Testing hotspot's Atomic::cmpxchg(jbyte*) ?
david.holmes at oracle.com
Fri Aug 19 05:15:16 UTC 2016
No I didn't send this to the wrong mailing list :)
I need to test the jbyte version of Atomic::cmpxchg in the VM, but so
far it doesn't seem to be the case that any library code will actually
invoke it. At the top Java level there is no AtomicByte class. Unsafe
defines compareAndSwapByte variants but implements them using
compareAndSwapInt and isolating the byte of interest. VarHandles seems
to have direct *SwapByte operations but I can't figure out what they map
to - there are VM intrinsics but again I can't the actual implementation
to see if it uses Atomic::cmpxchg(jbyte*).
So can someone (Aleksey?, Paul? :) ) tell me if this code does get used,
and if not what I need to change to make it get used. And then what
tests exist to exercise this?
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