RFR (S): 8222534: VerifyBeforeExit is not honored when System.exit is called

[David Holmes]

Thanks Robbin!

David

On 30/04/2019 4:51 pm, Robbin Ehn wrote:
> Hi David, looks good, thanks for fixing!
> 
> /Robbin
> 
> On 2019-04-30 05:54, David Holmes wrote:
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8222534
>> Webrev: http://cr.openjdk.java.net/~dholmes/8222534/webrev/
>>
>> Stefan noticed that VerifyBeforeExit was not honoured when a Java 
>> application terminates via System.exit.
>>
>> Examination of the exit code sequences revealed four differences 
>> between an exit due to the last non-daemon thread terminating (handled 
>> via jni_DestroyJavaVM) and a call to System.exit() (handled via 
>> JVM_Halt()). There are four missing actions on the System.exit() path:
>>
>> - No processing of VerifyBeforeExit
>> - No XML logging before exit
>> - No LogConfiguration::finalize()
>> - No IdealGraphPrinter::clean_up()
>>
>> The first three have now been added at the appropriate point. 
>> VerifyBefore exit was the main omission. The compiler team  (i.e. 
>> Vladimir K.) indicated they'd also like the XML logging. And the 
>> LogConfiguration::finalize while possibly not essential avoids any 
>> doubt as to whether buffered log output may get lost.
>>
>> The IdealGraphPrinter::cleanup was deemed unnecessary due to the fact 
>> the process is being blown away anyway.
>>
>> The bug report contains a lot of details on the exit sequences 
>> including a side-by-side comparison in the attached pdf, showing the 
>> relative positioning of each action and that the correct order has 
>> been maintained.
>>
>> The vm_exit() code affects a number of "abrupt" exit paths in the VM, 
>> not just JVM_Halt, and this is discussed in the bug report as well. In 
>> short the addition of the missing actions should not cause any issues.
>>
>> Testing:
>>   - some manual checking of exit paths and whether new code was executed
>>   - all hotspot/jtreg/gc tests with -XX:+VerifyBeforeExit added
>>   - mach5 tiers 1-3
>>
>> Thanks,
>> David