[NEW BUG]: Reduce allocations in sun.reflect.annotation.AnnotationInvocationHandler.invoke()

[Christoph Dreis]

Hey,

 

I'm new to the OpenJDK and not sure (yet) how the procedure especially for
new bugs/enhancement is. So I apologise upfront if I made any mistakes.

 

I'm working mostly with the Spring-Framework/Spring-Boot in my current
projects. In these frameworks a lot of dynamic proxying can happen.
Recently, I noticed that the JDK in versions 8 up to the current snapshots
produces some allocations coming from
sun.reflect.annotation.AnnotationInvocationHandler.invoke() we could avoid
in the majority of cases. Only the check for equality needs the actual
parameter types - all other cases only need the parameter count which JDK 8
luckily provides with Method.getParameterCount().

 

What about changing the current behaviour to something like my attached
proposal? I'd be happy if someone is willing to sponsor this change. Again -
if I made any mistakes here, please let me know for the next time.

 

Cheers,

Christoph Dreis

 

================================

Reduce allocations in
sun.reflect.annotation.AnnotationInvocationHandler.invoke()

 

diff -r ba70dcd8de76 -r 86bbc5442c1d
src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandl
er.java

---
a/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHan
dler.java     Fri Nov 11 13:11:27 2016 +0000

+++
b/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHan
dler.java  Mon Nov 14 19:04:33 2016 +0100

@@ -57,13 +57,13 @@

     public Object invoke(Object proxy, Method method, Object[] args) {

         String member = method.getName();

-        Class<?>[] paramTypes = method.getParameterTypes();

+        int parameterCount = method.getParameterCount();

         // Handle Object and Annotation methods

-        if (member.equals("equals") && paramTypes.length == 1 &&

-            paramTypes[0] == Object.class)

+        if (member.equals("equals") && parameterCount == 1 &&

+            method.getParameterTypes()[0] == Object.class)

             return equalsImpl(proxy, args[0]);

-        if (paramTypes.length != 0)

+        if (parameterCount != 0)

             throw new AssertionError("Too many parameters for an annotation
method");

         switch(member) {