RFR (S): 8237777 "Dumping core ..." is shown despite claiming that "# No core dump will be written."

gerard ziemski gerard.ziemski at oracle.com
Wed Apr 29 16:39:37 UTC 2020

On 4/24/20 11:44 PM, David Holmes wrote:
> On 25/04/2020 4:02 am, gerard ziemski wrote:
>> On 4/23/20 7:55 PM, David Holmes wrote:
>> [trimmed]
>>> Given that the "Dumping core ..." is only shown in non-product 
>>> builds I think we are way over-thinking/engineering this. We have:
>>>   if (dump_core) {
>>>   ...
>>> #ifndef PRODUCT
>>>     ...
>>>     out.print_raw_cr("Dumping core ...");
>>> #endif
>>>     ::abort(); // dump core
>>>   }
>>> so lets just change one line:
>>>     out.print_raw_cr("Requesting a core dump if possible ...");
>>> otherwise you need one boolean to control whether we call abort vs 
>>> exit, and a second boolean to control what we print.
>>> Or change that one line to:
>>>     out.print_raw_cr("Calling ::abort() ...");
>> Making sure we do not mess up the core creation logic is paramount, 
>> so I like your suggestion to keep it simple, but perhaps we can take 
>> it one small step further and just not bother with that message at all?
>> Maybe we should simply remove the line:
>>     out.print_raw_cr("Dumping core ...");
>> completely? After all, we print lots of core dumping related info 
>> anyhow.
> We've been printing
>   Current thread is xxx
>   Dumping core ...
> to the default output stream in non-product builds since day one of 
> this code - literally. Why only non-product and why only for when 
> dump_core is true I have no idea. The whole thing seems somewhat 
> superfluous. I'd suggest either tweaking the second line, or removing 
> it all, rather than just deleting the second line (which gives some 
> additional context to the first).

I gave it some thought, looked at a few Linux distros, and personally 
I'd like to see both of those lines to go away. We already print the 
crashed thread info in the hs_err crash log, even before we get to those 
2 lines, so we're not risking loosing the "current thread" info.

tests:  tested with Mach5 tier-hs1,2,3,4,5

Lastly, I believe that there is still much we can do to improve the core 
file related messages, but that will be covered in JDK-8243196


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