RFR (M) #2 CR 8003985: Support @Contended annotation

[Vitaly Davidovich]

Well, I think we agreed that using unsafe to get estimates is just that -
estimates.  I'd much rather have the VM report it precisely 100% of the
time reliably.  Plus, the code is already written by you; this is one bool
field and some extra code in the text section of the binary - is that
really too much footprint overhead?

If you and others are keen on keeping it notproduct then OK, no biggie -
unsafe it is then.

Sent from my phone
On Dec 4, 2012 5:15 PM, "Aleksey Shipilev" <aleksey.shipilev at oracle.com>
wrote:

> Frankly, I don't see the upsides, you can get the same level of
> diagnostics at Java level; on any VM, any time you want. Is the a use
> case which does not fit the bill of, say, java-field-layout [1]?
>
> -Aleksey.
>
> [1] https://github.com/shipilev/java-field-layout
>
> On 12/05/2012 02:10 AM, Vitaly Davidovich wrote:
> > PrintFieldLayout is still notproduct :) - did someone object to making
> > it diagnostic/product?
> >
> > Thanks
> >
> > Sent from my phone
> >
> > On Dec 4, 2012 4:27 PM, "Aleksey Shipilev" <aleksey.shipilev at oracle.com
> > <mailto:aleksey.shipilev at oracle.com>> wrote:
> >
> >     Hi,
> >
> >     This is the revamp of JEP-142 aka @Contended, taking into the account
> >     the feedbacks of Christian, Coleen and others:
> >       http://shipilev.net/pub/jdk/hotspot/contended/webrev-5/
> >
> >     The bottom line for most of the changes is dealing with footprint. I
> >     think I've managed to squeeze into the same footprint by reusing
> >     InstanceKlass::misc_flags to store class-level flag, and tagged
> field in
> >     FieldInfo (as the side effect, cleaning up the mess with "temporarily
> >     store type into offset field") to store per-field info.
> >
> >     Testing:
> >       - built and tested on Linux x86_64
> >       - Test8003985 is passing on Linux x86_64
> >
> >     Please take a look while I'm getting this through acceptance checks
> on
> >     other platforms.
> >
> >     -Aleksey
> >
>
>