RFR (XS): 8014890 : Reference queues may return more entries than expected

[Aleksey Shipilev]

On 07/01/2013 03:51 PM, Thomas Schatzl wrote:
> Hi all,
> 
> On Mon, 2013-07-01 at 15:44 +0400, Aleksey Shipilev wrote:
>> On 07/01/2013 03:37 PM, David Holmes wrote:
>>> On 1/07/2013 8:14 PM, Aleksey Shipilev wrote:
>>>> The same "thou shalt not do multiple volatile reads" applies to 
>>>> "(r.queue == NULL) || (r.queue == ENQUEUED)" now.
>>>
>>> Doesn't that just reduce to "r.queue != this" ? (The assert suggests
>>> so :) )
>>
>> Thomas' original patch had this in form of "r.queue != this". I argue it
>> is more future-proof to distinguish the concrete cases.
> 
> :)
> 
> I also thought it was more understandable if the cases were explicitly
> enumerated, in addition to the assert.
> 
> I changed this in 
> http://cr.openjdk.java.net/~tschatzl/8014890/webrev.refactor to that
> version now, using a temporary variable that stores r.queue before the
> checks to avoid the double volatile reads.
> 
> However for me either version is fine, just tell me what you favor.

I have no opinion on this. Fine with both versions.

-Aleksey.