Hi Alan,
On 10/14/2016 02:16 PM, Alan Bateman wrote:
On 13/10/2016 18:30, Peter Levart wrote:
Hi Paul, Alan,
I incorporated Paul's suggestions into new webrev:
http://cr.openjdk.java.net/~plevart/jdk9-dev/Class.getMethods.new/webrev.05/
This iteration also contains a nearly-exhaustive test of
Class.getMethods(): PublicMethodsTest. It is actually a test
generator. Given a Case template, it generates all variants of
methods for each of the types in the case. Case1 contains 4 interface
method variants ^ 3 interfaces * 4 class method variants ^ 3 classes
= 4^6 = 4096 different sub-cases of which only 1379 compile. The
results of those 1379 sub-cases are persisted in the Case1.results
file. Running the test compares the persisted results with actual
result of executing each sub-case. When running this test on plain
JDK 9 (without patch), the test finds 218 sub-cases where results
differ:
http://cr.openjdk.java.net/~plevart/jdk9-dev/Class.getMethods.new/PublicMethodsTest.jtr
Looking at those differences gives the impression of the effects of
the patch.
Overall I think this looks very good. I mostly focused on the
PublicMethods implementation to satisfy myself that it does selects
the most specific methods. In passing I wonder if "combine" or "merge"
might be better than "consolidate" for method name and terminology, a
minor point of course.
What about "coalesce" ?
Given the behavior change then I think we'll need to capture it in a
release notes. I can't think of any libraries or frameworks that might
have see but something might come out of the woodwork and would be
nice to be able to point to a summary.
What do you think of specifying new behavior in javadoc(s) of
getMethod() and getMethods() themselves? The description in those docs
was never very precise. It is composed of a few seemingly unconnected
statements which don't give a complete picture of what those methods
return. It is now plainly wrong in getMethod() and does not give any
clew about what it means to "inherit" a method from supertype in
getMethods(). I have tried to capture the precise behavior in the
changed javadocs that I present here:
http://cr.openjdk.java.net/~plevart/jdk9-dev/Class.getMethods.new/webrev.06/
Those javadocs refer to definitions of two other methods:
Class.getDeclaredMethods() and Class.isAssignableFrom(). Their
definitions are leveraged so javadocs of getMethod() and getMethods()
themselves can be simpler - I removed the redundant statements that are
a direct consequence of the algorithm description.
We could then perhaps point from release notes to the new javadocs or
even include them.
I assume that copyright headers will be added before this is pushed.
Added in above webrev.
Also there is a @SuppressWarnings arguments that I don't recognize
(IDE specific)? It would good to trim back some of the really long
times in the test too (there are some >150 char lines that will be a
pain to review side-by-side when there are future changes).
The trimming was done. I have missed the @SuppressWarnings. Will do it
in next iteration.
I have updated the test which now includes Class.getMethod() testing
too. It also presents results (differences from expected) in a more
pleasing way - just those results that differ are presented. Here's a
result of running the test on unpatched JDK 9:
http://cr.openjdk.java.net/~plevart/jdk9-dev/Class.getMethods.new/PublicMethodsTest.jtr
There are some more differences now that Class.getMethod() is also part
of the test. Some interesting consequences of the patch (expected=new
behavior, actual=old behavior):
interface I { void m(); }
interface J { }
interface K extends I, J { default void m() {} }
abstract class C { }
abstract class D extends C implements I { }
abstract class E extends D implements J, K { }
expected: E.gM: K.m
actual: E.gM: I.m
...here E.class.getMethods() has the same result between unpatched and
patched JDK 9, just getMethod() returns different method. Which means
that in present JDK, getMethod() returns a method that is not included
in the getMethods() result.
interface I { void m(); }
interface J { void m(); }
interface K extends I, J { void m(); }
abstract class C { public abstract void m(); }
abstract class D extends C implements I { }
abstract class E extends D implements J, K { }
expected: E.gMs: [C.m]
actual: E.gMs: [C.m, I.m, J.m, K.m]
expected: D.gMs: [C.m]
actual: D.gMs: [C.m, I.m]
...huge difference, huh.
interface I { default void m() {} }
interface J { void m(); }
interface K extends I, J { void m(); }
abstract class C { }
abstract class D extends C implements I { }
abstract class E extends D implements J, K { }
expected: E.gMs: [K.m]
actual: E.gMs: [I.m, J.m, K.m]
expected: E.gM: K.m
actual: E.gM: I.m
...difference in both getMethod() and getMethods().
Regards, Peter
