[Integrated] [foreign-memaccess] RFR: Add MemorySegment::mismatch

[Chris Hegarty]

On Wed, 20 May 2020 14:06:48 GMT, Chris Hegarty <chegar at openjdk.org> wrote:

> Hi,
> 
> As part of feedback on the Foreign Memory API (when experimenting with its usage internally in the JDK), a small number
> of potential usability enhancements could be made to the API. This is the fourth such, and last on my current todo
> list.  This change proposes to add a new method:
> MemorySegment::mismatch
> 
> The mismatch semantic is very useful for building equality and comparison logic on top of segments. I found that I
> needed such when modeling and comparing native socket address in the JDK implementation. It is possible to write your
> own, but requires a non-trivial amount of not-trivial code - to do it right! I also think that we can provide a more
> efficient implementation building on top of the JDK's internal mismatch support.  I still need to do some perf testing
> and add a micro-benchmake ( Maurizio suggested possibly amending TestBulkOps ). There is also the question about
> possibly improving the JDK's internal implementation to work on long sizes (which could be done separately). For now, I
> just want to share the idea, along with the proposed specification and initial implementation.  Comments welcome.

This pull request has now been integrated.

Changeset: cd397502
Author:    Chris Hegarty <chegar at openjdk.org>
Committer: Maurizio Cimadamore <mcimadamore at openjdk.org>
URL:       https://git.openjdk.java.net/panama-foreign/commit/cd397502
Stats:     335 lines in 5 files changed: 0 ins; 335 del; 0 mod

Add MemorySegment::mismatch

Reviewed-by: mcimadamore, psandoz

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PR: https://git.openjdk.java.net/panama-foreign/pull/180