You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@commons.apache.org by "Adrian Crum (Commented) (JIRA)" <ji...@apache.org> on 2011/10/29 12:01:32 UTC
[jira] [Commented] (OGNL-34) OgnlRuntime.getCompiler and
thread-safety.
[ https://issues.apache.org/jira/browse/OGNL-34?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13139169#comment-13139169 ]
Adrian Crum commented on OGNL-34:
---------------------------------
In the code you posted, more than one thread can enter the if block. That is how you get more than one instance of the compiler.
> OgnlRuntime.getCompiler and thread-safety.
> ------------------------------------------
>
> Key: OGNL-34
> URL: https://issues.apache.org/jira/browse/OGNL-34
> Project: OGNL
> Issue Type: Bug
> Reporter: Maurizio Cucchiara
> Priority: Minor
> Labels: concurrency, thread-safety
>
> As you can see, {{getCompiler}} is not thread safe.
> I recently added a new performance benchmark to test its 3d-safety and performance: during my tests I have experienced a fast execution on unsafe version vs the safe one (though every concurrent test instantiated a new compiler).
> I have not yet investigated and I still don't know what can cause running more than one instance of the compiler in the same jvm. If necessary we can consider to make compiler a singleton in order to enforce this concept.
>
> What do you think guys?
> {code}
> public static OgnlExpressionCompiler getCompiler( OgnlContext ognlContext )
> {
> if ( _compiler == null )
> {
> try
> {
> OgnlRuntime.classForName( ognlContext, "javassist.ClassPool" );
> _compiler = new ExpressionCompiler();
> }
> catch ( ClassNotFoundException e )
> {
> throw new IllegalArgumentException(
> "Javassist library is missing in classpath! Please add missed dependency!", e );
> }
> }
> return _compiler;
> }
> {code}
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira