[rvm-research] soft handshake

I was reading the implementation of
[softHandshake](https://github.com/JikesRVM/JikesRVM/blob/master/rvm/src/org/jikesrvm/scheduler/RVMThread.java#L3766),
and my impression is that this method tells all `softHandshake`
threads to process a yield point on their own pace, assuming all of
them are running java code (`isInJava() == true`).

Is it possible that those threads reaches the yield point at the same
point, and produces a STW? If so, then it would have the same effect
as hard handshake, right? In other words, it's possible that more than
one (mutator) thread is stopped even using soft handshake.


-- 
Best Regards

Yours faithfully
Albert Netymk

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