Hi Rich,
Still can't reply on that thread, but I was able to start this one.
"MVCC history in Clojure's STM is dynamic, created by need. There
is no
read tracking, and more important for this case, no transaction
tracking."
What's the issue with keeping a singly linked list of transactions to
set up object dependencies so that the GC can trim your history list
for you? You only add to the list, it gets GC'd so you don't have to
touch it again. I can get my transaction time-stamp and add to the
list by relying on just 1 AtomicReference CAS. The overhead seems
minimal.
I've had a play with this and the only real issue I've found is that
doing a Thread.sleep(5000) in the middle of a read-only transaction
will cause your histories to become long because values are changed.
But they GC after the transaction finishes. So a badly performing
transaction that blocks may end up using all available memory for
history.
Other than that, letting the GC do the work seems to be a more
efficient and
simpler approach.
I was just curious about the reason you decided to go for the manual
approach, that's all. Maybe there is something I hadn't considered.
Thanks,
Peter
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
