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

Mandy Chung mandy.chung at oracle.com
Fri Nov 1 18:15:39 UTC 2013

Webrev at:

This fixes the finalization implementation to invoke the finalize method 
via shared secret so that it will call the same method as the bytecode 

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 

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.

[2] https://bugs.openjdk.java.net/browse/JDK-8027351

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