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https://issues.jboss.org/browse/JGRP-2043?page=com.atlassian.jira.plugin....
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Bela Ban commented on JGRP-2043:
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Turns out this is useless: if a {{MethodHandle}} is not _static_, apparently it cannot be
optimized: if we store handles in a map (keyed by magic ID), then performance is about the
same as using a constructor, or reflection.
The onyl fast way I found so far is to create a methd handle _indirectly_ via a lambda,
ie.:
{code:java}
Supplier<? extends Header> supplier;
Header hdr=supplier.get();
{code}
This requires all headers to implement a Creationable interface which returns a supplier.
[1]
https://github.com/belaban/PerfTests/blob/master/src/main/java/org/perfte...
Improve performance of Message#readHeader
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Key: JGRP-2043
URL:
https://issues.jboss.org/browse/JGRP-2043
Project: JGroups
Issue Type: Enhancement
Reporter: Sanne Grinovero
Assignee: Bela Ban
Priority: Minor
Fix For: 4.0
A CPU hot spot highlighed by profiling via JFR:
{noformat}Stack Trace Sample Count Percentage(%)
java.lang.reflect.Constructor.newInstance(Object[]) 71 2.392
java.lang.Class.newInstance() 71 2.392
org.jgroups.Message.readHeader(DataInput) 71 2.392
{noformat}
I'd have expected the reflective constructor to perform well on a recent JVM, but
apparently it's not in this case. A theory is that the {{Class}} type being unknown
makes this code harder to optimise; needs to be looked into.
It might be possible to patch the {{ClassConfigurator}} to provide instances of the
required {{Header}} type rather than returning the class, and optimise that instead.
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