[OpenJDK 2D-Dev] [PATCH] 8220231: Cache HarfBuzz face object for same font's text layout calls

[Dmitry Batrak]

> Sorry for the delay. I've now finished verifying this and it is a +1 from
me.
Thanks!

Anyone else, please? A second reviewer is required.

On Mon, Mar 25, 2019 at 11:19 PM Philip Race <philip.race at oracle.com> wrote:

> Sorry for the delay. I've now finished verifying this and it is a +1 from
> me.
>
> -phil.
>
> On 3/12/19, 1:32 AM, Dmitry Batrak wrote:
>
> > This looks good to me, if I understand correctly that we now create
> > the face on first use and cache it fin Java or as long as the Font2D is
> > alive.
> > And the JNIEnv is always found on
> That's correct. The assumption is that HarfBuzz doesn't create its own
> threads,
> so HarfBuzz-related native code will always be invoked from a Java thread
> (as part of 'shape' call), and so JNIEnv will be available in that context.
>
> I've updated the webrev by including a stress test for multi-threaded
> behaviour
> testing. Apart from the test, webrev also has some cosmetic differences
> from the previous version (like a comment fix or parameter order changing),
> appeared during 'splitting' process. To simplify the review, I'm also
> providing
> the links to the 'split' version of the same webrev - three parts that
> produce
> the same result when combined. I've not tested the changes separately
> (except basic compilation check).
>
> Complete change:
>     http://cr.openjdk.java.net/~dbatrak/8220231/webrev.01/
> Part 1 (caching hb_face_t):
>     http://cr.openjdk.java.net/~dbatrak/8220231/webrev.01-1/
> Part 2 (tables caching removal):
>     http://cr.openjdk.java.net/~dbatrak/8220231/webrev.01-2/
> Part 3 (scaler pointer passing removal):
>     http://cr.openjdk.java.net/~dbatrak/8220231/webrev.01-3/
>
> Best regards,
> Dmitry Batrak
>
> On Fri, Mar 8, 2019 at 3:21 AM Philip Race <philip.race at oracle.com> wrote:
>
>> This looks good to me, if I understand correctly that we now create
>> the face on first use and cache it fin Java or as long as the Font2D is
>> alive.
>> And the JNIEnv is always found on
>>
>> I think you are right that we don't need the caching of the tables since
>> now the face will do it. The unfortunate thing is that the removal of
>> this code is
>> well over half the changes and as such it greatly muddied finding the
>> changes
>> that make the performance difference so my review was harder and less
>> certain
>> because of that.
>> It could have been separated into a follow-on change I think so that it
>> would have
>> been easier to review the important change.
>>
>> The pScaler parameter looks like it is unused these days which is why I
>> expect you removed it but also not directly relevant.
>>
>> I have run builds + some tests - but I'm not in a position to run more
>> tests
>> for a couple of weeks.
>>
>> A (mild) stress test re-using the same font from multiple threads
>> eachmaking
>> multiple calls into layout would be a good addition here. That should
>> help tell
>> us if there are any MT or re-entrancy problems. Can you provide such a
>> test ?
>> It will be a good thing to have automatically run to catch any problems
>> introduced later either on the Java side or by an update to harfbuzz.
>>
>> -phil.
>>
>>
>>
>> On 3/6/19, 5:45 PM, Dmitry Batrak wrote:
>> > Hello,
>> >
>> > I'd like to submit a patch for JDK-8220231. I'm not a Committer, so
>> > I'll need someone to sponsor this change.
>> >
>> > The proposed approach is used without known issues in OpenJDK-based
>> > JetBrains Runtime for almost three years now. I've mentioned it
>> > previously on this mailing list
>> > (https://mail.openjdk.java.net/pipermail/2d-dev/2017-August/008497.html
>> ).
>> > The change has been refactored as compared to the version mentioned
>> > above (the logic has been moved to SunLayoutEngine), and includes the
>> > removal of font tables caching (JDK-8186317). The latter, I believe,
>> > becomes redundant with this fix.
>> >
>> > Issue: https://bugs.openjdk.java.net/browse/JDK-8220231
>> > Webrev: http://cr.openjdk.java.net/~dbatrak/8220231/webrev.00/
>> > <http://cr.openjdk.java.net/%7Edbatrak/8220231/webrev.00/>
>> >
>> > Best regards,
>> > Dmitry Batrak
>> >
>>
>
>
>

-- 
Dmitry Batrak
Senior Software Developer
JetBrains
http://www.jetbrains.com
The Drive to Develop
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