On Tue, 12 Oct 2021 20:51:02 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org> wrote:
>> This PR contains the API and implementation changes for JEP-419 [1]. A more >> detailed description of such changes, to avoid repetitions during the review >> process, is included as a separate comment. >> >> [1] - https://openjdk.java.net/jeps/419 > > Maurizio Cimadamore has updated the pull request incrementally with one > additional commit since the last revision: > > Fix TestLinkToNativeRBP test Like with previous reviews of code for Panama JEPs there are not many comments on this PR, since prior reviews occurred for PRs in the panama-foreign repo. src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/CLinker.java line 77: > 75: * Furthermore, if the function descriptor's return layout is a group > layout, the resulting downcall method handle accepts > 76: * an extra parameter of type {@link SegmentAllocator}, which is used by > the linker runtime to allocate the > 77: * memory region associated with the struct returned by the downcall > method handle. Suggestion: * memory region associated with the struct returned by the downcall method handle. src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/CLinker.java line 88: > 86: * in which the specialized signature of a given variable arity callsite > is described in full. Alternatively, > 87: * if the foreign library allows it, clients might also be able to > interact with variable arity methods > 88: * using by passing a trailing parameter of type {@link VaList}. Suggestion: * by passing a trailing parameter of type {@link VaList}. src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/CLinker.java line 145: > 143: * Lookup a symbol in the standard libraries associated with this > linker. > 144: * The set of symbols available for lookup is unspecified, as it > depends on the platform and on the operating system. > 145: * @return a linker-specific library lookup which is suitable to > find symbols in the standard libraries associated with this linker. Suggestion: * @return a symbol in the standard libraries associated with this linker. src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/FunctionDescriptor.java line 93: > 91: Objects.requireNonNull(argLayouts); > 92: Arrays.stream(argLayouts).forEach(Objects::requireNonNull); > 93: return new FunctionDescriptor(null, argLayouts); We need to clone `argLayouts`, otherwise the user can modify the contents. Internally, using `List.of` is useful, since it does the cloning and null checks, and that is the type that is returned. Also `argumentLayouts` uses `Arrays.asList` which supports modification of the contents. src/jdk.incubator.foreign/share/classes/jdk/incubator/foreign/SegmentAllocator.java line 394: > 392: * <p> > 393: * The returned allocator might throw an {@link OutOfMemoryError} if > the total memory allocated with this allocator > 394: * exceeds the arena size, or the system capacity. Furthermore, the > returned allocator is not thread safe, and all The "the returned allocator is not thread safe" contradicts the prior sentence "An allocator associated with a <em>shared</em> resource scope is thread-safe and allocation requests may be performed concurrently". Perhaps just say: " <p> The returned allocator is not thread safe if the given scope is a shared scope. Concurrent allocation needs to be guarded with synchronization primitives. " src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java line 260: > 258: > 259: @Override > 260: public final MemorySegment asOverlappingSlice(MemorySegment other) { Please ignore these comments if you wish. Adding `max() // exclusive` to complement `min()` might be useful. In these cases i find it easier to sort the segments e.g. `var a = this; var b = other; if (a.min() > b.min()) { // swap a and b }` then the subsequent logic tends to get simpler e.g. overlap test is `if (b.min() < a.max())`, `segmentOffset` is always +ve. src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/ConfinedScope.java line 100: > 98: do { > 99: value = (int)ASYNC_RELEASE_COUNT.getVolatile(this); > 100: } while (!ASYNC_RELEASE_COUNT.compareAndSet(this, value, > value + 1)); Use `getAndAdd` (and ignore the return value). ------------- PR: https://git.openjdk.java.net/jdk/pull/5907
