On 29/04/2010 22:52, Sylvain Laurent wrote: > While experimenting with clearing threadlocal in afterExecute, I found out > that tomcat itself use ThreadLocal in hope of improving performance : > - org.apache.catalina.util.DateTool > - org.apache.catalina.valves.AccessLogValve > - org.apache.tomcat.util.http.ServerCookie > - ... > > this is mainly to cache Date formatter or parsers...
Maybe to prevent issues with synchronisation rather than to improve performance? p > Sylvain > > On 29 avr. 2010, at 23:17, Caldarale, Charles R wrote: > >>> From: Sylvain Laurent [mailto:sylvain.laur...@gmail.com] On Behalf Of >>> Sylvain Laurent >>> Subject: Re: Need advice to notify StandardExecutor when a webapp is >>> stopped >>> >>> Furthermore, there is probably some frameworks out there that >>> do save things in ThreadLocals in a manner that does not cause >>> classloader leaks but improve their performance. Cleaning their >>> threadlocals after each request would decrease their performance. >> >> It would seem difficult to achieve any kind of consistent performance >> improvement using ThreadLocal objects in conjunction with a thread pool. If >> the server had a very limited number of webapps and the pool size were >> reasonably small, the webapp could show improvement, but otherwise there's >> little chance of a particular request being processed by a thread that has >> already been enhanced with a ThreadLocal for that webapp. To me, it's much >> cleaner and less disruptive to discard the ThreadLocal objects when a thread >> returns to the pool, rather than making all webapps suffer when any one of >> them is restarted. >> >> This is an area where some byte code modification might be appropriate in a >> container environment, so that the ThreadLocal behavior could be modified to >> be "ContextLocal" instead. >> >> - Chuck >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: dev-h...@tomcat.apache.org >> > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org > For additional commands, e-mail: dev-h...@tomcat.apache.org >
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