JDK-8027351: (ref) Base's class finalize method not invoked if a private finalize method exists in its subclass

[Jeroen Frijters]

Hi Mandy,

Thank you. Patch looks good.

Regards,
Jeroen

> -----Original Message-----
> From: core-libs-dev-bounces at openjdk.java.net [mailto:core-libs-dev-
> bounces at openjdk.java.net] On Behalf Of Mandy Chung
> Sent: Friday, November 1, 2013 19:16
> To: core-libs-dev at openjdk.java.net
> Subject: JDK-8027351: (ref) Base's class finalize method not invoked if
> a private finalize method exists in its subclass
> 
> Webrev at:
> http://cr.openjdk.java.net/~mchung/jdk8/webrevs/8027351/webrev.00/
> 
> This fixes the finalization implementation to invoke the finalize method
> via shared secret so that it will call the same method as the bytecode
> invocation.
> 
> The current implementation uses JNI_GetMethodID to find the finalize
> method of a given instance. JNI_GetMethodID returns the private finalize
> method which gets invoked during finalization (which is different than
> the method looked up via invokevirtual).  If there is a static method
> matching the name and descriptor, it will throw NoSuchMethodError even
> if the base class has a matching instance method.  JDK-8027270 is filed
> for this JNI_GetMethodID issue.
> 
> This change replaces the JNI call to the finalize method with the shared
> secret as Jeroen suggests [1].  This will resolve this bug independent
> of JDK-8027270 and also avoid the overhead of the JNI calls.
> 
> The behavioral change with this fix should rarely impact any existing
> application.  It would only impact code that defines a finalize method
> in a base class and also a private finalize method in a subclass.  The
> only way to have a private finalize method is to write to the bytecode
> directly.
> 
> thanks
> Mandy
> P.S. I would love to use Martin's beloved GcFinalization utility that we
> can extend our testlibrary in the future.  The new regression test is
> simple enough that a counter would do its work.
> 
> [1]
> http://weblog.ikvm.net/PermaLink.aspx?guid=87432f77-7e58-4f37-9f6d-
> d5bac453c7d6
> [2] https://bugs.openjdk.java.net/browse/JDK-8027351