Donnchadh Ó Donnabháin updated FREEMARKER-214:
    Attachment: javacc-7.1.2-diff.txt

> New LookAheadSuccess instance created for each instance of FMParser
> -------------------------------------------------------------------
>                 Key: FREEMARKER-214
>                 URL: https://issues.apache.org/jira/browse/FREEMARKER-214
>             Project: Apache Freemarker
>          Issue Type: Bug
>            Reporter: Donnchadh Ó Donnabháin
>            Priority: Major
>         Attachments: javacc-7.1.2-diff.txt
> Each instance of FMParser creates a new instance of LookAheadSuccess.
> In our case, where we tend to work with a lot of FreeMarker templates (in 
> some cases generating freemarker template as an intermediate representation 
> of a more abstract form), this has had a couple of impacts:
> 1. LookAheadSuccess extends java.lang.Error which adds noise to our Java 
> Flight Recorder recordings, similar to the situation described in 
> [http://hirt.se/blog/?p=1288]
> 2. Each instance fills in a stack trace, causing unnecessary object 
> allocation, given that
> These issues (non-static LookAheadSuccess instance, extending 
> java.lang.Error, populating a stack trace) have been addressed in JavaCC 7 in 
> the following PR
> [https://github.com/javacc/javacc/pull/99/files]
> If it seems reasonable, I would be willing to create a PR to update 
> FreeMarker 2.3 to Java CC 7.x. The unit tests do seem to pass with Java CC 7.
> If upgrading JavaCC is deemed undesirable, the approach used to make the 
> class static in 
> [https://github.com/apache/freemarker/blob/2.3-gae/build.xml#L157] could 
> probably also be used to make the instance final.

This message was sent by Atlassian Jira

Reply via email to