RFR(S) Contended Locking fast notify bucket (8075171)

[Daniel D. Daugherty]

Greetings,

I have the Contended Locking fast notify bucket ready for review.

The code changes in this bucket are the final piece in the triad
of {fast-enter, fast-exit, fast-notify} changes. There are no
macro assembler changes in this bucket (yeah!), but there are
code review cleanups motivated by comments on other buckets, e.g.,
changing variables like 'Tally' -> 'tally'.

This work is being tracked by the following bug ID:

     JDK-8075171 Contended Locking fast notify bucket
     https://bugs.openjdk.java.net/browse/JDK-8075171

Here is the webrev URL:

http://cr.openjdk.java.net/~dcubed/8075171-webrev/0-jdk9-hs-rt/

Here is the JEP link:

     https://bugs.openjdk.java.net/browse/JDK-8046133

Testing:

- Aurora Adhoc RT/SVC baseline batch
- JPRT test jobs
- MonitorWaitNotifyStresser micro-benchmark (in process)
- CallTimerGrid stress testing (in process)
- Aurora performance testing:
   - out of the box for the "promotion" and 32-bit server configs
   - heavy weight monitors for the "promotion" and 32-bit server configs
     (-XX:-UseBiasedLocking -XX:+UseHeavyMonitors)
     (in process)

The hang somehow introduced by the "fast enter" bucket is still
unresolved, but progress is being made. That work is being tracked
by the following bug:

     JDK-8077392 Stream fork/join tasks occasionally fail to complete
     https://bugs.openjdk.java.net/browse/JDK-8077392

You'll see a change that re-enables the "fast enter" bucket in this
webrev, but that change will not be pushed when we're done with the
review of this bucket unless JDK-8077392 is resolved.

Thanks, in advance, for any comments, questions or suggestions.

Gory details about the changes are below...

Dan


8075171 summary of changes:

src/share/vm/classfile/vmSymbols.hpp
   - Add do_intrinsic() entries for _notify and _notifyAll

src/share/vm/opto/library_call.cpp
   - Add optional inline_notify() that is controlled by new
     '-XX:[+-]InlineNotify' option

src/share/vm/opto/runtime.cpp
src/share/vm/opto/runtime.hpp
   - Add OptoRuntime::monitor_notify_C() and
     OptoRuntime::monitor_notifyAll_C() functions to support
     the new "fast notify" code paths
   - Add new OptoRuntime::monitor_notify_Type() to support
     the above two new functions

src/share/vm/runtime/globals.hpp
   - Add '-XX:[+-]InlineNotify' option; default option value is
     enabled (true)

src/share/vm/runtime/objectMonitor.cpp
src/share/vm/runtime/objectMonitor.hpp
   - Refactor ObjectMonitor::notify() and ObjectMonitor::notifyAll()
     into wrappers that call the new ObjectMonitor::INotify()
   - Add new ObjectMonitor::INotify() to reduce code duplication
     between "notify" and "notifyAll" code paths

src/share/vm/runtime/sharedRuntime.cpp
   - Temporarily re-enable the "fast enter" optimization in order
     to do performance testing. JDK-8077392 is still unresolved,
     but progress is being made.

src/share/vm/runtime/synchronizer.cpp
src/share/vm/runtime/synchronizer.hpp
   - Add ObjectSynchronizer::quick_notify() that implements the
     new "fast notify" code paths
   - The new code handles a couple of special cases where the
     "notify" can be done without the heavy weight slow-path
     (thread state transitions and other baggage)