RFR 8189208: Cleanup ancient argument processing code

[Harold Seigel]

Hi Gerard,

I don't think you can remove the post_vm_init_hook support in 
thread.cpp.  It is still being used.

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…