RFR: 8319799: Recursive lightweight locking: x86 implementation [v2]

Mon Nov 13 10:45:13 UTC 2023

On Fri, 10 Nov 2023 14:55:00 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

>> Axel Boldt-Christmas has updated the pull request incrementally with three additional commits since the last revision:
>> 
>>  - Fix type
>>  - Move inflated check in fast_locked
>>  - Move top load
>
> src/hotspot/cpu/x86/c2_CodeStubs_x86.cpp line 123:
> 
>> 121:     __ movptr(Address(monitor, OM_OFFSET_NO_MONITOR_VALUE_TAG(owner)), _thread);
>> 122: 
>> 123:     // succsesor null check.
> 
> typo: succsesor -> successor

Done.

> src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp line 971:
> 
>> 969: 
>> 970:     // Check if lock-stack is full.
>> 971:     cmpl(Address(thread, JavaThread::lock_stack_top_offset()), LockStack::end_offset() - 1);
> 
> I believe you can mov the movl(top, Address(thread, JavaThread::lock_stack_top_offset())) here, and use top in both checks.

Done.

> src/hotspot/cpu/x86/macroAssembler_x86.cpp line 9817:
> 
>> 9815: 
>> 9816:   // Check if the lock-stack is full.
>> 9817:   cmpl(Address(thread, JavaThread::lock_stack_top_offset()), LockStack::end_offset());
> 
> I believe you can mov the movl(top, Address(thread, JavaThread::lock_stack_top_offset())) here, and use top in both checks.

Done.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/16607#discussion_r1390939354
PR Review Comment: https://git.openjdk.org/jdk/pull/16607#discussion_r1390938003
PR Review Comment: https://git.openjdk.org/jdk/pull/16607#discussion_r1390937811