aarch64: Concurrent class unloading, nmethod barriers, ZGC

[Andrew Haley]

On 1/9/20 4:02 PM, Stuart Monteith wrote:
> Thank you Andrew, that compiles and runs without error - the
> deoptimize method is definitely being provoked. and continues without
> apparent problems.
> 
> I've been trying to insert constants, and the issue you mention is
> tripped when we enter a native method wrapper. Eric can perhaps
> correct me, but I presume we might have to deoptimise a native method
> if it was overriding a JIT-compiled method and it is subsequently been
> unloaded.

OK, so we can stick with a field in nmethod. It is probably more economical
on space anyway.

You should be able to use adr(rscratch1, InternalAddress(nmethod field));

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671