[concurrency-interest] The JSR-133 Cookbook for Compiler Writers

Andrew Haley aph at redhat.com
Tue Nov 22 13:11:17 EST 2011


OK, I see.  So, the only place you'd need this is in the cpu-specific
code, and all the cpu-specific code is on arches that don't need
StoreStore.

Thanks,

Andrew.

On 11/22/2011 03:56 PM, Nathan Reynolds wrote:
> On x86 and Sparc TSO, the StoreStore barrier becomes a no-op.  (See the 
> table in the Multiprocessors section.)  These processors will not allow 
> stores to go before other stores.  Thus, the StoreStore barrier is 
> already enforced for all store operations by the processor.  The only 
> barrier required on x86 and Sparc TSO is the StoreLoad barrier.
> 
> Nathan Reynolds 
> <http://psr.us.oracle.com/wiki/index.php/User:Nathan_Reynolds> | 
> Consulting Member of Technical Staff | 602.333.9091
> Oracle PSR Engineering <http://psr.us.oracle.com/> | Server Technology
> 
> On 11/22/2011 7:40 AM, Andrew Haley wrote:
>> A little mystery:
>>
>> Inserting Barriers
>> ...
>>
>>     2. Issue a StoreStore barrier after all stores but before return
>>     from any constructor for any class with a final field.
>>
>> So, I'm looking for this barrier in the HotSpot code but I have been
>> unable to find it.  Can someone please put me out of my misery and
>> tell me where it is?


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