RFR(S): 8024368: private methods are allocated vtable slots

[serguei.spitsyn at oracle.com]

Re-sending my RFR.
Behive managed not to deliver it to the target mailing lists.
David got it because he was on the cc-list.


Please, review a fix for:
https://bugs.openjdk.java.net/browse/JDK-8024368

Webrev:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2018/8024368-priv-vtable.2/


Summary:

   Private method should not allocate vtable indeces.
   The fix tweaks several conditions in the functions:
klassVtable::update_inherited_vtable() and 
klassVtable::needs_new_vtable_entry(),
   adds a couple of asserts and makes several comments up-to-date.

   The fix was preliminary reviewed by Karen, David H. and Lois.

Testing:

   The fix was verified with 
runtime/{appcds+Nestmates+RedefineTests+SelectionResolution}
   and vmTestbase/vm/runtime/defmeth tests.
   Also, I ran a mach5 job with the flags: 
tier1,tier2,hs-tier3,hs-tier4,hs-tier5.

   By suggestion from David, it was also tested with the -Xlog output 
for vtables before and after the fix.
   I've done this comparison (awk was used to get rid of the first 
column with the time stamps).
   It shows that private methods were included into vtable before the 
fix but not included after.
   Please, see one fragment as an example:

    166c166
    <  copy vtable from java.lang.Object to java.lang.StackFrameInfo 
size 17
    ---
    >  copy vtable from java.lang.Object to java.lang.StackFrameInfo 
size 16
    180d179
    <  adding java.lang.StackFrameInfo.ensureRetainClassRefEnabled()V at 
index 16, flags: private
    182c181
    <  copy vtable from java.lang.StackFrameInfo to 
java.lang.LiveStackFrameInfo size 17
    ---
    >  copy vtable from java.lang.StackFrameInfo to 
java.lang.LiveStackFrameInfo size 16
    188,201c187,191
    <  copy vtable from java.lang.Object to 
java.lang.StackStreamFactory$AbstractStackWalker size 18
    <  adding java.lang.StackStreamFactory$AbstractStackWalker.close()V 
at index 5, flags: private
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.toStackWalkMode(Ljava/lang/StackWalker;I)I 
at index 6, flags: private
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.consumeFrames()Ljava/lang/Object; 
at index 7, flags: protected abstract
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.initFrameBuffer()V at 
index 8, flags: protected abstract
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.batchSize(I)I at index 
9, flags: protected abstract
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.getNextBatchSize()I at 
index 10, flags: protected
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.skipReflectionFrames()Z 
at index 11, flags: private
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.doStackWalk(JIIII)Ljava/lang/Object; 
at index 12, flags: private
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.getNextBatch()I at 
index 13, flags: private
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.beginStackWalk()Ljava/lang/Object; 
at index 14, flags: private
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.fetchStackFrames(I)I at 
index 15, flags: private
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.fetchStackFrames(JJII[Ljava/lang/Object;)I 
at index 16, flags: private native
    <  adding 
java.lang.StackStreamFactory$AbstractStackWalker.callStackWalk(JIII[Ljava/lang/Object;)Ljava/lang/Object; 
at index 17, flags: private native
    ---
    >  copy vtable from java.lang.Object to 
java.lang.StackStreamFactory$AbstractStackWalker size 9
    >  adding 
java.lang.StackStreamFactory$AbstractStackWalker.consumeFrames()Ljava/lang/Object; 
at index 5, flags: protected abstract
    >  adding 
java.lang.StackStreamFactory$AbstractStackWalker.initFrameBuffer()V at 
index 6, flags: protected abstract
    >  adding 
java.lang.StackStreamFactory$AbstractStackWalker.batchSize(I)I at index 
7, flags: protected abstract
    >  adding 
java.lang.StackStreamFactory$AbstractStackWalker.getNextBatchSize()I at 
index 8, flags: protected


Thanks,
Serguei