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https://issues.apache.org/jira/browse/OGNL-20?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13101002#comment-13101002
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Daniel Pitts commented on OGNL-20:
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Simone, I never meant to imply it was Ognl by anyone other than smart people
:-). I'm always suspicious of using custom code over the Java collections
classes (which were also written, and maintained, by very smart people). I'm
suspicious of code *I've* written where I could have used Java collections.
Which is why I was curious about the History. If the reasoning was about
performance or some such, it may no longer be relevant (especially in light of
the concurrency issues).
In any case, it is probably a worthwhile exercise creating a benchmark to
explore the performance characteristics amongst the existing impl, and one
based on using a ConcurrentHashMap and a plain HashMap). My guess is
ConcurrentHashMap scales better, even if it might be slower for the
single-threaded use case. For a "generic" library such as Ognl, allowing the
user the ability to plug in "high concurrent" vs "high throughput" seems like a
useful feature.
> Performance - Replace synchronized blocks with ReentrantReadWriteLock
> ---------------------------------------------------------------------
>
> Key: OGNL-20
> URL: https://issues.apache.org/jira/browse/OGNL-20
> Project: OGNL
> Issue Type: Improvement
> Environment: ALL
> Reporter: Greg Lively
>
> I've noticed a lot of synchronized blocks of code in OGNL. For the most part,
> these synchronized blocks are controlling access to HashMaps, etc. I believe
> this could be done far better using ReentrantReadWriteLocks.
> ReentrantReadWriteLock allows unlimited concurrent access, and single threads
> only for writes. Perfect in an environment where the ratio of reads is far
> higher than writes; which is typically the scenario for caching. Plus the
> access control can be tuned for reads and writes; not just a big
> synchronized{} wrapping a bunch of code.
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