RFR: JDK-8074696: Remote debugging session hangs for several minutes when calling findBootType

[serguei.spitsyn at oracle.com]

Hi Andreas,

The fix looks good to me.
Thank you for taking care about this issue!

Thanks,
Serguei


On 10/28/15 05:46, Andreas Eriksson wrote:
> Hi,
>
> Please review this change to JDI to address a performance bottleneck 
> in findBootType for high delay networks.
>
> Bug:
> 8074696: Remote debugging session hangs for several minutes when 
> calling findBootType
> https://bugs.openjdk.java.net/browse/JDK-8074696
>
> Webrev:
> http://cr.openjdk.java.net/~aeriksso/8074696/webrev.01/
>
> Description:
> VirtualMachineImpl.findBootType loops over all loaded classes and does 
> a remote call to check if the signature matches.
> It will wait for the server response for each class before moving on 
> to the next class, thus for many classes and high delay this will take 
> a long time.
>
> Solution:
> Since we have a signature that should match, use 
> retrieveClassesBySignature command that only returns matching classes.
> At worst we have to loop over the number of active classloader since 
> we want the class loaded by the boot classloader (null class loader);
>
> Note:
> This bug was split in two, and this is only for the findBootType part.
> The more problematic visibleClasses change that was part of a previous 
> review will be handled as a separate bug (JDK-8140515).
>
> Regards,
> Andreas