RFR (S): 8033380: Experimental VM flag to enforce access atomicity (original) (raw)

Dean Long dean.long at oracle.com
Tue Feb 11 13:08:19 PST 2014

It looks to me that C2 will only look at the atomic flag for longs, not doubles, so if you need atomic access to doubles, I think more work needs to be done.

dl

On 2/11/2014 3:02 AM, Aleksey Shipilev wrote:

Hi,

I understand we are still closed for integration? Please review this small feature meanwhile: https://bugs.openjdk.java.net/browse/JDK-8033380 http://cr.openjdk.java.net/~shade/8033380/webrev.02/ TL;DR: JMM 9 may need to extend the access atomicity over longs and doubles. Luckily, our logic in emitting the relevant access-atomic instructions is decoupled from memory barriers logic, and so we can "just" unconditionally go through needsatomicaccess where appropriate. Testing: - full cycle JPRT - targeted microbenchmarks on x86/ARM/PPC Thanks, -Aleksey

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