Question on TemplateCache synchronization

I'm currently analyzing a thread dump from a production environment
where I have 100 threads in waiting on the CacheStorage lock in
TemplateCache:

at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:246)
- waiting to lock <0x27445a20> (a freemarker.cache.MruCacheStorage)
at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:229)
at freemarker.template.Configuration.getTemplate(Configuration.java:487)
at freemarker.template.Configuration.getTemplate(Configuration.java:452)

and one thread actually holding the lock:

at java.lang.Throwable.fillInStackTrace(Native Method)
at java.lang.Throwable.<init>(Throwable.java:196)
at java.lang.Exception.<init>(Exception.java:41)
at javax.naming.NamingException.<init>(NamingException.java:109)
at org.apache.naming.resources.FileDirContext.lookup(FileDirContext.java:208)
at org.apache.naming.resources.ProxyDirContext.lookup(ProxyDirContext.java:294)
at org.apache.catalina.loader.WebappClassLoader.findResourceInternal(WebappClassLoader.java:1891)
at org.apache.catalina.loader.WebappClassLoader.findResource(WebappClassLoader.java:934)
at org.apache.catalina.loader.WebappClassLoader.getResource(WebappClassLoader.java:1069)
at com.jivesoftware.community.util.ChainingClassLoader.getResource(ChainingClassLoader.java:91)
at com.jivesoftware.community.web.struts.JiveClassTemplateLoader.getURL(JiveClassTemplateLoader.java:27)
at freemarker.cache.URLTemplateLoader.findTemplateSource(URLTemplateLoader.java:75)
at freemarker.cache.MultiTemplateLoader.findTemplateSource(MultiTemplateLoader.java:111)
at freemarker.cache.TemplateCache.acquireTemplateSource(TemplateCache.java:520)
at freemarker.cache.TemplateCache.findTemplateSource(TemplateCache.java:510)
at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:315)
- locked <0x27445a20> (a freemarker.cache.MruCacheStorage)
at freemarker.cache.TemplateCache.getTemplate(TemplateCache.java:229)
at freemarker.template.Configuration.getTemplate(Configuration.java:487)
at freemarker.template.Configuration.getTemplate(Configuration.java:452)


Is there really a good reason for synchronizing on the CacheStorage?
>From my reading of the code there might be a small race between
storage.get()l and storage.remove() but I'm not sure it's really worth
synchronizing for. Am I wrong in this statement? If so, can someone
suggest an alternate approach that doesn't require synchronization? In
production we set the templateUpdateDelay to Integer.MAX_VALUE so
basically we should never have to worry about the template changing or
being removed after it's loaded.


Regards,

Bruce Ritchie

-------------------------------------------------------------------------
This SF.net email is sponsored by the 2008 JavaOne(SM) Conference 
Don't miss this year's exciting event. There's still time to save $100. 
Use priority code J8TL2D2. 
http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone