Long chains created by direct Buffer::slice

[Paul Sandoz]

Got caught up with JVMLS this week…

I searched but could not find a test, so i added one, see:

  http://cr.openjdk.java.net/~psandoz/jdk/JDK-8208362-direct-buffer-att/webrev/ <http://cr.openjdk.java.net/~psandoz/jdk/JDK-8208362-direct-buffer-att/webrev/>

Paul.

> On Jul 27, 2018, at 12:35 PM, Paul Sandoz <Paul.Sandoz at oracle.com> wrote:
> 
> 
> 
>> On Jul 27, 2018, at 1:09 AM, Florian Weimer <fw at deneb.enyo.de> wrote:
>> 
>> * Paul Sandoz:
>> 
>>> I created this issue:
>>> 
>>> https://bugs.openjdk.java.net/browse/JDK-8208362
>> 
>> Thanks.
>> 
>>> The suggested fix requires a tweak though since an instance of a
>>> DirectBuffer interface is passed. This is required because views
>>> over direct ByteBuffers can be created.
>> 
>> Noticed that as well.
>> 
>>> diff -r 448cd909c9e2 src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template
>>> --- a/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template	Thu Jul 26 11:53:59 2018 -0700
>>> +++ b/src/java.base/share/classes/java/nio/Direct-X-Buffer.java.template	Thu Jul 26 16:46:20 2018 -0700
>>> @@ -194,7 +194,8 @@
>>> #if[byte]
>>>        cleaner = null;
>>> #end[byte]
>>> -        att = db;
>>> +        Object attachment = db.attachment();
>>> +        att = (attachment == null ? db : attachment);
>> 
>> This is essentially what I put through jtreg (jdk_core), without any
>> obvious issues,
> 
> Thanks for testing.
> 
> 
>> but I had not time yet to file a bug and create a
>> webrev.
> 
> Ah, my apologies, i did not realize you had author status.
> 
> 
>> 
>> The parenthesis seem unnecessary.  If this is an official JDK coding
>> style, it is not widely used.
> 
> 
> It is unusual but I chose to keep consistent with the style in the source.
> 
> Paul.