RFR 8189208: Cleanup ancient argument processing code

[David Holmes]

On 3/05/2019 5:09 am, Harold Seigel wrote:
> Hi Gerard,
> 
> I don't think you can remove the post_vm_init_hook support in 
> thread.cpp.  It is still being used.

Right. When I said remove all the "post_vm_init_hook_enabled code" I 
meant only in relation to the flag itself - which is always "true". The 
hook itself must be called.

Otherwise additional changes seem fine.

Thanks,
David

> Harold
> 
> On 5/2/2019 2:34 PM, gerard ziemski wrote:
>> Thank you Claes, Harold, David for your reviews!
>>
>>
>> On 5/1/19 5:27 PM, David Holmes wrote:
>>> Hi Gerard,
>>>
>>> Mostly looks good - a couple of comments below.
>>>
>>> On 2/05/2019 1:45 am, gerard ziemski wrote:
>>>> Hi all,
>>>>
>>>> Please review this fix, which:
>>>>
>>>> #1 removes overriding of “UseLinuxPosixThreadCPUClocks” to different 
>>>> default values in older JDKs
>>>> #2 removes checks for “supports_thread_park_blocker” and all of the 
>>>> supporting code
>>>
>>> src/hotspot/share/include/jvm.h
>>>
>>> -     unsigned int reserved2;
>>> +     unsigned int reserved2 : 2;
>>>
>>> This change seems wrong to me. reserved2 is a full size int (I don't 
>>> know why this struct has been laid out this way but it has). To 
>>> handle the deleted _thread_park_blocker field you can either:
>>>
>>> a) don't delete it but rename it to unused_slot; or
>>> b) change the following "unsigned int : 29;" to "unsigned int : 30;" 
>>> to take up the extra bit.
>>
>> Fixed.
>>
>>
>>>
>>> Also note that the entire comment block from line 1284 can be deleted.
>>>
>>> As a follow up we should also remove all the 
>>> post_vm_init_hook_enabled code and pending_list_uses_discovered_field 
>>> code.
>>
>> Since I had to put in the above fix, I decided to also remove 
>> "post_vm_init_hook_enabled" and "pending_list_uses_discovered_field" 
>> code as you pointed out.
>>
>>
>>> Or more generally cleanup all the legacy code in JDK_Version that was 
>>> there to allow different JDKs to run on different versions of hotspot 
>>> (eg dll_lookup of JDK_GetVersionInfo0).
>>
>> I will handle that in a followup 
>> https://bugs.openjdk.java.net/browse/JDK-8223261
>>
>>
>>>
>>> Minor nit in threadService.cpp
>>>
>>>     // Support for JSR-166 locks
>>> !   if (_thread_status == java_lang_Thread::PARKED ||
>>> !          _thread_status == java_lang_Thread::PARKED_TIMED) {
>>>
>>> Please fix the indent so _thread_status line up. (The original code 
>>> wasn't correctly indented.)
>>
>> Fixed, following the existing style.
>>
>> New webrev: http://cr.openjdk.java.net/~gziemski/8189208_rev2
>>
>>
>> Cheers
>>
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8189208
>>>> Web rev: http://cr.openjdk.java.net/~gziemski/8189208_rev1
>>>> Tested with Mach5 tier1,2,3, another Mach5 tier1,2,3,4,5 in progress…