RFR: 8062870: src/share/vm/services/mallocTracker.hpp:64 assert(_count > 0) failed: Negative ,counter

[Coleen Phillimore]

On 11/11/14, 4:10 AM, Aleksey Shipilev wrote:
> On 11.11.2014 05:28, Coleen Phillimore wrote:
>> I've made the change to use right_n_bits and run the NMT tests
>> (including the one that crashed in a loop for a while).
>>
>> open webrev at http://cr.openjdk.java.net/~coleenp/8062870_3/
> Looks good.
>
> What confused me initially is a conceptual impedance: _pos_idx is
> bounded by MAX_BUCKET_LENGTH, and _bucket_idx is bounded by
> MAX_MALLOCSITE_TABLE_SIZE. Notice the mention of "bucket" in both cases.
> So it does not look correct from the first glance, and I had to push
> myself from believing the defined values are not accidentally swapped.
> Granted, you can get used to this oddity, but it only takes a valuable
> space in a brain ;)

Hi Aleksey,

Thanks for the code review.  The MAX_BUCKET_LENGTH concept is used in 
the MallocSiteTable::lookup_or_add function when we add things to the 
hash table for updating counters later.  It makes sense in that 
context.  If I were changing more things in this code, I might be likely 
to make changes to save brain cells.  We have to backport these changes 
to 8u though.

Thanks!
Coleen

>
> -Aleksey.
>