Multi-thread state visibility in Java: is there a way to turn the JVM into the worst case scenario?

Question

Suppose our code has 2 threads (A and B) have a reference to the same instance of this class somewhere:

public class MyValueHolder {

    private int value = 1;
         


        

Answer 1

It would be great to have a Java compiler that would intentionally perform as many weird (but allowed) transfirmations as possible to be able to break thread unsafe code more easily, like Csmith for C. Unfortunately, such a compiler does not exist (as far as I know).

In the meantime, you can try the jcstress library* and exercise your code on several architectures, if possible with weaker memory models (i.e. not x86) to try and break your code:

The Java Concurrency Stress tests (jcstress) is an experimental harness and a suite of tests aid research in the correctness of concurrency support in the JVM, class libraries, and hardware.

But in the end, unfortunately, the only way to prove that a piece of code is 100% correct is code inspection (and I don't know of a static code analysis tool able to detect all race conditions).

_{*I have not used it and I am unclear which of jcstress and the java-concurrency-torture library is more up to date (I would suspect jcstress).}