RFR: ZGC: Simplify the ZPage life cycle

[Erik Österlund]

Hi Per,

Seems like this safe delete business should have a scoped object for 
enabling/disabling the deferred deletes. But let's leave it for now and 
think about that for another day. Looks good!

/Erik

On 2019-03-15 21:28, Per Liden wrote:
> On 03/15/2019 03:08 PM, Per Liden wrote:
>> On 03/14/2019 03:20 PM, Stefan Karlsson wrote:
>>> Hi Per,
>>>
>>> Most of this look good.
>>
>> Thanks for reviewing, Stefan!
>>
>> [...]
>>>> 8220600: ZGC: Delete ZPages using ZSafeDelete
>>>> ---------------------------------------------
>>>> Remove the concept of deferred destruction of detached ZPages, and 
>>>> instead delete ZPages using ZSafeDelete.
>>>>
>>>> https://bugs.openjdk.java.net/browse/JDK-8220600
>>>> http://cr.openjdk.java.net/~pliden/8220600/webrev.0
>>>>
>>>
>>> +  // Do not allow pages to be destroyed
>>> +  _page_allocator.enable_safe_delete();
>>>
>>> +  // Allow pages to be destroyed
>>> +  _page_allocator.disable_safe_delete();
>>>
>>> It sounds weird to disable safe deletes. Maybe rename these 
>>> functions to enable_deferred_deletes/disable_deferred_deletes?
>>
>> I agree, renamed.
>>
>>>
>>> ------
>>>
>>> We also need to use the safe delete mechanism when printing the page 
>>> table. That code gets exercised when run jcmd VM.info.
>>
>> Good point, fixed.
>>
>> Updated affected webrev:
>
> Err, those URLs should be s/dff/diff/ ...
>
>>
>> 8220599: ZGC: Introduce ZSafeDelete
>> -----------------------------------
>> http://cr.openjdk.java.net/~pliden/8220599/webrev.1-dff
>
> http://cr.openjdk.java.net/~pliden/8220599/webrev.1-diff
>
>> http://cr.openjdk.java.net/~pliden/8220599/webrev.1
>>
>>
>> 8220600: ZGC: Delete ZPages using ZSafeDelete
>> ---------------------------------------------
>> http://cr.openjdk.java.net/~pliden/8220600/webrev.1-dff
>
> http://cr.openjdk.java.net/~pliden/8220600/webrev.1-diff
>
>> http://cr.openjdk.java.net/~pliden/8220600/webrev.1
>>
>>
>> 8220601: ZGC: Delete ZNMethodTableEntry arrays using ZSafeDelete
>> ----------------------------------------------------------------
>> http://cr.openjdk.java.net/~pliden/8220601/webrev.1-dff
>
> http://cr.openjdk.java.net/~pliden/8220601/webrev.1-diff
>
>> http://cr.openjdk.java.net/~pliden/8220601/webrev.1
>>
>>
>> /Per