Hello This letter is actually about HARMONY-4965, I just changed a little bit a subject. :)
During my play with SPECjAppServer2004 on OC4J I've found out that we have a way to optimize the class loader. Or in other words currently Lets say we have class loaders CL1 and CL2, and CL2.getParent() == CL1. And lets say we have a class C which is loaded by the CL1 (the parent one). And then we try to load class via the class loader CL2: of course CL2 first of all tries to load it via its parent CL1 and succeed in it. When we try to load class C via CL2 again we will have the same chain of calls: CL2 -> CL1. But if CL2 have support of caching of classes loaded by not itself - the chain can become much shorter - it could end at CL2.findFinishedClass(). For example RI behaves like this. See JIRA's demo. Back to the SPECjAppServer2004 @ OC4J. In this case we have a deeper chain: we have a concrete class which is been searched so deep that we looking for this class in boot strap class path. And this is what we have in steady state of the benchmark. Don't you think it is useless? :) Talking about numbers: my measurements show that we can take up to 20% of burst having this bug fixed. Could some competent guy take a look into this? Thanks Sergey
