RFR: 7902982: jcstress: Add samples for some mutex algorithms [v10]

[Vladimir Sitnikov]

On Tue, 29 Jun 2021 15:44:45 GMT, mmirwaldt for openjdk <github.com+86246875+mmirwaldt-openjdk at openjdk.org> wrote:

>> I have implemented 3 more samples:
>> *) the NoAlgorithm sample should show users of JCStress how they can define a critical section in a simple way
>> *) one sample for the Peterson's algorithm 
>> *) one sample for the Dekker's algorithm 
>> I have translated the pseudo code implementations of the English wikipedia articles into Java.
>> I have also tried out those examples: they compile and they run without any problems.
>
> mmirwaldt for openjdk has updated the pull request incrementally with three additional commits since the last revision:
> 
>  - gave state annotation its own line
>  - reorganized the imports
>  - changed the outcomes of the mutex samples

jcstress-samples/src/main/java/org/openjdk/jcstress/samples/concurreny/mutex/Mutex_03_AtomicBoolean.java line 53:

> 51:     @Actor
> 52:     public void actor1(II_Result r) {
> 53:         while(taken.get() || !taken.compareAndSet(false, true)); // spin

Suggestion:

        while(!taken.compareAndSet(false, true)) {
            // wait for entering into the critical section
        }


I think `taken.get()` is not needed here, and adding explicit braces makes it easier to understand that the braces for "critical section" are different ones.

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

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