RFR(M,v9): JDK-8059036 : Implement Diagnostic Commands for heap and finalizerinfo
derek.white at oracle.com
Tue May 26 18:43:46 UTC 2015
On 5/26/15 10:16 AM, Dmitry Samersoff wrote:
> Hi Everybody,
> Please review updated webrev -
> printFinalizationQueue now returns and array of Map.Entry<String, int)
> and all formatting is done on VM side.
I looked at the jdk_webrev. Everything looks great except the spacing
looks off in line 124 of Finalizer.java.
My JNI is too rusty to provide a quick opinion on the hotspot_webrev
> On 2015-05-21 02:07, Mandy Chung wrote:
>>> On May 19, 2015, at 11:51 PM, Dmitry Samersoff
>>> <dmitry.samersoff at oracle.com <mailto:dmitry.samersoff at oracle.com>> wrote:
>>> Other alternatives could be to do all hashing/sorting/printing on native
>>> layer i.e. implement printFinalizationQueue inside VM.
>>> Both options has pros and cons - Java based solution requires less JNI
>>> calls and better readable but takes more memory.
>>> It might be better to return an array of Map.Entry<String, int>
>>> objects to VM rather than one huge string.
>> The output and formatting should be done by jcmd. What you really need
>> to get a peek on the finalizer queue and print the histogram. The VM
>> has the heap histogram implementation. Have you considered leveraging
>> 5: 1012 40480 java.lang.ref.Finalizer
>> You can find the registered Finalizer instances. The downside is that
>> icmd -finalizerinfo stops the world. I think it’s not unreasonable for
>> this diagnostic command to be expensive like -heap command.
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