db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Dyre.Tjeldv...@Sun.COM
Subject Re: [jira] Commented: (DERBY-2114) Let Clock embed a HashMap rather than inherit from Hashtable
Date Thu, 15 Mar 2007 13:42:29 GMT
"Knut Anders Hatlen (JIRA)" <jira@apache.org> writes:

>     [ https://issues.apache.org/jira/browse/DERBY-2114?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12481114
] 
>
> Knut Anders Hatlen commented on DERBY-2114:
> -------------------------------------------
>
> This is not so much about the implementation of StatementCache. My
> worry is that by requiring the callers of CacheManager.values() to
> synchronize on the CacheManager and hold the synchronization while
> traversing the returned collection, it will be harder to replace
> Clock with another implementation of CacheManager later because the
> interface implicitly dictates how the internal synchronization must
> be implemented. If someone wants to rewrite the cache manager, say,
> to allow threads to enter it concurrently, she couldn't just
> implement the interface and plug in the new implementation since the
> interface required that there was a global synchronization point.

I accept this argument, but there's still nothing preventing any
CacheManager/Clock client from synchronizing on it, so whoever takes
on that rewrite will still have to carefully check that this doesn't
happen. 

-- 
dt


Mime
View raw message