[foreign] thoughts on finalizing foreign APIs

[Uwe Schindler]

Hi Maurizio,

Thanks, great new API. I fully agree (see also other response in this thread)!

When reviewing the API, I found a small problem (I think it already exists in JDK 17): The return value of method "MemorySegment#mapFile(...)" has a wrong description of the @return value: It says that the scope is "confined", which is wrong. It uses the scope given as parameter! The @return should possibly be copied over from the other static "allocate" methods taking a ResourceScope.

Uwe

-----
Uwe Schindler
uschindler at apache.org 
ASF Member, Member of PMC and Committer of Apache Lucene and Apache Solr
Bremen, Germany
https://lucene.apache.org/
https://solr.apache.org/

> -----Original Message-----
> From: panama-dev <panama-dev-retn at openjdk.java.net> On Behalf Of
> Maurizio Cimadamore
> Sent: Thursday, September 16, 2021 4:59 PM
> To: panama-dev at openjdk.java.net
> Subject: [foreign] thoughts on finalizing foreign APIs
> 
> Hi,
> we have spent the last few weeks looking at the foreign APIs more
> holistically, to see what we could do to improve them, in order to get
> them preview/finalization ready. The resulting changes are described in
> the following write up:
> 
> https://inside.java/2021/09/16/finalizing-the-foreign-apis/
> 
> We think the proposed API [2, 3] is much simpler, tighter and safer -
> while retaining the same expressiveness of the existing API.
> 
> Moving forward, we would like to start integrating the proposed changes
> into the panama repo, and incubate those changes in 18. We will then
> (finger crossed!) move towards finalizing the API, by making it a
> preview API in 19 (the document describes some basic shuffling moves on
> how we might want to do that). While we could technically preview things
> in 18, we believe that the extra steps required to move the API into
> java.base would push us too close to the code freeze deadline; besides
> there are still outstanding performance issues (such as [1]) which we'd
> like to have addressed, so that user experience can be as smooth as
> possible. For these reasons, incubating in 18 and previewing in 19 seems
> like the most sensible option at this point in time.
> 
> Cheers
> Maurizio
> 
> [1] - https://bugs.openjdk.java.net/browse/JDK-8259609
> [2] -
> http://cr.openjdk.java.net/~mcimadamore/panama/foreign-finalize-
> javadoc/javadoc/jdk/incubator/foreign/package-summary.html
> [3] -
> https://github.com/mcimadamore/panama-foreign/tree/foreign-
> finalize%2Bjextract