[ 
https://issues.apache.org/jira/browse/ARTEMIS-2017?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16573569#comment-16573569
 ] 

ASF GitHub Bot commented on ARTEMIS-2017:
-----------------------------------------

Github user franz1981 commented on a diff in the pull request:

    https://github.com/apache/activemq-artemis/pull/2228#discussion_r208672703
  
    --- Diff: 
artemis-selector/src/main/java/org/apache/activemq/artemis/selector/impl/SelectorParser.java
 ---
    @@ -80,11 +78,15 @@ public static BooleanExpression parse(String sql) 
throws FilterException {
                    StrictParser parser = new StrictParser(new 
StringReader(actual));
                    e = parser.JmsSelector();
                 }
    -            cache.put(sql, e);
    +            synchronized (cache) {
    --- End diff --
    
    @jbertram @michaelandrepearce If it is not an hot path I thing that what 
Justin is suggesting makes totally sense: anyway if we can afford to put guava 
in place I believe that 
https://google.github.io/guava/releases/16.0/api/docs/com/google/common/cache/CacheBuilder.html#maximumSize(long)
 would be a good option too.
    It will scale with a factor specified by the concurrent level specified, 
but it could (I do not remember TBH) introduce some behavioural changes from 
the current impl.
    I understand both @michaelandrepearce and @jbertram opinions so I think 
that the general rule to balance changes vs effectiveness on common case apply 
here: I leave you decide how much this tradeoff apply here...
    I'm honored to be "summoned" :+1: 


> SelectorParser cache not thread-safe
> ------------------------------------
>
>                 Key: ARTEMIS-2017
>                 URL: https://issues.apache.org/jira/browse/ARTEMIS-2017
>             Project: ActiveMQ Artemis
>          Issue Type: Bug
>    Affects Versions: 2.6.2
>            Reporter: Justin Bertram
>            Assignee: Justin Bertram
>            Priority: Major
>             Fix For: 2.7.0, 2.6.3
>
>
> Concurrent usage of {{SelectorParser.parse()}} can cause the {{cache}} to 
> grow past its hard-coded size of 100.  Synchronizing {{put}} operations 
> eliminates this problem.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to