RFR (XL): Backport JDK9 Shenandoah to JDK8u

[Aleksey Shipilev]

On 12/06/2016 10:24 PM, Roman Kennke wrote:
> This huge change backports the current state of JDK9 (minus the last
> bunch of patches) to jdk8u:
> 
> http://cr.openjdk.java.net/~rkennke/backport-jdk8/webrev.00/

Spot-checking:

*) src/cpu/aarch64/vm/c1_LIRAssembler_aarch64.cpp

These are not conditional for Shenandoah, do we hit these guarantees with other GCs?

  2032       guarantee(opr2->type() != T_OBJECT && opr2->type() != T_ARRAY,
"need acmp barrier?");
  2033       guarantee(opr1->type() != T_OBJECT && opr1->type() != T_ARRAY,
"need acmp barrier?");

*) src/share/vm/c1/c1_Runtime1.cpp

Bad indent:

  688 Handle h_obj(thread, obj);

*) src/share/vm/memory/barrierSet.cpp

Why we moved BarrierSet::write_ref_array here? Was that the upstream jdk-9 move?
Should probably stay closer to jdk-8 version.

*) src/share/vm/runtime/fieldDescriptor.hpp

Another leak from jdk-9?

  101   bool is_stable()                const    { return
access_flags().is_stable(); }

*) src/share/vm/runtime/os.hpp

Leak?

  56 class methodHandle;

*) src/share/vm/utilities/growableArray.hpp

Leak?

  30 #include "oops/oop.hpp"


Otherwise looks good.

Thanks,
-Aleksey