Share MethodParameter cache between HandlerMethods [SPR-9748]

[spring-projects-issues]

Patrick Linskey opened SPR-9748 and commented

RequestMappingHandlerAdapter creates a new HandlerMethod for each request. HandlerMethods cache their MethodParameters to avoid costly reflection calls each time annotation stats are needed, but the per-request copy circumvents this cache. This patch explicitly copies the MethodParameter cache from a HandlerMethod and its request-scoped dependents.

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Affects: 3.1.1, 3.1.2, 3.2 M2

Issue Links:

• monitor contention at org.springframework.core.MethodParameter.getParameterAnnotations() [SPR-9298] #13936 monitor contention at org.springframework.core.MethodParameter.getParameterAnnotations() ("is duplicated by")
• NPE in org.springframework.core.MethodParameter.getParameterName (possible race condition) [SPR-12453] #17058 NPE in org.springframework.core.MethodParameter.getParameterName (possible race condition)
• Thread contention in HandlerMethod due to unnecessary BeanFactory.getType call [SPR-12832] #17429 Thread contention in HandlerMethod due to unnecessary BeanFactory.getType call

Referenced from: commits 2295372, 0a877af

1 votes, 3 watchers

[spring-projects-issues]

Patrick Linskey commented

GitHub commit for 3.1.1: pcl@15a9eee
GitHub commit for master: pcl@4939518

Note that this and #14381 both contain edits to HandlerMethod. The GitHub commits above are applied on top of the #14381 patch; applying them out-of-order might take some manual tweaking.

'./gradlew build' succeeds with this patch on master. I'm still trying to figure out how to get 3.1.1 to build on my machine (http://forum.springsource.org/showthread.php?129846-Spring-3-1-1-compilation&p=423733#post423733)

[spring-projects-issues]

Patrick Linskey commented

FYI, this eliminates 2.1% of the CPU burn in my Spring-MVC app.

[spring-projects-issues]

Patrick Linskey commented

On closer inspection, this eliminates 4.2% of the CPU burn.

[spring-projects-issues]

Rossen Stoyanchev commented

This should now be resolved although using a slightly different approach. Here is the commit with the changes. It has also been applied to 3.1.x (and will be in 3.1.3) with a few other changes. Note however that currently there are (unrelated) build failures in both master and 3.1.x, so no snapshots are available yet.

Thanks for raising this issue!

[spring-projects-issues]

Patrick Linskey commented

Looks good... and incidentally, this fix might resolve a follow-on optimization that we noticed around ServletInvocableHandlerMethod. I'll try these out once a snapshot for 3.1.3 is available and see what the impact is. Thanks!