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8338728: Misc issues in memory layout javadoc

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Reviewed-by: pminborg, psandoz
This commit is contained in:
Maurizio Cimadamore 2024-08-27 14:26:31 +00:00
parent 414d23cb8f
commit b25095b08e
2 changed files with 32 additions and 7 deletions
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15
src/java.base/share/classes/java/lang/foreign/MemoryLayout.java
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@ -664,14 +664,15 @@ public sealed interface MemoryLayout
* <p>
* If the provided layout path has size {@code m} and contains a dereference path
* element in position {@code k} (where {@code k <= m}) then two layout paths
* {@code P} and {@code P'} are derived, where P contains all the path elements from
* 0 to {@code k - 1} and {@code P'} contains all the path elements from {@code k + 1}
* to {@code m} (if any). Then, the returned var handle is computed as follows:
* {@code P} and {@code Q} are derived, where P contains all the path elements from
* 0 to {@code k - 1} and {@code Q} contains all the path elements from {@code k + 1}
* to {@code m} ({@code Q} could be an empty layout path if {@code k == m}).
* Then, the returned var handle is computed as follows:
*
* {@snippet lang = "java":
* VarHandle baseHandle = this.varHandle(P);
* MemoryLayout target = ((AddressLayout)this.select(P)).targetLayout().get();
* VarHandle targetHandle = target.varHandle(P);
* VarHandle targetHandle = target.varHandle(Q);
* targetHandle = MethodHandles.insertCoordinates(targetHandle, 1, 0L); // always access nested targets at offset 0
* targetHandle = MethodHandles.collectCoordinates(targetHandle, 0,
* baseHandle.toMethodHandle(VarHandle.AccessMode.GET));
@ -944,7 +945,7 @@ public sealed interface MemoryLayout
* is computed as follows:
* <ul>
* <li>if {@code F > 0}, then {@code B = ceilDiv(C - S, F)}</li>
* <li>if {@code F < 0}, then {@code B = ceilDiv(-(S + 1), -F)}</li>
* <li>if {@code F < 0}, then {@code B = ceilDiv(S + 1, -F)}</li>
* </ul>
* That is, the size of the returned open path element is {@code B}.
*
@ -972,8 +973,8 @@ public sealed interface MemoryLayout
}
/**
* {@return a path element that dereferences an address layout as its
* {@linkplain AddressLayout#targetLayout() target layout} (where set)}
* {@return a path element that selects the {@linkplain AddressLayout#targetLayout() target layout} of
* an address layout (where set)}
*/
static PathElement dereferenceElement() {
return LayoutPath.DereferenceElement.instance();