RFR 8203174: [Graal] JDI tests fail with Unexpected exception: com.sun.jdi.ObjectCollectedException

[serguei.spitsyn at oracle.com]

We need to understand/formulate what requirements/limits the Graal 
compiler has to follow and then negotiate it with the Compiler team.
I feel it is not a good idea to work around these issues to make the 
tests to pass.
Sorry that I've lost track of the discussion - will need to re-read the 
email thread thoroughly.

Thanks,
Serguei


On 11/9/18 11:42, Chris Plummer wrote:
> This sounds like a general issue with debugging and graal. Debuggers 
> expect to be able to suspend all threads, and then resume just the 
> ones they want to see executed. You're saying there are situations in 
> which the resumed thread will end up blocking on the suspended 
> compiler thread(s).
>
> Chris
>
>
> On 11/9/18 10:19 AM, dean.long at oracle.com wrote:
>> With OSR, a compile can be initiated in a for loop, so I'd say this 
>> is still not safe if the compile can be blocking, which happens if:
>>
>>     bool is_blocking = !directive->BackgroundCompilationOption || 
>> CompileTheWorld || ReplayCompiles;
>>
>> So that probably means the test cannot be run with -Xcomp.
>>
>> dl
>>
>> On 11/8/18 3:12 PM, Daniil Titov wrote:
>>> The proposed fix for this case is to suspend VM while the body of 
>>> the "for" loop (lines 150 - 356) is executed while ensuring that for 
>>> line 151 ( line = pipe.printlln()) VM is temporary resumed ( line 
>>> numbers are given for an original version of 
>>> test/hotspot/jtreg/vmTestbase/nsk/jdi/ArrayType/newInstance/newinstance001.java)
>>
>
>