Yes, this saves creating the type and wrapper object altogether, while testing suggest it's only the getResource() == null cases wecommonly seehurting startup in our tests. I'd say let's go with your patch. New webrev: http://cr.openjdk.java.net/~redestad/8057936/webrev.4/ Benchmark referred to in bug (java -jar benchmarks.jar -f 4 -wi 5 -i 10 -p file=classes.jar)show similar benefits (somewhere in the 4-12% range, statistically): Benchmark (file) Mode Samples Score Score error Units baseline: o.o.ClassLoaderBenchmark.loadAll classes.jar avgt 40 0.679 0.037 s/op patched: o.o.ClassLoaderBenchmark.loadAll classes.jar avgt 40 0.598 0.007 s/op /Claes ps. I think lambdas give little or no benefit here, and as Alan points out it could lead to tricky classloading bugs. On 09/10/2014 01:21 PM, Michael McMahon wrote:

or how about just returning a null Class<?> from the privileged block instead of the new result type only in the case where URLClassPath.getResource() returns null? That's the main "normal" case where the resource doesn't exist, I think.

If defineClass() throws an IOException, then that is more likely to be a "genuine" exception

- Michael

diff --git a/src/java.base/share/classes/java/net/URLClassLoader.java b/src/java.base/share/classes/java/net/URLClassLoader.java --- a/src/java.base/share/classes/java/net/URLClassLoader.java +++ b/src/java.base/share/classes/java/net/URLClassLoader.java @@ -356,8 +356,9 @@ protected Class<?> findClass(final String name) throws ClassNotFoundException { + final Class<?> result; try { - return AccessController.doPrivileged( + result = AccessController.doPrivileged( new PrivilegedExceptionAction<Class<?>>() { public Class<?> run() throws ClassNotFoundException { String path = name.replace('.', '/').concat(".class"); @@ -369,13 +370,17 @@ throw new ClassNotFoundException(name, e); } } else { - throw new ClassNotFoundException(name); + return null; } } }, acc); } catch (java.security.PrivilegedActionException pae) { throw (ClassNotFoundException) pae.getException(); } + if (result == null) { + throw new ClassNotFoundException(name); + } + return result; }

/*

On 10/09/14 11:55, Ivan Gerasimov wrote:

...

If a lambda were used instead of an anonymous class, it would save us one line of code :-)

Sincerely yours, Ivan

On 10.09.2014 14:11, Claes Redestad wrote:

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Hi,

please review this simple patch to avoid raising PrivilegedActionExceptions when failing to find a class in URLClassLoader.

bug: https://bugs.openjdk.java.net/browse/JDK-8057936 webrev: http://cr.openjdk.java.net/~redestad/8057936/webrev.2/ /Claes