On Mon, 24 Jun 2024 18:07:11 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org>
wrote:
>> src/java.desktop/share/classes/sun/font/StrikeCache.java line 151:
>>
>>> 149:
>>> 150: @SuppressWarnings("restricted")
>>> 151: static final float getGlyphXAdvance(long ptr) {
>>
>> now, I'm not an expert of this code, but I notice that you have accessors
>> that seem to take a bare `long` instead of `MemorySegment`. Have you tried
>> pushing segments deeper in the implementation? That way I think you could
>> completely auto-generate this code using jextract. (of course what you have
>> is not bad - I'm mostly trying to see if there's a way to get there w/o all
>> these calls to `MemorySegment::reinterpret`).
>
> To be clear - I'm assuming the `ptr` parameter comes from a single native
> call. That call returns a pointer to a struct, or maybe an array of structs.
> If so, we could reinterpret right after the native call, with the right size
> (the number of structs returned by the native call), and then all the
> accessors will be just "plain" memory segment accessors, no need to
> reinterpret (as the segment will already have the correct size).
Each pointer refers to a single struct, not an array.
In this fix I am focused on not using Unsafe.
I don't want the change to go further than that.
The 'long's are retrieved/ passed around/ back down to native in lots of places
so it would turn a focused change into a much bigger change.
grep in java.desktop for "getGlyphImage" to see the tip of the iceberg.
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PR Review Comment: https://git.openjdk.org/jdk/pull/19777#discussion_r1651455679
