RFR: 7902982: jcstress: Add samples for some mutex algorithms [v3]

[Aleksey Shipilev]

On Tue, 29 Jun 2021 13:36:30 GMT, Michael Mirwaldt <github.com+6693355+mmirwaldt at openjdk.org> wrote:

>> It might be fun to use code block like
>> 
>> 
>>     /* critical_section */ {
>>         taken1 = true;
>>         r.r1 = taken2;
>>         taken1 = false;
>>     }
>
> What about this?
>         taken1 = true; // critical section starts
>         r.r1 = taken2;
>         taken1 = false; // critical section ends

Maybe we should recast the whole thing into atomicity test. This would alleviate any questions about how `taken` fields are actually working. I.e.:


int v;

@Actor 
public void actor1(II_Result r) {
  { // critical section (broken)
    r.r1 = ++v;
  }
}

@Actor 
public void actor2(II_Result r) {
  { // critical section (broken)
     r.r2 = ++v;
  }
}


...then check that `(1, 1)` case is not possible in case of properly working lock.

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PR: https://git.openjdk.java.net/jcstress/pull/85