[PATCH] test/jdk/java/rmi/transport/runtimeThreadInheritanceLeak/RuntimeThreadInheritanceLeak.java failed in JITed code

[David Holmes]

Hi Jie,

On 11/01/2019 12:44 am, Jie Fu wrote:
> Hi all,
> 
> My name is Jie Fu, a JVM developer at Loongson working on the MIPS port 
> of OpenJDK.
> I hope this is the right place to discuss the issue.
> 
> test/jdk/java/rmi/transport/runtimeThreadInheritanceLeak/RuntimeThreadInheritanceLeak.java 
> failed with "java -Xcomp RuntimeThreadInheritanceLeak".
> 
> The failure was caused by the lost of an OopMap item for "loaderRef" 
> which was optimized out by the JIT with the liveness analysis optimization.
> For more details, see [1].
> 
> It seems that RuntimeThreadInheritanceLeak.java is only suitable for 
> testing interpreters which is not adapted to JITs at all.
> Different behaviors performed by the interpreter and JITs with the same 
> test case really confused us a lot.
> And I think it's worth making the test also suitable for JITs.
> 
> A tiny change can fix this issue
> ---------------------------------
> diff -r 02e648ae46c3 
> test/jdk/java/rmi/transport/runtimeThreadInheritanceLeak/RuntimeThreadInheritanceLeak.java 
> 
> --- 
> a/test/jdk/java/rmi/transport/runtimeThreadInheritanceLeak/RuntimeThreadInheritanceLeak.java 
> Wed Jan 09 01:06:19 2019 +0100
> +++ 
> b/test/jdk/java/rmi/transport/runtimeThreadInheritanceLeak/RuntimeThreadInheritanceLeak.java 
> Thu Jan 10 20:49:22 2019 +0800
> @@ -106,7 +106,10 @@
>                * context class loader-- by giving it a chance to pass away.
>                */
>               Thread.sleep(2000);
> -            System.gc();
> +            while (loaderRef.get() != null) {
> +                System.gc();
> +                Thread.sleep(100);
> +            }
> 
>               System.err.println(
>                   "waiting to be notified of loader being weakly 
> reachable...");
> ---------------------------------
> 
> Could you please review it and tell me if it's OK to file a bug on JBS.
> Thanks.

For hotspot testing we have certain sets of tests that are run under 
-Xcomp, but this is obviously not one of them. Did you discover this by 
chance or because you are attempting to do broad -Xcomp testing? Not 
every test will work with Xcomp (for various reasons) and we aren't 
actively trying to make every test pass with Xcomp.

But by all means file a bug and fix it.

Cheers,
David

> [1] 
> https://github.com/DamonFool/MyBlog/blob/master/JVM/RuntimeThreadInheritanceLeak.md 
> 
> 
> 
> Best Regards,
> Jie
> 
>