RFR: 8345322: RISC-V: Add concurrent gtests for cmpxchg variants

[Hamlin Li]

On Fri, 6 Dec 2024 12:44:29 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Hi, please consider these additional concurrent tests.
>> 
>> (this will not go into 24)
>> 
>> There are two concurrent counter versions:
>> - Each thread is exclusively responsible for an certain increment steps
>> - Each thread plainly tries to CAS increment by one
>> 
>> I refactored the code, so these concurrent versions can reuse the generated CAS functions.
>> 
>> 
>> [ RUN      ] RiscV.cmpxchg_int64_concurrent_lr_sc_vm
>> [       OK ] RiscV.cmpxchg_int64_concurrent_lr_sc_vm (24 ms)
>> [ RUN      ] RiscV.cmpxchg_int64_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.cmpxchg_int64_concurrent_maybe_zacas_vm (12 ms)
>> [ RUN      ] RiscV.cmpxchg_int32_concurrent_lr_sc_vm
>> [       OK ] RiscV.cmpxchg_int32_concurrent_lr_sc_vm (14 ms)
>> [ RUN      ] RiscV.cmpxchg_int32_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.cmpxchg_int32_concurrent_maybe_zacas_vm (14 ms)
>> [ RUN      ] RiscV.cmpxchg_int16_concurrent_lr_sc_vm
>> [       OK ] RiscV.cmpxchg_int16_concurrent_lr_sc_vm (15 ms)
>> [ RUN      ] RiscV.cmpxchg_int16_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.cmpxchg_int16_concurrent_maybe_zacas_vm (14 ms)
>> [ RUN      ] RiscV.cmpxchg_int8_concurrent_lr_sc_vm
>> [       OK ] RiscV.cmpxchg_int8_concurrent_lr_sc_vm (14 ms)
>> [ RUN      ] RiscV.cmpxchg_int8_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.cmpxchg_int8_concurrent_maybe_zacas_vm (14 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int64_concurrent_lr_sc_vm
>> [       OK ] RiscV.weak_cmpxchg_int64_concurrent_lr_sc_vm (15 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int64_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.weak_cmpxchg_int64_concurrent_maybe_zacas_vm (11 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int32_concurrent_lr_sc_vm
>> [       OK ] RiscV.weak_cmpxchg_int32_concurrent_lr_sc_vm (15 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int32_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.weak_cmpxchg_int32_concurrent_maybe_zacas_vm (12 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int16_concurrent_lr_sc_vm
>> [       OK ] RiscV.weak_cmpxchg_int16_concurrent_lr_sc_vm (13 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int16_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.weak_cmpxchg_int16_concurrent_maybe_zacas_vm (14 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int8_concurrent_lr_sc_vm
>> [       OK ] RiscV.weak_cmpxchg_int8_concurrent_lr_sc_vm (13 ms)
>> [ RUN      ] RiscV.weak_cmpxchg_int8_concurrent_maybe_zacas_vm
>> [       OK ] RiscV.weak_cmpxchg_int8_concurrent_maybe_zacas_vm (15 ms)
>> 
>> 
>> Execute with +UseZacas, and without on BPI-F3.
>> 
>> Thanks, Robbin
>
> test/hotspot/gtest/riscv/test_assembler_riscv.cpp line 279:
> 
>> 277:   int num_threads = 4;
>> 278:   CmpxchgTester<TESTSIZE, ASMSIZE> cmpxchg(0, false); // variant 0, not bool ret
>> 279:   auto incThread = [&](Thread* _current, int _id) {
> 
> By checking the test framework code, seems passed-in `_id` starts from `0` for the first thread in thread group and increment `1` for every other thread?
> It might be good have some comment here to state it explicitly to help read the code in the future.

And same for other `_id`s below.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22574#discussion_r1873278824