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8308281: Java snippets in the FFM API need to be updated

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Reviewed-by: mcimadamore
This commit is contained in:
Per Minborg 2023-05-23 11:29:05 +00:00
parent 26227a6ff8
commit eb11508eff
7 changed files with 734 additions and 49 deletions
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34
src/java.base/share/classes/java/lang/foreign/Linker.java
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@ -77,7 +77,7 @@ import java.util.stream.Stream;
* {@snippet lang = java:
* Linker linker = Linker.nativeLinker();
* MethodHandle strlen = linker.downcallHandle(
* linker.defaultLookup().find("strlen").get(),
* linker.defaultLookup().find("strlen").orElseThrow(),
* FunctionDescriptor.of(JAVA_LONG, ADDRESS)
* );
* }
@ -91,9 +91,9 @@ import java.util.stream.Stream;
* The obtained downcall method handle is then invoked as follows:
*
* {@snippet lang = java:
* try (Arena arena = Arena.openConfined()) {
* try (Arena arena = Arena.ofConfined()) {
* MemorySegment str = arena.allocateUtf8String("Hello");
* long len = strlen.invoke(str); // 5
* long len = (long) strlen.invokeExact(str); // 5
* }
* }
* <h3 id="describing-c-sigs">Describing C signatures</h3>
@ -226,7 +226,7 @@ import java.util.stream.Stream;
* {@snippet lang = java:
* Linker linker = Linker.nativeLinker();
* MethodHandle qsort = linker.downcallHandle(
* linker.defaultLookup().find("qsort").get(),
* linker.defaultLookup().find("qsort").orElseThrow(),
* FunctionDescriptor.ofVoid(ADDRESS, JAVA_LONG, JAVA_LONG, ADDRESS)
* );
* }
@ -240,7 +240,7 @@ import java.util.stream.Stream;
*
* {@snippet lang = java:
* class Qsort {
* static int qsortCompare(MemorySegment elem1, MemorySegmet elem2) {
* static int qsortCompare(MemorySegment elem1, MemorySegment elem2) {
* return Integer.compare(elem1.get(JAVA_INT, 0), elem2.get(JAVA_INT, 0));
* }
* }
@ -268,7 +268,7 @@ import java.util.stream.Stream;
* {@snippet lang = java:
* try (Arena arena = Arena.ofConfined()) {
* MemorySegment comparFunc = linker.upcallStub(comparHandle, comparDesc, arena);
* MemorySegment array = session.allocateArray(0, 9, 3, 4, 6, 5, 1, 8, 2, 7);
* MemorySegment array = arena.allocateArray(JAVA_INT, 0, 9, 3, 4, 6, 5, 1, 8, 2, 7);
* qsort.invokeExact(array, 10L, 4L, comparFunc);
* int[] sorted = array.toArray(JAVA_INT); // [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
* }
@ -307,12 +307,12 @@ import java.util.stream.Stream;
* Linker linker = Linker.nativeLinker();
*
* MethodHandle malloc = linker.downcallHandle(
* linker.defaultLookup().find("malloc").get(),
* linker.defaultLookup().find("malloc").orElseThrow(),
* FunctionDescriptor.of(ADDRESS, JAVA_LONG)
* );
*
* MethodHandle free = linker.downcallHandle(
* linker.defaultLookup().find("free").get(),
* linker.defaultLookup().find("free").orElseThrow(),
* FunctionDescriptor.ofVoid(ADDRESS)
* );
* }
@ -334,9 +334,15 @@ import java.util.stream.Stream;
* method, as follows:
*
* {@snippet lang = java:
* MemorySegment allocateMemory(long byteSize, Arena arena) {
* MemorySegment segment = (MemorySegment)malloc.invokeExact(byteSize); // size = 0, scope = always alive
* return segment.reinterpret(byteSize, arena, s -> free.invokeExact(s)); // size = byteSize, scope = arena.scope()
* MemorySegment allocateMemory(long byteSize, Arena arena) throws Throwable {
* MemorySegment segment = (MemorySegment) malloc.invokeExact(byteSize); // size = 0, scope = always alive
* return segment.reinterpret(byteSize, arena, s -> {
* try {
* free.invokeExact(s);
* } catch (Throwable e) {
* throw new RuntimeException(e);
* }
* }); // size = byteSize, scope = arena.scope()
* }
* }
*
@ -389,7 +395,7 @@ import java.util.stream.Stream;
* {@snippet lang = java:
* Linker linker = Linker.nativeLinker();
* MethodHandle printf = linker.downcallHandle(
* linker.defaultLookup().lookup("printf").get(),
* linker.defaultLookup().find("printf").orElseThrow(),
* FunctionDescriptor.of(JAVA_INT, ADDRESS, JAVA_INT, JAVA_INT, JAVA_INT),
* Linker.Option.firstVariadicArg(1) // first int is variadic
* );
@ -616,12 +622,12 @@ public sealed interface Linker permits AbstractLinker {
* Linker.Option ccs = Linker.Option.captureCallState("errno");
* MethodHandle handle = Linker.nativeLinker().downcallHandle(targetAddress, FunctionDescriptor.ofVoid(), ccs);
*
* StructLayout capturedStateLayout = Linker.Option.capturedStateLayout();
* StructLayout capturedStateLayout = Linker.Option.captureStateLayout();
* VarHandle errnoHandle = capturedStateLayout.varHandle(PathElement.groupElement("errno"));
* try (Arena arena = Arena.ofConfined()) {
* MemorySegment capturedState = arena.allocate(capturedStateLayout);
* handle.invoke(capturedState);
* int errno = errnoHandle.get(capturedState);
* int errno = (int) errnoHandle.get(capturedState);
* // use errno
* }
* }