On Mon, 5 May 2025 17:13:02 GMT, Per Minborg <pminb...@openjdk.org> wrote:
>> As we advance, converting older JDK code to use the relatively new FFM API
>> requires system calls that can provide `errno` and the likes to explicitly
>> allocate a MemorySegment to capture potential error states. This can lead to
>> negative performance implications if not designed carefully and also
>> introduces unnecessary code complexity.
>>
>> Hence, this PR proposes adding a JDK internal method handle adapter that can
>> be used to handle system calls with `errno`, `GetLastError`, and
>> `WSAGetLastError`.
>>
>> It relies on an efficient carrier-thread-local cache of memory regions to
>> allide allocations.
>
> Per Minborg has updated the pull request incrementally with three additional
> commits since the last revision:
>
> - Fix empty line at the end of a third file
> - Fix empty line at the end of another file
> - Fix empty line at the end of a file
src/java.base/share/classes/jdk/internal/foreign/BufferStack.java line 176:
> 174: @ForceInline
> 175: @Override
> 176: public NativeMemorySegmentImpl allocateNoInit(long byteSize,
> long byteAlignment) {
This probably also needs `@SuppressWarnings("restricted")`:
Suggestion:
@ForceInline
@Override
@SuppressWarnings("restricted")
public NativeMemorySegmentImpl allocateNoInit(long byteSize, long
byteAlignment) {
src/java.base/share/classes/jdk/internal/foreign/CaptureStateUtil.java line 85:
> 83: // specific "basic handle" in the `BASIC_HANDLE_CACHE`.
> 84: // returnType in {int.class | long.class}
> 85: // stateName can be anything non-null but should be in
> {"GetLastError" | "WSAGetLastError"} | "errno")}
Suggestion:
// stateName can be anything non-null but should be in {"GetLastError" |
"WSAGetLastError" | "errno"}
src/java.base/share/classes/jdk/internal/invoke/MhUtil.java line 88:
> 86: public static MethodHandle findStatic(MethodHandles.Lookup lookup,
> 87: String name,
> 88: MethodType type) {
Suggestion:
String name,
MethodType type) {
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/25043#discussion_r2073948786
PR Review Comment: https://git.openjdk.org/jdk/pull/25043#discussion_r2073955345
PR Review Comment: https://git.openjdk.org/jdk/pull/25043#discussion_r2073949485
