check that the test thread is suspended at a right place where the top frame executes the test method rather than JVMCI code triggered by invocation counter overflow. That results in the early return happens for a wrong method and the test fails.
>
>     The fix changes the test to do resume/suspend in the loop until the target method is executed in the top frame or the loop counter exceeds the limit.
>
>     There is another problem with this test that requires changes on VM side and is currently covered by JDK-8195635:" [Graal] nsk/jvmti/unit/ForceEarlyReturn/earlyretbase crashes with assertion "compilation level out of bounds"".  The test will have to be removed from test/hotspot/jtreg/ProblemList-graal.txt only after both these issues are fixed.
>
>     Bug:https://bugs.openjdk.java.net/browse/JDK-8214572
>
>     Webrev:http://cr.openjdk.java.net/~dtitov/8214572/webrev.01/
>     <http://cr.openjdk.java.net/%7Edtitov/8214572/webrev.01/>  
>
>     Thanks,
>
>     Daniil
>
>
>

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