Proposal for adding O_DIRECT support into JDK 9

[Lu, Yingqi]

Hi Christoph,

Thank you very much for trying our patch. 

We are still seeking the feedback from the community. When we get closer to the final version of the patch, we will modify the copyright years. Thank you for reminding us!

Anyone else has any feedback/comments?

Thanks,
Lucy

-----Original Message-----
From: Langer, Christoph [mailto:christoph.langer at sap.com] 
Sent: Tuesday, October 04, 2016 1:33 AM
To: Lu, Yingqi <yingqi.lu at intel.com>; Alan Bateman <Alan.Bateman at oracle.com>; core-libs-dev at openjdk.java.net
Cc: nio-dev at openjdk.java.net; Kaczmarek, Eric <eric.kaczmarek at intel.com>; Kharbas, Kishor <kishor.kharbas at intel.com>
Subject: RE: Proposal for adding O_DIRECT support into JDK 9

Hi Lucy,

FWIW: I ran a build on AIX and this looks ok.

I also assume in your final version you'll update all copyright years where it's not 2016 yet? Other than that the changes look ok to me - but I'm neither a reviewer nor a deep expert in the area of your changes.

Best regards
Christoph

> -----Original Message-----
> From: nio-dev [mailto:nio-dev-bounces at openjdk.java.net] On Behalf Of 
> Lu, Yingqi
> Sent: Freitag, 30. September 2016 18:55
> To: Lu, Yingqi <yingqi.lu at intel.com>; Alan Bateman 
> <Alan.Bateman at oracle.com>; core-libs-dev at openjdk.java.net
> Cc: nio-dev at openjdk.java.net; Kaczmarek, Eric 
> <eric.kaczmarek at intel.com>; Kharbas, Kishor <kishor.kharbas at intel.com>
> Subject: RE: Proposal for adding O_DIRECT support into JDK 9
> 
> Hi All,
> 
> Please find the most recent version of the patch available at 
> http://cr.openjdk.java.net/~igraves/8164900-2/
> 
> In this version, we have following two changes:
> 
> 1. Move O_DIRECT flag from StandardOpenOption to ExtendedOpenOption 2. 
> Move the checks of O_DIRECT from native code to Java code.
> 
> Please let us know your feedback.
> 
> Thanks,
> Lucy
> 
> -----Original Message-----
> From: nio-dev [mailto:nio-dev-bounces at openjdk.java.net] On Behalf Of 
> Lu, Yingqi
> Sent: Tuesday, September 27, 2016 9:57 AM
> To: Alan Bateman <Alan.Bateman at oracle.com>; core-libs- 
> dev at openjdk.java.net
> Cc: nio-dev at openjdk.java.net
> Subject: RE: Proposal for adding O_DIRECT support into JDK 9
> 
> Alan,
> 
> Thank you for the explanation, we will modify the code accordingly and 
> send it out soon for review.
> 
> Thanks,
> Lucy
> 
> -----Original Message-----
> From: Alan Bateman [mailto:Alan.Bateman at oracle.com]
> Sent: Tuesday, September 27, 2016 8:45 AM
> To: Lu, Yingqi <yingqi.lu at intel.com>; core-libs-dev at openjdk.java.net
> Cc: nio-dev at openjdk.java.net
> Subject: Re: Proposal for adding O_DIRECT support into JDK 9
> 
> On 26/09/2016 19:50, Lu, Yingqi wrote:
> 
> > Alan, you mean readv0/write0 or read0/write0? I just want to make 
> > sure
> > :-)
> Apologies, I meant each of the native methods where the decision to 
> use direct I/O or not would be a lot more maintainable in Java. You'll 
> see that there are already code paths for direct vs. heap buffers.
> 
> 
> >
> > Anyone else has other opinions on where is the best home for O_DIRECT flag?
> The flags under jdk.unsupported will eventually be removed in the 
> future JDK release?
> >
> > If we agree ExtendedOpenOpen is the best home for O_DIRECT, we can
> modify that for sure.
> >
> I think ExtendedOpenOption is the right place. It's still TDB as to 
> whether to put these extensions but that should be transparent to 
> anyone using this when on the class path.
> 
> -Alan