RFR(s): 8222327: java_lang_Thread _thread_status_offset, remove pre 1.5 code paths

[Robbin Ehn]

Hi David,

On 4/16/19 10:27 AM, David Holmes wrote:
> Hi Robbin,
> 
> On 16/04/2019 6:17 pm, Robbin Ehn wrote:
>> Hi Claes and David,
>>
>> Here is v2:
>> http://cr.openjdk.java.net/~rehn/8222327/v2/
> 
> This is missing any check that the offsets are always initialized before use. 
> Can you guarantee none of these will be used in such a case? If so asserts at 
> least would be good.

The other ones don't have assert.

1698 bool java_lang_Thread::is_daemon(oop java_thread) {
1699   return java_thread->bool_field(_daemon_offset) != 0;
1700 }
1701
1702
1703 void java_lang_Thread::set_daemon(oop java_thread) {
1704   java_thread->bool_field_put(_daemon_offset, true);
1705 }

> 
>    oop java_lang_Thread::park_blocker(oop java_thread) {
> !   assert(JDK_Version::current().supports_thread_park_blocker(),
> !          "Must support parkBlocker field");
> 
> This assert can be removed as can JDK_Version::supports_thread_park_blocker() 
> and possibly other stuff, as they also represent pre-1.5 code paths.

Yes, I know, but this is part of the JDK_Version API, which means I get a load 
of collateral changes. And I did not want to do cleanup JDK_Version in this patch.

 From other mail:
 >If the offset is not initialized you will now crash (most likely) instead of 
 >getting a zero etc. This would only be a potential issue during VM 
 >initialization, and possibly only on initialization failures which makes this 
 >very hard to test.

But the other ones don't have assert so that is the case today.

Thanks, Robbin


> 
> Thanks,
> David
> -----
> 
>> Inc:
>> http://cr.openjdk.java.net/~rehn/8222327/v2/inc/
>>
>> Passed t1-2.
>>
>> Thanks, Robbin
>>
>> On 4/15/19 11:04 AM, Robbin Ehn wrote:
>>> Hi all, please review.
>>>
>>> Removing some dead code.
>>>
>>> Code:
>>> http://cr.openjdk.java.net/~rehn/8222327/webrev/
>>> Issue:
>>> https://bugs.openjdk.java.net/browse/JDK-8222327
>>>
>>> Passes t1-5.
>>>
>>> Thanks, Robbin