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

[Chris Plummer]

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)
>