RFR (L) 8174749: Use hash table/oops for MemberName table (original) (raw)

coleen.phillimore at oracle.com coleen.phillimore at oracle.com
Tue May 23 14:10:54 UTC 2017

On 5/22/17 11:23 PM, serguei.spitsyn at oracle.com wrote:

Hi Coleen,

I've finished reviewing, it looks great!

Thank you, Serguei!

Just some nits. http://cr.openjdk.java.net/~coleenp/8174749.01/webrev/src/share/vm/classfile/javaClasses.cpp.frames.html A dot is missed at the end of the comment line 3259: 3258 // Add a reference to the loader (actually mirror because anonymous classes will not have 3259 // distinct loaders) to ensure the metadata is kept alive 3260 // This mirror may be different than the one in clazz field. ok.

Dots are also missed in a couple of places in the resolvedMethodTable.?pp comments: resolvedMethodTable.hpp: L31, L35 resolvedMethodTable.cpp: L130, L141 (L140 has an unnecessary dot)

Those comments didn't get fixed when I changed the code. I wish the compiler would check this! I fixed them:

// Serially invoke removed unused oops from the table. // This is done late during GC. void ResolvedMethodTable::unlink(BoolObjectClosure* is_alive) {

...

// Serially invoke "f->do_oop" on the locations of all oops in the table. void ResolvedMethodTable::oops_do(OopClosure* f) { ...

resolvedMethodTable.cpp:

Values of the counters oopsremoved andoopscounted are not used. Is it a leftover from the debugging or there was a plan to log them?

They are used for counting and I added this logging message to the end of ResolvedMethodTable::unlink() to print them.

log_debug(membername, table) ("ResolvedMethod entries counted %d removed %d", _oos_counted, _oops_removed);

195 // For each entry in MNT, change to new method MNT should be RMT now. :)

Changed it. Nice catch.

Thank you for reviewing this! Coleen

Thanks, Serguei

On 5/17/17 09:01, coleen.phillimore at oracle.com wrote: Summary: Add a Java type called ResolvedMethodName which is immutable and can be stored in a hashtable, that is weakly collected by gc Thanks to John for his help with MemberName, and to-be-filed RFEs for further improvements. Thanks to Stefan for GC help. open webrev at http://cr.openjdk.java.net/~coleenp/8174749.01/webrev open webrev at http://cr.openjdk.java.net/~coleenp/8174749.jdk.01/webrev bug link https://bugs.openjdk.java.net/browse/JDK-8174749 Tested with RBT nightly, compiler/jsr292 tests (included in rbt nightly), JPRT, jdk/test/java/lang/invoke, jdk/test/java/lang/instrument tests. There are platform dependent changes in this change. They are very straightforward, ie. add an indirection to MemberName invocations, but could people with access to these platforms test this out for me? Performance testing showed no regression, and large 1000% improvement for the cases that caused us to backout previous attempts at this change. Thanks, Coleen

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