[11u] RFR (S) 8218879: Keep track of memory accesses originated from Unsafe

[Aleksey Shipilev]

On 8/7/19 12:16 PM, Aleksey Shipilev wrote:
>> 11u webrev:
>>   https://cr.openjdk.java.net/~shade/8218879/webrev.11u.01/

Ha, no wait, there is the odd conflict here:

  37 // Use the C1_UNSAFE_ACCESS decorator to mark unsafe accesses.
  38 const DecoratorSet C1_UNSAFE_ACCESS  = DECORATOR_LAST << 3;
  39 // The C1_WRITE_ACCESS decorator is used to mark writing accesses.
  40 const DecoratorSet C1_WRITE_ACCESS   = DECORATOR_LAST << 3;

Notice C1_UNSAFE_ACCESS and C1_WRITE_ACCESS would be mapped to the same constant! This does not
happen in jdk/jdk, because JDK-8209801 have removed (READ|WRITE) accessors. JDK-8209801 does not
look backportable, because it drags in significant part of Access API.

So, the alternative is to push C1_UNSAFE_ACCESS to other index:
  http://cr.openjdk.java.net/~shade/8218879/webrev.11u.02/

Testing: tier1

-- 
Thanks,
-Aleksey