RFR: 8305093: Linker cache should not take layout names into account [v2]

[Maurizio Cimadamore]

On Fri, 21 Apr 2023 01:03:57 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

>> Strip names from the function descriptors used in linkage requests. The names are not important for classification, and this will allow the cached MethodHandle/UpcallStubFactory to be shared across linkage request with the same structure, but with layouts that have different names.
>> 
>> I also have another implementation that avoids copying all the layouts, and instead re-implemented equals and hashCode in the LinkRequest wrapper: https://github.com/openjdk/jdk/compare/pr/13079...JornVernee:jdk:NoNameCache But, this seems too complex. Linking code is not very performance sensitive, so I instead went with a simpler approach in this patch.
>
> Jorn Vernee has updated the pull request incrementally with one additional commit since the last revision:
> 
>   use al instead of ValueLayout.ADDRESS

src/java.base/share/classes/jdk/internal/foreign/abi/AbstractLinker.java line 142:

> 140:         // since the linker already restricts those such that they will always be the same
> 141:         return switch (ml) {
> 142:             case StructLayout sl -> MemoryLayout.structLayout(stripNames(sl.memberLayouts()));

shouldn't names be also stripped from enclosing struct/union/sequence?

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PR Review Comment: https://git.openjdk.org/jdk/pull/13562#discussion_r1175169777