On 12/07/2010 06:40, Jeremy Boynes wrote: > Implementation seems to work but does not provide as much benefit as > expected. Jasper tag pooling does not pool tags with the same attribute > values so the select attribute is set every time causing recompilation. The > time taken to iterate 1000 <x:out> tags drops from around 2800ms to 1800ms.
Providing the same attributes with the same values are present, Jasper should be pooling the tags. There was a bug in this area [1] but it was fixed some time ago. If this isn't the case then please open a Tomcat bug and provide a test case. > To work around this I added a thread-local cache of compiled XPath > expressions. This does reduce the initial time taken for the first few > iterations but the time taken to evaluate the compiled expression grows from > 500us to 2100us toward the end of the loop (measured with nanoTime() around > the call to evaluate). There may be some issue with Xalan; the same behaviour > is seen with Sun's JAXP implementation included in JDK1.6 (which is based on > Xalan). Use of ThreadLocals in this way is almost certainly going to trigger memory leaks on web application reload. > The same slowdown is seen if the expression is evaluated each time, or if the > xpath is run in a standalone testcase outside taglibs entirely. There may be > an issue here with Xalan and/or the JDK. > > We might be advised to consider a different XPath implementation. Does anyone > have any thoughts on Jaxen? Sorry, no idea on this. Mark [1] https://issues.apache.org/bugzilla/show_bug.cgi?id=38197 --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
