Hi Christoph,
I agree to bring-in optimizations in small chunks. So your proposed
handler invoke() method is as follows:
public Object invoke(Object proxy, Method method, Object[] args) {
String member = method.getName();
int parameterCount = method.getParameterCount();
// Handle Object and Annotation methods
if (parameterCount == 1 && member.equals("equals") &&
method.getParameterTypes()[0] == Object.class)
return equalsImpl(proxy, args[0]);
if (parameterCount != 0)
throw new AssertionError("Too many parameters for an
annotation method");
switch(member) {
case "toString":
return toStringImpl();
case "hashCode":
return hashCodeImpl();
case "annotationType":
return type;
}
// Handle annotation member accessors
Object result = memberValues.get(member);
if (result == null)
throw new IncompleteAnnotationException(type, member);
if (result instanceof ExceptionProxy)
throw ((ExceptionProxy) result).generateException();
if (result.getClass().isArray() && Array.getLength(result) != 0)
result = cloneArray(result);
return result;
}
This is good, because it only retrieves/clones the parameterTypes array
for equals() method invocation. But we might do even slightly better if
we consider the following:
- Method.getName() returns an interned String and String literals are
interned strings. Reference comparison is therefore possible
- The pair (declaringClass, methodName) uniquely identifies the method
for a bunch of interesting methods when declaringClass is either
java.lang.Object or java.lang.annotation.Annotation, so we don't need to
obtain method's parameterTypes even for equals().
For example:
public Object invoke(Object proxy, Method method, Object[] args) {
String memberName = method.getName(); // guaranteed interned String
Class<?> dtype = method.getDeclaringClass();
if (dtype == Object.class || // equals/hashCode/toString
dtype == Annotation.class //
annotationType/equals/hashCode/toString
) {
assert memberName == "equals" &&
method.getParameterCount() == 1 ||
memberName != "equals" &&
method.getParameterCount() == 0;
if (memberName == "equals") return equalsImpl(proxy, args[0]);
if (memberName == "hashCode") return hashCodeImpl();
if (memberName == "annotationType") return type;
if (memberName == "toString") return toStringImpl();
// unreachable statement
throw new AssertionError("Invalid method: " + method);
}
assert dtype == type;
assert method.getParameterCount() == 0;
// Handle annotation member accessors
Object result = memberValues.get(memberName);
if (result == null)
throw new IncompleteAnnotationException(type, memberName);
if (result instanceof ExceptionProxy)
throw ((ExceptionProxy) result).generateException();
if (result.getClass().isArray() && Array.getLength(result) != 0)
result = cloneArray(result);
return result;
}
What do you think?
Regards, Peter
On 10/10/17 19:59, Christoph Dreis wrote:
Hi Claes,
with JDK 9 being out - congrats to everyone - I'll try my chance to raise issue
https://bugs.openjdk.java.net/browse/JDK-8029019 again.
A little recap: In November 2016 I reported the unnecessary allocation of
Method.getParameterTypes() in AnnotationInvocationHandler.invoke() and a patch
that would fix this. As it turned out, this and other improvements were already
suggested by Peter in above mentioned ticket. Because it was reasonably late in
February 2017 to cover the complete story for 9, I suggested to only include
the low-risk patch, which was understandably also too late.
So I'm trying again to bring this into the JDK - I hope you don't mind me being
so persistent on this one.
For completeness find the initial patch attached below for the initial problem
I was trying to solve.
Cheers,
Christoph
================================
Reduce allocations in
sun.reflect.annotation.AnnotationInvocationHandler.invoke()
diff -r ba70dcd8de76 -r 86bbc5442c1d
src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.java
---
a/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.java
Fri Nov 11 13:11:27 2016 +0000
+++
b/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocationHandler.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 (parameterCount == 1 && member.equals("equals") &&
+ 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) {
-----Original Message-----
From: Christoph Dreis [mailto:christoph.dr...@freenet.de]
Sent: Friday, February 10, 2017 11:22 AM
To: 'Claes Redestad' <claes.redes...@oracle.com>; 'Peter Levart'
<peter.lev...@gmail.com>; 'Core-Libs-Dev' <core-libs-
d...@openjdk.java.net>
Subject: RE: RFR: 8029019: (ann) Optimize annotation handling in core
reflection
Hi Claes,
I think this all seems reasonable, but subtle behavior changes like
this needs more scrutiny than I can provide. I've discussed this
offline with Joe and sadly concluded it's probably too much, too late
for 9 at this point.
Hope you don't mind re-targetting this to JDK 10.
Do you mean the error handling change or the ticket in general? In case of
the latter, may I start a proposal?
As the original issue for me was to reduce the allocations coming from
AnnotationInvocationHandler.invoke() caused by
Method.getParameterTypes(), what about creating a sub-ticket of 8029019
and just take care of the low-risk change below? That would eventually allow
a backbort to JDK 8 as well, although I'm not quite sure yet how the backport
process is working.
What do you think?
Cheers,
Christoph
========= PATCH ===========
diff --git
a/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocation
Handler.java
b/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocation
Handler.java
---
a/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvocation
Handler.java
+++ b/src/java.base/share/classes/sun/reflect/annotation/AnnotationInvoc
+++ ationHandler.java
@@ -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 (parameterCount == 1 && member.equals("equals") &&
+ 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) {
