RFR (S): JEP-142: Reduce Cache Contention on Specified Fields (original) (raw)
Doug Lea dl at cs.oswego.edu
Mon Nov 26 16:20:09 PST 2012
- Previous message: RFR (S): JEP-142: Reduce Cache Contention on Specified Fields
- Next message: RFR (S): JEP-142: Reduce Cache Contention on Specified Fields
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
On 11/26/12 14:08, Doug Lea wrote:
I think you should re-write the javadoc ... The Contended.java file and its javadoc in Aleksey's webrev is just a placeholder to get things moving. We expect to solicit reviews in the usual way (mainly on concurrency-interest list) for a version that will make it into JDK8.
The initial javadoc is pasted below; updates will appear in jsr166 CVS viewable at: http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/main/java/util/concurrent/Contended.java?view=log
/**
An annotation expressing that objects and/or their fields are
expected to encounter memory contention, generally in the form of
"false sharing". This annotation serves as a hint that such objects
and fields should reside in locations isolated from those of other
objects or fields. The effects of this annotation will nearly
always add space overhead to programs. Its use is warranted only
when the performance impact of this time/space tradeoff is
intrinsically worthwhile; for example, in concurrent contexts in
which each instance of the annotated object is often accessed by a
different thread.
A {@code @Contended} field annotation may optionally include a
contention group tag. All fields with the same tag are considered
as a group with respect to isolation from other groups. A default
annotation without a tag indicates contention with all other
fields, including other {@code @Contended} ones.
When the annotation is used at the class level, all unannotated
fields of the object are considered to be in the same default
group, separate from any fields that carry their own (possibly
tagged) {@code @Contended} annotations.
Sample Usages. (Forthcoming.)
@since 1.8 */
- Previous message: RFR (S): JEP-142: Reduce Cache Contention on Specified Fields
- Next message: RFR (S): JEP-142: Reduce Cache Contention on Specified Fields
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]