MemberName$Factory.resolve() and the Eclipse debugger.

[MacGregor, Duncan (GE Energy Management)]

https://bugs.eclipse.org/bugs/show_bug.cgi?id=449791


On 18/11/2014 14:06, "Marcus Lagergren" <marcus.lagergren at oracle.com>
wrote:

>Nicely done, Duncan. Do you have a link to the issue report?
>
>Regards
>Marcus
>
>> On 03 Nov 2014, at 16:48, MacGregor, Duncan (GE Energy Management)
>><duncan.macgregor at ge.com> wrote:
>> 
>> I’ve reported an Eclipse bug. Doesn’t look like their debugger has ever
>> done quite the right thing, unless the behaviour of the JVM has changed
>> significantly.
>> 
>> On 03/11/2014 15:33, "Christian Thalinger"
>> <christian.thalinger at oracle.com> wrote:
>> 
>>> Interesting.  Thanks for digging deep.
>>> 
>>>> On Oct 31, 2014, at 8:36 AM, MacGregor, Duncan (GE Energy Management)
>>>> <duncan.macgregor at ge.com> wrote:
>>>> 
>>>> Okay, I now know why the JVM is stuck for so long, just not why
>>>>Eclipse
>>>> is
>>>> doing what it does.
>>>> 
>>>> At certain points during the loading of our application Eclipse will
>>>> make
>>>> a large number (upto 10000) jdwp classesForSignature requests, each of
>>>> which causes the jdwp lib to trawl over a large number of classes
>>>> (several
>>>> 10s of thousands), resulting in upto a couple hundred million jvmti
>>>> GetClassSignature calls, and is particularly pointless because it
>>>>fails
>>>> to
>>>> find any of these classes.
>>>> 
>>>> That last bit gave me a clue. These large numbers of
>>>>classesForSignature
>>>> requests occur when classes have been GCed, and a request is being
>>>> issued
>>>> for every single class that has been successfully Gced. Since we¹re
>>>> careful to ensure that all the code we dynamically execute at startup
>>>>is
>>>> done in temporary class loaders so that the everything can be Gced
>>>>away,
>>>> and since variance LF stuff can also be Gced, the problem is much
>>>>worse
>>>> than it would be in other applications.
>>>> 
>>>> It¹s really bad in earlier 8 updates without the LF editor work
>>>>because
>>>> there¹s more classes and more getting Gced, so I¹ve seen 3 minute long
>>>> pauses with that version.
>>>> 
>>>> I guess this should be reported as a bug to the Eclipse debug team,
>>>>but
>>>> I
>>>> wonder if classesForSignature can¹t be made faster in some way.
>>>> 
>>>> Regards, Duncan.
>>>> 
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