[concurrency-interest] question the about the JMM

Larry Riedel larryr at saturn.sdsu.edu
Thu Dec 6 20:27:39 EST 2007


> > If "x" is volatile though, I would expect the cache
> > coherence protocol to make sure r3==1 if r2==1.
> 
> The cache coherence protocol knows nothing about "volatile".

Then I think "The cache coherence protocol" may not
be a good choice for use as a cache coherence protocol
in a model for the behavior of a Java program.


> [...] My system (like most) uses a write-through cache [...]

Then I think the cache in "My system" may not be
a good choice for use as the cache in a model for
the behavior of a Java program.


> [...] "cache coherence" doesn't address reorderings
> that the runtime compiler is allowed to do.

Is there a canonical or ubiquitous example of this?  I
am interested in the difficulties with using a model
which includes, for example, a simple object cache
coherence protocol based on a distributed directory.


Larry



More information about the Concurrency-interest mailing list