RFR(XS) Contended Locking speedup PlatformEvent unpark bucket (8061552)

[David Holmes]

Hi Dan,

On 28/10/2014 8:34 AM, Daniel D. Daugherty wrote:
> Greetings,
>
> I have the Contended Locking speedup PlatformEvent unpark bucket
> ready for review. These are small comment only changes that have
> already been reviewed by Karen Kinnear (acorn) and Dave Dice (dice).
> It would be good to get one or two more pair of eyes on these
> comment additions/updates/synchronizations.

So there's a bit of cross-platform inconsistency. For example you 
deleted the TO-DO/FIXME chunk of comments on Solaris but left them on 
Windows. Granted parts are different (and my not be true/relevant any 
more) but parts are basically the same eg:

-  Reconcile Doug's JSR166 j.u.c park-unpark with the objectmonitor 
implementation.

-  Collapse the JSR166 parker event, and the objectmonitor ParkEvent 
into a single "Event" construct.

Also linux/bsd have the transition information only in the park/unpark 
functions, but solaris and windows have it both in the functions and as 
part of the preeamble - which seems redundant to me.

Also os_aix.cpp is missing, but is presumably similar to the linux/bsd 
cases.

Cheers,
David

> Historial reminder:
>
>      Back in 2012.12 and 2013.01, work on the "bug fix bucket" for the
>      Contended Locking project was being done. One of the bug fixes was:
>
>      JDK-8004902 correctness fixes motivated by contended locking work
> (6607129)
>      https://bugs.openjdk.java.net/browse/JDK-8004902
>
>      The work on JDK-8004902 picked up all of the code changes and many of
>      comments that were part of this bucket (speedup PlatformEvent unpark).
>
>      Here's the webrev for "bug fix bucket":
>
>      http://cr.openjdk.java.net/~dcubed/cl_bug_fix_bucket-webrev/2/
>
>      The bug fix bucket included fixes for 6444286, 8004902 and 8004903,
>      but the majority of the work was done for 8004902. Now back to the
>      current thread...
>
> This work is being tracked by the following bug ID:
>
>      JDK-8061552 Contended Locking speedup PlatformEvent unpark bucket
>      https://bugs.openjdk.java.net/browse/JDK-8061552
>
> Here is the webrev URL:
>
> http://cr.openjdk.java.net/~dcubed/8061552-webrev/2-jdk9-hs-rt/
>
> Here is the JEP link:
>
>      https://bugs.openjdk.java.net/browse/JDK-8046133
>
> Testing:
>
> - JPRT test jobs