Proposal for adding O_DIRECT support into JDK 9

[Lu, Yingqi]

Hi Brian,

Here is the updated version of the patch: http://cr.openjdk.java.net/~kkharbas/8164900/webrev.16/

In this version, I applied your clean-up fix.

Please let me know if there is anything missing.

Thanks,
Lucy

>-----Original Message-----
>From: Lu, Yingqi
>Sent: Monday, September 18, 2017 6:35 PM
>To: 'Brian Burkhalter' <brian.burkhalter at oracle.com>
>Cc: nio-dev at openjdk.java.net
>Subject: RE: Proposal for adding O_DIRECT support into JDK 9
>
>Hi Brian/Alan,
>
>Thank you very much for all the help! I will apply your patch and send another
>version tomorrow. At the meantime, please let me know if you see any additional
>issues.
>
>All, please let us know if you have any comments/feedback in this patch.
>
>Thank you!
>Lucy
>
>>-----Original Message-----
>>From: Brian Burkhalter [mailto:brian.burkhalter at oracle.com]
>>Sent: Monday, September 18, 2017 6:08 PM
>>To: Lu, Yingqi <yingqi.lu at intel.com>
>>Cc: nio-dev at openjdk.java.net
>>Subject: Re: Proposal for adding O_DIRECT support into JDK 9
>>
>>Hi Lucy,
>>
>>I ran the tests manually on Linux and macOS and did not see any
>>problems. I ran your script for 5000 iterations of DirectIOTest on
>>Solaris and did not see any problems. I still need to run the other
>>four tests on Solaris as they do not really execute in the test harness which is on
>ZFS.
>>
>>I created a small patch
>>http://cr.openjdk.java.net/~bpb/8164900/webrev.15-fix/
>>which has a couple of minor cleanups in DirectIOTest.java and trailing
>>whitespace fixes in the other files in the this patch. You should be able to apply it
>directly.
>>
>>It looks like you fixed the things Alan commented on, viz., the need to
>>do the position check in FileChannelImpl with the position lock held,
>>and the use of rem instead of dst.remaining() in IOUtil::read. I don't
>>myself see any other problems in the code but we shall see what Alan and others
>think.
>>
>>I intend to look over the read/write tests one more time.
>>
>>Thanks,
>>
>>Brian